WO2007136425A2 - Manufacture of dimethyl ether or olefins from methane, using di(methyl-sulfonyl) peroxide as radical initiator - Google Patents

Abstract

Enhancements and options are disclosed for converting methane into other compounds, via methane-sulfonic acid (MSA). One enhancement involves using di(methyl- sulfonyl) peroxide (DMSP, formed by electrolysis of MSA) as the initiator to start a chain reaction that bonds methane to SO3. Also disclosed are improvements in: (i) using catalysts to convert MSA into olefins, or into methyl-methane-sulfonate, an ester intermediate; (ii) converting MSA into dimethyl ether, a fuel that can be stored and transported under low pressures as a liquid; and, (iii) injecting DME directly into natural gas pipelines as 'makeup' gas, to supplement natural gas supplies.

Description

MANUFACTURE OF DIMETHYL ETHER OR OLEFINS FROM METHANE, USING DI(METHYL-SULFONYL) PEROXIDE AS RADICAL INITIATOR

BACKGROUND

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

New methods for converting methane gas into liquids that can be transported efficiently and economically, via pipelines or tankers, are described in three previous Patent Cooperation Treaty (PCT) applications by the same inventor herein. Briefly, PCT application WO 2004/041399 describes the use of a "radical initiator" to initiate a chain reaction, which will bond methane (CH₄) to sulfur trioxide (SO₃). That chain reaction is initiated by using any of various known methods to remove an entire hydrogen atom (both a proton and an electron) from methane. This generates aggressively reactive methyl "radicals" having unpaired electrons, indicated as H₃C*. When these radicals contact sulfur trioxide, they bond to the SO₃, in a way that creates larger and heavier radicals with the formula H₃CSO₃*. These radicals have enough strength to remove hydrogen atoms from fresh methane being pumped into the reactor. When that happens, the H₃CSO₃* radicals are converted into stabilized methane-sulfonic acid, H₃CSO₃H (abbreviated as MSA), and new methyl radicals are created in a way that sustains a chain reaction, which creates more MSA as fresh methane and SO₃ continue to be pumped into the reactor.

Liquid MSA is continuously removed from reactor outlet(s). It can be used in several ways (such as in electroplating and semiconductor manufacture), but those uses have only small, limited markets. Therefore, various products can be created using MSA as an intermediate. For example, MSA can be heated over a catalyst in a manner that "cracks" the MSA to release methanol and sulfur dioxide. Methanol (also called methyl alcohol, H₃COH) is a stable liquid that can be stored, shipped, and used as a chemical feedstock, liquid fuel, or fuel additive. It is a clean-burning fuel with virtually unlimited markets; however, it is not ideal for shipping, since it corrodes steel fairly rapidly, and since it does not have a high "energy density" compared to other liquid fuels. Therefore, several methods (discussed below) have been developed for converting MSA and/or methanol into other products.

Any sulfur dioxide that is released, either when MSA is "cracked" to release methanol or when MSA is processed by more complex methods to create other products, can be oxidized back into sulfur trioxide, which can be recycled back into the reactor vessel that is creating the MSA. That is a very exothermic reaction; it releases large amounts of heat, which can be used to drive other endothermic (energy-consuming) processes in a complete processing system.

Several improvements to that basic process are described in PCT application WO 2005/069751, published in August 2005. For example, the first application, WO 2004/041399, described the use of a compound called Marshall's acid as a radical initiator, for starting the chain reaction that will bond methane to SO₃. The second application, WO 2005/069751, expanded that disclosure to describe alternate methods for creating methyl radicals, to start the chain reaction. In addition, WO 2005/069751 described several methods for converting MSA into other chemicals, such as alkylamines, formaldehyde, aromatic compounds, dimethyl ether, etc.

The radical-initiated system disclosed in those PCT applications was never developed by anyone prior to the Applicant, because other researchers believed that any pathway which uses methyl radicals (which are extremely unstable and reactive) would create low-value mixtures, having only relatively small quantities of desired products, outweighed by much large quantities of undesired byproducts. When scaled up to the huge volumes involved in oil and gas processing, any process that suffers from low selectivity and yields would create huge problems of product purification and waste byproducts, which would render any such system uneconomic and unfeasible. That belief, under the prior art, is described in articles such as Periana et al 1993. Accordingly, even though chemistry professors at several universities were testing salt-and-acid mixtures for converting methane into liquids (e.g., Basickes et al 1996, Lobree et al 2001, and Mukhopadhyay et al 2002, 2003, and 2004), that work was regarded by industry as impractical and not at all promising (e.g., Golombok et al 2003), when scaled up to the huge volumes of methane that must be processed at large oil or gas fields. Therefore, industrial attention focused either on liquified natural gas (LNG) systems, or on "Fischer-Tropsch" processing, instead of radical processing pathways.

However, the inventor herein discovered that if a reactor system keeps the number of reagents to an absolute minimum, while using a radical-initiated chain reaction to create MSA, the system can convert methane into MSA with yields and selectivities that can exceed 90%, and that appear capable of exceeding 95% or even 98%, when optimized. Furthermore, the reaction is anhydrous (i.e., no water is formed or released during any reaction; this minimizes corrosion and toxic waste problems), and it does not use or create any salts (this avoids creating toxic wastes, and it avoids the problem of pipes, valves, reactors, and other equipment becoming coated and clogged by mineral deposits).

Subsequently, a third PCT application, WO 2005/044789, described several pathways that can be used for "downstream" processing of MSA that is formed by reacting methane with SO₃. This includes the use of a compound called sulfene, an anhydride compound that is formed when a molecule of water is removed from a molecule of MSA. Sulfene has the formula H₂C=SO₂, with a double-bond between the carbon and sulfur atoms. It is an unstable intermediate, which can be used in either of two types of reactions. In one reaction, two molecules of sulfene will react with each other to form ethylene, H₂C=CH₂, an olefin that is a valuable building block for making plastics and polymers. In another type of reaction, sulfene can act as a "methylene donor", which will contribute a -CH₂- group to another molecule. For example, if light alkanes (such as ethane, propane, or butane) are converted into larger and heavier alkanes, by using sulfene to donate methylene groups to the light alkanes, their energy content increases, and they become much less volatile, which makes it much easier to transport them as liquids under the types of low or moderate pressures that can be sustained by conventional tankers and pipelines. Similarly, if a light alcohol (such as methanol or ethanol) is converted into a heavier alcohol (such as propanol), by using sulfene to add one or more methylene groups to a lighter alcohol, the heavier alcohol becomes less corrosive and its energy content increases, making it a better additive or even substitute for gasoline.

The contents of all three PCT applications cited above are incorporated herein by reference, as though fully set forth herein. The new disclosures herein describe additional and optional ways to improve and enhance the conversion of methane into other compounds. AH of these new disclosures build upon, supplement, and enhance the methods disclosed in the above-cited PCT applications for converting methane into MSA, and then converting the MSA into other compounds.

For a number of economic, industrial, commercial, and other reasons, different types of downstream processing, to create an assortment of different products or intermediates, preferably will be constructed and run at different supply sites around the world. This type of assortment of various products and intermediates can provide a better balance of fuels and feedstocks, compared to "flooding the market" with huge quantities of only a single type of fuel or chemical. However, two particular compounds are likely to provide generally optimal "default options" for large numbers of processing facilities at oil and/or gas fields and other methane sources around the world. One compound is ethylene, a building block used to make plastics and polymers. Another compound is dimethyl ether, which is stable and noncorrosive for convenient and efficient storage, shipping, and use, and which performs quite well as a fuel in a wide range of machines and systems.

Accordingly, one object of this invention is to disclose improved "upstream" processing steps and methods for converting methane into methane-sulfonic acid (MSA), such as by using an improved radical initiator compound called di(methyl-sulfonyl) peroxide (abbreviated as DMSP), which can be formed by simple electrolysis of MSA, and which will not form any unwanted byproducts when used to trigger the chain reaction that bonds methane to SO₃.

Another object of this invention is to disclose improved pathways for converting MSA into methanol or other oxygenated organic fuels or reagents.

Another object of this invention is to disclose improved pathways for converting MSA into dimethyl ether, which is convenient and efficient for numerous uses.

Another object of this invention is to disclose improved catalysts, containing tungsten or similar metals, for converting MSA into ethylene or other high- value products.

Another object of this invention is to disclose improved pathways for converting MSA into various types of liquids or gases, using liquid-phase processing methods that will minimize or eliminate any need for solid catalytic surfaces.

These and other objects of the invention will become more apparent from the following summary, drawings, and description.

SUMMARY OF THE INVENTION

Enhancements and options are disclosed for converting methane into other compounds, via methane-sulfonic acid (MSA). One enhancement involves using di(methyl- sulfonyl) peroxide (DMSP) as a radical initiator to start a chain reaction that bonds methane to SO₃. DMSP can be formed by simple electrolysis of MSA; it is easier to handle, store, and transport than Marshall's acid; and, when it initiates the chain reaction, it will form the desired MSA product, rather than an unwanted byproduct as such as sulfuric acid. Other enhancements disclose improved methods for: (i) converting MSA into dimethyl ether, a very useful fuel that can be stored and transported under low pressures as a liquid; and, (ii) injecting DME directly into natural gas pipelines as "makeup" gas, to supplement natural gas supplies. Other enhancements disclose the use of tungsten or similar metals as catalysts to convert MSA into olefins such as ethylene, a building block for plastics and polymers.

DRAWINGS

FIGURE 1 depicts electrolytic formation of a dimethyl variant of Marshall's acid, referred to as di(methyl-sulfonyl) peroxide (abbreviated as DMSP), and the use of DMSP as a radical initiator that will not create any unwanted byproducts when used to bond methane to SO₃, forming methane-sulfonic acid (MSA).

FIGURE 2 depicts a candidate pathway for converting MSA into a fuel called dimethyl ether.

FIGURE 3 depicts a pathway for converting sulfene into ethylene, using a tungsten or other metal catalyst that has been driven to a +6 oxidation state.

FIGURE 4 depicts several candidate conversion pathways that pass through an intermediate called methyl-methanesulfonate (MMS), which is an ester or thioester. The MMS intermediate can be converted into either methanol or DME, by means such as liquid- phase processing that can avoid any requirements for catalytic surfaces, which can become fouled and clogged.

DETAILED DESCRIPTION

As summarized above, this application discloses enhancements that can improve the efficiency and economics of converting methane into dimethyl ether, ethylene, and other valuable compounds.

The intermediate methane-sulfonic acid (MSA) divides the processing methods and reagents discussed herein into "upstream" and "downstream" stages. Any references herein to "upstream" processing or steps refer to step, reagents, reactors, etc., that are used to make, purify, or separate MSA, using a step that includes bonding methane to SO₃. After MSA has been formed and removed from that reaction mixture, any reaction used to process or convert the MSA into other compounds is referred to as a "downstream" operation.

Accordingly, improvements in both "upstream" and "downstream" processing are combined in this application, for two reasons. First, improvements in the "upstream" processing are required to properly disclose the "best mode" for creating any final products, since the upstream steps play an essential role in making the final products. Second, these disclosures involve ways of making efficient and benevolent use of energy, while helping protect the environment and reduce greenhouse gas emissions. Rather than generating large numbers of different but overlapping patent applications, the goals of this technology can be aided by compiling these discoveries and advances into a few coordinated and consistent patent applications. By taking that approach, the Applicant can help create a better understanding of what is being taught, and how it can be developed into efficient use of resources to help both humanity and the environment.

USE OF DMSP AS A RADICAL INITIATOR

The reaction that causes methane to bond to SO₃, to form MSA, requires the use of small quantities of a "radical initiator" that will initiate (or trigger, commence, launch, etc.) a chain reaction. Although various candidate radical initiators are illustrated in PCT application WO 2005/069751 (by the same inventor herein), none of them are ideal, since they all create unwanted byproducts. For example, if Marshall's acid is used as a radical initiator, it will create sulfuric acid as a byproduct. Even though the sulfuric acid will be created only in small quantities, when compared to the large outputs of MSA, the creation of unwanted sulfuric acid can pose potentially very serious problems, when scaled up to the huge quantities of methane being produced at large oil and gas fields. As an illustration, even if any sulfuric acid that is formed as a byproduct can be collected, separated, and electrolyzed, to re-form Marshall's acid (which can be recycled back into die system), each of those steps will require additional equipment, and the presence of sulfuric acid will increase the corrosiveness of the chemicals being handled, requiring more expensive alloys to be used in the reactors, pipes, pumps, valves, and other equipment. Furthermore, Marshall's acid is moderately unstable, and poses its own set of problems and handling requirements.

Accordingly, a compound called di(methane-sulfonyl) peroxide (abbreviated as DMSP) is disclosed herein as an alternate candidate for use as a radical initiator.

DMSP is a peroxide compound, with a formula that can be written as H₃CSO₂O-OSO₂CH₃, where the hyphen in the center calls attention to a peroxide bond between two oxygen atoms. DMSP can be prepared directly from MSA, by using electrolysis to form a condensate (which can also be called a "dimer", since it is made from two identical subunits). To carry out this process, electrodes are placed in a liquid solution of MSA, and an electrical voltage is applied to the electrodes.

The electrodes can have any desired shapes. In laboratory settings, they often are rod- shaped, and can be lowered into a beaker and held in position by a clamp. In industrial settings, electrodes often are flat parallel plates, and can be a series of multiple plates with alternating positive and negative charges.

Unless and until testing (to evaluate various solvents or additives that may be able to promote the process) indicates otherwise, a presumption arises that the MSA solution should be as pure as possible. The supply of MSA for the electrolysis can be provided from any available source. When a plant is getting started, the MSA can be delivered in containers, from an outside source. After the plant is running, MSA can be obtained as a small portion of the output from an MSA-forming reactor vessel.

Since MSA is an acid, some of the molecules in a liquid solution will spontaneously dissociate, in a way that releases H⁺ cations and H₃CSO₃ ^" anions. When voltage is imposed across electrodes immersed in the acidic liquid, the negative charge on the cathode will attract H⁺ cations, while the positive charge on the anode will attract H₃CSO₃" anions. Routine testing can be used to determine an optimal voltage range for electrodes having any particular size and shape, at any distance of interest.

As H⁺ cations gather around the cathode, they will be provided with electrons, by the electric current being driven through the liquid by the voltage. Those electrons will initially convert hydrogen ions (H⁺) into hydrogen radicals, indicated as H*, where the asterisk indicates an unpaired negatively-charged electron that has "jumped" from a metal cathode surface, onto a positively-charged hydrogen ion in the liquid that contacts the electrode surface. These radicals are unstable, and since numerous radicals are being formed adjacent to each other in a thin layer of liquid that contacts or surrounds the cathode, some of the H* radicals will bond to each other. This creates hydrogen gas, H₂, which initially will cling to the surface of the cathode, forming bubbles. The bubbles will grow as electrolysis continues, until their buoyancy pulls them off of the cathode surface, and they will rise to the top of the liquid. Whenever hydrogen gas is formed by large electrolysis units, gas collectors must be used, because hydrogen gas is explosive and must be handled safely.

At the same time, negatively-charged H₃CSO₃" anions (released by MSA as it dissociates) will gather around the positive surfaces of the anode. These anions will surrender electrons to the anode, completing the electrical circuit that is being driven by the voltage imposed on the electrodes. When an MSA anion loses an electron, it becomes an MSA radical, as shown in FIG. 1. Two such radicals will bond to each other, forming a peroxide link at the center of a condensate, or dimer. That condensate is di(methane-sulfonyl) peroxide, abbreviated as DMSP.

In effect, DMSP is an analog or variant of Marshall's acid, which is a disulfuric acid peroxide having a formula that can be written as HO₃SO-OSO₃H. DMSP has two dimethyl groups, added symmetrically to the two ends of Marshall's acid. The presence of those two methyl groups helps stabilize DMSP, making DMSP easier to store, handle, transport, and use than Marshall's acid.

More information on equipment and methods that can be used to form DMSP, by electrolysis of MSA, can be found in sources such as US 4,680,095 (Wheaton 1987), which relates to dialkane-sulfonyl-peroxides. For example, Wheaton taught that such electrolysis should be carried out at elevated temperatures, and that a cooling process should be used to precipitate the peroxide conjugates, allowing unreacted supernatants to be returned to the electrolysis cell.

When the time arrives to use DMSP as a radical initiator, to trigger the chain reaction that will combine methane with SO₃, thereby forming MSA, the DMSP reagent can be "activated" by a suitable energy input (such as mild heating, ultraviolet radiation, or a tuned laser), in a way that will break the peroxide bond in the center of the DMSP. The activation step will release two identical radicals. These will be radical forms of MSA, having the formula H₃CSO₂O*.

In one candidate method, DMSP can be fed directly into an MSA-forming reactor that is operating at a moderately elevated temperature. When the DMSP is heated to the operating temperature of the reactor-, the peroxide bond will be broken, thereby creating two MSA radicals, each of which can trigger a chain reaction that will bond methane molecules to SO₃ molecules, forming MSA.

In an alternate candidate method, DMSP can be passed through a heating, ultraviolet, laser, or similar radical-creating device, immediately before it enters the MSA-forming reactor. These types of devices can be referred to by terms such as radical gun, radical nozzle, radical injector, etc. Such devices are 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. They can be affixed directly to a side or end of an MSA- forming reactor; for example, liquid DMSP can be passed through a rectangular conduit having a transparent material on one side (made from an acid-resistant glass, polycarbonate, or other clear material that allows passage of the UV or laser light into the DMSP liquid). A reflective mirror can be placed on the opposing side of the conduit, to reflect back any unabsorbed radiation for "second pass" absorption by the DMSP. If desired, a plurality of such "radical guns" can be distributed around the methane inlet of such a reactor.

Regardless of how the DMSP is cleaved and activated, when its peroxide bond is broken, it will release two MSA radicals. Each radical will react with fresh methane, by removing a hydrogen atom (both proton and electron) from a molecule of methane, and transferring that hydrogen atom to an MSA radical. Each hydrogen transfer reaction will create one molecule of stable MSA (the desired product), and a new methyl radical, which will keep a chain reaction going. Since the newly-formed methyl radicals are not strong enough to take anything away from SO₃, they will bond to fresh SO₃ molecules that are being pumped into the reactor. Each such reaction will form a new MSA radical, and the newly formed MSA radical will then react with fresh methane, by taking a hydrogen atom away from the methane in the same manner described above, thereby continuing and extending the chain reaction.

Since DMSP can be formed by electrolyzing a small fraction of the MSA being created by the MSA-forming reactor, and since it will create the exact desired product (rather than sulfuric acid or some other unwanted and potentially hazardous and toxic byproduct), DMSP appears to offer an improved and apparently optimal radical initiator, compared to other candidate initiators.

Accordingly, a composition of matter is disclosed herein, comprising a reaction mixture that will continuously manufacture MSA, using DMSP as the radical initiator. This composition of matter contains a mixture of methane, methyl radicals, SO₃, MSA, and MSA radicals, and it is characterized by the absence of any significant quantity of any unwanted byproduct (such as sulfuric acid) that would be created by a radical initiator other than DMSP. The components of this reaction mixture (i.e., methane, methyl radicals, SO₃, MSA, and MSA radicals) will be present in concentrations that enable the mixture to sustain an ongoing chain reaction, allowing MSA to be continually removed from the reaction while fresh methane and SO₃ are continually added.

It should also be noted that since the use of DMSP can eliminate the formation of sulfuric acid, it can also help enable and facilitate the use of less expensive materials to fabricate at least some of the reactors, pipes, valves, and other components of a processing system. In particular, it appears likely that certain types of polymeric coatings, if applied to the surfaces of normal or moderately-high grades of steel, can eliminate the need for highly expensive chemical-resistant specialty alloys. Such coatings are available from companies such as Curran International (www.curranintl.com).

As mentioned in prior applications by the same applicant herein, MSA appears to act as an ideal solvent that enables gaseous methane and liquid SO₃ to be brought together, rapidly and in high volumes, in close contact so they will react with each other. This arises from the fact that MSA is an "amphoteric" solvent having two different domains. The methyl domain of MSA promotes greater solubility of methane in the solvent, and the sulfonic domain of MSA promotes greater solubility of SO₃ in the solvent.

It also should be noted that US 2,868,624 (Shaver et al 1959) described how MSA can help stabilize sulfur trioxide in a desired reactive form. Briefly, SO₃ is easiest to handle and work with in liquid form; however, it can condense or precipitate into a sludge-like or solidified form, especially in the presence of moisture. There are three forms of solidified SO₃, lαiown as the alpha and beta forms (both are polymeric, and both tend to reduce the reactivity of SO₃), and the gamma form (with three SO₃ molecules in a ring). The Shaver '624 patent stated that MSA is a good additive for keeping SO₃ in the monomeric (liquid) or gamma forms, which are more reactive and desirable than the alpha or beta forms, even when moisture is present. Accordingly, this is another reason why MSA appears to be a good solvent for bonding methane to SO₃.

Above-cited PCT application WO 2005/044789, by the same applicant, also contains (on pages 43-46) additional comments on other "upstream" options that may help the MSA- forming reaction run more efficiently. For example, supercritical carbon dioxide may help promote gas/liquid reactions, borate compounds may help prevent unwanted SO₃ reactions, etc.

METAL CATALYSTS FOR ETHYLENE MANUFACTURE FROM MSA

As mentioned above, ethylene can be formed when sulfene reacts with itself. However, because sulfene is highly unstable and reactive, other byproducts also can be formed. Therefore, certain types of catalysts (exemplified by tungsten) can improve the yields and purity of ethylene production from sμlfene.

One advantage of this approach is that some catalysts appear capable of catalyzing two reactions that occur in rapid succession at essentially the same site. The first reaction converts stable MSA into unstable sulfene, by means of an "internal dewatering" step. Then, without delay and without requiring diffusion or other transport of the unstable sulfene to a different site, the sulfene can react with the same or nearby catalytic atoms on the same catalytic surface (which can be coated onto an inert support, such as packed or stirred beads, a porous monolith disc, etc.) in a manner that rapidly creates and releases ethylene, as a gas. This type of processing, which creates and then consumes sulfene in a "straight-through" pathway, is also called a "single pot" reaction.

One type of catalyst that can promote ethylene formation uses metal atoms that can be driven to a -f-6 oxidation state without requiring extreme conditions. An exemplary candidate that was computer-modeled, and that was tested in a laboratory and confirmed with good results, is tungsten. Other candidate metals that can be driven to a +6 oxidation state, and that can be evaluated for use as disclosed herein if desired, include molybdenum, vanadium, ruthenium, and other metals listed below.

Accordingly, the preparation of a tungsten oxide catalyst, and the use of that catalyst to efficiently convert MSA into ethylene, are described in the examples below. Those tests indicated that when a tungsten catalyst was used, ethylene production from MSA had an apparent selectivity of about 95%.

This discovery and invention does not depend on any particular reaction pathway, or on any particular transitional intermediates or transition states; instead, it depends on the disclosure of a practical means for using certain types of catalytic materials to efficiently manufacture olefins, from MSA. Nevertheless, a reaction pathway with apparently favorable thermodynamics, which can help experts gain greater insight into this approach, is illustrated in FIG. 3. This pathway was calculated using the Amsterdam Density Functional software, (release 2.3.3, by Scientific Computation and Modelling (www.scm.com), described in te Velde et al 2001).

As shown in FIG. 3, the catalytic material uses a metal atom (represented by M in the drawing, and exemplified by tungsten) that has been driven to a +6 oxidation state before it reacts with MSA. This can be done by oxidation treatment of a preexisting surface, by selection of suitable tungsten oxide reagents for making the catalyst, or by other means known to those skilled in the art. To render the process practical and economic for large- scale industrial operations, the catalytic metal should be affixed to a solid support that can be trapped and retained within a reactor vessel. A silicate support material is shown in FIG. 3; since the support is essentially inert, other types of solid supports (such as activated carbon, mineral or ceramic materials used in porous monoliths, etc.) also can be used. Any suitable physical configuration can be evaluated, such as porous monoliths, packed or stirred beads or other particulates, coated wire mesh, etc.

When the tungstate catalytic surface (shown in the upper left corner of FIG. 3) is first contacted by sulfene, it will lead to the formation of a first intermediate with a stressed three-membered "tungstate-sulfoxy" ring containing tungsten, sulfur, and oxygen, shown on the right side of FIG. 3. This can be regarded as a "priming" operation. It is likely to release some quantity of formaldehyde; however, if the conditions have been optimized for ethylene production, formaldehyde production will occur only during the "priming" step, and will cease or drop to small quantities when the main cycle of the reaction commences. Formaldehyde can be removed by a device such as a liquid trap, without requiring distillation or other complex processing, while the ethylene (or possibly other products) will be gaseous and can be removed via a gas outlet. Alternately, since formaldehyde is a valuable byproduct, the reaction disclosed in FIG. 3 (or analogous reaction pathways) can be adjusted and adapted in ways that can generate continuous quantities of formaldehyde, if desired. For example, computer modeling indicates that if oxygen is added to the catalytic material while it has a CH₂ group bonded to the tungsten molecule, as shown in the lower right corner of FIG. 3, the formation and release of formaldehyde is likely to occur in an exothermic reaction.

When a second sulfene molecule contacts the tungstate-sulfoxy intermediate (shown in the upper right corner of FIG. 3), the sulfene will effectively "knock off" the SO₂ group from the surface-attached catalytic intermediate. In that same reaction, the newly-arriving sulfene will also release its SO₂ group. This causes the release of two molecules of SO₂, which will be released from the catalytic surface in gaseous form. The gas can be collected and oxidized back into SO₃, for recycling back into the MSA-forming reactor.

That second sulfene reaction mentioned above causes a CH₂ group to become double- bonded to the tungsten atom on the catalytic surface, as shown in the lower right corner of FIG. 3. This intermediate is contacted by yet another sulfene molecule, forming another unstable intermediate, as shown in the lower left corner of FIG. 3. This intermediate has a sulfoxide group and two CH₂ groups (in a stressed ring structure) bonded to the tungsten atom.

The two CH₂ groups in the stressed ring structure will break away from the tungsten, in a way that forms a double bond between the two carbon atoms. This releases ethylene, in gaseous form, from the catalytic surface. When this occurs, the sulfoxide group attached to the tungsten also rearranges, reforming the sulfoxide ring shown in the upper right corner of FIG. 3.

As long as sulfene continues to be formed on or near that catalytic surface (due to an MSA dewatering reaction, occurring on or near the same surface), the three-part cycle shown in FIG. 3 will continue. In each cycle, two molecules of sulfene are consumed, and the SO₂ in the sulfene will act as "leaving groups". The CH₂ groups from two sulfene molecules will be bonded to each other, forming ethylene, which will be released as a gas.

Additional insight into the molecular intermediates and transitional states involved can be gleaned by analyzing articles that illustrate and describe transition states in various other chemical reactions. For example, reaction 2 on page 202 of Chuchani et al 1989 illustrates a transitional six-membered ring involving a "tight intimate ion pair" that enables the methanesulfonate group of an alkyl-methanesulfonate to act as a leaving group, in a manner that causes the residual alkyl group to become an olefin. Reactions 1 and 2 on page 390 of Corey et al 1989 illustrate how a nearby electronegative atom (nitrogen, in a ring structure such as pyridine) can promote the release of the alkyl group from an alkylsulfonate moiety, in a manner that creates an olefin. Scheme 1 shown on page 72 of McCulla et al 2002, and Equation 2 shown on page 3714 of Postel et al 2003, also illustrate ringed intermediates that can be formed by alkyl-methanesulfonates.

Since the reactions herein involve MSA, which has only a single methyl group rather than a longer alkyl group, it is postulated that: (1) MSA conversion, on a tungsten or similar catalyst, may release methylene (-CH₂-) intermediates; (ii) the methylene intermediates will cluster around a metal ion that has been driven to a highly oxidized state, such as a +6 oxidation state as described above; and, (iii) methylene intermediates that have clustered around a metal catalytic ion or surface can react with each other, to form ethylene, which will be released.

As stated above, this invention does not depend on any particular, hypothesized, or calculated intermediates or transition states. Instead, this invention rests on the practical discovery that a highly oxidized metallic surface provided a good and efficient catalyst for converting MSA into an olefin, in a "single pot" reaction.

As described in more detail in Examples 4 and 5, the tungstate catalytic surface that was tested for creating ethylene from MSA, with very good results, was created in the following manner. A disc of conventional silica monolith material (i.e., an essentially inert but porous and permeable support) was immersed into a solution of ammonium tungstate ((NH₄)₂WO₄) in water, then removed. The disc was then dried, to remove all or most of the ammonium ions, leaving behind tungsten and presumably oxygen atoms. The immersion and drying process was repeated until the disc appeared to be saturated with tungsten, as evidence by a powdery residue in the bottom of the drying dish after the third cycle was completed. It was tested as described in Example 5, and shown to be very efficient in converting MSA into ethylene, presumably via the sulfene intermediate described above, using one or more pathways such as (or similar to) the route shown in FIG. 3.

Alternate methods are known or can be developed for coating tungsten (or other similar metals or metal oxides) onto surfaces of a solid support material. For example, other tungsten- containing compounds (such as sodium or potassium tungstate, as examples) can be evaluated for such use, and methods can be developed for rinsing and washing nonadsorbed sodium, potassium, or other ions out of (or off of) a solid support. Alternately or additionally, any other known or hereafter discovered coating method can be used, such as "sputter coating" or other vapor-deposition methods, which can be promoted by gas flow through a porous material.

Similarly, a catalytic metal or metal oxide can be incorporated into a solid material that is being formed. However, since that approach tends to distribute an expensive metal throughout the entire bulk of a catalyst, it usually is more expensive than merely coating a very thin layer of an expensive catalyst onto the surface of a low-cost support material.

Other transition metals that have various similarities to tungsten merit evaluation for such use. Such metals include elements that are in certain columns of the periodic table, including:

(1) the 5b column, with vanadium (symbol V). This column also includes niobium (Nb) and tantalum (Ta), but those metals are rare and very expensive;

(2) the 6b column, with chromium (Cr), molybdenum (Mo), and tungsten (W);

(3) the 7b column, which includes manganese (Mn); it also includes technicium (Tc) and rhenium (Re), but those are relatively rare and expensive;

(4) the 8 column, which includes iron (Fe); it also includes ruthenium (Ru) and osmium (Os), but those are rare and expensive.

In addition, other "transition metal" columns in the period table (including the 4b column, with titanium, and the 9 through 12 columns, headed by cobalt, nickel, copper, and zinc and which include various soft and/or "noble" metals such as palladium, silver, platinum, and gold) also merit testing and evaluation for use as described herein. Based on computer modeling to date, it is believed, as this is being written, that metals that can assume a +6 oxidation state, under reasonable processing conditions as anticipated herein, offer good candidates for use as disclosed herein, and merit evaluation. This includes metals (such as iron, which normally will remain in a +2 or +3 oxidation state under most conditions) that can be forced or "driven" to a +6 oxidation state under the types of pressures and temperatures that are commonly used in oil and gas processing. This is not an assertion that all such metals will work efficiently or economically; it is, instead, an assertion that tungsten offers a demonstrative example that apparently performs with good efficiency, and that other candidates from a certain class of metal atoms also merit evaluation, to determine whether they can work with comparable or possibly even better efficiency.

Automated machines and methods also are known, for screening and optimizing candidate catalyst formulations as disclosed herein. For example, methods and equipment for evaluating dozens of candidate formulations in a single screening cycle, are described in Muller et al 2003, and other articles cited therein. Such devices typically use either: (i) reactors with multiple parallel tubes, which can be packed with coated beads, fibers, screens or meshes, or similar supports; or, (ii) titer plates containing multiple wells, such as 24, 48, or 96 wells per plate. Each tube or well will contain a specific candidate catalyst formulation. When a reagent (such as MSA) is passed through or loaded into all of the tubes or wells, the product generated in each tube or well, by each candidate catalyst, is collected and/or maintained separately. The output samples (still kept separate) are delivered to an automated analytical device, such as a mass spectrometer or chromatograph, which uses a transport mechanism to temporarily move each output sample into position for analysis (such as into the path of a beam of light, for analysis by a spectrometer). The tubes or wells that created the highest yields of the desired compound can be identified. The catalyst material(s) contained in those particular tubes or wells can be identified, and then studied more closely, as candidates for optimization.

This can be done by using the best-performing candidate catalyst, from one round of tests, as a "baseline" or "centerpoint" material, in a subsequent round of tests. Any subsequent round of screening tests can use variants that resemble, or that were derived from, the best-performing catalyst(s) from an earlier screening test. Such variants can include candidate catalyst formulations having known and controlled compositions; alternately or additionally, "combinatorial chemistry" methods and reagents can be used, to generate random or semi-random variants or derivatives of a candidate material that provided good results in a previous screening test.

These types of automated screening systems and methods offer powerful tools for rapidly identifying and/or improving catalyst formulations that can efficiently carry out nearly any reaction of interest. Furthermore, those types of screening tests are likely to identify one or more catalytic formulations that can create formulations containing enriched quantities of propylene or other olefins.

In addition, various combinations of two or more different catalytic elements merit evaluation. For example, iron catalysts tend to be less efficient than other catalysts that contain more expensive metals. However, iron-containing catalysts are relatively inexpensive, and many of them can operate at high temperatures that will destroy catalysts containing more expensive metals. Therefore, a processing system might use a first-stage reactor with an iron or other low-cost catalyst for "rough" (or "first-pass") MSA-to-ethylene conversion (such as, for example, with yields in a range of about 40 to 80 percent), followed by second- stage conversion using a more expensive catalyst that can provide higher yields.

Various combinations of catalytic materials also can be mixed and included in a single reactor vessel. As an example, US 6,596,912 (Lunsford et al 2003) and Makri et al 2003 describe the use of catalysts containing both manganese and sodium tungstate on a silica support, in a different type of processing (a process referred to by some as "direct" processing of methane, in which methane gas directly contacts a catalyst at high temperature, to form higher hydrocarbons) .

Another factor worth noting involves catalytic agents that use symphoric, anchimeric, or "neighboring group" effects to enable "two-handed" manipulation MSA or other compounds. MSA, which has the chemical formula H₃C-SO₃H, has a methyl domain (H₃C-) and a sulfonic (or sulfonic acid) domain (-SO₃H). More potent and efficient catalysts might be developed, by providing a catalytic surface with two different functional agents or groups, with regular and controllable spacing between them. That type of controlled surface can allow one type of catalytic group to attract and interact with the sulfonic portion of MSA, while the second type of catalytic group attracts and interacts with the methyl portion. This factor can be better understood, if the reader considers additional comments about symphoric and/or anchimeric reagents in PCT application WO 2004/041399.

A number of additional articles and patents, which contain information that can shed more light on the catalyst-related disclosures herein, are listed below, and each listed item also cites other articles and/or patents, in its footnotes and/or prior art citations. These items merit careful evaluation by any experts who are focusing specifically on ways to better understand and possibly broaden the catalyst-related disclosures herein. In particular:

(i) Various articles and patents describe processes that are sometimes called "direct" processing of methane gas, on various catalysts. These processes involve contacting methane gas directly with a catalyst, under conditions that cause the methane to be converted into something else. In some cases, the methane is mixed with a second reagent (such as an oxygen-containing reagent) that also contacts the catalyst, so that oxygen atoms will be transferred to the methane, thereby creating an oxygenate (such as methanol, dimethyl ether, or formaldehyde). In other cases, hydrogens are removed from the methane, causing the remaining CH₃ and/or CH₂ groups or radicals to condense into larger hydrocarbons. Pyatnitskii 2003 provides a good review of "direct" catalytic processing of methane, and examples are provided by Wang et al 1995, Pak et al 1998, Makri et al 2003, and US 6,596,912 (Lunsford et al 2003).

(ii) Handzlik et al 2001 describes and illustrates (e.g., in their Figure 3) complexes and transition states that may occur when certain types of organic molecules or moieties react with metallic atoms.

(iii) Waters et al 2003 describes transition states that may be formed when molybdenum or tungsten are used to catalytically dehydrate acetic acid, to form ketene; it also discloses that the chromium compounds they tested did not efficiently catalyze that reaction.

(iv) Libby et al 1994 describes the synthesis of C2 through C5 ketenes from their corresponding carboxylic acids, using alkaline (hydroxylated) catalysts.

(v) Wang et al 2004 describes various reactions that tested various catalytic surfaces, which included 100% acidic, 100% basic, 100% redox, mixed redox-acidic, and mixed redox-basic surfaces, using vanadium oxide supports.

(vi) Various enzymes involved in photosynthesis suggest that manganese can facilitate reactions that involve breaking apart O₂ molecules, to allow "activated" oxygen to be added to organic molecules. Those types of metallo-enzyme complexes use "tetra-manganese clusters", containing four manganese atoms coupled together by oxygen linkages, as described in, e.g., Tommos et al 1998, Westphal et al 2000, and Cukier 2002. Those examples in nature suggest that manganese dopants (including manganese-oxygen complexes that resemble or emulate tetra-manganese clusters in plant cells) may provide improved catalysts for promoting certain reactions described herein, and merit evaluation.

Despite the extensive prior work in the field of catalytic processing of hydrocarbons, no one has previously disclosed any system that can enable efficient "single pot" conversion of MSA (which will soon become available in huge quantities, from "waste" or "stranded" methane) into ethylene or other valuable products, or into methyl-methanesulfonate (MMS), an ester intermediate described herein.

It also should be noted that in the prior art, very little attention has been given to the advantages of processing intermediates that have a direct bond between carbon and sulfur, as occurs in MSA. Because of the strong electronegativity of sulfur, a "direct" carbon-sulfur bond (with no oxygen or other atom between the carbon and the sulfur) offers opportunities to manipulate a compound such as MSA in highly useful ways. In the prior art, those opportunities and potentials have received little attention or research; instead, in oil and gas processing, sulfur usually is regarded as an unwanted toxic pollutant that preferably should be eliminated as quickly as possible, whenever the final product will be something such as a fuel or olefin. That attitude has contributed to a mindset that has prevented the oil and gas industry from recognizing that, under controlled conditions and when using certain reagents and pathways, sulfur can provide an ideal "handle" for carrying out various reactions that can provide high selectivity and yield. The methane-to-MSA-to-ethylene pathway offers a good example of that principle.

THE METHYL-METHANESULFONATE (MMS) ESTER INTERMEDIATE

One intermediate merits attention because it can play a role in a number of processing pathways that appear to provide efficient and economic routes to various products. That compound, methyl-methanesulfonate (MMS), has a formula that can be written as H₃CS(O₂)OCH₃, with a structure as shown in FIG. 4. Because of the arrangement of the oxygen atoms around the sulfur atom, this compound can be called an ester; because the ester structure contains a sulfur atom, it also can be called a thioester.

Because MMS contains sulfur and three oxygen atoms, it is heavier and may also be more corrosive than is desirable for a commodity chemical that will be shipped in bulk. Therefore, although it can be shipped if desired, its preferred uses generally will be as processing intermediates, in pathways that lead to other products.

MMS can be created by any of several routes that begin with MSA. In one pathway, shown in the upper left corner of FIG. 4, one molecule of MSA is de watered, to create the unstable sulfene intermediate; then, the sulfene intermediate is reacted with a second molecule of MSA, to form the MMS ester while releasing SO₂ as a gas.

In another pathway, in the upper right corner of FIG. 4, a portion of an MSA supply stream is "cracked", to release methanol and SO₂. The methanol is reacted with additional MSA, to form the MMS ester, by means of a condensation reaction that removes water.

Since both of the two pathways mentioned above and shown in FIG. 4 involve removal of water when MSA is reacted, MMS can be regarded as one form of dewatered MSA, or, stated in other words, as one form of MSA anhydride (or MMS ester anhydride). At least some quantity of water tends to be released (as steam) whenever organic compounds such as MSA that contain both hydroxy groups, and hydrogen moieties, are heated to elevated temperatures. Therefore, it is likely that some quantities of the inner and outer anhydrides of MSA, and of the MMS ester anhydride, are likely to be present whenever MSA is heated to elevated temperatures, especially temperatures well over 10O⁰C. Accordingly, various claims use phrases such as, "reacting a reactant compound selected from the group consisting of methanesulfonic acid, methanesulfonic acid anhydride, and esterified methanesulfonic acid, with a catalytic surface ...", since any of those three types of compounds may be the most active species at a catalytic surface, and may be promoting a certain reaction by means that can include, for example: (i) "priming" a catalytic surface, by means such as preparing an organic intermediate; and, (ii) converting additional MSA into a more reactive anhydride, ester, or other form.

Other ways of forming the MMS ester also are known, such as by reacting MSA with any of various types of methyl donors. Such methyl donors generally have a formula that can be written as H₃C-X, where X is a negatively-charged "leaving group" , such as a chloride or other halide atom, or any of various other known chemical moieties. A hydrogen atom from the hydroxy group at the sulfonate end of MSA will tend to leave on its own, since MSA is an acid that will dissociate spontaneously. That will leave behind an ionized sulfonate group (-SO₃") on the MSA anion, and the anion will tend to attract and bond to positively-charged methyl ions from methyl donor compounds, such as methyl chloride.

It is believed and anticipated that formation of MMS directly from MSA, using a catalytic surface, can be enhanced by using certain catalyst compounds known as "weakly- coordinated" ions, anions, or compounds. Such "weakly-coordinated" ions that are used as catalysts are referred to in numerous references, as McAuliffe 1977 at page 153 (which discusses certain mercury compounds), and Periana et al 2002 (which discusses certain iodine compounds), as just two examples. Weakly-coordinated ions are also referred to as poorly- coordinated ions, or non-coordinated ions. Many references also refer only to anions (i.e. , negatively-charged ions), rather than all ions or cations; this arises from the fact that the positioning of electrons (which are negatively charged) is crucial in weakly-coordinated ionic bonding, and the relevant electrons in a cation/anion pairing are attributed to the anion (which has one or more surplus electrons), rather than the cation (which is missing one or more electrons). However, cations also are directly involved in these matters, and such cations (often referred to as "coordinatively unsaturated" cations) are used as catalysts for certain types, of chemistry, including olefin polymerization.

Briefly, weakly-coordinated ions (or salts, compounds, etc.) include compounds in which electron densities are spread out, rather than tightly constrained at specific locations. As a result, weakly-coordinated ions (or salts, compounds, etc.) form weaker ionic bonds than strongly-coordinated ions (or salts, compounds, etc.). This can enable certain types of compounds to function very efficiently as catalysts, because it enables intermediates to be formed that have mid-level bond strengths, which can be both: (i) strong enough to hold a certain type of atom or molecule in position until the proper displacing agent arrives, yet (ii) relaxed enough to rapidly and efficiently let go of the atom or molecule, when the proper displacing agent arrives.

In the catalytic conversion of MSA into MMS, it is believed that the catalytic activity likely involves, to at least some extent, a series of intermediates as follows:

(1) a molecule of MSA will become associated with a weakly coordinated catalytic surface. Depending on the catalyst, this association can involve the negatively-charged sulfonate end of an ionized MSA being pulled close to a metal cation; alternately, in some cases, it may involve both the negatively-charged sulfonate domain, and the positively- charged methyl domain, being attracted to two different localized regions of a "symphoric" or "anchimeric" catalyst surface;

(2) a second molecule of MSA, in the liquid that is contacting the weakly coordinated catalytic surface, will dissociate, causing a hydrogen proton to leave the sulfonate group, thereby creating an MSA anion that has a negative charge on its sulfonate end;

(3) the negatively-charge sulfonate end of the MSA ion in solution will be attracted to a positively-charged hydrogen proton, on the methyl group of a surface-associated MSA molecule;

(4) the MSA ion in solution will pull off and detach the methyl group, from the surface-associated MSA molecule.

That transfer of a methyl group, from a surface-associated MSA molecule to a second MSA ion in solution, will form the MMS ester compound. That methyl transfer is likely to be promoted by weakly-coordinated catalytic compounds that can help stretch and weaken the carbon-sulfur bonds, in MSA molecules that become associated with the catalytic surface.

Accordingly, weakly-coordinated catalytic compounds that are already known will be screened, using routine experimentation, to identify one or more such catalytic compounds that will provide substantial increases in the yields and selectivities of the olefin-forming, cycloalkane-forming, or ether-forming reactions described above, all of which use methanesulfonic acid or one of its anhydride derivatives (which include sulfene and MMS).

Once the MMS ester has been formed, it can be treated as a stable liquid that can be stored, transferred to a different reactor, etc. It has several potential uses. For example, as mentioned in PCT application WO 2005/044789 (by the same applicant herein) at pages 29- 32, MMS can be a useful intermediate for creating sulfene.

Another valuable use for MMS arises from the fact that it can function efficiently as a methyl donor. Unlike sulfene, which can insert methylene groups (-CH₂-) into carbon chains, MMS can add methyl groups (-CH₃) to the sides or ends of various types of molecules. The methyl group that is donated will be the methyl group linked to the sulfur atom via an oxygen atom. The remaining portion of the MMS, which acts as a "leaving group", is called a mesylate group, and has the structure H₃CSO₃.

Three other potentially valuable uses for MMS are also disclosed herein. These involve rapid and efficient methods for manufacturing large quantities of olefins, methyl- alkyl ethers, and cycloalkanes. This type of mass-manufacture requires large continuous-flow reactors that have been optimized for rapid production of either: (i) a single relatively pure output compound, or (ii) a known and controlled mixture of desired output compounds, which can be separated from each other by known and practical means (for example, in many cases, one or more products will leave as a gas from an upper outlet while other products will leave as liquids from a lower outlet). If a mixture of products is formed when handling the huge volumes that are involved in methane processing, the manufacturing process preferably should form either: (i) no "intractable solids"; or, (ii) relatively small quantities of solids that can be removed from any processing vessels, and can be handled and used safely (such as, for example, by adding them to asphalt-type mixtures).

It should also be noted that certain claims (such as claim 6) are limited to, "A method of manufacturing . . . wherein the method is carried out in commercial quantities, using at least one continuous-flow reactor. " Those claim limitations are specifically intended to avoid reading upon prior art such as set forth in US patent 2,553,576 (Grosse & Snyder, 1951). As described in that patent, issued more than half a century ago, batches of MSA were continuously refluxed, for four hours each, at about 310⁰C, forming various combinations of methanol, MMS, and/or dimethyl ether. However, that type of processing is extremely slow, and would consume enormous amounts of energy for each ton of product formed. Therefore, it simply cannot be scaled up to commercial quantities, and the discovery, by the applicant herein, of improved processing methods that can be scaled up to rapid and efficient manufacturing, in large commercial quantities, is a major step forward.

Furthermore, an important aspect of the advances that are disclosed and embodied herein involves insights into certain specific mechanisms, in the chemical reactions that are involved. Unlike a disclosure that merely says, "Heat it up and reflux it for several hours, at more than 300⁰C, and you'll get a mixture of several different products", the disclosures herein define and focus upon improved and efficient methods for rapidly and efficiently performing the crucial steps that will lead to the exact product desired, in pure or nearly pure form.

In specific, if an olefin compound (or a cycloalkane compound, such as cyclopropane, which can be converted into an olefin compound, such as propylene, if desired) is to be manufactured from methanesulfonic acid (or from methanesulfonic acid anhydride, or from the MMS ester), it can be done rapidly and efficiently with a catalytic surface comprising a metal oxide compound that promotes: a. formation of organic metallocyclic intermediates comprising at least one carbon- carbon bond, wherein each of said carbon atoms in said carbon-carbon bond is supplied by a different molecule of methanesulfonic acid, methanesulfonic acid anhydride, or esterified methanesulfonic acid; and, b. release of a portion of the organic metallocyclic intermediates from the catalytic surface, in a form selected from the group consisting of olefins and cycloalkanes.

Once that sequence of crucial steps has been recognized, metal oxide catalysts that can rapidly and efficiently perform those steps can be (and indeed already have been) identified, which will, finally, enable efficient commercial manufacturing operations.

In an alternate pathway, if the desired product is dimethyl ether (or another methyl- alky 1 ether), the necessary processing can be done rapidly and efficiently, and in commercial quantities, by: a. converting methanesulfonic acid into an ester compound having a sulfiir-oxy gen- carbon linkage (such as MMS); b. reacting the ester compound under continuous flow conditions that break a sulfur- oxygen bond in the sulfur-oxygen-carbon linkage of the ester, thereby releasing an alkoxy group from a sulfur-containing group, and,

(ii) reacting the alkoxy group with a methyl donor compound, thereby forming the desired methyl-alkyl ether.

In brief, the key to forming a desired ether product arises form the realization that: (i) if MSA is converted into an ester intermediate, such as MMS, that ester intermediate will contain a sulfur-oxygen-carbon linkage; and, (ii) it then becomes possible to efficiently and rapidly manipulate the sulfur-oxygen-carbon linkage in a way that will break the sulfur- oxygen bond, rather than the oxygen-carbon bond. Breakage of the sulfur-oxygen bond causes the oxygen atom to remain with the methyl group, thereby forming a methoxy group. That methoxy group can then react with a methyl donor compound, such as the very same MMS ester compound that is already present in the reaction mix. In that reaction, the "mesylate" group of the MMS ester acts as a leaving group; the ester-type oxygen structure is preserved, and the direct carbon-sulfur bond is broken.

Accordingly, it has been discovered that a rapid and efficient commercial-scale reaction that will form dimethyl ether can be carried out, using reaction conditions that will simultaneously cause MMS molecules to behave in two very different manners. Some of the MMS molecules will be cleaved in a manner that breaks the H₃C(O₂)S-OCH₃ sulfur-oxygen bond, while other MMS molecules will be cleaved in a manner that breaks the H₃C-S(O₂)OCH₃ carbon-sulfur bond. In both reactions, the sulfurous group will act as a leaving group, leaving behind a combination of methyl groups, and alkoxy groups. The methyl and alkoxy groups will bond to each other, forming dimethyl ether, the desired product, with surprisingly high yield and purity levels.

For example, in an early test that used a non-optimized, off-the-shelf zeolite compound as the catalyst, preliminary analysis indicated that dimethyl ether was produced with a yield of 89% of all gases released by the reaction; methane comprised 2.3 %, ethylene comprised 2.7%, cyclopropane comprised 4.1 %, and all other gases comprises 1 %. Furthermore, roughly 15 % of the liquid MMS was consumed, and converted into a gaseous state, in those early tests. MANUFACTURE AND USE OF DIMETHYL ETHER (DME) FROM MSA

Various methods are known in the prior art for making dimethyl ether (DME, H₃COCH₃). For example, a dehydrating agent can be used to remove water when two molecules of methanol are condensed (as described in US 2,492,984, Grosse & Snyder 1950), using methods such as reactive distillation, of passing methanol through a Zeolite-type material (e.g. , US 3,036,134, Mattox 1962).

Based on comments in items such as US 4,373,109 (Olah 1983), Olah 1987, and Zhou et al 2003 , it also appears likely to be possible to convert MSA directly into DME, by passing the MSA through a suitable Zeolite material.

Since DME is a condensed version of methanol, with water removed, manufacture of DME at remote oil or gas fields (or other methane supply sites) can provide two important benefits. First, if water is removed from methanol, at an oil or gas production site, the water (normally released in the form of steam) can be condensed into clean, pure, fresh water, for drinking, cooking, irrigation, livestock, etc. This can be highly valuable in countries with large oil and/or gas reserves but without sufficient fresh water (such as in the Middle East, the Arabian peninsula, northern Africa, etc.).

The second benefit arises from reduced transportation costs, which occurs when water is removed from a heavy load of cargo at the source location, instead of paying to ship water across an ocean or through a pipeline. Even if the ultimate goal is to get methanol to a destination point, it can be more economic to remove water from the methanol at a remote supply location, ship the "dehydrated methanol" (in the form of DME) via a tanker or pipeline, and then add water back to the DME, to reconstitute methanol at the destination port. Similar processes are used to minimize the costs of storing and shipping other dewatered products, such as condensed fruit juices.

Because of several factors, DME appears to be ideally suited for a number of uses. Since it is less corrosive than methanol, it can be shipped and stored in pipelines, tanks, or other vessels made of conventional steel, without requiring special precautions. It will readily convert between a liquid and a gas, at moderate pressures that can be sustained by inexpensive tanks. It burns quickly, cleanly, and thoroughly, without creating any soot, smoke, odors, or other residues, and with very low risk of carbon monoxide poisoning in homes that are not adequately ventilated. Because of these properties, DME is used as a "bottled gas" (usually in steel tanks, comparable to the propane tanks widely used in the US for barbecue pits) in many areas, for indoor cooking or similar uses, using the same types of valves and burners that can handle propane, butane, or "liquefied petroleum gas" (LPG, which mainly contains propane and butane). DME also has enough energy content to be well- suited for use in diesel engines or turbines, and it can be used as a propellant for aerosol sprays, to substitute for chlorofluorocarbons (CFCs), which harm the atmosphere. More information is available from the International DME Association (IDA, www.vs.ag/ida), and from www.aboutdme.org and www.jfe-holdings.co.jp/en/dme.

In addition, as described below, DME appears to be well-suited for use in supplementing methane, in natural gas pipelines that distribute methane to homes, factories, offices, etc. This is comparable to using propane-air mixtures for an operation called "peak shaving". When DME is used for that purpose, it will not require any adjustments to burners or other residential, office, or factory devices, so long as a mixture of DME and a second gas (such as air, nitrogen, or carbon dioxide) is adjusted to approximate the "Wobbe index" of the natural gas mixture being carried by that pipeline.

Accordingly, several methods for converting MSA into DME have been identified, and are disclosed and illustrated herein. One such method, shown in FIG. 5, begins by combining MSA with methanol. As described in PCT application WO 2004/041399, the methanol can be created by. "cracking" MSA at an elevated temperature and pressure, using a catalyst. Accordingly, MSA is the only feedstock that will be needed for the process, if a portion of the MSA stream is diverted to a cracking unit that is used to provide methanol.

When MSA and methanol are combined in the presence of a dehydrating catalyst (various metals and other catalysts are known for such use, including aluminum, beryllium, silver, copper, zinc, etc.), the two compounds will form condensation products such as MMS, as described above and shown in FIG. 4. If additional methanol is added to the MMS, DME will be formed, while MSA will be released. The MSA can be recycled back into the reactor inlet; alternately, since it will be at an elevated temperature, it can be sent to a cracking unit, to release more methanol with minimal heating costs.

Either or both of the main steps in that pathway can be carried out in a reactor that can be designed and operated as a "reactive distillation column", using methods known to those skilled in the art. DME will be one of the lighter products, and it can be withdrawn in the distillate fraction.

In some respects, this pathway is analogous to a different pathway disclosed in US patent 6,518,465 (Hoyme et al 2003), which converted an alkyl ester (such as methyl acetate) into a carboxylic acid (such as acetic acid). An ether compound such as dimethyl ether was formed as a byproduct of that pathway. However, in that patent, DME was treated as an unwanted byproduct, rather than a desired product, and Hoyme '465 teaches that any DME formed as a byproduct can be hydrolyzed, to convert it into methanol. That was logical and proper, based on what Hoyme was trying to accomplish. Methanol is a stable liquid, while DME wants to become a gas, and requires constant pressure to prevent it from vaporizing. Therefore, in the settings and uses contemplated by Hoyme, methanol is easier and safer to handle than DME. However, different conditions and factors are relevant herein, and as mentioned above, it is more efficient to ship DME (rather than methanol) using tankers or pipelines, partly because DME is a dehydrated form of methanol, with reduced weight and bulk for an equivalent energy content, and partly because DME is less corrosive than methanol.

USING DME TO SUPPLEMENT NATURAL GAS IN LOW-PRESSURE PIPELINES

It is also disclosed herein that DME can be used to make up shortages of natural gas that is being distributed via pipelines to homes, factories, offices, and other locations, by local distribution companies (abbreviated as LDCs, which should not be confused with same acronym for "less developed countries").

In numerous parts of the world, threats of natural gas shortages are becoming serious and even acute, in light of factors such as: (i) increased energy demand in various nations, notably including China and India; (ii) disruptions to oil and gas production in offshore and coastal regions, due to natural factors (including hurricanes and typhoons) and human factors (including political instability, insurgents, terrorists, thieves, etc.); (iii) accidents involving aging equipment; and, (iv) political and economic conflicts between various nations, including former members of the Soviet Union which now must struggle to help their own separate economies.

To help address those problems, a method for using propane to supplement natural gas supplies has been developed. This process is often called "peak shaving", since it was developed to help smooth out the peaks in demand that local distributors must meet, during the busiest hours of the day/night cycle. Machines and methods for creating propane-air mixtures, and for injecting those mixtures into gas that is being distributed to factories and homes by local or regional pipelines, are described in sources such as the website of Standby Systems, Inc. (www.standby.com), which manufactures equipment for such use. In addition, the U.S. Federal Energy Regulatory Commission (FERC) has issued statements on the subject, such as the "Whitepaper on Natural Gas Interchangeability and Non-Combustion End Use" (FERC Docket PL04-3-000, issued February 28, 2005).

One of the crucial measurements that enables pipeline companies to smoothly and efficiently mix propane-air blends with natural gas supplies, without requiring any adjustments to burners or other devices in factories, homes, or offices, is called the "Wobbe index". This number is calculated, first, by determining the "higher heating value" of a fuel gas. The reference to "higher" heating value (also called gross heating value) assumes that water vapor in exhaust gases is condensed back to liquid, in a way that releases heat energy; "lower" Wobbe index numbers also can be calculated, if desired. The "higher heating value" is then divided by the square root of a fuel gas's specific gravity (i.e., the ratio of a gas's molecular weight, to the molecular weight of air, which is about 29 daltons, based on about 80% nitrogen and 20% oxygen).

Accordingly, a Wobbe number indicates a heating value, divided by a density value. If the heating value is measured in kilocalories, the resulting numbers are greater than 10,000. To avoid those awkward numbers, the commonly-used system uses "megajoules" (abbreviated as MJ) to indicate the heating value of a fuel gas. Typical Wobbe index numbers for most fuels of interest range from about 40 to about 80; for example, the Wobbe index for pure methane (with one carbon) is 53.454, while the Wobbe index for pure propane (with three carbon) is 81.181.

More information on Wobbe index numbers and calculations is available from an Internet search, and from sources such as US 6,896,707 (O'Rear et al 2005), entitled, "Methods of adjusting the Wobbe Index of a fuel and compositions thereof".

Natural gas that runs through pipelines can vary substantially in its energy content and/or specific gravity, depending on the concentrations of non-methane components. For example, ethane and propane have higher energy content, so they will make a gas supply "richer". Nitrogen and carbon dioxide are inert, and will make a gas supply "leaner". Each gas supplier knows the Wobbe index of the gas it is pumping into its pipelines on any given day; therefore, if its gas supply must be supplemented by a propane-air mixture, the pipeline company will blend the propane-air mixture until it closely matches the Wobbe index of the gas it is pumping into its pipelines at that time.

Using similar methods, DME can be mixed with air (or another inert gas, such as nitrogen, carbon dioxide, etc.), in a way that causes the mixture to approximate the Wobbe index of a gas supply. This can allow the DME mixture to be mixed "seamlessly" with a gas supply being pumped into a pipeline system that supplies factories, offices, homes, etc., without causing any disruptions in the burners of stoves, heaters, furnaces, etc., that are receiving gas from that distribution system.

On a practical level, non-flickering blue flames provide a good indicator that combustion is ideal, at some particular burner. If the Wobbe index of a blended gas additive containing propane and/or DME is too high (when compared to the "baseline" gas being carried by a local pipeline system), burner flames will become yellow, initially at their tips, and in some cases in large portions of the flames. This indicates that combustion is not efficient, and the yellow flames will generate soot and particulates, and unburned hydrocarbons, which are air pollutants. In the other direction, if the Wobbe index of an added gas blend is too low, the burner flames will begin "dancing", and may even go out; that can be extremely dangerous, potentially leading to fires and explosions, since some burners and appliances, in a large area of factories, homes, offices, and other buildings, may not have well-designed and properly-functioning pilot lights and other safety devices. In addition, in some locations, if a gas supply shuts off, it may not turn on again automatically, which can lead to freezing and bursting of pipes, and other severe problems.

Most gas distribution companies are fully comfortable mixing a peak shaving gas (such as propane/air) with their baseline gas supply, so long as the Wobbe indexes of the two gas supplies are within about 5% of each other. If the "Wobbe differential" increases above 5%, to about 10%, it causes increasing concern. Companies will not mix gas supplies with "Wobbe differentials" higher than 10%, except in severe emergencies.

It is believed that DME has never previously been used to supplement natural gas supplies, in gas pipelines. Accordingly, in addition to disclosing a new method for supplementing natural gas in pipelines, this application also discloses new compositions of matter, comprising pressurized mixtures of natural gas, DME, and air or an inert gas, in which the DME, and the air or an inert gas, are mixed in controlled ratios that will match or approximate the Wobbe index of a particular natural gas supply that is being supplemented.

In addition, one other factor must also be taken into account. After a Wobbe-adjusted DME/gas mixture has been created, it cannot be subjected to a pressure that would cause the DME to condense into a liquid, and drop out of the gaseous mixture.

It should be noted that US patent application 2004/0244279 (Briscoe & Fleisch, assigned to British Petroleum, published on December 9, 2004) relates to adding DME to certain types of natural gas supplies, at certain locations in a handling or supply stream. As examples, that application states that DME can be added to a "lean" gas (such as natural gas containing high levels of carbon dioxide) to provide a richer gas that more closely approximates pure methane; similarly, it states that DME can be added to natural gas that is being refrigerated to very low temperatures, to facilitate condensation into liquefied natural gas. However, that patent application does not mention the Wobbe. index, and it does not describe any of the measurements, calculations, or adjustments that need to be made, before DME can be safely added to a natural gas mixture that is being distributed to homes, factories, etc. The disclosures herein are necessary to enable that additional type of use.

Accordingly, when described in language suitable for a patent claim, this invention discloses a method of supplementing natural gas supplies being distributed via a pipeline system to burners, comprising: a. preparing a gaseous mixture comprising dimethyl ether and at least one second gas, wherein said gaseous mixture is formulated to have a Wobbe index that is within a range of plus-or-minus ten.- percent (and preferably within plus-or-minus five percent) of a known Wobbe index for a natural gas supply being distributed to burners via the pipeline system; and, b. mixing said gaseous mixture with natural gas supplies being distributed to burners via the pipeline system, using pressures that cause said gaseous mixture to remain gaseous, without condensation of dimethyl ether from said gaseous mixture.

EXAMPLES EXAMPLE 1: MAKING AND CRACKING MSA

Methods and reagents used to make Marshall's acid and MSA in laboratory conditions, using a batch reactor, have been described in PCT applications WO 2004/041399 and WO 2005/069751, by the same Applicant herein. Therefore, those descriptions are not repeated herein.

To crack MSA in a manner that releases methanol and SO₂, nitrogen gas (N₂) at a flow rate of 6 to 8 mL/second was passed through a gas bubbler containing 10.0-15.0 g of MSA at 120-140⁰C. The outlet of the bubbler was connected to a quartz tube with an inner diameter of 2 cm and a length of 20 cm, which (except for short inlet and outlet segments) passed through a furnace In various different tests, the tube was either empty, or a 10 cm length of the tube was loaded with 4 to 8 mesh zeolite beads (Davison Chemicals, code number 54208080237). The outlet of the tube was connected to two bubblers, each containing 5.0 g of D₂O (i.e., water containing the heavier deuterium isotope of hydrogen, for analysis using ,H-nuclear magnetic resonance) at 4-6⁰C, for trapping any emerging liquids.

When the tube did not contain zeolite packing, significant quantities of the methyl ester of MSA (a byproduct that was unwanted, in these particular tests) were obtained. However, when zeolite packing was provided in the tubes and the furnace was run at 385°C, the yield of methanol increased greatly, and reportedly approached 100%.

EXAMPLE 2: SYNTHESIS OF ETHYLENE AND LIQUIDS ON MONOLITH

The Applicant purchased (from Vesuvius Hi-Tech Ceramics) the same type of "low surface area reticulated silica monolith" described in Barteau 1996, and processed an MSA preparation (purchased from Aldrich Chemical) on it, using reflux temperatures for several hours. Analysis of the gases that emerged from the refluxing liquid, using ¹H-NMR, ¹³C- NMR, and gas chromatography, indicated that the gases contained ethylene, and liquid alkanes.

The presence of those compounds in those gases indicated that: (i) when MSA is processed on a suitable activated surface, it can pass through intermediates that will create olefins (such as ethylene) and higher alkanes; (ii) the postulated mechanisms and molecular rearrangements described herein have received experimental support; and, (iii) methods for creating olefins and alkanes from MSA can indeed be provided, by one or more pathways that 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 and then began to form a clear liquid over a black solid. The liquid and the solid were analyzed, using ¹H-NMR, ¹³C-NMR, and gas chromatography. The results indicated that the clear liquid consisted mainly of MSA and cycloalkanes. The black solid was found to contain cyclic hydrocarbons, naphthenics, and a relatively high quantity of aromatic structures. Some of the aromatic rings were bridged by sulfonate or methylene bridges, and some of the aromatic rings had cyclopropane rings attached to them.

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

EXAMPLE 4: TUNGSTEN CATALYST FOR CONVERTING MSA TO ETHYLENE

A conventional silica disc (purchased from the Vesuvius company, Alfred, NY) was used, having a monolith configuration with essentially linear and parallel flow channels, with a diameter of about 1 inch and a thickness of about 1/2 inch, and a weight of 1.8927 grams. It was immersed in a 5% solution of ammonium tungstate, (NH₃)₂WO₂, in distilled water 15 minutes, giving it a wet weight of 5.5667 grams. It was dried in an oven at 110⁰C for 90 minutes, and the dried weight was 2.0676 grams. The immersion and drying process was repeated two more times, using 60 minute drying times, leading to successive wet and dry weights of 5.6744 g, 2.5106 g, 5.8603 g, and 2.2670 g. After the third drying operation was completed, a white powdery residue was present in the bottom of the drying dish; this suggested that the disc may have been saturated. It is generally presumed that all or nearly all of the ammonium emerged from the disc in vapor form during the drying periods, and the additional dry weight was due primarily to tungsten oxide on the surfaces of the silica flow channels.

Following a procedure suggested by Barteau et al in their reports of ketene synthesis, the disc was then "silanized" as follows. 10.5 ml of tetraethyl-orthosilicate (TEOS, purchased from Aldrich Chemical) was put in a 100 ml beaker, and a mixture of 10 ml distilled water containing 6 ml 37% HCl was added. The mixture comprised two distinct layers, visible in the clear beaker. It was heated to 7O⁰C , at which time the boundary layer began to disappear, indicating the formation of a single-phase gel that was slightly cloudy. As the mixture began to gel, the tungstate-treated disc was placed in the liquid. The temperature was sustained at 120⁰C for 3 hours, then the disc was removed. Excess gel was scraped from the surfaces of the disc. The wet weight was 6.1611 grams.

Since the results disclosed herein are only preliminary, based on initial testing in a small contract lab that does not have extensive analytical equipment, it is not yet known exactly what effect the TEOS treatment had on the silica-tungstate surfaces of the monolith (e.g., in terms of what types of chemical moieties were added to silicon, oxygen, or tungsten atoms on the support surfaces, or the density of such moieties), or whether the TEOS treatment step was necessary or beneficial for enabling or increasing the yields of ethylene from the reaction. The disc was dried at 17O⁰C for 16 hours. Its weight was 2.6033 grams. It was designated as disc 0401-170-1, and was calculated to contain 14.5 % of the tungstate residue (presumably tungsten oxide, with little or no ammonium), and 12.9% added material from the TEOS treatment.

EXAMPLE 5: TREATMENT OF MSA WITH TUNGSTEN CATALYST

The silicate disc, coated with tungsten and silanized as described in Example 4, was wrapped in a thin-layer glass cloth (to form a seal comparable to a gasket) and pushed into a reactor tube. It was heated from a starting temperature of 9⁰C to a maximum operating temperature of 344°C, while helium flowed through the reactor at 4 liters/hr. The MSA feed pot was heated from 34⁰C to 21O⁰C over the same span of time.

Ethylene was formed at 344⁰C. However, its concentration fell with time, as the temperature was increased. When the temperature was decreased back to 344⁰C, no more ethylene was formed, indicating that the activity of the catalyst had been lost.

At the best operating conditions in the best runs, ethylene comprised 95% of total gaseous hydrocarbons that were released, with the balance apparently being methane, as determined by gas chromatography. A relatively small quantity of liquid (apparently methanol) was also recovered in a liquid trap.

EXAMPLE 6: TREATMENT OF MSA USING STANDARD ZEOLITE CATALYST

A standard commercially-available zeolite catalyst (Davison 542HP, with an average pore size of 10 angstroms and a mesh side ranging from 4 to 8, was used to treat MSA at atmospheric pressure, at either 300⁰C or 310⁰C. The catalyst volume was 25 ml, and the feed rate was 4 grams/hour. An analysis of the gases that emerged from the catalyst vessel indicated that, when treated at 300⁰C, the following gases were present: dimethyl ether 79.1 %; cyclopropane 7.2%; ethylene 5.9%; methane 1.6%; and all other gases (presumably higher hydrocarbons) 6.2%. Roughly 75% of the liquid was converted into gases.

When the same treatment was carried out at 31O⁰C, the gas concentrations were dimethyl ether 38.0%; cyclopropane 19.9%; ethylene 15.8%; methane 4.8%; and all other gases (presumably higher hydrocarbons) 21.5%. Roughly 75% of the liquid was converted into gases.

EXAMPLE 7: TREATMENT OF MMS USING STANDARD ZEOLITE CATALYST The same catalyst described in Example 6 was used to treat MMS, under the same conditions. Analysis of the gases that emerged from the catalyst vessel indicated that, when treated at 30O⁰C, the following gases were present: dimethyl ether 89.9%; cyclopropane 4.1 %; ethylene 2.7 %; methane 2.3 %; and all other gases (presumably higher hydrocarbons) 1.0%. Roughly 75% of the liquid was converted into gases.

Thus, there has been shown and described a new and useful means and improvements for creating olefins, dimethyl ether, and other valuable products from methane, via various reagents (including the DMSP radical initiator) and intermediates (including MSA, MMS, and sulfene). Although this invention has been exemplified for purposes of illustration and description by reference to certain specific embodiments, it will be apparent to those skilled in the art that various modifications, alterations, and equivalents of the illustrated examples are possible. Any such changes which derive directly from the teachings herein, and which do not depart from the spirit and scope of the invention, are deemed to be covered by this invention.

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Claims

1. A method of making methanesulfonic acid, comprising the following steps: a. treating di(methyl-sulfonyl) peroxide in a manner that breaks its peroxide bond, thereby causing it to release two methanesulfonic acid radicals; and, b. contacting said methanesulfonic acid radicals with methane, in a reaction mixture that also contains sulfur trioxide.

2. The method of Claim 1, wherein said di(methyl-sulfonyl) peroxide is formed by electrolysis of methanesulfonic acid.

3. The method of Claim 1, wherein said di(methyl-sulfonyl) peroxide is treated by photolysis, to break its peroxide bond.

4. The method of Claim 1, wherein said di(methyl-sulfonyl) peroxide is broken into radicals by inserting it into a reactor vessel containing methane and sulfur trioxide, wherein said reactor is operating at an elevated temperature that causes thermolysis of the peroxide bond.

5. In the method of making methanesulfonic acid by coupling methane to sulfur trioxide by means of a chain reaction, an improvement consisting of using radicals obtained from di(methyl-sulfonyl) peroxide to initiate the chain reaction.

6. A method of manufacturing a product selected from the group consisting of olefins and cycloalkanes, comprising the step of reacting, in a continuous-flow reactor, a reactant compound selected from the group consisting of methanesulfonic acid, methanesulfonic acid anhydride, and esterified methanesulfonic acid, with a catalytic surface comprising a metal oxide compound that promotes: a. formation of organic metallocyclic intermediates comprising at least one carbon- carbon bond, wherein each of said carbon atoms in said carbon-carbon bond is supplied by a different molecule of methanesulfonic acid, methanesulfonic acid anhydride, or esterified methanesulfonic acid; and, b. release of a portion of the organic metallocyclic intermediates from the catalytic surface, in a form selected from the group consisting of olefins and cycloalkanes; wherein the method is carried out in commercial quantities, using at least one continuous-flow reactor.

7. The method of claim 6, wherein the catalytic surface converts at least about 80 percent of all carbon atoms carried by reactant compounds that are altered by catalytic conversion, into carbon atoms contained within molecules selected from the group consisting of olefins, cycloalkanes, and methyl-alky 1 ethers.

8. The method of Claim 6 wherein at least some metal atoms on the catalytic surface are in a +6 oxidation state.

9. The method of Claim 6 wherein at least some metal atoms on the catalytic surface are selected from the group consisting of tungsten, vanadium, ruthenium, and molybdenum.

10. The method of Claim 6 wherein at least some metal atom's on the catalytic surface are aluminum.

11. The method of Claim 6 wherein at least some metal atoms on the catalytic surface promote: (i) formation of organic metallocyclic intermediates that do not contain sulfur atoms, and (ii) release of sulfur dioxide in gaseous form by reactant compounds.

12. A method of manufacturing a methyl-alkyl ether compound, comprising the steps of: a. converting methanesulfonic acid into an ester compound having a sulfur-oxygen- carbon linkage; b. reacting said ester compound under continuous flow conditions that break a sulfur- oxygen bond in the sulfur-oxygen-carbon linkage of the ester compound, thereby releasing an alkoxy group from a sulfur-containing group, and,

(ii) reacting said alkoxy group with a methyl donor compound, thereby forming a methyl-alkyl ether compound, wherein the method is carried out in commercial quantities using at least one continuous-flow reactor, and wherein said methyl-alkyl ether compound is continuously removed from said continuous-flow reactor.

13. The method of claim 12 wherein said methanesulfonic acid is converted into an ester compound by means of condensing said methanesulfonic acid with an alcohol while removing water.

14. The method of claim 13 wherein said alcohol comprises methanol, and wherein said methyl-alkyl ether compound comprises dimethyl ether.

15. The method of claim 12 wherein said methanesulfonic acid is converted into an ester compound in a continuous flow reactor by means of dewatering a portion of said said methanesulfonic acid to form a methanesulfonic acid anhydride intermediate, under conditions that cause said methanesulfonic acid anhydride to react with previously unreacted methanesulfonic acid in the continuous flow reactor, in a manner that forms the ester compound.

16. The method of claim 12 wherein said methanesulfonic acid is converted into an ester compound by reacting said methanesulfonic acid with a methyl donor compound.

17. The method of Claim 12 wherein all steps of said conversion are carried out in a reactive distillation vessel.

18. The method of claim 12 wherein at least 50% of methanesulfonic acid present in a continuous flow reactor is converted into an ester compound, and wherein at least 50% of said ester compound is converted into a methyl-alkyl ether.

19. The method of claim 12 wherein conversion of said organic oxygenate into said methyl-alkyl ether compound is promoted by a catalytic surface comprising a weakly- coordinated ion.

20. A method of supplementing natural gas supplies being distributed via a pipeline system to burners, comprising: a. preparing a gaseous mixture comprising dimethyl ether and at least one second gas, wherein said gaseous mixture is formulated to have a Wobbe index that is within a range of plus-or-minus ten percent of a known Wobbe index for a natural gas supply being distributed to burners via the pipeline system; and, b. mixing said gaseous mixture with natural gas supplies being distributed to burners via the pipeline system, using pressures that cause said gaseous mixture to remain gaseous, without condensation of dimethyl ether from said gaseous mixture.