OA13283A - Manufacture of higher hydrocarbons from methane, via methanesulfonic acid, sulfene, and other pathways. - Google Patents

Abstract

The present invention is drawn to the manufacture of higher hydrocarbons from methane via mathanesulfonic acid, sulfene, and other pathways.

Description

1 q 9 R Q I v £ O u MANUFACTURE OF HIGHER HYDROCARBONS FROM METHANE,

VIA METHANESULFONIC ACID, SULFENE, AND OTHER PATHWAYS

BACKGROUND OF THE INVENTION

This invention relates to organic chemistry, hydrocarbon chemistry, and processingof methane gas.

Because there hâve been no adéquate methods for converting methane gas intoliquids that can be transported efficiently to commercial markets, huge volumes of methaneare wasted every day, mainly by flaring or reinjection, at fields that produce crude oil. Inaddition, numerous gas fields are simply shut in, at numerous locations around the world.Skilled chemists hâve tried for at least 100 years to develop methods for convertingmethane gas into various types of liquids. While various efforts in the prior art couldproduce relatively small quantifies and low yields of methanol or other liquids, none ofthose efforts ever created yields that were sufficient to support commercial use at oil-producing sites. Such efforts prior to 1990 are described in reviews such as Gesser et al1985 and Olah 1987 (full citations to ail articles and books are provided below), and effortsafiter 1990 are described in articles such as Periana et al 1993, 1998, and 2002, Basickes etal 1996, Lobree et al 2001, and Mukhopadhyay 2002 and 2003.

As a resuit, oil and Chemical companies are making huge investments in liquifiednatural gas (LNG) facilities, and in a processing System known as "Fischer-Tropsch", toconvert methane into liquids. However, both of those Systems are very inefficient andwasteful. LNG processing burns about 40% of a methane stream, to refrigerate the remainderto somewhere between -260 and -330°F, causing it to liquefy so it can be loaded intospecialized ocean-going tankers. After a tanker reaches its destination, another large portionof the methane must be bumed, to warm the remainder back up to températures that allowit to be handled by normal pipes and pumps. Therefore, LNG wastes roughly half of amethane stream. Nevertheless, as of mid 2004, oil companies had committed an estimated$30 billion to build LNG facilities.

Fischer-Tropsch processing burns about 30% of a methane stream, to convert the 1 1 3283 remainder into a carbon monoxide and hydrogen mix called "synthetic gas" or "syngas".

The syngas is then converted (using expensive catalysts) into heavy oils and paraffins,which then must be cracked and/or distilled to convert them into diesel fuel, heating oil,and other products. The syngas conversion, the catalyst costs, and the requirement for ' 5 cracking thick and heavy oils and waxes ail create inefficiencies, but as of mid 2004,companies hâve committed tens of billions of dollars to Fischer-Tropsch facilities.

The wastes and inefficiencies of LNG and Fischer-Tropsch Systems prove theassertion that any methane-to-methanol Systems previously proposed, based on small-scalelaboratory work, hâve not been regarded as commercially practical, by any major 10 companies. In addition, most methanol conversion Systems proposed to date generate largequantifies of acidic and hazardous byproducts and toxic wastes. Even if they can berecycled, byproducts and wastes are major obstacles to efficient and économie use. A processing System that is believed to offer major improvements in the conversionof methane into methanol and other stable and easily-transported liquids is described in two 15 Patent Coopération Treaty applications by the same inventor herein. The first one, PCTapplication PCT/US03/035396, was filed on 5 November 2003 and was published in May2004 as WO 2004/041399. The second PCT application, PCT/US04/019977, was filed on21 June 2004.

Both of those applications were filed less than a year before the filing date herein, 20 and both are claimed as priority documents. Therefore, even though their teachings are summarized herein in the Background section, for convenience, they are not conceded to beprior art against this invention. The contents of both of those applications are incorporatedherein by reference, as though fully set forth herein.

Those two applications can be consulted for a brief history of (i) prior art efforts to 25 convert methane into transportable liquids, such as methanol, and (ii) prior art methods formanufacturing methane-sulfonic acid (MSA, H3C-SO3H). MSA, a major intermediate invarious pathways disclosed herein, has been known for décades, and is sold as a commodityChemical, mainly for use in métal clearing, electroplating, and semiconductormanufacturing. 30 The methane-to-methanol conversion System disclosed in those two applications is illustrated in FIGURES 1 and 2 herein, and can be briefly summarized as follows: (1) An "initiator" compound is used to trigger a reaction that will become a chainreaction that will continue indefinitely. This is accomplished by creating and using a 2 *"'13283 "strong radical" that can effïciently remove a complété hydrogen atom (both a proton, andan électron) from methane, thereby creating a methane radical with an unpaired electonr,represented herein as H3C*, where * represents the unpaired électron.

Various methods and compounds for creating methyl radicals are known, and severalare illustrated in FIG. 1, and described in PCTÆJS2004/019977. The principal methoddescribed herein and in the two prior PCT applications involves the use of a compoundcalled Marshall's acid, the common name for peroxy-disulfuric acid, which has the formulaHO3SO-OSO3H. This unstable compound is, effectively, two molécules of sulfuric acid,joined to each other through a peroxide (double-oxygen) linkage. It can be made by variousmethods, such as described in US patents 3,927,189 (Jayawant 1975), 6,200,440 (Moran et al2001) or 6,503,386 (Lehmann et al 2003). When subjected to mild excitation (such as byheating, or laser or ultraviolet radiation, which can use a "radical pump" or "radical gun"as described in articles such as Danon et al 1987, Peng et al 1992, Chuang et al 1999,

Romm et al 2001, Schwarz-Selinger et al 2001, Blavins et al 2001, and Zhai et al 2004),the peroxide link will break. This releases two identical radicals with the formula HO3SO*.These can be regarded either as Marshall's acid radicals (since they came from Marshall'sacid), or as sulfuric acid radicals (since they are sulfuric acid that is missing a hydrogenatom). These radicals are much stronger than conventional hydroxy radicals (HO*) fromcompounds such as hydrogen peroxide. Unlike hydroxy radicals, sulfuric acid radicals willremove hydrogen atoms from methane, to create stabilized sulfuric acid while convertingthe methane into methyl radicals. Because a small quantity of Marshall's acid will trigger achain reaction that will keep going and convert a large quantity of methane into MSAand/or methanol, the amount of sulfuric acid waste will be small, if Marshall's acid is usedas a radical initiator. (2) Inside a continuous-flow reactor vessel, the unstable methyl radicals are mixedwith sulfur trioxide. Since methyl radicals are not strong enough to remove anything fromSO3, they will bond to it, thereby forming radicals of methane-sulfonic acid. (3) The MSA radicals, which are quite strong, will attack fresh methane that isbeing continuously pumped into the reactor vessel. Each MSA radical will remove a singlehydrogen atom (both proton and électron) from a methane molécule. This créâtes stabilizedMSA, in liquid form. It also créâtes new methyl radicals, which will keep the chainreaction going, as long as proper quantities of methane and SO3 continue to be added to thereactor vessel. 3 ^3283 (4) In addition to continuously forming MSA as a product, liquid MSA in thereactor vessel also acts as an "amphoteric" solvent (i.e., a solvent having two domains withdifferent traits). The methyl domain of MSA helps methane gas dissolve and mix rapidly inthe solution, while the sulfonic domain helps liquid SO3 mix rapidly in the solution. (5) Liquid MSA, which is being formed in the reactor, is continuously removedfrom the outlet of the reactor. It is then passed through a "cracking" vessel, which breaks itapart (this process can also be called thermolysis, since it is carried out at elevatedtempératures). If carried out under proper conditions and in the presence of a suitablecatalyst, the "cracking" operation causes a rearrangement of the molécule, in a way thatcauses the hydroxy group of the SO3H sulfonic domain of MSA to leave with the methylgroup. This allows the cracking operation to release methanol (H3COH) and sulfur dioxide(SO2).

As a resuit, an endless cycle is carried out, using the sulfur compounds shown onthe right side of FIG. 2. SO3 is pumped into the reactor, and it combines with methane gasto form MSA. The MSA is cracked, in a way that transfers a hydroxy group to the methylcarbon, to form methanol while releasing SO2. The SO2 is then passed through a separatereactor, which oxidizes it back to SO3, using oxygen from the atmosphère. The SO3 is thenretumed to the MSA reactor, to complété the cycle.

Meanwhile, the reaction shown on the left side of FIG. 2 is not an endless cycle.Instead, methane (a gas) is pumped into the System, and methanol (a liquid) is pumped out.

That reaction pathway is described in more detail in the two above-cited PCTapplications.

It should be noted that MSA does not need to be cracked, to release methanol, toaccomplish the goal of converting methane gas into a stable and transportable liquid.

Instead, as described in the PCT applications cited above, it is also possible to processMSA directly on Zeolite, SAPO, or other porous catalysts, to directly create various othercompounds, without passing through methanol as an intermediate.

For convenience, the MSA intermediate is regarded as the dividing point between"upstream" and "downstream" processing. Any steps, reactors, or deviccs uscd to make orpurify MSA (or its precursors, such as Marshall's acid or any other radical initiator), or tokeep an MSA-forming reactor running properly, are regarded as being on the upstream sideof an operation. By contrast, any steps, reactors, or devices that receive MSA as afeedstock, intermediate, or product are on the "downstream" side of an operation. The 4 1 3283 MSA-forming reactor is analogous to a dam on a river; it is neither upstream nordownstream, and instead is what créâtes and defines the different upstream and downstreamzones. The oxidation of SO2 to SO3 also is neither upstream nor downstream; in most cases,it will be carried out in a separate and isolated reactor System that will not receive orprocess any organic compounds at ail (although it may contain organic catalysts to speed upthe SO2 to SO3 oxidation).

Catalytic Surfaces, Zeolites, and Monolithe

Many Chemical reactions involved in this invention use catalysts that are coated ontothe surfaces of hard supporting materials, such as wire meshes, particulates in packed orfluidized beds, zeolites or other porous solids, etc. "Supported" (or immobilized) catalystsare widely used in petroleum and Chemical processing, since they allow expensive catalyststo be held and retained inside a reactor while large volumes of gas and/or liquid arepumped through the reactor. Accordingly, supported catalysts are well known, and aredescribed in numerous books (such asHayes et al 1997), articles (such as Raja et al 2000),and patents (various examples are cited below, most of which briefly mention one or moretypes of support and then focus on the catalysts that are coated onto the support surface).This section contains a brief overview of three major types of catalysts, which arezeolite, SAPO, and monolith materials. This is followed by a discussion of how "ketene"compounds hâve been created by catalytic surfaces, which can help explain some of theprinciples that arise in creating a compound called "sulfene", which is important in thisinvention. "Zeolite" is the common name that has been given to porous "aluminosilicate"materials that contain Silicon, aluminum, and oxygen, in crystalline lattices. The latticeshâve molecular-sized cavities (also called cages) that are connected to each other by smallertunnels (channels), in repeating géométrie formations. The sizes of the cavities can bemodifïed, in controlled ways, by varying the formulation of a zeolite, thereby providing acertain zeolite formulation with cavities that are an optimal size to hold a particular type ofmolécule that will be processed by that zeolite. In addition, the narrow tunnels betweencavities are small enough to force molécules being treated to line up in certain orientations,before they can pass from one cavity to the next, driven by pressure from a gas or liquid.

In addition, the crystalline lattice that forms the cavities and tunnels can be embedded (or"doped") with catalytic atoms, ions, or molécules. Because of these factors, zeolites and 5 1 3283 other porous catalysts can cause organic molécules to react in controllable ways that cannotbe easily achieved by other materials.

As one example of how zeolite materials can be used, a major advance in methanol-to-gasoline (MTG) processing was discovered in the 1970's, when Glarence Chang and hiscoworkers at Mobil Oil Corporation (now Exxon-Mobil) discovered that if methanol ispassed through certain types of Zeolite, methylene groups (-CH2-) contributed by themethanol will begin condensing into chains, in a way that will create hydrocarbon liquidsthat can be used as gasoline. Early patents include US 3,899,544 (Chang et al 1975),4,076,761 (Chang et al 1978) and 4,138,442 (Chang et al 1979). Reviews include a bookby Chang, Hydrocarbons From Methanol (Dekker, 1983), a chapter by Chang in MethanolProduction and Use (W. Cheng & ΗΉ. Kung, editors, Dekker, 1994), and Stocker 1999,an extensive review article that cites 350 articles published by other authors. Stocker 1999is followed in the same journal by Keil 1999, which describes a number of commercialMTG facilities.

Zeolite materials that also contain phosphorus are often called "SAPO" materials,since they contain Silicon, aluminum, phosphorus, and oxygen. During the research thatfollowed the MTG discoveries of the early 1970's, it was discovered that processing ofmethanol on SAPO materials could create olefins, which are valuable unsaturatedcompounds that form the building blocks of plastics and polymers. "Methanol-to-olefm"(MTO) processing is described in US patent 3,911,041 (Kaeding et al 1975) and in articlessuch as Liu et al 1999, Sassi et al 2002, and Dubois et al 2003.

However, because their cavities are connected by tunnels, "semi-permeable" or"meso-permeable" materials such as zeolite and SAPO tend to suffer from relatively largepressure drops, if gases or liquids are pumped through them. They also tend to suffer fromfouling and clogging, due to the formation of sludge-like materials and/or "coke" (solidparticulates or cakes, comparable to the materials used to make charcoal briquets oractivated carbon powders). Therefore, zeolite or SAPO beds usually require periodiccleaning and régénération, usually at high températures.

To minimize problems of clogging and pressure drops, many types of zeolites andsimilar catalytic materials hâve been developed that are designed to hâve surface activityonly. Some of these materials hâve microscopie pores, comparable to pits, which encouragecertain molécules to nestle into those pits in certain orientations, causing a certain atom ordomain of the molécule to remain exposed to gases or liquids that are passed over the 6 1 3283 surface of the "charged" or "loaded" material. Other materials may be chemically treated,to bond positively- or negatively-charged atoms or groups to their surfaces, usually at acontrolled density or spacing. Since these types of surface-only materials do not need tohâve a gas or liquid actually pass through flow channels in the material, they often are usedin particulate forms, such as in packed or fluidized beds.

Alternately, a different class of catalytic supports has been developed with porousmaterials that hâve tiny flow-through channels that are essentially straight and linear,passing through the otherwise solid material. These materials, called "monoliths", arecommonly manufactured in the form of round dises (often called "cakes") that will fît intocylindrical containers, which usually are provided with inlet and outlet filters to hold themonolith in place while a gas or liquid flows through it. Because the flow. channels inmonoliths are essentially straight, linear, and parallel, and do not hâve any constrictions orchanges in internai size, monoliths can provide higher and faster flow rates, lower pressuredrops, and fewer clogging and fouling problems, compared to zeolites or other materialshaving non-linear flow channels. Therefore, catalytic monoliths are often used in devicesthat cannot be easily or periodically shut down and cleaned out (such as catalytic convertersthat remove pollutant gases from automobile exhausts).

Monoliths can be prepared with various channel sizes and densities, usuallyexpressed as channels per square inch (epsi). Monoliths that handle gases usually hâve epsivalues ranging from about 400 to over 1000. Monoliths that handle liquids or foams requirelarger channels, with correspondingly lower epsi numbers, to achieve an optimal balancebetween (i) reasonable and acceptably low "pressure drops" across the material, and (ii)desirably high levels of contact between the solid surfaces and the liquids flowing throughthe channels. Because thousands of flow channels pass through a monolith of anysubstantial size, very large total surface areas, inside the thousands of tiny flow channels,will be contacted by a gas or liquid that passes through a monolith.

The material that provides the porous supporting structure of a catalytic monolith isusually called the "support". It is sometimes referred to as the "substrate", to distinguish itfrom the catalytic coating material, but that term is confusing and should be avoided, since"substrate" also refers to a Chemical compound that is acted upon by a catalyst, enzyme, orother Chemical reagent.

In general, monolith supports must be able to withstand strong acids (whichéliminâtes most metals and alloys) and high températures (which éliminâtes most plastics 7 1 3283 and starch-type polymers). These requirements usually lead to the use of minerais and/orceramics, which frequently contain Silicon and oxygen (often referred to as "silicate"materials), which are comparable to quartz but with porous lattices that provide flowchannels. Support compounds such as cordierite, mullite, or Silicon Carbide are widelyused, and are sold by companies such as Corning Inc. (www.coming.com) and RauschertProcess Technologies (www.rauschertus.com).

Various types of surfaces can be provided on a hard support material. One class ofsuch surfaces is called "porous" supports, which implies irregular and uneven surfaces,which may be created by the material itself, or by surface treatment processes such asanodic or acidic etching. Altemately, "abraded" supports usually provide smoothersurfaces, formed by processes comparable to sanding. The suitability of any such porous,abraded, or other support surface, for hydrocarbon or Chemical processing as disclosedherein, can be evaluated through routine testing.

Ail of the foregoing relates to the support material, which in most cases is presumedto be chemically inert, and uninvolved in the molecular rearrangements involved in aChemical reaction. Regardless of how an inert supporting material is prepared, or whatphysical form it is in, the real value and functionality of any supported catalyst will dépendon how the surfaces are "activated" (also called "functionalized"). This usually is done ineither of two manners. In one approach, the surface of a hard and presumably inert supportaterial is coated with catalytic atoms, ions, or groups; the term "coating" is used broadlyherein, and involves plating, liquid immersion, sputter coating or other gaseous diffusion,or any other process that créâtes a surface layer that is somehow different from anunderlying support material). The second approach involves incorporating the catalyticatoms, ions, or groups into the reagents used to form a supported catalyst, in some mannerthat distributes the catalytic atoms, ions, or groups throughout the resulting material. Thissecond method is conventionally used to make zeolite, SAPO, and monolith materials thatrequire catalytic "dopant" atoms to be positioned at regular intervals in a crystalline lattice.Either of those two approaches can be regarded as "functionalizing" a catalyst, in a waythat tums an inert supporting material into a chemically active material that can helptrigger, drive, and control valuable reactions.

This is a brief and simplified overview, intended to help readers who do notspecialize in these types of materials develop a basic understanding of how these types ofmaterials are made and used. Any reader who wants more information on supported 8 13283 catalysts can locate numerous articles and books on the subject, and in websites that providelecture and course notes for chemistry courses at various universities.

Chemists and researchers who specialize in working with zeolites and similarmaterials hâve formed an organization called the International Zeolite Association, whichruns a highly useful website, www.iza-online.org. The IZA has been designated by theIUPAC (the International Union of Pure and Applied Chemists) as having officialresponsibility for nomenclature and other matters relating to zeolites and other compoundswith structural lattices that enable them to function as molecular sieves and/or catalysts.

The IZA has three major working groups, devoted to structures, synthesis, and catalysis.Anyone who wishes to identify zeolite or similar compounds that offer good candidates forProcessing a particular Chemical (such as methanesulfonic acid, one of the key intermediatesin this invention) can quickly locate experts in the field, through the IZA. In addition, anycompany that sells zeolite compounds for Chemical processing, either as a manufacturer ordistributor, will hâve on its staff at least one technical expert who can advise potentialpurchasers on: (i) which compounds offer the best candidates for early évaluation, forcarrying out a particular réaction; and, (ii) the names of experts who can be consulted formore information.

At least one professional journal, Microporous and Mesoporous Materials, is entirelydevoted to zeolite and similar materials, and several other joumals (including the Journal ofMolecular Catalysis, the Journal of Physical Chemistry, and Fuel Processing Technology)ffequently publish articles on processing and research using porous catalysts. Accordingly,experts who specialize in particular formulations, or in processing certain classes ofChemicals on porous catalysts, can be located by contacting an editor who works with oneof those journals, or by reviewing the titles of articles that hâve been published in suchjoumals.

Also, methods and machines hâve been developed for screening large numbers ofcandidate catalyst formulations, in a rapid and automated manner. These methods andmachines are described in articles such as Muller et al 2003, and other articles citedtherein, Such devices use, for example: (i) reactors with multiple parallel tubes, each tubecontaining a different candidate catalyst, or (ii) titer plates with multiple wells, each wellcontaining a candidate catalyst. When a certain reagent is passed through or loaded into ailof the tubes or wells, the product generated by each individual tube or well (and thereforeby each candidate catalyst) is collected separately, and delivered to an automated analytical 9 1 3283 device, such as a mass spectrometer or chromatograph. The tubes or wells that created thehighest yields of the desired compound can be identifïed, and the exact content of thecatalysts in any tubes or wells that resulted in good and désirable yields can be identifïedand studied more closely. For example, the best-performing candidate catalyst from oneround of tests can be used as a "baseline" or "centerpoint" material, in a subséquent roundof tests that will use variants that resemble the best-performing catalyst from the previousround of screening. Those variants can include known and controlled compounds, havingexact compositions; alternately or additionally, "combinatorial chemistry" methods andreagents can be used, to generate random or semi-random variants of a material thatprovided good results in an earlier screening test. Accordingly, these types of automatedscreening Systems offer powerful and useful tools for rapidly identifying and/or improvingporous catalyst formulations that can efficiently promote any particular desired reaction.

Another factor worth noting involves catalytic agents that use symphoric,anchimeric, or "neighboring group" effects to enable "two-handed" manipulation MSA orother compounds. MSA has two very different domains, methyl and sulfonic. In thepathway shown in FIG. 3 (discussed below), the silicate support merely uses hydroxygroups to attract and interact with MSA. More potent and efficient catalysts might bedeveloped, by providing a catalytic surface with two different types of functional agents,allowing one type of catalytic group to attract and interact with the sulfonic portion ofMSA, while the second type of catalytic group attracts and interacts with the methylportion. This factor can be better understood, if the reader will consider additionalcomments in PCT application PCT/US03/35396 (published in May 2004), about thesymphoric and/or anchimeric traits of a bromate-sulfate reagent that can convert methaneinto a methyl-bis-sulfate compound.

Surface Adsorption, Transition States, and Ketene Chemistry

Once a reader has a working knowledge of how surface-active catalysts can beformulated, and how various different classes of physical configurations are known andavailable, the next step is to consider how gases or liquids will interact with those types ofcatalytic materials that are supported on monolithic, particulate, or other solid supports.Several terms and concepts are briefly explained below, then these terms are considered inthe context of a prior art method for making a compound called ketene, which is analogousin some respects to sulfene, a key intermediate in this invention. 10 1 3283

The term "adsorbed" refers to a molécule that is closely associated with the surfaceof a solid material. In the types of reactions of interest herein, this "close association" willlast only very brief time (typically measured in milliseconds), and it will occur solelyduring the transition from one State to a different State (especially in reactions that run athigh températures). This association usually is initiated by some form of charged (positive-to-negative) attraction, in which hydrogen protons or other positively-charged ions or atomsare attracted to localized négative charges (such as unshared électron pairs, on the surfacesof exposed oxygen atoms). This charge attraction draws a liquid or gaseous compound intoclose proximity with certain molécules on the surface of the support material. When the"lowest energy" distance is reached, the association between the reagent and the catalyticcoating then progresses through one or more types or stages of "coordinate" or "metastable" bond transitions, which may or may not rise to the strength of covalentbonding.

Because of various factors, it is not always possible to clearly and definitelycategorize the various transitional molécules and bonds. For example, an atom or moléculecan pass through transitional States that can be regarded as intermediate or halfway points,somewhere between an ionic State, and a radical State; similarly, the types of "coordinate"or "metastable" bonds that arise can be at an intermediate or halfway point between anionic attraction or a covalent bond. Therefore, in any narrative descriptions herein (inBarteau's pathway for the production of ketenes, and in the Applicant's pathway for theproduction of sulfene), any reference to any transitional or intermediate State of anyparticular atom, ion, or radical can be regarded as merely a convenient reference term,comparable to an estimate or approximation, intended to provide a map or narrativedescription of the relevant terrain, for the use of experts who wish to analyze these types ofeactions in greater detail. Much more information on intermediate States, transitionalbondings, and "hybridized" valence-shell structures that can occur during the course ofcatalytic reactions, is available in numerous published reference works (such as, forexample, March's Advanced Organic Chemistry, by M. Smith and J. March, WylieInterscience, 2001).

It should also be kept in mind that the patent law generally does not require atheory, to explain a new invention. Instead, the patent law requires a description of afeasible method for accomplishing a desired resuit, in adéquate detail to teach those skilledin the art how to mix the reagents, and run the process. In this invention, the resuit and the 11 1 3283 invention center on the conversion of MSA into sulfene, and the subséquent conversion ofsulfene into other useful Chemicals, such as olefins. Accordingly, any spécifie or postulatedreaction steps, and any transitional or intermediate bondings or molecular complexes thatare hypothesized, proposed, or otherwise discussed herein, are not essential to carrying outthis invention. Instead, this invention résides in the récognition and disclosure of severalpractical and useful results (including but not limited to the realization that MSA, which canbe formed from "waste" methane, can be pushed into forming a sulfene intermediate, andthe sulfene will then react in ways that will form ethene or other valuable compounds).Those and other practical teachings herein form the essence of this invention, and anydiscussion of postulated, hypothesized, probable, or modeled atomic or molecularinteractions or transition States is offered merely as additional commentary, in the hope thatsuch commentary might be useful to experts who wish to study and analyze these or similarreactions in greater detail. This commentary is not asserted to be the final answer ordefinitive theory, and instead should be regarded as suggesting certain places and referenceswhere experts might wish to look, among the huge mass of published and availablematerial.

The concepts above, regarding liquid or gaseous Chemicals that are temporarily"adsorbed" onto the activated surfaces of catalysts, in ways that: (i) promote or enable adesired reaction, and then (ii) release the product compound from the catalytic surface, canbe illustrated by a discussion of "ketene" compounds, described by Mark Barteau in articlessuch as Barteau 1996. The simplest ketene compound is H2C=C=O. More complexketenes also can be created, by replacing either or both of the two hydrogen atoms withother groups, to create RiR.2C=C=O, where Ri and R2 are variables.

In a sériés of reactions described in Barteau 1996, the suffix (ad) was used toindicate a compound that was temporarily "adsorbed" to the surface of a solid catalyticmaterial. The suffix (g) referred to a compound that was released, from the catalyticsurface, as a gas (in the case of water, this will be steam, since these reactions are carriedout at high températures). The suffix "O(/)" referred to "surface oxide anions" (i.e., oxygenatoms or ions that are closely associated with, but not covalently bonded to, the supportsurface).

One reaction described in Barteau 1996 involved the processing of acetic acid, onsilicate supports using catalytic surfaces that contain exposed oxygen atoms, to form ketene.In the first step of Barteau's pathway, written as: 12 13283 CH3COOH + 0(/) --> CH3COO(ad) + OH(ad) a molécule of acetic acid ionizes, and transfers its hydrogen proton to an oxygen atom/ionon the silicate surface. This causes the acetate ion (which has a négative charge, after losingits hydrogen proton) to be attracted to, and adsorbed onto, the support surface, which haspositive charges on it due to hydrogen protons it is receiving from the acetic acid solution.

In the second step of Barteau's pathway: CH3COOH + OH(ad) --> CH3COO(ad) + H2O(g) a second molécule of acetic acid ionizes, and transfers its hydrogen proton to an adsorbedhydroxy group on the support surface. This causes the hydroxy group to be converted into afull molécule of water, which leaves the support surface, in the form of steam. The secondacetate anion becomes adsorbed onto the support, which continues to hâve positive chargeson it due to other hydrogen protons that are being donated to it by the acetic acid solutionthat continues to contact the support.

In the third step of Barteau's pathway: CH3COO(ad) --> H2C=C=O(g) - H(ad) + O(/) an acetate ion that was adsorbed onto the support surface rearranges its molecularconfiguration. A hydrogen atom (or proton) on the methyl group leaves, and becomesadsorbed on the support surface. The électron (or électron pair) that formed an H-C bond,in the acetate ion, moves around that carbon atom, and forms a double bond between themethyl carbon, and the other (carboxy) carbon. This électron shift also causes the single-bonded oxygen ion from the second (carboxy) carbon to leave the acetate ion; it willbecome adsorbed on the support surface, thereby regenerating that support as a catalyst,rather than as a consumed reagent.

The fourth step of Barteau's pathway: H(ad) + OH(ad) -> H2O(g) partially balances out the équations above, by releasing water, as a gas (steam). This water 13 13283 is formed from the hydrogen atom (or ion) that was adsorbed on the support surface in thethird reaction step, and the hydroxy group (or ion) that was adsorbed on the support surfacein the first reaction step.

It should be noted that the reactions listed above are only partially balanced; anacetate ion remains adsorbed on the support, presumably able to rearrange itself to formadditional ketene while also releasing H and O for adsorption on the support. As noted byBarteau in the text following the reactions listed on page 1423 of his article, side reactionsalso occur, including unselective décarboxylation of the adsorbed acetate ions. This releasesCO2, and it also deposits hydrocarbon fragments (from the methyl groups) on the support.

After studying and analyzing a number of articles, books, and patents (including the1996 article and several other articles and patents by Barteau, and by other authors andinventors), the Applicant herein suspected that similar processes may also be able to occurif MSA (rather than acetic acid) is processed on a comparable type of support. To inquireinto that possibility, he had the MSA reaction analyzed by computer modeling, with thepaid assistance of a doctoral candidate who had access to powerful computers at auniversity. This modeling used the Amsterdam Density Functional software, release 2.3.3,sold by Scientific Computation and Modeling (www.scm.com), described in articles such aste Velde et al 2001. The results were positive and promising, and are described below, inthe Detailed Description section.

Accordingly, the remainder of this application describes and daims variousenhancements of the MSA pathway that were identified or developed by the Applicantsince the filing of the earlier PCT applications. These options and enhancements include: (1) processing options that can be carried out, either by using the MSA-to-methanolSystem as a starting point, or by branching out from that pathway at one or more junctionpoints (such as by converting MSA into an unstable anhydride called sulfene, H2C=SC>2,which can then be processed in various ways to create stable and valuable products, such asliquid hydrocarbon condensâtes that can be used as fuels or feedstocks; (2) enhanced methods for oxidizing SO2 into SO3, so that the cycle of sulfurcompounds, shown on the right side of FIG. 2, can be carried out more efficiently andeconomically; and, (3) methods and catalysts for carrying out a similar and related type of reaction,which will cause methyl radicals to react with carbon dioxide, rather than SO3, in a waythat will form acetic acid (a useful and valuable Chemical) rather than MSA, in a way that 14 13283 can reduce carbon dioxide émissions into the atmosphère by exhaust gases from powerplants, factories, and other sources.

One object of this invention is to disclose various enhancements and options that canbe used to expand and improve upon various teachings of two previous PCT applications(serial numbers PCT/US03/035396, published as WO 2004/041399, andPCT/US2004/019977) that were previously filed by the same Applicant.

Another object of this invention is to disclose various processing pathways andoptions, using methane-sulfonic acid (from methane gas) as a feedstock or intermediate, tocreate various types of valuable organic Chemicals.

Another object of this invention is to disclose processing pathways and options,using methane-sulfonic acid (from methane gas) to create an unstable anhydrideintermediate called sulfene (H2C=SO2), which can be processed to create stable and valuableorganic Chemicals.

Another object of this invention is to disclose enhanced methods for oxidizing SO2into SO3, so that the cycling of sulfur compounds, as part of a larger processing System thatconverts methane into methanol or other compounds, can be carried out more efficientlyand economically.

Another object of this invention is to disclose methods and catalysts for causingmethyl radicals to react with carbon dioxide, to form acetic acid, thereby forming avaluable Chemical while also reducing carbon dioxide émissions into the atmosphère.

These and other objects of the invention will become more apparent through thefollowing summary, drawings, and detailed description.

SUMMARY OF THE INVENTION

Enhancements and options are disclosed for Chemical processing methods describedpreviously by the Applicant, for converting methane into methanol or other organiccompounds, via methyl radicals and methane-sulfonic acid (MSA). A major set of optionsand enhancements, which are the primary focus of the daims herein, relate to convertingMSA into an unstable and highly reactive anhydride intermediate called sulfene, H2C-SO2.This compound is a potent and useful donor of methylene groups (-CH2-), which can be usedfor purposes such as creating heavier liquid fuels or olefîn compounds, or for creating plasticor polymeric compounds in particulate or other form. Other options and 15 " 13283 enhancements disclosed herein can be divided into four main categories: (1) various"upstream" processing options, such as improved methods for making Marshall's acid, onetype of radical initiator that can be used to convert methane into MSA; (2) various"downstream" processing options, such as methods for treating MSA methyl-esterimpurities that may be created during MSA cracking or other processes; and, (3) improvedmethods and catalysts for oxidizing SO2 into SO3, so that recycling of sulfur compounds inthe MSA pathway can be carried out more efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 depicts several known Chemical reactions that can "activate" methane(CH4) by removing a hydrogen atom (both a proton and an électron), to convert themethane into a methyl radical (H3C*, where the asterisk represents an unpaired électron). FIGURE 2 depicts a reaction System that combines methyl radicals (H3C*) andsulfur trioxide, to form methane-sulfonic acid (MSA) by a multi-step process that créâtes anew methyl radical. This establishes a chain reaction, and the newly-created methyl radicalswill react with newly-added SO3. MSA can be removed from the vessel and sold as aproduct, used as a reagent, or "cracked" to release methanol (which can be shipped as aliquid, or used as a feedstock for other reactions) and sulfur dioxide (which can be oxidizedto SO3 and recycled back into the reactor). FIGURE 3 depicts transitional intermediates that are likely to be formed if MSA isdewatered with the assistance of a silicate monolith material having hydroxy groups on itssurface. FIGURE 4 depicts a reaction of two molécules of sulfene (H2OSO2) to formethene, in gaseous form. This reaction releases gaseous SO2, which can be oxidized to SO3and recycled back into the reactor vessel that is used to convert methane into MSA. FIGURE 5 depicts an altemate candidate pathway for dewatering MSA to formsulfene, using tungsto-phosphoric acid (also called phospho-tungstic acid). FIGURE 6 depicts an altemate candidate pathway for making sulfene, using amethyl-MSA compound that is reacted with methanol, which is recovered and recycled. FIGURE 7 depicts a pathway for using sulfene to convert ethene into cyclopropane,which can be converted into propene (propylene), propanol (propyl alcohol), or otherproducts. FIGURE 8 depicts a reaction pathway that proceeds through an "outer" anhydride 16 1 3283 form of MSA, formed by condensing two molécules of MSA while removing a watermolécule. FIGURE 9 depicts a potential polymerization pathway, in which sulfene will insertmultiple methylene groups into a growing alkane molécule or dérivative, which may be abranched alkane or dérivative if certain types of diimine or other catalysts are used. FIGURE 10 shows a pathway that enables a vanadium diformate catalyst to convertSO2 into SO3, using pathways that appear from computer modeling to be thermodynamicallyfavorable. FIGURE 11 is a schematic depiction of a System for converting SO2 to SO3, whichuses heat from the SO2 oxidation reaction to heat MSA from its relatively cool formationtempérature, up to a much higher cracking température.

DETAILED DESCRIPTION

As summarized above, this application focuses mainly on making and using sulfene,H2C=SO2, a highly reactive anhydride form of MSA that can be used to manufacture olefins,liquid fuels, or other valuable compounds from stranded methane gas. These disçlosures areaddressed in the immediately following subsections.

After that discussion of sulfene, two additional sets of disçlosures are provided.

These disçlosures focus on: (1) options and enhancements in "upstream" processing (i.e., reagents, devices, andmethods used to manufacture MSA as an intermediate), and (2) methods and catalysts for more efficient oxidation of SO2, to regenerate andrecycle SO3.

These disçlosures are included herein, because they are believed to be necessary toensure disclosure of the "best mode" for carrying out the processing methods and reagentsdisclosed herein.

The second reason is this: these disçlosures are believed to reveal substantiallyimproved ways of making good, efficient, humanitarian, and benevolent use of energyresources, while providing enhanced levels of environmental protection as well.Accordingly, rather than generating a profusion of dozens of confusingly different-yet-interrelated patent applications, ail of which would need to be located and studied carefully, 17 1 3283 and any of which could be written and crafted in ways deliberately intended to confuse andthwart any clear understanding (by competitors and adversaries, who often are the onlyones who read such patents) of what was actually discovered and taught, the humanitarian,energy-conserving, environment-protecting goals of this technology (and of the Applicant)can be better served by compiling a number of discoveries and advancements into a smallnumber of patent applications. By taking that approach, a single inventor can help establisha functional and efficient foundation and framework that can help support and enable a clearunderstanding, by ail interested parties, of what is being taught, and how it can bedeveloped as rapidly as possible into commercial and industrial use that will help thepublic, and the planet.

Accordingly, the following subsections focus on making and using sulfene. Afterthose subsections, two additional section headings are provided, to cover:

SYNTHESIS OF SULFENE

As briefly summarized above, methods are disclosed herein for converting methane-sulfonic acid (MSA, which can be prepared from methane gas as described in PCTapplications PCT/US03/035396 and PCT/US04/019977) into an "inner anhydride" calledsulfene, H2C=SO2 (also called thioformaldehyde dioxide).

Sulfene is unstable, and if formed in large quantifies and/or high concentrations, twomolécules of sulfene will react with each other, in a rapid and highly exothermic reaction,to form ethylene (also called ethene), H2C=CH2, a valuable olefin used in the manufacture ofplastics and polymers. The SO2 group in sulfene will act as a leaving group in mosttypes of reactions, causing most sulfene reactions to release SO2 in gaseous form. This gascan be collected, oxidized back into SO3, and retumed to the reactor vessel that is beingused to convert methane into MSA, in a recycling operation that minimizes wastes andunwanted byproducts.

Under some conditions, sulfene can be used as a "methylene transfer agent", which caninsert methylene groups (which can be represented as -CH2- or as H2C:) into othercompounds, qas discussed in more detail below. This reaction can be used to convertvarious hÿdrocarbon compounds (include gaseous or other relatively light or "thin"hydrocarbons, such as short-chain hydrocarbons with 2 to 5 carbon atoms) into larger andheavier compounds, which generally will be easier to handle (since they will be lessvolatile) and more valuable (since they will hâve higher energy density). As just one 18 1 3283 example, if sulfene reacts with ethylene, the methylene group from sulfene will convert theethylene into cyclopropane, which can be (1) used as a Chemical feedstock, which will behighly reactive due to its stressed bond angles, (2) isomerized to form propylene (alsocalled propene), another valuable olefin, or (3) hydrated to form propyl alcohol, a valuableChemical and a gasoline additive or substitute. In general, transfer of methylene groups intomost types of gaseous and/or volatile hydrocarbons will decrease their volatility, makingthem easier to store, transport, and handle, and will also increase their energy density,utility, and value.

The conversion of MSA into sulfene requires the "dewatering" of MSA (H3C-SO3H). This "dewatering" process can also be called déhydration; however, déhydration isa broader and less précisé term, and can be used when hydroxy groups (HO-) rather thancomplété water molécules (H2O) are removed. Accordingly, the term "dewatering" ispreferred herein, to indicate that two hydrogen atoms and an oxygen atom must be removedfrom each molécule of MSA that is fully converted into sulfene. The term "anhydride" canalso be used, to refer to molécules of MSA from which water molécules hâve beenremoved.

If desired, terms such as "inner" or "internai" dewatering or déhydration can beused, to indicate that a complété molecular équivalent of water is being (or has been)removed from a single molécule of MSA, to form sulfene. However, it should beunderstood that in most cases, each water molécule that is released during a dewateringprocess typically will contain a hydroxy group from the sulfate domain of one MSAmolécule, and a hydrogen proton from the methyl domain of a different molécule of MSA.

There is also an "outer" anhydride of MSA, H3CSO2-O-SO2CH3, formed bycondensing two molécules of MSA while removing a single molécule of water. Under someconditions, this intermediate can rearrange to form sulfene, while releasing MSA. Outeranhydrides of MSA can be useful, and are discussed below.

Several candidate methods for converting MSA into sulfene are disclosed herein.Preferred methods for different manufacturing sites may dépend on various factors, such asflow rates and flow rate consistency levels at that site, the purity levels and contaminantloads in the methane stream as well as the MSA intermediate, the ability of other equipmentat a site to handle any wastes or unwanted byproducts that may be created by the variouscandidate methods, and the targeted purity levels for sulfene or downstream products thatwill enable operations at a particular site to be optimized on an économie basis. 19 13283

Accordingly, any candidate method disclosed herein (and any other candidate method that iscurrently known or hereafter discovered) can be evaluated, both in batch-processing andcontinuous-flow modes of operation, to détermine its suitability and économies for use atany particular site.

It should be recognized that until this point in time, sulfene has received littleattention from Chemical researchers, mainly because of two reasons: (i) it is unstable, andwill not last long even when created; and, (ii) the only prior art methods for preparing itare difficult and tedious, and generate too much toxic and hazardous waste to enable sulfenemanufacture to be used as a practical and économie route toward creating other valuableProducts. Two of the relatively few items published to date on sulfenes are: (i) chapter 17,by King and Rathore, in a book edited by Patai and Rappaport 1991, and (ii) Prajapati et al1993, which describes a method of generating sulfene that consumes SOCh and generateshydrochloric acid as a byproduct. To the best of the Applicant's knowledge and belief,neither of those items, both published more than a decade ago, ever led to any signifîcantcommercial or industrial interest in sulfene.

However, the level of interest in sulfenes may increase dramatically, after thedisclosures herein hâve been made known to Chemical and petroleum companies andacademie researchers, since a feedstock that can be used to make sulfene (i.e., MSA fromstranded methane gas) is likely to become available soon, at lower cost, and in quantitiesthat are many times greater than the currently-available worldwide supplies of MSA.

Accordingly, the disclosure of synthesis pathways that pass from stranded methanethrough MSA and then through sulfene, to create olefins or other highly valuablecompounds, is likely to trigger substantial research interest in this field of research, and itis likely that these pathways can be supplemented and enhanced by other methods.Accordingly, these pathways are being disclosed at an early stage of évaluation, after theyapparently hâve been tentatively confirmed in batch processing but before they hâve beentested or evaluated in continuous-flow operations, to confirm that these pathways are indeedfeasible, and to help researchers and engineers interested in this field of research becomefamiliar with various factors and options.

Several of the synthesis pathways that pass through sulfene will require: (i) elevatedtempératures, to overcome certain thermodynamic barriers, and (ii) active removal of water(usually in the form of steam), to pull certain reactions in the desired direction. In somepathways, water can be removed from MSA directly, as discussed relative to hydrated 20 13283 silica, below. Alternately, in some pathways (such as pathways involving methyl-methanesulfonate ester, or the outer anhydride of MSA), water may be removed fromcertain components prior to the création of sulfene. This can provide benefits in varioustypes of downstream processing.

Three main categories of candidate pathways are described below, for synthesizingsulfene. Each candidate pathway is discussed under its own subsection.

CANDIDATE PATHWAY #1 : SOLID-SUPPORTED CATALYSTS

The fîrst candidate pathway disclosed herein for dewatering MSA to form sulfeneuses catalytic materials on the surfaces of solid supports. Catalysts that are coated onto (orotherwise made accessible on) the surfaces of solid support materials are widely used in thePetroleum and Chemical industries, because they allow expensive catalytic materials to beretained inside a reactor while large volumes of gas or liquidare pumped through thereactor. As discussed in the Background section, the types of solid-support catalystsdisclosed herein can be provided in any of several candidate forms, such as: (i) "monolith"materials, with essentially linear and parallel flow channels passing through a highly porousmaterial that can be manufactured in a "cake" or similar form that can be placed inside areactor device, or (ii) particulate materials, which can be loaded into a packed bed,fluidized bed, stirred reactor, or comparable device.

The conversion of MSA into sulfene will be comparable in some respects to theconversion of acetic acid into ketene (H2C=C=O), which is summarized in the Backgroundsection by describing certain reactions disclosed in Barteau 1996. After studying andanalyzing a number of published articles by Barteau, and other articles and patents by otherauthors and inventors, the Applicant herein suspected that similar processes may occur ifMSA (rather than acetic acid) is processed on a suitable supported catalyst.

To evaluate that possibility, he had the MSA reaction analyzed by computermodeling, using the Amsterdam Density Functional software, release 2.3.3, sold byScientific Computation and Modeling (www.scm.com), described in articles such as teVelde et al 2001.

Results from that computer modeling are provided in FIG. 3, which depicts a three-dimensional model of how a molécule of MSA can interact with a silicate support that hashydroxy groups exposed on its surface, represented by (Si(OH) 3)20.

In the initial step of this sériés of reactions, one of the double-bonded oxygens of the 21 13283 sulfate portion of MSA is attracted to one of the hydrogen protons on the silicate support,and the hydrogen proton on the hydroxy group of the sulfate portion of MSA is attracted toone of the oxygen atoms in one of the hydroxy groups on the silicate support. At the sametime, a coordinate bond between the two Silicon atoms is also disrupted or reconfigured.

This combination of steps forms an adsorbate, in which MSA has become closely associatedwith the silicate surface. This attraction and affiliation is an exothermic reaction that occursspontaneously, with a AE value of-10.72 kcal/mol (kilocalories per mole). The term AErefers to bonding energies, which correspond to AH (enthalpy) values when certain “zéropoint energy” (ZPE) corrections are made, as known to those skilled in the art.

In the second step, which will occur only at elevated températures, a water moléculewill leave, most likely containing a hydroxy group that initially was on the silicate support,along with a hydrogen proton or atom from the sulfate group of the MSA. This leads toformation of a silicon-oxygen-sulfur linkage, on the right side of the molécule shown inFIG. 3. This reaction is endothermie, which means it requires energy input, with acalculated value of AE = 10.79 kcal/mole. Since that figure is nearly equal to theexothermic energy release of the initial step, the net resuit is nearly “thermoneutral”, and itwill occur on an equilibrium basis, at high température. This equilibrium can be shiftedand pulled in the desired direction, to provide greater yields, by actively removing from thereactor vessel any water that is released (in the form of steam) from that reaction.

Accordingly, the first and second steps, taken together as described above andillustrated in FIG. 3, can be written as follows:

H3C-SO3H + OH(ad) --> CH3SO3 (ad) + H2O

In the next step of the reaction, the MSA residue will pivot and swing around an"axle" that is provided by the silicon-oxygen-sulfur linkage, until one of the positively-charged hydrogen protons, on the methyl group of the MSA residue, àpproaches anegatively-charged hydroxy group, which might be bonded to the same Silicon atom that thesulfur is bonded to, but which more likely will be bonded to some other nearby Siliconatom in the matrix of the silicate support.

In the fourth step, three proton and électron shifts take place, which functiontogether to set the stage for the disengagement of sulfene from the substrate. In one shift,the hydrogen proton that formed the bridge between the methyl group of MSA, and the 22 1 3283 hydroxy group of the substrate, shifts toward the hydroxy group of the substrate, therebyweakening its bond and its attraction to the carbon atom of the MSA. In a secondcoordinated shift, the électron pair that previously formed the carbon-hydrogen bond (whichhas now become weakened because of the hydrogen proton's attraction to the hydroxygroup on the substrate) will be pulled toward the electronegative sulfur atom. This sets upthe formation of a double bond between the carbon atom and the sulfur atom. In the thirdcoordinated shift, this formation of the double bond between the sulfur and the carbon willweaken the single bond between the sulfur atom, and the oxygen atom that forms thesulfür-oxygen-silicon linkage.

After these three shifts occur, in what can be regarded as the fourth step of thereaction, the fïfth step can occur, in which the MSA residue will detach from the silicatesupport, in a way that créâtes a double bond between the carbon and the sulfur. Thehydrogen proton from the methyl group, and the oxygen atom from the sulfate group, willboth be left behind, adsorbed on the solid support material. When this detachment occurs,the H2C=SO2 molécule that remains from the original MSA has become sulfene.

The detachment of the sulfene from the solid support will leave a polarized conditionon the support, with a positive charge on the hydroxy group that received a hydrogenproton from the methyl group of MSA, and a négative charge on the oxygen atom that wasdonated by the sulfate group of MSA. Under the acidic conditions that will exist in theSystem (due to the continued addition of fresh MSA, an acid, to the System), those localizedcharges can be resolved in any of numerous ways involving migrating or mobilized protons,in ways that will regenerate the hydroxy groups on the support, and restore the silicatesupport, thereby rendering it a catalyst, rather than a consumed reagent.

Accordingly, when the third, fourth, and fifth steps in the pathway are combinedtogether and written in the aggregate, they become: CH3SO3 (ad) --> CH2SO2 + OH(ad)

When this reaction is combined with the reaction above, and then balanced by eliminatingidentical items on the left and right sides, the net resuit of both reactions becomes: CH3SO3H —> CH2SO2 + H2O(released as gas/steam) 23 13283

Table 1 pro vides the À H (change in enthalpy) values and the AG (change in Gibbsfree energy) values for the formation of ethene via either of two routes: (1) ffom acetic acidvia ketene, as described in Barteau 1996, for comparative purposes; and, (2) from MSA viasulfene, as disclosed herein. These units are in kilocalories per mole, but since two moles 5 of sulfene make only one mole of ethene, attention needs to be paid to whether the one- mole compound is on the left or the right side of the reaction arrow, as discussed in moredetail following the table.

Both sets of values were calculated at 3 different températures, which are 300, 600,and 900 Kelvin. The Kelvin scale begins at theoretical absolute zéro, at which ail atomic 10 motion completely stops. A Kelvin température can be converted into centigrade bysubtracting 273.15; therefore, the modeling températures were equal to 26.85, 326.85, and626.85oC. Those températures are equal to 80, 620, and 1130o, in the Fahrenheit scale,which is mentioned to emphasize the range they cover, and to point out that the lowestmodeled température (which is close to room température) would not be useful or practical 15 or manufacturing ethene from MSA, since the initial barrier to reach sulfene is too high. TABLE 1

THERMODYNAMICS OF KETENE OR SULFENE REACTIONS

Ketene reactions AH AG-300K AG-600K AG-900K CH3COOH -> H2C=C=O + H2O 30.66 18.36 4.5 -8.82 2H2C=C=O -> C2H4 + 2CO 5.61 -3.63 -12.08 -19.87 Sulfene reactions CH3SO3H -> H2C=SO2 + H2O 34.83 23.30 11.79 1.12 2CH3SO3H -> 2H2C=SO2 + 2H2O 69.66 2H2C=SO2 -> C2H4 + 2SO2 -54.09 -66.67 -77.68 -87.85 SO2 + l/2O2 - > SO3 -20.86 24 β" 13283

Overall reaction: 2CH3SO3H + O2 - > C2H4 + 2H2O + 2SO3 -26.15

The conversion of MSA to sulfene will require a very hot reactor. One candidateclass of reactors that can handle such températures includes reactors that contain monolithsupports, made of quartz-like but porous silicate materials having essentially linear andparallel flow channels, as described in the Background section.

It should also be noted that many scientific articles refer to "adiabatic" monolithicreactors. The term "adiabatic" indicates that a reaction is carried out without addingextemal heat to the reactor, and without using heat exchangers or other means to activelydraw heat away from the reactor vessel. When used during research, that approach cansimplify and clarify various data and calculations. However, when highly exothermic (heat-generating and heat-releasing) reactions are carried out on a commercial scale, in largemanufacturing operations, it would be wastefui to let the heat simply dissipate, rather thanputting it to productive use. Therefore, it is presumed that in most industrial operations,any reactor that generates intense heat from an exothermic reaction will be surrounded bysome type of heat exchanger, and will not be run as an adiabatic process.

If the sulfene that is generated in this manner is converted into ethylene, as shown inFIG. 4, that reaction will be extremely rapid and exothermic, and it will release energy,calculated as a AH value -54.09 kcal/mol for each mole of ethene created. However, itrequires two moles of sulfene to create a mole of ethene. Therefore, the endothermie(energy-consuming) AH value of 34.83, for creating a mole of sulfene from MSA, must bedoubled, when overall energy requirements are considered. This leads to an endothermievalue of 69.66 for creating two moles of sulfene, followed by a -54.09 "partial payback" ofenergy that is released when the two moles of sulfene are combined to- form one mole ofethene.

That leaves a net energy consumption requirement of 15.57 kcal/mole for producingethene from MSA; however, the calculations do not stop there. Two moles of SO2 will bereleased by the sulfene-to-ethene reaction, and the SO2 must be oxidized back into SO3,which will be recycled back into the reactor that is converting methane into MSA. Theoxidation of SO2 to SO3 is highly exothermic, releasing -20.86 kcal/mole, and that value is 25 13283 doubled (to -41.72 kcal) when two moles of SO2 are oxidized. Therefore, the entire System,which starts with MSA and ends with ethene and SO3, is exothermic, and yields a netenergy release of -26.15 kcal/mole, when two moles of MSA are converted into one moleof ethene and two moles of SO3.

These computer-modeled numbers were calculated based on a simple andnon-optimized solid support, involving nothing more than hydroxy groups on a silicatematerial. Now that a pathway has been disclosed for converting methane gas (which iswasted by flaring and reinjection, at rates of roughly $100 million worth of methane, everyday) into ethene (a highly valuable olefin), via MSA and sulfene intermediates, those whospecialize in designing and testing solid catalytic materials (including silicates, cordierite,mullite, Silicon Carbide, etc.) can identify and optimize various combinations of supportsand activating agents that are likely to create solid catalysts that can increase the yields,selectivity, processing rates, and other desired traits of these reactions.

CANDIDATE PATHWAY #2: BIFUNCTIONAL (FRIEDEL-CRAFTS) CATALYSTS

Anyone attempting to develop improved catalysts for use as disclosed herein shouldalso consider "bi-functional" catalysts that use symphoric, anchimeric, and/or "neighboringgroup" effects to increase their ability to manipulate MSA. Such catalysts are also referredto as Friedel-Crafts catalysts (described in various patents and articles, such as US patent2,334,565), as acid-base (or acidic-alkaline) catalysts, or by similar terms. These catalystspresumably should be affixed to solid supports, to enable them to be retained inside areactor vessel while large quantities of gas or liquid are being pumped through the vessel.Therefore, these types of catalysts can be regarded as a subset of Candidate Pathway #1,discussed in the preceding subsection, and they build upon and extend the teachings of thatprior subsection.

In layman's terms, bifunctional catalysts can be regarded as "two-handed" catalysts.By way of analogy, most people cannot securely grip and hold a basketball with just onehand; however, nearly anyone can do it, using two hands. Similarly, it is easier (and faster)to eut a piece of steak, or an uncooked carrot or potato, if someone uses one hand (eitherwith or without a fork) to hold the food stationary, while using the other hand to hold anduse a knife.

In analogous ways, "two-handed" catalysts can attract, grasp, and manipulate sometypes of molécules more rapidly, efficiently, and securely than catalysts having only one 26 "'1 3283 type of active site or group. This is especially true with a molécule such as MSA, whichhas methyl and sulfonic. domains that are very different from each other.

Therefore, rather than using a silicate support that only has hydroxy groups as theactive sites (as described in the first candidate pathway, above), more efficient catalysts canbe developed by providing a catalytic surface with two or more types of functional groups,allowing one type of group to attract and interact with the sulfonic domain of MSA, while adifferent group attracts and interacts with the methyl domain.

In general, most bi-functional catalysts use either or both of the following: (1) twodistinct mechanisms that occur in sequence, usually quite rapidly (such as within nano-,micro-, or milliseconds); and/or, (2) anchimeric, symphoric, or neighboring group effects,in which a partial shift in one part of a molécule enables and promûtes a secondary shift inanother part of the molécule. In either case, an initial reaction or shift usually avoids orminimizes some type of transitional barrier that otherwise would hinder or block the secondpart of the desired reaction.

This approach to using bi-functional catalysts can be illustrated by a description ofhow a "hetero-polyacid" compound, such as tungsto-phosphoric acid (also calledphospho-tungstic acid) can function in a desired manner, in a liquid solution. This teachingcan then be adapted for use with immobilized catalysts on solid supports.

Hetero-polyacid compounds usually are formed by combining two or more types ofsalts, then using a strong acid to acidify the sait mixture. For example, tungsto-phosphoricacid can be created by: (1) mixing a tungsten sait such as sodium tungstate dihydrate,Na2WO4.2H2, with a sodium phosphate hydrate such as Na2HPO4.12H2O, in distilled water;(2) adding concentrated hydrochloric acid, slowly and with vigorous stirring; (3) evaporating the water under a vacuum; (4) extracting tungsto-phosphoric acid from theresidue, using a solvent such as ethyl alcohol; and, (5) removing the solvent under avacuum, to provide a crystalline acid. This mixture will contains various species that can berepresented as WOX (W is the Symbol for tungsten) and HyPOz, where x, y, and z arevariable numbers (usually but not always represented as integers). If desired, the acidmixture can be represented by one or more dominant species, such as WO3.H3PO3. Thiscompound is sold by Alfa-Aesar (www.alfa.com). Additional information is contained insources such as US patent 3,974,232 (Aizawa et al 1976, assigned to Toray Industries),which describes both (i) the déhydration of cyclohexanol into cyclohexene, and (ii) the useof other hetero-polyacid compounds, such as tungsto-silicic acid, molybdo-silicic acid, and 27 "'1 3283 molybdo-phosphoric acid.

If tungsto-phosphoric acid is mixed with MSA under suitable conditions andpressures, at least some of the MSA is likely to react with the acid in a manner shown inFIG. 5. In one part of the reaction, tungsten trioxide (WO3) will extract a hydrogen atomfrom the methyl portion of the MSA. In a second part of the reaction, phosphoric acid willdonate a hydrogen to the sulfate group on the MSA, causing it to become an ionic groupwith an extra hydrogen proton, -SO2OH2+. The -OH2 group will then leave, as water (i.e., assteam, if the reaction is carried out at high température), leaving behind an ionic sulfategroup, -SO2+. This generates a transitional MSA ion that is likely to rearrange into sulfene,while releasing water, as shown in FIG. 5. These réactions also allow positively-chargedtungsten ions (WO3H+) and negatively-charged phosphate ions (H2PO3-) to reassociate,through ionic attraction, to reform a tungsto-phosphoric acid mixture. Accordingly, thiscompound functions as a catalyst, rather than as a consumed reagent.

To render it useful for continuous-flow processing of liquids or gases, bifunctionalcatalysts can be immobilized on solid supports, to prevent the catalyst from being washedout of a reactor by the gas or liquid flowing through the reactor. Immobilization of abi-functional catalysts can be accomplished by using and/or adapting various synthesisroutes that are already known to skilled experts who specialize in creating and testing newtypes of zeolites and other semi-permeable catalysts. As one example, the "SAPO" class ofzeolite catalysts already contains phosphorus atoms, in an aluminosilicate matrix.

Therefore, an activating agent can be used to donate tungsten atoms or groups in a mannerthat will coat the accessible surfaces of a SAPO material, in a manner that will createimmobilized groups that are similar to tungsto-phosphoric acid mixtures as described above.

Altemately, if desired, a donor compound can be added to a reagent mixture that isbeing used to synthesize a porous catalyst. However, this approach tends to make lessefficient use of an expensive "dopant" compound, since much of the dopant is likely to beinaccessible, inside the final material, rather than merely coated onto accessible surfaces.

Examples of hydrocarbon processing using bi-functional catalysts are provided innumerous published articles. As one example, scheme III shown on page 427 of Olah 1987represents two sequential reactions that are triggered, first, by an acidic domain of acatalyst, and second, by an alkaline domain of the same catalyst material. Olah et al 1984(entitled, "Onium Ylide Chemistry: 1. Bifunctional Acid-Base-Catalyzed Conversion of...")contains more information on this subject. 28 13283

It should also be noted that many métal oxide catalysts (such as vanadium oxidecatalysts, platinum oxide catalysts, etc.) act as bi-iunctional catalysts, in which a vanadium,platinum, or other métal atom interacts with one domain of a compound being treated,while one or more oxygen atoms bonded to the métal atom interact with a different domainof the compound being treated.

Accordingly, since MSA has two different domains that will respond differently todifferent catalytic sites, bi-functional catalysts hold exceptionally good promise forconverting MSA into sulfene, in ways that adapt and extend the teachings set forth above,conceming solid-supported catalysts in general.

CANDIDATE PATHWAY #3: MSA METHYL ESTER PATHWAY

During the course of the laboratory research that confirmed the computer-modeledMSA-forming pathway shown in FIG. 2, a question arose as to whether the MSA was (ormight be, under certain conditions) contaminated by a methyl-methanesulfonate ester, witha structure shown at the top of FIG. 6. That question triggered some additional analysis andcomputer modeling, as well as a careful rereading of every patent issued to Snyder andGrosse in the early 1950's.

That work eventually resulted in a postulated pathway that (according to thecomputer modeling results) appears to offer an improved pathway to sulfene, with lowerthermodynamic hurdles than candidate pathway 1, above.

This candidate pathway is illustrated in FIG. 6. It is commenced by reacting MSAwith methanol, in the presence of a déhydration catalyst (various metals, such as aluminum,béryllium, silver, and copper offer candidates for évaluation for such use), in order todeliberately convert the MSA into the methyl-methanesulfonate (MMS) ester. Thisdéhydration reaction will be carried out at an elevated température, and the water that isreleased will be removed from the reactor, as steam. Additional information that can shedadditional light on this déhydration reaction, and on catalysts that can promote it, can begleaned from US patent 2,553,576 (Grosse & Snyder, 1951).

The MMS ester compound is then treated with a highly polarized metallic sait, suchas a zinc halide, such as zinc chloride, ZnCh, which can act as a "Friedel-Crafts" catalyst.

As suggested by various comments in US patent 2,492,984 (Grosse & Snyder, 1950), whenthose comments are combined with and interpreted in the light of a modem understandingof "ylide" compounds and structures (which are briefly summarized below), the métal 29 >- -,3283 halide will effectively pry off the -OCH3 (methoxy) group from the sulfate group. Thismethoxy group will then react with a hydrogen proton, which will be available from one ormore other sources in the reactor vessel (such as from a methyl group on MSA or MMS,which will be releasing protons as they convert from an H3C- methyl group into an H2C=sulfene group). The reaction of the methoxy group with a hydrogen proton complétés there-formation and release of methanol, which is recycled back into the déhydration reactor.

The release of methanol, from the MMS ester, leaves behind an "ylide" form ofsulfene, as the residue. Various candidate solvents can be tested, to deterine whichsolvent(s) can maximize the yields of this reaction. Tetrahydrofuran, dimethylsulfoxide, andother candidate solvents can provide a range of polarity levels, which will merit évaluationfor such use. In general, the preferred solvent selected for a particular manufacturingfacility is likely to dépend on the operating température that is used, at that site. Solventswith lower polarity levels can be used to slow down SO2 removal, in ways that can be usedto control reaction kinetics, to maximize desired yields.

The sulfene ylide compound will react with sulfene to form ethylene, a valuableolefin used to make plastics and polymers. These reactions are complex, involving varioustypes of pi and sigma bonds. They potentially involve four-member "dimer" intermediatesthat will décomposé at suitable températures, enabling the SO2 groups to act as leavinggroups while ethylene is formed (for more information on such dimers, chapter 17 by Kingand Rathore, from Patai and Rappaport 1991, and Arnaud et al 1999, should be consulted.However, computer modeling indicates that sulfene is sufficiently electronegative andreactive that it is likely to avoid any thermodynamic barriers, and may bypass any suchdimer formation. This modeling further supports the conclusion that sulfene may be one ofthe most active and effective methylene transfer agents ever identified, and may open upexceptionally efficient pathways to various types of hydrocarbon chemistry that hâve notpreviously been available. In addition, various options can be evaluated for controlling thelevels of sulfene reactivity, including, for example: (i) carrying out such reactions at lowtempératures, under reduced pressures, and/or in the presence of various solvents that willhelp sustain reactions at lower rates; and, (ii) modifying MSA, prior to dewatering it, inways that may, for example, modify one or more of the oxygen atoms on the sulfonicgroup.

If the ethylene remains in solution while additional sulfene is being formed, at leastsome of the ethylene is likely to react with sulfene, to form cyclopropane. This is a 30 '""1 3283 relatively unstable molécule, due to the fact that its bond angles are stressed, at 60 degrees,compared to the normal 109.5 degrees for unstressed bonds in an aliphatic chain.Accordingly, cyclopropane can be isomerized by steps such as mild heating, to formpropylene (a valuable olefin that is easier to handle and transport than ethylene), or it canbe reacted with water to convert it into propyl alcohol, which makes a very good gasolineadditive or substitute, with an energy density higher than methanol or éthanol.

While the modeling data generated to date rely on various assumptions, and are notregarded or represented as final and authoritative, a comparison of certain numbers fordifferent pathways that were generated using fairly consistent assumptions can provide someindication of the relative merits of the MMS-plus-methanol pathway, compared to the firstpathway described above, using a silicate support with exposed hydroxy groups. Understandard conditions, at 300 degrees Kelvin, the déhydration reaction (to reach the MMScompound and release steam) showed an endothermie aH value of +11.7 kcal/mol, and aGibbs free energy value of a G 12.3 kcal/mol, and the reaction that released methanol andformed sulfene ylide showed an endothermie value of aH = +23.1 kcal/mol, and a Gibbsfree energy value of aG = 11 kcal/mol. For comparison, MSA conversion on silica withhydroxy groups showed an endothermie value of aH - +34.8 kcal/mol, and a Gibbs freeenergy value of a G = 23.3 kcal/mol.

The fact that ail three of the candidate pathways disclosed above, for makingsulfene, regenerate their starting materials, and treat those materials as catalysts rather thanconsumed reagents, deserves attention, especially when compared to pathways reported inthe prior art, which could gerterate sulfene only by consuming reagents and generatedunwanted byproducts (as one example, Prajapati et al 1993 describes a method ofgenerating sulfene which consumed SOCI2, and generated hydrochloric acid). Since catalyticprocesses are generally superior to processes that generate unwanted wastes (especiallyacidic and/or sait wastes), it is believed that this invention discloses a new and usefulimprovement in synthesizing sulfene, regardless of what is subsequently done with thesulfene.

With regard to ail of the candidate pathways listed above, the enthalpy calculationsin Table 1 merit considération, and certain factors that dwell within those numbers shouldbe noted in spécifie. The conversion of MSA into sulfene is endothermie, and requiresenergy to drive it, at a aH value calculated as 34.83 kcal/mole. However, the aH value forsubsequently converting sulfene into ethene is exothermic, and releases 54.09 kcal/mol. The 31 " 13283 net release of energy is about 20 kcal/mol, to move from MSA to ethene. This is a crucialfactor that sits at the heart of this aspect of the invention, and ail of the candidate pathwaysdisclosed herein should be regarded as ways to drive the MSA dewatering reaction over aninitial "hump", so that the reaction can reach the downhill slope of the energy curve, whereit will continue on its own, releasing substantial net energy.

Accordingly, a proper understanding of this invention herein should not focus solelyon converting methane or MSA into sulfene, since sulfene is an unstable high-energyintermediate. Instead, this invention discloses a useful pathway for converting methane orMSA into olefïns or other valuable and useful products, by passing through sulfene, anintermediate that effectively provides a pathway for making olefins and other materials,with lower thermodynamic barriers than other alternative pathways.

It also should be emphasized that the candidate pathways described above are notregarded as exhaustive or exclusive. Instead, other candidate pathways for reaching sulfene,or for reaching other useful intermediates that can be converted into olefins or othervaluable products, are likely to be recognized by those skilled in the art, after the Chemicalpathways and commercial prospects for converting stranded and wasted methane into MSA,then sulfene, and then ethylene, hâve been disclosed.

USE OF SULFENE AND OTHER YLIDES; METHYLENE TRANSFER AGENTS

In addition to being useful for the manufacture of ethylene, sulfene may bepotentially useful as a "methylene transfer agent" (MTA) in various other situations. Thispotential utility will be limited by the tendency of sulfene to react with itself, rapidly andexothermically, to form ethylene; nevertheless, by controlling reaction conditions such astempératures, pressures, and ratios of reagents, it may be possible and practical to inducesulfene to react with various other compounds, in various ways and at commercial levels.

Cyclopropane offers a good example, since it can be formed by reacting ethylene(formed by condensing sulfene, or by any other known method) with additional sulfene. If afixed quantity of sulfene is placed or created in a closed reactor, much of the sulfene islikely to form ethylene, fairly rapidly; then, as the ratio of ethylene to sulfene in the reactorrises, the remaining sulfene will become more likely to react with the growing quantity ofethylene, than with the dwindling quantity of remaining sulfene. In a similar manner, if agaseous ethylene feedstock is continuously fed into a reactor along with a limited quantityof sulfene, at least some of the sulfene will react with the ethylene. 32 *"1 3283

Accordingly, FIG. 7 depicts a reaction pathway for using sulfene to convert ethyleneinto cyclopropane. Briefly, when a molécule of sulfene contacts a compound having adouble bond, the sulfur dioxide group from the sulfene will leave, and the methylene group(which has two unshared électrons, and which can be represented as either H2C: or -CH2-)will react with the double bond, in a way that generates a triangular structure, as shown inFIG. 7. If the reagent with the double bond comprises ethylene, the triangular product willbe cyclopropane, which is useful and valuable because it is highly reactive, due to the factthat its bonds are stressed at 60 degree angles in a planar structure (by contrast, theconventional bond angle in alkane molécules is 109.5 degrees).

If a limited and appropriate amount of energy is put into cyclopropane, thecyclopropane can overcome a transitional energy barrier and undergo an isomerizationreaction, as shown in the lower portion of FIG. 8, to form propylene (also called propene),H2C=CH-CH3. This is a valuable olefin, useful for making polypropylene and otherplastics and polymers. Since propylene is larger and heavier than ethylene, it is lessvolatile, and more inclined to behave as a liquid rather than a gas, at températures andpressures that can be achieved more easily and at less expense than required for ethylene.Propylene can be stored and transported as a liquid, using tanks that can operate at loweroperating pressures and/or warmer températures than required to store or transport ethyleneas a liquid. Therefore, ethylene-to-propylene conversion, using sulfene as shown in FIG. 7,may hâve important commercial implications.

Altemately, cyclopropane can be reacted with water, in a manner that breaks one ofthe stressed triangular bonds, in a way that créâtes propyl alcohol (also called propanol).

This reaction can be referred to either as hydrolysis (since one of the carbon-carbon bondsis broken), or as hydration (since the components of a water molécule are being added tothe cyclopropane). Propyl alcohol is a clean-buming fuel, which can be used as a gasolineadditive or substitute with higher energy content than methanol or éthanol, and it has othervaluable uses as a Chemical feedstock, skin disinfectant, etc.

Prior to these discoveries and disclosures, sulfene has not received any close orcareful attention by chemists, for three main reasons: (i) it is highly reactive, unstable, andshort-lived; (ii) it is very difficult to store or transport, and, (iii) it was difficult tosynthesize, and the known methods created serious problems of toxic and hazardous wastes.

However, if efficient and économie methods for manufacturing sulfene fromstranded methane (which currently is being wasted and destroyed in huge volumes, every 33 1 13283 day) are made available by the discoveries and disclosures of the Applicant, sulfene willdeserve and receive much more attention and analysis.

In particular, sulfene can be regarded and used as a dipolar compound that has both"super-nucleophile" and "super-electrophile" traits. This gives it an exceptionally potentability to react with double bonds, in ways that can avoid the destruction and élimination ofthe double bonds.

Indeed, in addition to regarding sulfene as a dipolar compound (due to thedifférences between the CH2 component and the SO2 component), a methylene radical, byitself, can be regarded as a dipolar and bi-functional agent that is both a super-nucleophile,and a super-electrophile. On one level, a methylene radical has two extra and unpairedélectrons exposed on its surface, and those électrons will aggressively seek out and bind tothe positively-charged nucléus of another carbon atom. That makes methylene radicalshighly potent nucleophiles. However, at the same time, a methylene radical is missing twoélectrons from its valence shell, and it will aggressively seek out and bind to an electron-rich structure which can help it fdl those gaps (such as a double bond, in an olefinmolécule). That makes methylene radicals highly potent electrophiles.

These combined traits are believed to make sulfene a highly potent "methylenetransfer agent", which can insert -CH2- groups into various types of compounds. In oneparticular type of reaction that is likely to become of scientific and commercial interest, itis believed that sulfene will be able to insert methylene groups into olefins, withoutdestroying the double-bonded constituents of the targeted olefins. As such, it is believed tobe able to convert propene into butene, butene into pentene, pentene into hexene, etc., bychain-lengthening reactions in which the sulfene is most likely to react with the electron-rich double bond, in each step of the reaction. The initial step in a "methylene insertion"reaction will create a three-membered ring, comparable to a cyclopropane molécule that hasa "tail" attached to one of the three carbons. The ring having three carbon atoms (withstressed bonds, having bond angles of 60 degrees) can then be induced (such as bymoderate heating) to cross a relatively low transitional energy barrier, in a way thatisomerizes the three-member ring to form an "alpha" olefin, with the double bondpositioned between the first and second carbon atoms in the chain. This isomerization formis believed to be preferred over a 2,3-olefin formation, because the #3 carbon atom in athree-membered ring (i.e., the carbon atom that has a hydrocarbon "tail" attached to it) willbe less electron-rich, and less likely to participate in the formation of a double-bond. 34 " 13283

By screening and optimizing different zeolite or other porous catalyst formulations,and by manipulating the use of "seeding" compounds that can serve in a mannercomparable to "condensation nuclei", this approach can be used to manufacture liquidmixtures that will be comparable to "fractions" that can be obtained by distillation or otherconventional hydrocarbon processing, with sufficient quality and consistency to enable theiruse as gasoline or other fuels, or as fuel additives, blending agents, etc., without requiringdistillation or other purification (although distillation or other purification can be provided,if desired, to increase the purity and value of any resulting product(s)). In some cases, itlikely will also be possible to generate liquids that are sufficiently enriched in one or moredominant compounds that they can be used as Chemical feedstocks, either without additionalpurification, or after purification by means such as by distillation, molecular sieves, etc.

It also is likely and anticipated that methods will become known and available (suchas by manipulating température, pressure, and time conditions, catalyst formulations, and/orcondensation nuclei) for manufacturing various different categories of liquid hydrocarbons,including straight-chain alkanes, branched alkanes, alkenes (also called olefins),cycloalkanes and cycloalkenes, aromatics, and possibly even substituted hydrocarbons (suchas halogenated or oxygenated dérivatives, etc.).

As a démonstration of that potential, some of the initial tests carried out to date,described in Example 3, indicate that under some conditions, methane reagents thathâve passed through MSA and then sulfene intermediates can generate liquid hydrocarbonmixtures that qualify as naphtha-type mixtures (generally defined as a crude oil fraction thatcan be obtained by distillation, containing molécules within the C4 through 02 range).

This resuit indicates that this approach may offer the most efficient and economical methodever discovered to date, for converting methane gas into liquid hydrocarbons that can beused for high-quality gasoline or other fuels, or for Chemical feedstocks (which can beespecially valuable if a double bond remains présent in the hydrocarbon molécules).

In addition, early tests involving different conditions, described in Example 3,indicate that under some conditions, sulfene-containing préparations can generate solidpolymeric materials. Such plastic and/or polymeric materials, when manufactured in thismanner at methane-producing sites, hâve a wide range of uses; for example, they can bestored and transported in particulate form, in ways that allow them to be melted and moldedinto desired shapes, at a factory.

Because of the reactivity of sulfene, it is likely that most commercial-scale reactions 35 ""13283 involving sulfene will generate a mixture of products, rather than a single relatively pureproduct. However, various types of séparation processes (such as distillation,centrifugation, molecular sieves, etc.) can be used to separate mixed product streams intorelatively pure product fractions, if desired. Accordingly, preferred product mixtures orpurified product streams will dépend more heavily on économie factors and preferencesthan on technical constraints. It should also be noted that the presence of a substantialquantity of cyclopropane and/or propene, in a liquid or gaseous mixture that also containsethene, is likely to lower the vapor pressure of the ethene, in ways that will make it moreefficient and économie to transport a mixture in liquid form. Similar effects occur withother hydrocarbons, including "liquified natural gas" (LNG) mixtures, in which butaneand/or pentane effectively help to "solubilize" propane in a liquid mixture. This allowslarge quantities of propane to be stored and transported, in LNG mixtures, at pressuressubstantially lower than would be required for propane alone.

Therefore, the ability to use sulfene in various types of Chemical synthesis andmanufacturing operations, and the économie, technical, and commercial possibilities that will become available if reactions that pass through sulfene as a reactive and unstableintermediate can be efficiently and economically carried out in large quantities by themethods disclosed herein, appear to hâve the potential to open up a number of new pathways and fïelds, in organic chemistry. These options and opportunities will meritcareful évaluation, after the disclosures herein hâve been revealed to chemists who areskilled in these branches of organic chemistry.

YLIDES AND CARBANIONS

Chemists interested in sulfene chemistry should understand (or at least study)compounds called ylides and ylids, and so-called "Wittig reactions" (named after GeorgWittig, a German chemist who won the Nobel Prize in 1979). A complété analysis of ylid and ylide chemistry is beyond the scope of thisapplication; however, they are discussed in detail in various review articles (e.g., Li et al1997 and Lakeev 2001), and full-length books (e.g., Trost 1975, Clark 2002, and Bertrand2002).

Very briefly, ylides and ylids that are of interest herein will hâve a "carbanion", aterm that combines "carbon" with "anion". This refers to what is, in effect, a carbon atomwith an unshared électron pair. This unshared électron pair is created by positioning the 36 ' 13283 carbon atom next to a positively-charged "hetero-atom", which will donate one of itsélectrons to the carbon atom (a more complété description of this électron shift requires ananalysis of électron valence shells, "p" and "d" orbitals, pi bonding, etc.). In most cases ofcommercial interest, the heteroatom will be sulfur, nitrogen, or phosphorus, although somechemists regard oxygen as also having suffïcient strength to form compounds that canbehave as ylides under at least some conditions).

Ylides and other compounds that contain negatively-charged, electron-rich"carbanions" are relevant to the manufacture of olefins, for the following reason: if twomolécules that contain electron-rich "carbanions" react with each other, the electron-rich"carbanions" in the reagent molécules are likely to form an electron-rich double bond,between the two carbon atoms, in a new molécule created by the reaction, while thepositively-charged heteroatoms act as leaving groups.

Examples of ylide chemistry are discussed in Corey et al 1965, which addresses twoparticular ylides: dimethylsulfonium methylide, (CH3)2S=CH2, and dimethyloxosulfoniummethylide, (CH3) 2 S(O)=CH2 (the parenthèses arôund the oxygen atom, in the oxosulfoniumylide, indicate that the oxygen is double-bonded to the sulfur atom, rather than beingpositioned between the sulfur and carbon atoms). In both of those ylide compounds, thebond between the sulfur atom and the carbon atom can be written in any of three ways(often called "canonical" forms, comparable to a musical piece such as "Pachelbel'sCanon", in which the same melody is played repeatedly, but in slightly different ways).

One written version depicts a standard double bond, such as RiR2S=CH2. A second writtenversion depicts a single bond with charge indicators, RiR.2S+C'H2. A third written versioncombines those two formats, and depicts a double bond with charge indicators, RiR2S+=C' H2.

The terni "resonating structure" is often used to describe électron configurations thatcannot be cleanly represented as one particular form. Most commonly, resonating (orrésonant) électron structures can hâve either or both of: (i) two distinctly different formswhich will shift back and forth, to coexist with each other, in equilibrium; or, (ii) a quasi-stable intermediate form, located somewhere between the two ends of the continuum, andhaving some combination of mid-point properties. Resonating électron structures are fairlycommon in chemistry, and are used to explain a wide variety of semi-stable molécules,including carbon monoxide, sulfur dioxide, and molécules that shift back and forth between"tautomeriç" forms (such as sugar molécules, which shift back and forth between rings, and 37 straight chains).

One set of teachings in Corey et al 1965 is worth noting. When Corey et al used thereagents described in the lower right column of page 1363 to synthesize dimethylsulfoniummethylide (which Corey et al described as CH3) 2S+-C‘H2, shown as compound XIII in theleft column of page 1356), the température of the reaction mixture rose slightly, andreleased a gas, most of which evolved within 5 minutes. That gas was passed through abromine solution, and the resulting gas was analyzed and found to be ethylene dibromide.This indicated that the gas, released by spontaneous exothermic décomposition of Corey'smethylide compound (which contained the S+=C‘ ylide structure) was ethylene, and thedimethylsulfide group of the ylide compound acted as a leaving group. That report providesadditional support for the assertion that sulfene will spontaneously react with itself, in away that releases ethylene.

The disclosures herein also suggest that dewatering of other alkane-sulfonic acids(such as ethanesulfonic acid, propanesulfonic acid, etc.), using agents and methods such asdescribed above to create sulfene analogs or other ylide compounds, can provide usefulapproaches to manufacturing other types of longer and heavier olefins.

Accordingly, the disclosures herein can be combined with additional disclosures(already published in the art) involving ylides, ylids, and Wittig reactions, in ways that willenable commercial and industrial adaptation of sulfene and sulfene-analog chemistry for usewith additional types of ylids and ylides, in ways that will become apparent to those skilledin that particular field of chemistry, after they hâve analyzed and evaluated the disclosuresherein.

"OUTER" ANHYDRIDES

Analysis of another article (Karger and Mazur 1971, entitled, "Mixed sulfonic-carboxylic anhydrides: I. Synthesis and thermal stability. New synthesis of sulfonicanhydrides") suggested to the Applicant herein that certain additional processes might alsobe involved (or might be created, by controlling reaction conditions) in the formation ofsulfene from MSA, and in subséquent polymerization reactions involving the sulfene.

Karger and Mazur worked with MSA (which is listed as their formula CH3SO3H anumber of times, such as in their Tables I and II on page 530); however, they werecombining MSA with various acid chloride compounds, in ways that displaced the chloridemoieties and created various ether and/or ester linkages in the resulting anhydrides. One 38 ' '13283 passage on page 531 is worth particular attention. It reports, "Thus, methanesulfonicanhydrides decomposed only above 250°" (it should be noted that that phrase is ambiguous;it may refer to only those anhydrides that would décomposé only above the 250°Ctempérature, or it may refer to ail anhydrides, if treated at températures above 250°C) "togive methanesulfonic acid (70%), residual intractable polymer (15%), and sulfene whichpresumably did not survive its conditions of génération (équation 8)." Their équation 8 was: CH3SO2OSO2CH3 —> CH3SO3H + (CH2=SO2) at 250°C.

Two reaction pathways that offer candidate mechanisms for explaining the formationand then destruction of the MSA "outer anhydride" are shown in FIG. 8. The first reactionin FIG. 8 shows a condensation step involving two molécules of MSA, which créâtes an"outer anhydride" of MSA (shown as the starting reagent in Karger's Equation 8) whilereleasing a molécule of water. To create this condensate, the sulfate group on a firstmolécule of MSA releases a hydrogen proton, and the sulfate group on a second moléculeof MSA releases a hydroxy group. These two reactions join the MSA residues togetherthrough a single-bonded oxygen linkage, which can be regarded as an ether bond (orthioether bond, since the oxygen atom links two sulfur atoms), or as an ester (or thioester)bond, since the sulfur atoms also hâve double-bonded oxygen atoms. Presumably, thisreaction can be promoted by dehydrating agents such as mentioned elsewhere herein, and invarious passages in Karger et al 1971.

In Step 2 in FIG. 8, which likely will occur only at relatively high températures, the"outer anhydride" molécule rearranges. This reaction is postulated to involve: (i) release ofa hydrogen proton from the methyl group of the anhydride; (ii) migration of the électronsfrom the C-H bond over to the C-S bond, thereby forming a double bond; and, (iii)breakage of the S-0 linkage, in the presence of protons in the acidic MSA solution. It ispossible but not especially likely that the same hydrogen proton from a particular moléculewill bond to the oxygen atom from an S-0 linkage that is being broken in that samemolécule. In addition to generating sulfene, as shown in FIG. 8, the rearrangement in step2 also regenerates and releases a molécule of MSA.

It is also worth noting that because of how the "outer anhydride" breaks apart, itmight be useful as a radical initiator compound, to trigger the conversion of methane into 39 " 13283 methyl radicals, during the processing that converts methane into MSA as shown in FIGS.1 and 2. If the "outer anhydride" compound is broken apart by means such as passing itacross a heating element in a device such as "radical gun", it may release at least one andpossibly two "strong radical initiator" compounds that can efficiently remove hydrogenatoms from methane. This possibility is especially interesting because its products may beable to reform MSA, rather than creating a sulfuric acid waste, which will be created ifMarshall's acid is used.

Additional comments on sulfene formation, and on Karger et al 1971, are providedin King and Rathore 1991. Those comments, while focusing on different aspects of thechemistry (such as IR spectroscopy of sulfene at low températures) are neverthelessbelieved to be consistent with ail disclosures and postulated mechanisms herein.

POLYMERIZATION AND DENDRIMERS

As mentioned above, one comment made in passing by Karger et al 1971 reported,on page 531, "a black intractable polymeric solid, which gave no acid reaction on boilingwith water, was the only nonvolatile product". The yield of Karger's polymer was low(15%), their compound was never anâlyzed, and it clearly did not teach or suggest anypractical way to manufacture a commercially viable polymer. Their publication occurredmore than 30 years ago, and it never led to any commercialization.

However, the discoveries and disclosures of the Applicant herein appear to beapproaching a point where practical and efficient methods can now be disclosed formanufacturing various types of polymers from methane, via MSA and MSA anhydrides. Inparticular, the Applicant herein believes and anticipâtes that polymeric material can becreated by repeated insertions of methylene groups (-CH2-) into growing carbon chains, asindicated in FIG. 9. It is possible that methylene groups can be inserted into the carbon-sulfur bond, shown in the MSA molécule that serves as the starting point for the chain-lengthening reaction; however, computer modeling indicates that the more likely point ofinsertion appears to be at a carbon-hydrogen bond in the methyl group.

Regardless of which bond provides the particular insertion site, a hard polymericcompound was indeed observed, when the "outer anhydride" of MSA (purchased incrystalline form, from Aldrich Chemicals) was heated to a température higher than 250°C,under nitrogen gas. The décomposition created both a clear liquid, and a black solid. Boththe liquid and the residue were chemically analyzed. The clear liquid was found to consist 40 1 3283 mainly of MSA and cycloalkanes. The black solid was found to contain cyclic hydrocarbons, naphthenics, and a relatively high quantity of aromatic structures. Some ofthe aromatic rings were bridged by sulfonate or methylene bridges, and some of thearomatic rings had cyclopropane rings attached to them.

Based on those results combined with other teachings herein, it is believed and anticipatedthat practical means for making commercial quantities of hydrocarbon liquids that can beused as fuels, and possibly as Chemical feedstocks, can now be identified and developed,using pathways that pass through MSA, MSA esters, and/or MSA anhydrides, by using steps that include the following: a. creating a préparation that contains sulfene and/or MSA outer anhydride, mixedwith a suitable solvent having a boiling point higher than the décomposition température ofthe sulfene or sulfene-containing starting material (dimethyl sulfoxide offers one candidatefor early évaluation, and other solvents with higher boiling points are known); and, b. heating the préparation, while bubbling nitrogen gas up through it at rates that will remove the desired products as they are being formed, without allowing them tocontinue to rearrange until they form aromatic rings.

In addition, it is believed and anticipated that practical means for makingcommercial quantities of solid polymers can now be identified and developed, usingpathways that pass through MSA and MSA anhydrides, by using steps that include thefollowing: a. creating a préparation that contains (i) sulfene and/or MSA outer anhydride, and(ii) any other desired starting reagent (such as a styrene precursor, acrylate precursor, vinylprecursor, etc.), in a suitable solvent having a boiling point higher than the décompositiontempérature of the starting mixture; and, b. subjecting the préparation to a "cooking" reaction (i.e., involving a controlledtemperature-pressure-time combination) that forms a desired solid, while bubbling an inertgas (such as nitrogen or CO2) through the mixture at rates that are sufficient to remove thedesired products before they form aromatic rings.

In either type of System, the use of solvents with boiling points that are well abovethe heating températures being used, combined with the use of gas "sweep" Systems topromptly remove desired products in gaseous phase as they are formed, provides a usefuland flexible means for controlling the reactions.

On the subject of reactions that can create hydrocarbon chains by insertion of 41 " 13283 methylene groups, a report by Michalak and Ziegler 2003 should also be noted. This reportindicates that branched polymers can be created, in controllable manners, by using certaintypes of catalysts, such as nickel-diimine or palladium diimine.

This approach to controlling the branching of hydrocarbon chains that are beingformed has a number of important commercial implications. One application worth notingrelates to the manufacture of liquid fuels having higher energy density per volume, as wellas higher quality (including higher "octane" ratings, for gasoline). These aspects, involvingincreased value and utility, arise from two facts. First, in a hydrocarbon liquid, moléculesthat hâve some degree of branching tend to fit together better (allowing greater weight pervolume) than entirely linear molécules. Second, molécules that hâve some degree ofbranching are not as long as straight-chain molécules, for a given number of carbon atoms,and there is less chance that the "far end" of some particular molécule will be pushed away,in unbumed form, when one of the molécules goes through rapid and explosive butimperfect combustion. As an illustration of this phenomenon, the molécule with the gold-standard "100" octane rating is 2,2,4-trimethyl pentane, rather than straight-chain octane.

Other potential applications (including the manufacture of various types of plasticsand polymers, including isotactic, atactic, or other "designed" polymers) will be recognizedby those skilled in the art, after they hâve studied the properties and potentials of sulfene asa methylene transfer agent.

Two additional classes of reactions also should be noted, involving C=O doublebonds, generally referred to as carbonyl bonds or groups. If sulfene transfers a methylenegroup into an aldéhyde group (i.e., a carbonyl group located at the end of a carbon chain)or into a ketone group (i.e., a carbonyl group located in the middle of a carbon chain), theinsertion will create a three-membered oxirane or epoxide ring, which will include thecarbon atom that had the carbonyl group. Epoxide and oxirane rings are unstable andreactive, due to their stressed bond angles. This makes them useful reactants in certaintypes of Chemical processing, if they can be used rapidly after they are generated, beforethey hâve time to spontaneously décomposé.

It should also be noted that sulfene may become useful in modifying the surfaces ofvarious types of silicate materials that will hâve spécial properties or uses following suchtreatments. Examples of such candidate uses include semiconductors, and an emergingcategory of materials that are creating new types of interfaces and interactions betweenbiological materials (such as antibody fragments or other proteins, DNA segments, etc.) 42 i: 1 3283 and nonbiological materials, for purposes such as diagnostic, therapeutic, or otheranalytical, processing, medical, or other physico-chemical uses. Anyone interested in thiscategory of uses should study Lie et al 2002, including passages such as the first fullparagraph on page 116, which discusses the formation of direct silicon-carbon bonds ratherthan silicon-oxygen-carbon linkages, and the last paragraph in column 1 of page 117, whichdiscusses the possible insertion of methylene groups (-CH2-) into silicon-silicon bonds.

"UPSTREAM" OPTIONS AND ENHANCEMENTS

In addition to the discussion of synthesis and use of MSA and its esters andanhydrides, in the foregoing sections, this application also contains a number of teachingson other aspects of the overall System. As described near the start of the "DetailedDiscussion" section, these disclosures are intended to help ensure that any and ail"disclosure of the best mode" requirements for valid patents are satisfied, since they relateto improved ways for designing and operating complété and functional Systems that can takemethane gas ail the way to liquid fuels, olefîns, polymers, and other valuable compounds.

The disclosures in this subsection relate to "upstream" processing, i.e., steps thathelp promote the synthesis of MSA, the crucial intermediate, from methane. These"upstream" options and enhancements include the following: (1) It is believed and anticipated that if carbon dioxide (CO2) is pressurized to apoint that causes it to become a supercritical liquid, it may be able to increase the solubilityof methane gas, in a liquid solution of SO3 and MSA. If this is confirmed in continuous-flow testing, the use of supercritical liquid CO2 may be able to increase and improve themass transfer rates that will transfer gaseous methane into a liquid solution. This may beable to increase the speed and efficiency of the reaction that converts methane into MSA. (2) It is believed and anticipated that it may be possible to adapt either the inneranhydride of MSA (i.e., sulfene), or the outer anhydride of MSA, for use as a radicalinitiator compound, instead of Marshall's acid or various other radical initiators that willgenerate acidic waste byproducts. Briefly, a radical initiator compound that can efficientlyremove a hydrogen atom (both a proton, and an électron) from methane, thereby convertingthe methane into a methyl radical, H3C*, is necessary to launch the chain reaction that willconvert methane into MSA, as shown in FIG. 2. As described above, sulfene can releasemethylene radicals. These radicals can be regarded as "double-strong" radicals, since theyhâve not just one, but two unpaired électrons. 43 1 13283

When a methylene radical (with two unpaired électrons) reacts with methane, the"double-strong" methylene radical is likely to remove a single hydrogen atom frommethane. This will balance out the two molécules, making them equal, thereby creating twomethyl radicals, H3C*. Each of these methyl radicals will be able to combine with sulfur 5 trioxide, SO3, to form MSA radicals, as shown in FIG. 2, and the MSA radicals will thenremove hydrogens from fresh methane, to form stable MSA while creating new methylradicals that will keep the chain reaction going.

Accordingly, if sulfene (in gaseous, mist, or similar form) can be injected into amethane stream, it may be an effective and useful radical initiator compound, which may 10 eliminate or reduce the need for Marshall's acid, halogen gases, or other compounds thatwould likely create acidic wastes.

If desired, an MSA anhydride can be pumped out of a device (which can be called a"radical gun") having a nozzle that contains a very hot electric filament or other heatingelement (which can be embedded in a quartz tube or other protective device, if desired) that 15 will break apart the radical-releasing molécules as they pass across the heating element.These types of devices are described in numerous articles, including Danon et al 1987,

Peng et al 1992, Chuang et al 1999, Romm et al 2001, Schwarz-Selinger et al 2001,

Blavins et al 2001, and Zhai et al 2004. Similar devices can be constructed and tested,which will pass a selected radical-releasing compound through a nozzle or other component 20 having a zone that is subjected to high levels of ultraviolet, tuned laser, or other radiation(or, indeed, any other form of energy input). (3) One or more types of borate compounds (such as trimethyl borate, or borateanhydride), if properly utilized in the MSA reactor vessel, may be able to help promote thesynthesis of MSA, mainly by reducing unwanted SO3 reactions (such as the formation of 25 CHx(SOy)nH polymers and other species, where x, y, and n are variables). In addition tohelping to minimize and prevent the formation of unwanted methyl-sulfonate species, theborate compound can also help maintain SO3 molécules in their aplha and gamma forms,which can help improve the overall conversion of SO3 to MSA. Such borate compounds canbe coated onto immobilized or particulate surfaces, to ensure that they remain inside the 30 MSA reactor. (4) If quantifies of both liquid and gaseous SO3 are pumped into the MSA reactorvessel (either separately, through different inlet nozzles, or in a mixed and entrained stream,or in any other suitable manner), the mixed liquid and gas streams may be able to 44 ''1 3283 react with methane gas, in the liquid/gas mixtures and interfaces that will be présent insidethe reactor, in ways that will increase the rates of MSA formation. (4) It may be possible to use methods for breaking apart a radical initiator (such asMarshall's acid), using methods such as photolysis, in ways that create or preserve certaintypes of électron "spin" in the two radicals that are formed when the radical initiator breaksapart. This is analogous to creating one radical with an électron having a "right-handed"spin, while the other radical has an électron with a "left-handed" spin. This can beimportant, because two right-handed radicals cannot recombine with each other, and twoleft-handed radicals cannot recombine with each other, in ways that would reform theinitiator and "quench" it as a radical. In other words, a left-handed spinning radical mustcombine with a right-handed spinning radical, to recombine. This approach suggests usefulmethods (such as continuing to shine light having a radical-breaking wavelength) into anMSA reactor vessel, through one or more transparent panels in one or more walls of thereactor.

By contrast, breakage of a radical initiator by means such as heating provides less ofthis useful effect, and allows radicals to recombine more readily.

These factors are discussed in more detail under the term "solvent cage" effects, invarious Chemical articles. If those factors are recognized and understood, they can be put togood use in the Systems disclosed herein. (5) It may be possible to create MSA, in bulk quantities, by using one or more typesof surface-active radical initiators, comparable to the immobilized catalytic compoundsdescribed by Barteau 1996 (for the formation of ketene, as described in the Backgroundsection) or described herein, in the passages on candidate pathways for making sulfene.

This approach is supported by those teachings, combined with the additional teachings ofLie et al 2002, which is entitled, "Photochemical reaction of diazomethane with hydrogen-terminated Silicon surfaces", describing work done in the laboratories of Benjamin Horrocksand Andrew Holton, at the University of Newcastle upon Tyne, in Great Britain.

The Lie et al 2002 article describes highly complex and sophisticated chemistry thatwas done using light-activated molécules on Silicon surfaces. Thus type of photo-catalyzedchemistry is used to create the extraordinarily tiny circuitry in integrated circuits, and thereis no reason to suspect or assume that this class of chemistry could be adapted andconverted into efficient methods for mass-manufacture of liquid Chemicals, at the scalesinvolved in methane conversion. 45 "13283

Nevertheless, various factors discussed herein led the Applicant's to carefully studyvarious articles on Chemical treatment of semiconductor surfaces (such as Barteau 1996 andLie et al 2002), and those articles triggered several insights by the Applicant, into ways thatcertain Chemical reactions and pathways used in preparing semiconductor surfaces might beadapted and expanded to enable the handling and processing of bulk liquids, such asmethane, MSA, and sulfene.

In particular, certain passages in Lie et al 2002 (especially a passage that beginswith the first full paragraph in column 2 of page 113) State or imply that certain types ofradical species can be generated, at or near the surfaces of silicon-containing materials,when compounds such as diazomethane are activated by using certain conditions (mainlyinvolving ultraviolet light radiation, when semiconductor manufacturing is involved). Thosepassages, combined with additional teachings in Barteau 1996 and other articles, hâvesuggested to the Applicant that if certain types of solid materials are surface-treated incertain ways, the resulting surface-treated supports may be ablé to function as efficientremovers of hydrogen atoms (both protons and électrons) from lower alkyl molécules suchas methane, or from other compounds (such as azomethane, sulfene, ketene, etc.) that cansubsequently function as "strong radical initiators" (i.e., compounds that can efficientlyremove hydrogen atoms from methane or other lower alkanes). This would generate methylradicals, in quantities that may be able to initiate the methane-to-MSA conversion réactionshown in FIG. 2, without requiring a slow and steady input of radicals from a radicalinitiator compound such as Marshall's acid or a halogen gas.

Accordingly, this approach offers a promising candidate pathway for use asdisclosed herein. Those skilled in this field of art can better understand and evaluate thesecomments if they study Lie et al 2002, Barteau 1996, and other published works cited bythose authors, especially including the items cited as footnotes 22, 33-34, and 41-52 by Lieet al. IMPROVED CONVERSION OF SO2 INTO SO3

The process illustrated in FIG. 2 pumps SO3 into an MSA-forming reactor, andremoves SO2 from an MSA cracker. To keep that sulfur cycle running, SO2 that emergesfrom the MSA cracker to be oxidized back into SO3. While that is a well-known process,used at numerous facilities around the world, the volumes that will be involved, inmethane-to-methanol conversion, are likely to dwarf any SO2 oxidizers that hâve ever been 46 1 13283 built. As mentioned in the Background section, roughly $100 million worth of methane iswasted by flaring or reinjection, every day. Those are huge volumes of methane, andcorrespondingly huge volumes of SO2 will need to be converted into SO3, every day. Toillustrate the volumes involved, it has been estimated that the volume of SO2 to SO3conversion to handle the methane gas output from even a single large oil field, in theMiddle East, will require an SO2 to SO3 processing facility that is roughly five times largerthan the largest facility that currently exists anywhere in the world.

Accordingly, this application discloses what is believed to offer potentially importantimprovements, not just over standard V2O5 Systems, but also over several items of recentart that offer their own improvements over V2O5 Systems. Accordingly, this aspect of theinvention requires a brief overview of several recent advances in SO2 to SO3 processing.

One major set of advances relates to using relatively small "monolith" catalysts,rather than large towers, for SO2 to SO3 conversion. As described elsewhere herein,monoliths are hard but porous materials with essentially linear and parallel flow channels,usually ranging from about 100 channels per square inch (cpsi) for liquids, up to 1000 ormore cpsi for gases. Their use in SO2 to SO3 conversion is described in patents such as US5,264,200 (Felthouse et al 1993). Other materials that can provide solid supports forcatalytic materials include woven glass fibers (e.g., Bal'zhinimaev et al 2003), and zeolite-type porous materials (e.g., US patent 6,500,402, Winkler et al 2002). Other relevantpatents that address fluid-handling and heat-exchanging machinery include US 6,572,835(MacArthur et al 2003).

Another interesting research lead involves the use of activated carbon as a catalyst,as described in US 6,521,200 (Silveston et al 2003). One interesting aspect of that work isits assertion that SO2 to SO3 conversion can be carried out at relatively low températures,ranging from room température up to about 60°C. It should be noted that room températureconversion of SO2 to SO3 was initially described in Davtyan 1955 (published in Russian),and subsequently in Hartman et al 1972.

Accordingly, those publications indicate that improved methods and catalysts alreadyhâve recently been discovered, mainly in academie laboratories and small companies, forconversion of SO2 to SO3. However, those recent advances hâve not yet been widelynoticed or adopted by industry, presumably because of two clusters of reasons. The First setof reasons centers on the fact that a large network (or "base") of existing V2O5 Systemsalready exists, and has been running for years. People and companies already know how to 47 1 3283 keep those Systems running, and if a System suffers an upset, local operators and availableexperts know how to get it running again, quickly. Replacement of those existing Systems,and training people not just to run them but also to diagnose and correct any upsets andmalfunctions, would be very expensive. The second cluster of reasons centers on the factthat the SO2 to SO3 reaction is highly exothermic. Since it releases a lot of heat and energy,which can be captured and used for steam génération or other useful purposes, there hasbeen no motivation or incentive for industrial companies that already own and run V2O5Systems to invest in other Systems that might be smaller, faster, or more efficient.

However, that situation will change dramatically, with the advent of a new processfor converting methane to methanol in huge quantities, using methods that will requireequally huge quantities of SO2 to be oxidized to SO3. Accordingly, the disclosure of newmethane conversion Systems will require a careful reappraisal of the best recently-identifiedtechnology for oxidizing SO2 into SO3.

As part of that reappraisal, the Applicant herein discloses what may offer anotherpotentially important advance in high-efficiency conversion of SO2 into SO3. This disclosureis based on computer modeling which indicates two potentially important results.

First, a new class of vanadium catalysts, including vanadium diformate andhalogenated analogs of vanadium diformate (such as vanadium fluoro- or perfluoro-diformate, in which some or ail of the hydrogen atoms hâve been replaced by fluorineatoms), may be able to offer a better catalytic pathway from SO2 to SO3, using steps andintermediates such as illustrated in FIG. 10.

Accordingly, it is disclosed herein that vanadium formate catalysts (or any othervanadium catalyst) can be coated onto activated carbon, for use (which may include lowtempérature use) in converting SO2 to SO3. In addition, reports by others (Fonseca et al2003, which involved adsorption rates of SO2 from exhaust gases) suggest that the presenceof a vanadium catalyst, on activated carbon, can increase the adsorption of SO2 onto thecatalytic surfaces, compared to activated carbon surfaces without vanadium. Accordingly,the disclosures herein, involving improved vanadium diformate catalysts on activatedcarbon, are believed capable of providing substantial improvements in rates and efficiencies. This type of processing preferably should be carried out in an aprotic medium,where the solvent has a low dielectric constant, such as supercritical CO2, to help promoterapid desorption of SO3 away from catalytic sites, and to prevent the hindrance of vanadiumcatalytic sites, as can occur with solvents having higher dielectric constants. 48 ' 13283

Other catalyst formulations that may deserve to be reevaluated, in light of theapproaching demand for improved ways to convert SO2 to SO3 in methane conversionSystems, are described in US patent 2,418,851 (Rosenblatt et al, 1947), which disclosedthat mixtures of platinum and palladium were substantially more effective than either métalby itself in converting SO2 to SO3, and in US patent 6,500,402 (Winkler et al 2002), whichdiscloses that relatively inexpensive iron catalysts can be used to convert SO2 to SO3 attempératures greater than 700°C, which is higher than can be withstood continuously bymost soft and/or noble metals. Although the highest reported yield in US 6,500,402 was77% (see Table 1, in column 3), that yield may be sufficient for operations as describedherein, if the SO2 and SO3 output streams are separated, and if unreacted SO2 is retumed tothe reactor for another pass. Altemately, that type of "first-pass" processing may be able toget most of the work done in a relatively inexpensive manner, in ways that can be followedand supplemented by "polishing" steps that will take the outputs to higher levels andpercentages using smaller quantities of more expensive catalysts.

These types of catalysts should be evaluated for use in conventional towers, insmaller monolith reactors, in packed and fluidized beds, and in any other type of processingvessel or reactor that may be of interest. They can be evaluated at any desired température,and either with or without supercritical carbon dioxide as a solvent.

The preferred choice of operating parameters (which will include a chosen operatingtempérature, and any heat exchangers or other subsystems that may be used tp activelyremove heat front the SO2 to SO3 conversion reactor) will be determined by économierather than technical factors. If a System is run at a relatively low température, it can becooled by using seawater or other means that may be available at that site.

However, it should also be noted that if an SO2 to SO3 conversion reactor is run at ahigher température, the heat it generates may be useful, for heating MSA from a relativelycool formation température (such as roughly 50°C), to a much higher cracking température(which is likely to exceed 250 or 300°C).

Accordingly, SO2 catalytic oxidation reactors that are run at high températures canbe placed inside tubular structures, which can be surrounded by annular or other flowchannels that will carry liquid MSA, preferably in a counterflow direction. This can providean efficient heat exchange mechanism, allowing heat that is released by SO2 oxidation, insidethe inner reactor tube, to be transferred to the MSA liquid in the annular space, toheat the MSA liquid up to cracking températures. 49 13283

Accordingly, FIG. 11 is a schematic depiction of a System for converting SO2 toSO3, using: (i) an oxidizing reactor that contains a catalyst on a monolithic, fiberglass, orother porous support; (ii) a heat exchanger that allows heat from the SO2 to SO3 reaction toheat MSA from its formation température (about 50°C) to its cracking température (morethan 300°C); (iii) an SO3 condenser, to allow liquid SO3 to be collected and pumped backinto the MSA reactor; and (iv) a device for separating SO2 from remnants of the air thatwas used as an oxygen source, allowing purified SO2 to be retumed to the catalytic reactorfor another conversion pass.

EXAMPLES

EXAMPLE 1: MAKING AND CRACKING MSA

Methods and reagents used to make Marshall's acid and MSA in laboratoryconditions, using a batch reactors, hâve already been described in PCT applicationsPCT/US03/035396 (published in May 2004 as WO 2004/041399) and PCT/US04/019977,both filed by the same Applicant herein. Therefore, those descriptions will not be repeatedherein.

To crack MSA in a manner that releases methanol and SO2, nitrogen gas (N2) at aflow rate of 6 to 8 mL/second was passed through a gas bubbler containing 10.0-15.0 g ofMSA at 120-140°C. The outlet of the bubbler was connected to a quartz tube with an innerdiameter of 2 cm and a length of 20 cm, which (except for short inlet and outlet segments)passed through a fumace In various different tests, the tube was either empty, or a 10 cmlength of the tube was loaded with 4 to 8 mesh zeolite beads (Davison Chemicals, codenumber 54208080237). The outlet of the tube was connected to two bubblers, eachcontaining 5.0 g of D2O (i.e., water containing the heavier deuterium isotope of hydrogen,for analysis using ιΗ-nuclear magnetic résonance) at 4-6°C, for trapping any emergingliquids.

When the tube did not contain zeolite packing, significant quantities of the methylester of MSA (a byproduct that was unwanted, in these particular tests) were obtained.However, when zeolite packing was provided in the tubes and the fumace was run at385°C, the yield of methanol increased greatly, and reportedly approached 100%. 50 I" 13283

EXAMPLE 2: SYNTHESIS OF ETHYLENE AND LIQUID ALKANES ONHYDROXYLATED SILICATE MONOLITH

The Applicant purchased (froin Vesuvius Hi-Tech Ceramics) the same type of "lowsurface area reticulated silica monolith" described in Barteau 1996, and processed an MSApréparation (purchased from Aldrich Chemical) on it, using reflux températures for severalhours. Analysis of the gases that emerged from the refluxing liquid, using H-NMR, C-NMR, and gas chromatography, indicated that the gases contained ethylene, and liquidalkanes.

The presence of those compounds in those gases indicated that: (i) when MSA isprocessed on a suitable activated surface, it can pass through intermediates that will createolefîns (such as ethylene) and higher alkanes; (ii) the postulated mechanisms and molecularrearrangements described herein hâve received experimental support; and, (iii) methods forcreating olefins and alkanes from MSA can indeed be provided, by one or more pathwaysthat apparently use MSA anhydride intermediates, apparently including sulfene.

EXAMPLE 3: DECOMPOSITION OF MSA OUTER ANHYDRIDE

The Applicant purchased the MSA "outer anhydride" compound, in crystalline form,from Aldrich Chemical. In a reaction beaker, it was heated until the crystals melted andthen began to form a clear liquid over a black solid. The liquid and the solid wereanalyzed, using 1 H-NMR, 13C-NMR, and gas chromatography. The results indicated that theclear liquid consisted mainly of MSA and cycloalkanes. The black solid was found to containcyclic hydrocarbons, naphthenics, and a relatively high quantity of aromatic structures. Someof the aromatic rings were bridged by sulfonate or methylene bridges, and some of thearomatic rings had cyclopropane rings attached to them.

Those results provide experimental support for various postulated mechanisms andmolecular rearrangements described herein, and confirm that methods for creating olefîns,alkanes (including cycloalkanes), and aromatics from MSA can be provided, by one ormore pathways that apparently use MSA anhydride intermediates.

Thus, there has been shown and described a new and useful means for synthesizinghigher alkanes from methane, via pathways that involve MSA and MSA anhydrides, andthere hâve also been disclosed various additional enhancements in this System. Althoughthis invention has been exemplified for purposes of illustration and description by referenceto certain spécifie embodiments, it will be apparent to those skilled in the art that various 51 13283 modifications, alterations, and équivalents of the illustrated examples are possible. Anysuch changes which dérivé directly from the teachings herein, and which do not départ fromthe spirit and scope of the invention, are deemed to be covered by this invention.

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Claims (7)

1 3283 CLAIMS

1. A method of making liquid alkanes, comprising the following steps : a. reacting methanesulfonic acid with a dehydrating agent, under conditions thatcreate a methanesulfonic acid anhydride; b. reacting the methanesulfonic acid anhydride in a manner that créâtes a liquidalkane préparation having a purity sufficient for use as fuel.

2. The method of Claim 1 wherein the methanesulfonic acid anhydride comprisesSulfené, and wherein the sulfene is reacted with at least one second compound underconditions that allow the sulfene to transfer at least one methylene group into the secondcompound.

3. A method of making olefins, comprising the step of reacting methanesulfonic acidwith a dehydrating agent, under conditions that create sulfene as a reactive intermediate,and allowing the sulfene to react with itself in a manner that forms at least one olefin.

4. The method of Claim 3 wherein the olefin comprises ethylene.

5. A method of making cyclopropane, comprising the step of reatingmethanesulfonic acid with a dehydrating agent, under conditions that create sulfene as areactive intermediate, and allowing the sulfene to react with itself in a manner that formsethylene, and allowing the sulfene to react with ethylene itself in a manner that formscyclopropane.

6. A method of making sulfene, comprising the step of treating methanesulfonic acidwith a catalytically active surface that promûtes formation of sulfene from methanesulfonicacid.

7. A method of making sulfene, comprising the step of treating a methyl-methanesulfonate ester with an agent that créâtes a sulfene ylide and releases methanol. 54