NZ616634B2

NZ616634B2 - Bubbling bed catalytic hydropyrolysis process utilizing larger catalyst particles and smaller biomass particles featuring an anti-slugging reactor

Info

Publication number: NZ616634B2
Application number: NZ616634A
Authority: NZ
Inventors: Larry G Felix; Martin B Linck; Terry L Marker; Michael J Roberts
Original assignee: Gas Technology Institute
Priority date: 2011-04-18
Filing date: 2012-03-23
Publication date: 2016-03-30

Abstract

Disclosed is a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert, obstacle or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid. genated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert, obstacle or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

Description

BUBBLING BED CATALYTIC HYDROPYROLYSIS S UTILIZING LARGER CATALYST PARTICLES AND SMALLER BIOMASS PARTICLES FEATURING AN ANTI-SLUGGING REACTOR BACKGROUND OF THE ION Field of the Invention This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels.

Description of Related Art Oxygenated feedstocks, such as solid biomass (wood, agricultural waste, waste paper, etc.) can be converted into liquid products via rapid heating in the absence of oxygen (pyrolysis). A solid char product (consisting mostly of carbon, but also containing any non— volatile, inert compounds found in the feedstock) and non-condensable vapors (such as C02 and CH4) are produced, along with condensable species such as: water, hydrocarbons, and molecules that contain carbon atoms, hydrogen atoms, and oxygen atoms. The proportions of the ing products obtained depends on the rate of heating of the feedstock particles, as described by Mohan, et a1. (Mohan, Pittman, and Steele, “Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review,” in Energy & fuels, Volume 20, pp. 848-889, 2006). A type of biomass pyrolysis, referred to as “fast pyrolysis,” minimizes the amount of char produced, and maximizes the amount of condensable liquid ed, by heating the biomass as rapidly as possible. Some char is always produced, particularly since biomass always ns some non-volatile, active compounds (generally referred to as ash). Conventional pyrolysis of biomass, typically fast pyrolysis, does not utilize or require gaseous hydrogen-or catalysts and produces a dense, acidic, reactive liquid product that contains water, oils, and char formed during the s. Because fast sis is most typically carried out in an inert atmosphere, much of the oxygen t in biomass is carried over into the liquid ts obtained, which ses their chemical reactivity. The s from fast pyrolysis also contain high levels of acids (such as acetic acid), as well as oleﬁns and polyaromatic hydrocarbons. The chemically unstable liquids produced by conventional pyrolysis tend to thicken over time and can also react to a point where hydrophilic and hydrophobic phases form. Dilution of pyrolysis liquids with methanol or other alcohols has been shown to reduce the subsequent ty and viscosity of the oils, but this approach is not ered to be practically or economically Viable, because large amounts of unrecoverable alcohol would be required to stabilize large amounts of pyrolysis s for transport and subsequent use.

In conventional pyrolysis of biomass, carried out in an inert environment, the water- miscible liquid product is highly oxygenated and reactive, for example, with total acid numbers (TAN) in the range of 100-200, has low chemical ity for polymerization, is incompatible with petroleum hydrocarbons due to inherent water miscibility and very high oxygen content (on the order of about 40% by weight), and has a low g value. As a , transport and utilization of this product are problematic and it is lt to upgrade this product to a liquid fuel due to retrograde reactions that lly occur in conventional pyrolysis and in conventional fast sis. Upgrading technologies, as applied to conventional pyrolysis liquids, tend to yield only small quantities of enated high- quality liquid hydrocarbons that are suitable for use as transportation fuels.

In addition, the separation of char generated during conventional pyrolysis from the liquid pyrolysis product presents a technical challenge due to the large amounts of oxygen, oleﬁns, acids, and free radicals in hot pyrolysis vapors which remain highly ve and form a pitch—like material when they come in intimate contact with char particles on the e of a barrier ﬁlter, inertial tion device, or electrostatic precipitator. In particular, barrier ﬁlters used to separate the char from the hot sis vapors (prior to cooling and condensation of the liquid pyrolysis products) can quickly experience irreversible clogging (blinding) due to the reactions of char and reactive vapors that occur on and within the layer of char on the surface of the ﬁlter.

In order to e conventional pyrolysis liquids, attempts have been made to react the conventional pyrolysis liquids with hydrogen, in the presence of solid catalysts, in order to remove oxygen from the liquids and produce a stable, useful hydrocarbon product. This process is ed to as hydroconversion. However, the upgrading of conventional pyrolysis liquids via hydroconversion is commercially non-viable. Hydroconversion of conventional pyrolysis liquids consumes signiﬁcant H2 at extreme process conditions, such as very high hydrogen pressures of 138 bar (2000 psig) or more. High speciﬁc pressures of hydrogen are required in order for the desired reactions to proceed, but these pressures create conditions wherein most of the oxygen d from the liquid is removed via the formation of water (H20). This approach consumes large amounts of hydrogen, thus making the process economically unattractive. In addition, hydroconversion reactors often plug due to accumulations of coke precursors present in the pyrolysis oils or from coke products resulting from catalysis. The coke is a solid product, consisting mostly of carbon, and the maintenance needed to remove it from hydroconversion reactors reduces further the economic viability of hydroconversion of conventional pyrolysis liquids.

The present state of the art also describes a ent means by which oxygenated feedstocks such as biomass can be converted to create useful liquid hydrocarbons, referred to as hydropyrolysis. Hydropyrolysis can be carried out with or without the aid of a catalyst However, lower hydrocarbon yields and lower enation tend to be a characteristic of noncatalytic hydropyrolytic processes. Therefore, as described herein, “hydropyrolysis” will be considered to refer to a catalytic pyrolysis process carried out in the presence of molecular hydrogen (H2). Typically, the objective of conventional hydropyrolysis processes has been to remove heteroatoms (atoms other than carbon and hydrogen) from biomass, and ze liquid hydrocarbon yield. In prior work by Meier, et a1. , Jakobi and Faix, “Catalytic Hydroliquefaction of Spruce Wood,” in the Journal of Wood try and Technology, Vol. 8, No. 4, pp. 523-542, 1988), the solid biomass feedstock was sed in a reactor containing liquid, in which solid biomass ock was suspended. The reaction was carried out at high internal pressures of over 138 bar (2000 psig) with recycled slurry oil and the lowest oxygen t reported for hydrocarbons produced was 7.6% by mass. This value was obtained when a precious metal palladium (Pd) catalyst was used. In another study by Meier and Faix (Meier and Faix, “Solvent-Free Hydroliquefaction of of Pine Wood and Miscanthus Stems,” in Proceedings of the ational Conference on s for Energy and Industry, Lisbon, Portugal, October 9-13, 1989), in which a slurry oil was not used, the lowest oxygen content reported in the hydrocarbon product was 9.7% oxygen by mass, and the reaction was still carried out at high internal hydrogen pressures of over 138 bar (2000 psig) within a heated reactor with a NiMo catalyst.

In studies of single-stage hydropyrolysis of cellulose and other biomass-derived feedstocks, Rocha, et a1. (Rocha, Luengo, and Snape, “The Scope for Generating Bio-Oils with Relatively Low Oxygen Contents via Hydropyrolysis,” in Organic Geochemistry, Vol. , pp. 1527-1534, 1999) demonstrated that, with a FeS st, as the partial pressure of en in the hydropyrolysis reactor was decreased, the oxygen content of hydrocarbon product tended to increase. ments carried out at lower hydrogen pressures typically produced hydrocarbon products with oxygen contents above 15%. In one case described by Rocha, et al., cellulose was subjected to yrolysis at a en pressure of 99 bar (1440 psig), and the lowest oxygen content of resulting hydrocarbon product was 11.5% by mass. Unfortunately, this approach compromises y, as it requires an external source of H2 and must be carried out at high reactor pressures. In addition to requiring a continuous external input of en, such conventional hydropyrolysis processes produce ive H20 which generally represents a waste stream. In this type of reactor, the hydropyrolysis of biomass has not been found to be ically attractive because the oxygen content of the hydrocarbon product was still fairly high after processing and the reaction ions required by the process were too severe to be practical.

Finally, hydropyrolysis may be carried out in a ﬂuidized bed (typically, a shallow ﬂuidized bed with lengthzdiameter ratio < 1.5). However, the present invention pertains to means by which effective hydropyrolysis can be carried out in a single step in a deep ﬂuidized bed of particles of an active catalyst, at H2 partial pressures from 200 to 600 psig, in such a manner that the oxygen content of the liquid hydrocarbon product is reduced to below 4% by mass. Also, in the present invention, the hydropyrolysis reaction is exothermic and provides the heat of reaction so that there is no need to provide external heating or circulate hot regenerated catalyst or sand through the ﬂuid bed reactor as is typically required for traditional pyrolysis. zed beds generally include solid particles, such as particles of sand or catalyst, that are agitated and ed by a stream of gas, which travels. upward through the bed and exits from the bed at or near the top of the reactor. The behavior of ed beds is known to at least partially depend on the depth (or , or length) of the bed. The bed depth is generally characterized by the L/D ratio, meaning the ratio of the depth, height, or length of the bed, divided by the bed diameter. The behavior of the bed will depend heavily on the particle size distribution of the material from which the bed is formed. Generally, ﬂuidized beds are designed with an L/D of 1-2, since beds in this range exhibit uniform ﬂuidization, once a ﬂow rate of ﬂuidizing gas, sufﬁcient to bring the bed particles into rapid motion, has been ed. In this case, "uniform ﬂuidization" means that, once fully- ﬂuidized, the particles in the bed are in universal, random . Mixing and internal heat transfer within a ﬂuidized bed are both very rapid, and a relatively-shallow bed can often be operated in a nearly-isothermal manner, meaning that the temperature at any point within the bed is almost completely uniform. zed beds may be adversely affected by a enon referred to as “slugging.” Slugging develops in beds that have L/D ratios greater than 1.5-2.0 and ﬂuidized beds composed of particles larger than a few hundred microns are especially prone to slugging.

Slugging is a phenomenon in which a gas-ﬁlled bubble forms in the bed, and the diameter of the bubble rapidly expands to reach the full diameter of the bed. Then the entire bed above the bubble begins to move upward as a coherent body (a “slug”), with very little relative motion between particles in the “slug.” The slug can rise for many bed diameters before the on of the slug begins to break down, and the particles in the slug then drop rapidly back down toward the lower levels of the reactor. Usually, the bubble forms at an elevation of 1.5- 2.0 reactor diameters above the bottom of the bed. While the slug is rising, a region of well- ﬂuidized bed al can be observed in the lowest parts of the bed, with an open space, containing only the ﬂuidizing gas, appearing n the top of the well-ﬂuidized region and the bottom of the coherent slug. As the slug disintegrates, the bed al from the slug drops down onto the bed material in the lowest parts of the bed, suppressing ﬂuidization until the bubble re-forms and the next slug is lifted. Slugging is usually cyclic or periodic, and, once it begins, it can continue with regularity until it is interrupted by a change in ing conditions. Slugging can also be affected by the properties of the bed material. Two beds, of equal depths and bulk densities, may behave very differently if the particle size distribution is different, or the sphericity of the particles in either bed is d.

Slugging is undesirable for several reasons. Most importantly, when slugging occurs, longitudinal mixing in the bed is retarded, and particles from the highest points in the bed move very slowly down toward the bottom of the bed (and vice versa). The uniformity of axial temperature is thereby compromised, and considerable gradients in temperature can be observed along the height of the bed. Slugging also creates cyclical stresses on the walls and ﬂoor of the bed, particularly if the bed is disposed within a reactor, and the effect of cyclic loading and unloading on the reactor support structure, and the concomitant effect on process chemistry, can destroy any semblance of process uniformity. The vibration, or cyclical loading, of the reactor walls and support structure, can lead to mechanical failures, and the variation in the process chemistry will also make it impossible to e with a useful level of process control. Slugging may also cantly increase the attrition of particles that comprise the ed bed, because the large-amplitude, cyclical motion of the bed tends to involve the bed particles in more energetic collisions with other particles and with the walls of the vessel within which the bed is contained.

As ned above, the problem of slugging can lly be avoided simply by using a shallower bed or, in some cases, using particles of smaller diameters. However, there are applications where a shallow bed is simply not practical. If the bed has catalytic properties that are essential to the process try, then the weight of catalyst in the ﬂuidized bed may need to be above some threshold, relative to the mass ﬂow rate of vapors g through the bed, in order for the desired reactions to occur. In the case of the present invention, the desired deoxygenation reactions that are required to carry out effective hydropyrolysis cannot be carried out in a shallow ﬂuidized bed of catalyst. If the bed is too shallow, the vapors will exit the bed before the desired effect is achieved. The mass ﬂow rate of ﬂuidizing gas ed to ﬂuidize a bed also depends on the diameter of the bed. In some situations, particularly in pressurized reactors, the diameter of the bed must be held below a certain value, so that a gas velocity sufﬁcient to ﬂuidize the bed can be achieved with the available mass ﬂow rate of ﬂuidizing gas. The process of the present invention, as described below, preferably includes the use of a deep ﬂuidized bed, composed of relatively large catalyst particles. Because this bed is inherently prone to slugging we have incorporated in this invention a means of curtailing slugging. Slugging is avoided or controlled via the use of an insert or other lugging modiﬁcation of the hydropyrolysis reactor, which is ed Within the ﬂuidized bed. The design and application of the insert within the reactor or other modiﬁcations of the hydropyrolysis reactor to t ng are important aspects of the invention. The use of the insert or other anti-slugging modiﬁcation of the hydropyrolysis reactor makes it possible for the ﬂuidized bed to maintain proper ﬂuidization and be of the ed depth to carry out the desired hydropyrolysis reactions. The insert further makes it possible for the bed to be ed of relatively-large st particles, which are large enough to be retained in the bed while smaller particles of solid residue (char) are elutriated and carried out of the bed within the gaseous product stream.

The behavior of a ﬂuidized bed will vary depending on the ﬂow rate of ﬂuidizing gas passing through the bed. The process of the present ion, as bed below, speciﬁcally involves a bubbling ﬂuidized bed. In a bubbling ﬂuidized bed, a ﬂow rate of ﬂuidizing gas is supplied that is sufﬁcient to usly agitate and mix the bed, and is large enough that open voids, ning almost exclusively ﬂuidizing gas, are formed. However, the ﬂow rate is not large enough to entrain the solid catalyst particles from which the bed is composed in the gaseous exhaust stream and permanently separate them from the bed.

SUMMARY OF THE INVENTION This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed (lengthzdiameter ratio > 1.5) of ﬂuidized catalyst particles is utilized. The reactor accepts particles of biomass or other Disclosed herein is a process and/or tus by which biomass, or other oxygenated organic feedstocks, including solid biomass, such as lignocellulosic biomass a wood, agricultural byproducts, crop residues, and wastes, industrial wastes derived from such materials (e.g. paper and waste sludges), animal wastes (manures, offals, and sewage sludges), algal and similar uni- and multi-cellular aquatic biomass, wastes from the processing of fish, and mixtures of the above, etc., can be substantially converted to obtain a product stream consisting of hydrocarbons that are liquid under t conditions, n less than approximately 4% oxygen by mass, and have properties, such as boiling points, heating values, and aromaticities, that are consistent with those of gasoline, kerosene and diesel fuel.

Also disclosed herein is a process and/or apparatus by which biomass, or other oxygenated organic feedstocks as described above, can be substantially converted to create the arbon liquid product bed herein above, under conditions where the l pressure of hydrogen in the r of the process of the present ion is kept between approximately 200 psig and 600 psig.

Also disclosed herein is a process and/or apparatus by which solid residues, remaining after the conversion of the feedstock in the s of the present invention, are removed from the reactor of the present invention as entrained particles, carried out of the reactor by the stream of product vapor leaving the reactor.

Also disclosed herein is a process and/or apparatus by which entrained solid residues, carried out of the reactor of the process of the present invention, can be easily filtered from the stream of product vapors.

AH26(10743111_1):LNB Also disclosed herein is a process and/or apparatus in which the exothermic deoxygenation reactions, occurring in the fluidized-bed hydropyrolysis r of the present invention, generate an amount of thermal energy sufficient to heat the incoming stream of feedstock to the temperature of the fluidized bed, as well as to overcome heat required to drive endothermic processes and reactions occurring in the bed during conversion of the feedstock.

Also disclosed herein is a process and/or apparatus by which the conversion of any of the entioned feedstocks can be carried out in a deep, bubbling fluidized bed, consisting of relatively-large catalyst particles, while employing the means of this invention to avoid slugging within the bubbling fluidized bed and minimize attrition of catalyst particles within the bubbling fluidized bed.

According to an aspect of the present invention there is provided a method of hydropyrolysis comprising: a. introducing an oxygenated organic feedstock into a fluidized bed reactor, wherein said feedstock is rapidly heated from ambient temperature to the temperature of the zed bed, and is thereby tilized; b. ucing a stream of fluidizing gas comprising mostly molecular hydrogen into the fluidized bed reactor, creating conditions under which rapid mixing and heat er occur throughout the fluidized bed; c. maintaining a deep bed of solid particles of catalyst, the depth of which is significantly greater than2 reactor diameters, in a state of vigorous motion, to e reactions ing in deoxygenation and chemical stabilization of vapors produced when the feedstock is devolatilized; d. removing solid residues, remaining after tilization and hydropyrolysis of the feedstock, from the fluidized bed reactor via nment in the stream of fluidizing gas and product vapors exiting the fluidized bed reactor; e. removing attritted es of catalyst, but not intact particles of catalyst, or particles of catalyst that have been minimally attritted, from the fluidized bed r via entrainment in the stream of fluidizing gas and product vapors exiting the fluidized bed AH26(10743111_1):LNB f. separating the solid residues, ned in the stream of fluidizing gas and product vapors exiting the fluidized bed reactor, from the stream of fluidizing gas and product vapors exiting the fluidized bed reactor; g. recovering a product stream of hydrocarbon vapors comprising hydrocarbon s with atmospheric-pressure boiling points, consistent with those of at least one of gasoline, ne and diesel fuel, from the hydropyrolysis process as condensed liquid; h. releasing enough exothermic heat from the deoxygenation reactions occurring during hydropyrolysis of the ock to supply process heat required by endothermic processes occurring during hydropyrolysis of the feedstock, including chemical reactions, heating of feedstock, and evaporation of liquids; and i. dispersing one or more modifications to an or of the reactor vessel in such a manner that slugging does not occur within the fluidized bed reactor.

AH26(10743111_1):LNB desired. The ease with which solid residues (char and ash) can be removed from process vapors via ﬁltration, is also desired. These characteristics derive from the high level of deoxygenation that is effected in the hydrocarbons that exit the hydropyrolysis reactor. When the highly deoxygenated gaseous hydrocarbons and char encounter a barrier ﬁlter, the s vapors preferably contain no high boiling point components that could be adsorbed or reside on char particles and so the highly deoxygenated gaseous hydrocarbons are effectively separated from the char, which can then be easily removed from the ﬁlter by l levels of backpulsing. In conventional pyrolysis, particles of char adsorb and retain reactive pyrolysis oils. When these particles encounter a barrier ﬁlter they aggregate and create a dense, almost impermeable layer of char that s cleanng by backpulsing.

Unlike the t ion, other processes described in the related art (conventional pyrolysis, hydropyrolysis, hydrotreating of conventional sis oils) all suffer from deﬁciencies which make it impossible to obtain the yields and products teristic of the hydropyrolysis s of the present invention. A ed comparison of experimental s ed during development of the hydropyrolysis process of the present invention to the performance of other conventional biomass pyrolysis, biomass hydropyrolysis and reating processes is presented in examples that follow, below.

The hydropyrolysis reactor vessel of the s of the present invention ably comprises an elongated deep bed ﬂuidized bed reactor with a bed that preferably includes relatively-large catalyst particles. In the case where a solid feedstock is conveyed into the hydropyrolysis reactor of the process of the present invention, the feedstock is fed into said reactor in the form of particles that are substantially smaller in size than the catalyst particles in the bed, in order to maximize thermal decomposition of the s, minimize catalyst particle attrition, and permit effective separation of char from the ﬂuidized bed and from the process vapor stream g the ﬂuidized bed. In addition, one or more inserts or other anti- slugging modiﬁcations of the reactor may be disposed within the reactor to inhibit slugging of the ﬂuidized bed during the hydropyrolysis process. A particular design approach, pertaining to inserts or other anti-slugging modiﬁcations of the hydropyrolysis reactor, is incorporated into the present invention, which makes it possible to prevent slugging of the bed disposed within the ﬂuidized—bed reactor, even under circumstances where slugging would generally be expected to occur.

In the description of the present invention, the term “hydropyrolysis” is used to describe a process by which a s feedstock (to include but not be limited to all of the varieties of biomass enumerated in the Summary of the Invention, above) is rapidly heated and thermally decomposed, in the presence of solid catalyst particles and an atmosphere consisting largely of en gas. Further, the term “hydropyrolysis” will be used to refer to all reactions carried out on the products of thermal decomposition of the feedstock within the yrolysis reactor. In the present invention, hydropyrolysis involves ﬁve classes of reactions. They are: 1) Devolatilization, wherein the feedstock is lly decomposed to produce a solid char product (which contains a non-volatile, inert ash fraction), and ts of decomposition that enter the vapor phase in the hydropyrolysis reactor. 2) Hydrodeoxygenation, wherein oxygen is removed from a molecule, and combined with en (H2) to make water (H20). 3) Decarbonylation, wherein a carbon monoxide (CO) molecule is d from the structure of a molecule. 4) Water-gas shift, wherein CO is reacted with H2O to make CO2 and H2. 5) Polymerization, wherein small oleﬁns combine to make large molecules. 6) Oleﬁn saturation, wherein hydrogen is added to an oleﬁn to make a parafﬁn.

In the description of the present ion, the term “deoxygenation” refers to chemical processes by which chemically-bonded oxygen is removed from molecules (principally arbon molecules) and transferred to other chemical species such as water (H2O), carbon de (CO), or carbon dioxide (CO2). As described above, the term “hydrodeoxygenation” refers to a subset of these processes where water is formed.

In the description of the present invention, the term “hydrotreating” refers to a range of chemical reactions in which hydrocarbon s (which may contain double and triple carbon-carbon bonds, benzene rings, ﬁve-carbon rings, chemically-bonded heteroatoms, and a wide variety of other functional groups) are reacted with molecular hydrogen (H2), generally in the presence of a catalyst. Hydrotreating generally involves breaking a bond in the hydrocarbon molecule, and adding hydrogen to the structure of the hydrocarbon le, so that heteroatoms (such as oxygen and nitrogen) are removed, double and triple carbon—carbon bonds are ted and substituted with carbon-hydrogen bonds, and ring structures are , resulting in linear hydrocarbon molecules. Hydrotreating can also involve “hydrocracking” (or “cracking”) which involves the breaking of long hydrocarbon chains into r hydrocarbon chains, producing smaller les with lower boiling points.

In the description of the t invention, the term “hydroconversion” is deﬁned as a reaction carried out in the presence of hydrogen, and generally a catalyst, which removes heteroatoms such as sulfur, nitrogen and oxygen or carries out cracking while adding hydrogen to the structure of the reactant molecule.

The catalytic hydropyrolysis process of the present invention provides a means to remove oxygen from biomass and other feedstocks containing signiﬁcant ties of carbon and chemically-bonded oxygen to produce light hydrocarbon products with a large portion of the oxygen d directly from the ock-derived liquids. This is referred to as “deoxygenation.” In the reactor bed in the present invention, deoxygenation of les derived from the s feedstock inherently releases a large heat of reaction which provides the energy necessary to heat up cold biomass as it enters the bubbling ﬂuid bed. However, one problem with conventional catalytic hydropyrolysis is the separation of the char and ash from the catalyst. Another potential problem with conventional catalytic hydropyrolysis, as carried out in a ﬂuidized bed, is that rapid catalyst particle attrition could lead to high st replacement costs and thus be omical. The reactor described in this invention, which involves a bubbling ﬂuidized bed hydropyrolysis system with catalyst particles that are much greater in size than the decomposed ed) feedstock residue, provides a novel way of mitigating catalyst attrition while at the same time ensuring that char and ash are separated from the catalyst by being attritted (reduced in size) and elutriated from the bubbling bed r. Elutriation occurs when a particle has been reduced in size to a point where it is entrained in the stream of gas exiting the top of the ﬂuidized bed, and is removed permanently from the bed. Within the ﬂuidized bed catalytic hydropyrolysis reactor described in the t invention, the char product of catalytic hydropyrolysis of the feedstock, being largely composed of carbon, acts as a lubricant within the ng bed and serves to protect the large st particles from self-attrition. However, the action of the bed on the soft char and ash is such that the char and ash are effectively attritted by the catalyst and reduced to a size where the char and ash are readily ated from the bubbling bed. The problem of char and ash removal from the ﬂuidized bed of catalyst is thereby addressed.

Note that in the present invention, it may be advantageous to process efﬁciency and quality for more than one type of catalyst to be disposed within the bed. In the st case, two physically and chemically different catalysts could be disposed within the bed. Because the two types of catalyst could be engineered to possess different densities or sizes, the catalysts could intermix within the ﬂuidized bubbling bed, or one catalyst could tend to rise to the top of the bed (e.g. by being lighter or being sized to possess a lower aerodynamic diameter) so that the chemistry of this s can be effected in a se manner. Clearly, in a vertically extended bubbling ﬂuidized bed, a number of catalysts could be ed so that some could intermix while others would maintain different vertical positions in the bed.

In the present invention, biomass or other solid feedstock particles are fed into the ﬂuidized-bed catalytic hydropyrolysis reactor preferably near the bottom of the bed, and are rapidly heated and decomposed to produce solid ash, char residue, and vapor-phase products.

The ash, char and vapors then travel up through the bed, where the s vapors (and solid particles small enough to be aerodynamically entrained) are carried permanently away from the upper surface of the ﬂuidized bed where they exit the reactor.

While the process described above could be carried out in a shallow ed bed ng that the bed has an L/D ratio of 2 or less), it is preferably carried out in a deep ﬂuidized bed (with an L/D of approximately 10 or greater). A deep ﬂuidized bed, particularly one comprised of relatively—large catalyst particles, will develop slugging, and cannot be operated without a slug-breaking . The insert should consist of obstacles, ctions, or constrictions, positioned at regular intervals within the bed, and oriented or contoured in such a way that a coherent slug of bed material cannot form along the full length of the bed.

The use of the insert makes operation of the reactor with a deep bed le, and provides three advantages, relative to operation of the reactor with a shallow bed: 1. The deep bed brings process vapors into contact with catalyst particles for a longer period of time, since the path taken by product vapor through the deep bed is much longer than it would be if it were traversing a shallow bed. 2. The mass ﬂow rate of ﬂuidizing gas , in the case of this invention, comprises of principally hydrogen) needed to ﬂuidize the bed depends on the bed diameter. If a deep bed is used, a large quantity of catalyst can be ﬂuidized by a relatively small mass ﬂow rate of ﬂuidizing gas. For example if the diameter of a catalyst bed is d, so that the L/D of the bed is increased from 1.5 to 10, while maintaining a constant volume of catalyst in the bed, the mass ﬂow rate of ﬂuidizing gas needed to obtain the same degree of ﬂuidization in the bed is reduced by a factor of 3.5. This effect is essential in order to improve the economic viability of the process. 3. The obstructions, obstacles, or constrictions associated with the slug—breaking insert can be instrumented, and equipped with internal es that allow them to . remove or add heat to the bed. The obstructions, les, or constrictions interact directly with the bed, at radial locations that may include the center of the reactor. This ch allows more efﬁcient heat transfer to occur at speciﬁc ons in the bed than would be the case if heat transfer were occurring only across the outer wall of the reactor, and enhances process control, since the local temperature at each point in the bed can be better managed.

The vapor stream leaving the top of the ﬂuidized bed includes the ﬂuidizing gas, any product vapors that have been generated by thermal decomposition and hydropyrolysis of the feedstock, and any solid particles (ash, char or attritted catalyst ﬁnes) that are small enough to be aerodynamically entrained in said vapor stream. The process described by this invention speciﬁes that product vapor species leaving the ﬂuidized bed must be sufﬁciently ally stable so that they will be substantially unable to react with other product vapor species, or with solids entrained in the vapor stream, or with solid surfaces with which the vapor stream comes into contact, such as a barrier ﬁlter. In practice, this means that the most unstable species produced by the initial thermal decomposition of the feedstock, such as aldehydes and acids, should be substantially deoxygenated via reaction with hydrogen in the catalytic ﬂuidized bed. The combined stream of vapors and entrained solids can be passed h an inertial separation device such as a cyclone or l impactor, an electrostatic precipitator (ESP), and/or ﬁlter elements, or some combination of the above, and will not form a dense cake on the cyclone, ESP plate, or ﬁlter surfaces, or create fouling as the solid particles are ﬁltered out of the vapor .

Any appropriate al separation device, porous ﬁlter, electrostatic precipitator, or other means of removing solids from the vapor stream may be employed once the vapor stream (with entrained solids) has exited the r containing the ﬂuidized bed. If a cyclone or virtual impactor is used ﬁrst to remove the larger solids entrained in the vapor stream, and a porous ﬁlter is then used to remove the remaining ﬁnes entrained in the vapor stream, the majority of the char and ash leaving the reactor can preferentially be collected from the cyclone, while the majority of the attritted catalyst can be recovered from the ﬁlter. This is because the catalyst is much harder than the char, and will break down primarily into very ﬁne les, which will pass through the cyclone to the ﬁlter. The char, on the other hand, is softer and less durable, and will be broken down into a range of particle sizes by the grinding action of the ﬂuidized bed. The larger particles of char will be trapped primarily by the e, and will not reach the ﬁlter. Finally, if the catalyst is disposed to remain as a metallic material that can be magnetized, les comprised of attrited catalysts may be efﬁciently collected in a ﬁlter or inertial tion device that can be periodically energized with a magnetic ﬁeld to entrap the magnetic les. Deenergizing the magnetic ﬁeld would allow these particles to be removed and recovered en masse.

Once the entrained solid particles have been removed from the stream of process , the vapors can either be cooled to ambient temperature immediately, at which point all s with boiling points below ambient temperature will condense to form liquids, or the stream of process vapors can be directed to a subsequent reactor or reactors for further treatment.

One approach is to send the ﬁltered process vapors from the yrolysis reactor to a second-stage reactor, where the process vapors can be further hydrogenated using a hydroconversion st. This approach can be used to produce a product stream containing substantially fully deoxygenated hydrocarbon species, water vapor, a gaseous mixture comprising C0, C02, and light hydrocarbon gases (C1-C4) and further process heat. If this approach is used, the overall process may be referred to as integrated hydropyrolysis and hydroconversion.

It must also be noted that, while s is an ideal feedstock for use in the hydropyrolysis process described above, the feedstock sent into the ﬂuidized-bed hydropyrolysis reactor need not be biomass, and need not be composed only of solids. Any feedstock which can be subjected to hydropyrolysis, under the ions described above, and which yields products similar to those described above, could be fed into the reactor.

Thus, feedstock streams containing rs or plastics, 0r feedstock streams comprising slurries of solid particles suspended in a carrier liquid, or feedstocks streams comprising a carrier gas, in which solids or liquids are entrained, or feedstock streams comprising, completely or in part, of liquids that can be deoxygenated and reacted with hydrogen to produce deoxygenated hydrocarbons, can be subjected to hydropyrolysis via the method described in the present invention. If liquids are t in the ock stream these liquids must be able to evaporate and enter the vapor phase very shortly after they are introduced into the ﬂuidized bed. The set of ons occurring in the s of the present invention are primarily vapor-phase reactions, and liquids initially present in the feedstock stream, or formed via chemical decomposition of the feedstock stream, must enter the vapor phase in order to be effectively processed by the ﬂuidized-bed reactor of the present ion.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of this invention will be better understood from the following ed description taken in conjunction with the drawings wherein: Figure 1 is a schematic ﬂow m of a hydropyrolysis process for producing liquid fuels from biomass or other feedstocks inaccordance with one embodiment of this invention; Figure 2A is a schematic View of a vessel containing an insert, with slug-breaking obstructions attached to an axial support in the center of the vessel, according to one embodiment of this invention; Figure 2B is a top down View of the insert shown in Figure 2A; Figure 3A is a schematic View of a vessel containing an insert, with slug-breaking constrictions attached to a support ‘at the circumference of the vessel, according to one embodiment of this invention; Figure 3B is a top down View of the insert shown in Figure 3A; and Figure 4 is a graph of liquid product oxygen content as a on of hydrogen partial pressure.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS A schematic diagram of the s described in the present invention is shown in Figure 1. A ﬂuidizing gas stream 150, consisting primarily of hydrogen, but possibly also containing other gases, is fed into the bottom of a ﬂuidized—bed reactor vessel, 100. The ﬂuidizing gas stream passes through a bed of catalyst les, contained within the ﬂuidized-bed reactor vessel, and ﬂuidizes the bed to a point where its state is consistent with that of a bubbling ed bed. An insert 130, or other modiﬁcation to the interior of the vessel, is present, and cts with the bed 140 in such a way that ng is prevented. The depth of the bed is ore not limited by the diameter of the vessel, and a deep bed, whose axial dimension may be many times greater than the diameter of the vessel, can therefore be employed.

The mass ﬂow rate of ﬂuidizing gas, passing through the bed, is determined by the size and ﬂuidization characteristics of the catalyst particles. In the present invention, the catalyst particles are approximately spherical, and are imately 3200 microns or more in diameter, but could be smaller or larger. The density of each particle can vary from 0.5 to 2 kilograms per liter. Based on laboratory studies, a superﬁcial velocity of ﬂuidizing gas of approximately 1 to 1.5 /second is needed to achieve effective ﬂuidization of a bed of this type. The superﬁcial velocity is deﬁned as the average velocity that the ﬂuidizing gas would achieve if it were passing through the empty reactor vessel, in the absence of a ﬂuidized bed. The diameter of the vessel is governed primarily by the amount of ﬂuidizing gas available, and the depth of the bed is governed by the amount of st needed to e the requisite deoxygenation of the feedstock. There is no deﬁnite upper limit to the depth of the bed, since the use of an anti-slugging insert, or anti-slugging modiﬁcations within the reactor, as speciﬁed in the t invention, ensures that slugging is avoided, no matter how deep the bed in the reactor becomes. The bed should be as deep as necessary to achieve the desired degree of reaction of the s vapors released by the feedstock. The mass ﬂow rate of ﬂuidizing gas should not exceed the m required to achieve ﬂuidization. If a higher ﬂow rate of ﬂuidizing gas is employed, the material and equipment costs associated with the ﬂuidizing gas stream will increase, and catalyst particles, which have been attritted to some extent, but are still useful, will be elutriated from the bed. This result is not desirable, so the mass ﬂow rate of ﬂuidizing gas is not increased above the m needed to ﬂuidize the bed.

The distribution of temperature within the ﬂuidized bed as described in the t invention is nearly uniform, due to the rapid exchange of heat n particles in motion throughout in the bed. The ature of the bed must be at least 343 degrees Celsius (650 degrees Fahrenheit) and need not be higher than 593 degrees Celsius (1100 degrees Fahrenheit). The exact operating temperature of the bed depends upon the composition of the feedstock that is to undergo hydropyrolysis, the characteristics of the catalyst, and the desired composition of products that is to be ed.

The pressure within the ﬂuidized—bed reactor vessel must be such that the partial pressure of hydrogen is about 200 psig to 600 psig. The exact operating re of the ed-bed reactor depends upon the composition of the feedstock that is to undergo yrolysis, the choice of catalyst, and the desired composition of products that are to be obtained.

The ock that is to undergo hydropyrolysis is fed into the bottom of the ﬂuidized bed, near the point where the ﬂuidizing gas enters the reactor. The feedstock is introduced in such a way that it is ,heated very rapidly from ambient temperature to the temperature of the ﬂuidized bed, by cting with the ﬂuidized bed. The feedstock is uced into the ﬂuidized bed in such a manner that any solid residues (remaining after the ock has been heated to the temperature of the bed) form distinct solid les, which are signiﬁcantly smaller in size than the particles of catalyst of which the bed is primarily composed. These particles will then be transported to the top of the bed, and, if they are sufﬁciently small, they will be entrained in the gas and vapor stream and carried out of the bed. If they are not sufﬁciently small to be entrained, the particles will continue to move around in the ﬂuidized bed, and will undergo attrition, until they are small enough to be entrained and d out of the bed. In the case of biomass feedstocks, the feedstock is prepared and introduced as '10 distinct, approximately-spherical, particles, up to, but not exceeding, the diameter of the catalyst particles in the bed. In the present invention, the rapid heating of the feedstock causes the feedstock to decompose, driving off phase products of l decomposition and leaving behind a solid product (referred to as char) which ses primarily carbon, but also includes any latile, nic material (ash) initially present in the feedstock.

Individual particles of solid residues remaining after decomposition generally contain both carbonaceous char and ash within a single coherent structure.

Since these particles of solid residue consist largely of carbon, and are physically softer than the catalysts that comprise the bed, they are more readily subject to abrasion, attrition, or grinding. They lubricate the catalyst particles as they move within the ﬂuidized bed, and are broken into smaller particles much more rapidly than the particles of catalyst.

This lubricating effect provides a signiﬁcant beneﬁt, since catalyst ﬁnes that are ground down to sizes small enough to be entrained in the stream of gas g the top of the bed will be carried out of the bed, and no longer be available to promote chemical reactions. The lubricating effect of char moving around in the ﬂuidized bed serves to reduce the rate of st attrition, and thereby reduce the need (and cost) for replacement catalyst needed to maintain the desired degree of chemical reactivity within the bed.- In one embodiment of the present invention, wherein solid particles of biomass comprise the feedstock, the feedstock undergoes very rapid l decomposition into product vapors and a relatively soft solid material composed of char and ash (char being the dominant portion). This residue is frequently referred to as char. This char is y ground .up (attritted) by particles of catalyst in the ﬂuidized-bed reactor, which are signiﬁcantly larger than the char particles, until the char is sufﬁciently reduced in size (and namic diameter) so that its terminal velocity is lower than the upward velocity of the ﬂuidizing gas W0 45123 and product vapors. At this point, the attritted char is ated and is d out of the bed while the relatively large and heavy catalyst particles remain behind in the bed. This effect can be promoted and accelerated if the solid particles in the biomass feed are signiﬁcantly smaller, in their largest dimension, than the catalyst particles in the ﬂuidized bed. Further, the ted particles of char in this embodiment of the present invention act as a scale lubricant, and reduce attrition of catalyst particles in the ﬂuidized bed. Thus, catalyst attrition is lower when biomass is hydropyrolyzed in the reactor than it would be if only the ﬂuidized catalyst particles were present; The rate at which feedstock is fed into the reactor depends upon the amount of catalyst and partial pressure of hydrogen within the reactor. The relationship between the rate at which feedstock is sent into the bed, and the amount of catalyst present in the bed, can be quantiﬁed in terms of a volume hourly space velocity . The VHSV can be calculated by dividing the volumetric ﬂow per hour of feedstock sent into the reactor by the bulk volume of the catalyst present in the bed, in the absence of any ﬂuidizing gas ﬂow. In the present invention, the hydropyrolysis r can be operated over a catalyst VHSV range of 1 hr'1 to 45 hr'l. The exact catalyst VHSV that is appropriate for a given combination of feedstock and catalyst depends on the nature of the feedstock and catalyst, and on the desired composition of the products that are to be obtained. The atmosphere in the r should consist y of en (though other inert gases, like CO2, may also be present), and the feedstock ﬂow rate cannot be so great that the vapor-phase products of feedstock decomposition dilute the hydrogen atmosphere to a point where the required partial pressure of hydrogen needed to carry out the desired set of reactions is no longer available.

The most important reactions that are'carried out in the hydropyrolysis reactor as described in the present invention involve deoxygenation of oxygenated hydrocarbon molecules. These ated hydrocarbon molecules contain oxygen that is initially present in the feedstock, and the oxygen is often present in the form of ﬁlnctional groups that make the ated hydrocarbons very chemically reactive. The hydropyrolysis reactor, of the present invention removes these oxygen atoms from the hydrocarbon molecules with which they are associated. Within the reactor, the oxygen can be converted either into water vapor (H2O) or the carbon-containing vapor-phase s carbon monoxide (CO) and carbon dioxide (CO2). If some of the oxygen from the feedstock is initially removed via a on that forms CO (decarboxylation), and some is initially removed in reactions that form H2O (hydrodeoxygenation), the CO and H20 molecules can react to form CO2 and H2. This latter - reaction is referred to as a water-gas shift reaction, and, since it tes an H2 molecule, it can be useful in reducing the amount of hydrogen that is sent into the reactor in the stream of ﬂuidizing gas. The relative amounts of C0, C02 and H20 that are present in vapors exiting from the top of the ﬂuidized bed in the reactor depends on the feedstock, operating conditions, and catalyst characteristics. The set of reactions that occur during deoxygenation of the feedstock e signiﬁcant net amounts of heat, since the heats of formation of C0, C02, and H20 are high enough to overcome the of heat required to effect heating and endothermic thermal decomposition of the feedstock, and the chemical decomposition of ated molecules in the process vapors. The surplus of heat generated via deoxygenation of the feedstock is at least sufﬁcient to heat the incoming feedstock up to the temperature of the ﬂuidized bed, and supply the heat consumed by any endothermic processes, including evaporation of liquid species, occurring during hydropyrolysis of the feedstock.

The product gases and vapors exiting the top of the ﬂuidized bed must have certain characteristics, in order for the process described in the present invention to be carried out sfully. First, they must consist largely of en. Second, small particles of solids (char and ash, as well as ted st) must be entrained within them. At steady-state, the mass ﬂow rate of entrained solids leaving the top of the ﬂuidized bed must equal the rate at which solid residue is ted by yrolysis of the feedstock in the ﬂuidized bed, plus the rate at which catalyst is being attritted to form ﬁnes small enough to be elutriated. Third, the vapors must contain the hydrocarbon species ed when the feedstock is hydropyrolyzed. Fourth, the molecules composing the hydrocarbon vapors must be sufﬁciently deoxygenated and chemically stabilized so that they do not react rapidly with other hydrocarbon molecules, or with solid surfaces with which they may come into contact.

Fifth, the total oxygen content, by mass, of condensable hydrocarbons in the product vapor stream must be 4% or less. The term condensable, in this case, indicates that the species in question have boiling points of 21 degrees Celsius (70 degees Fahrenheit) or lower, at atmospheric pressure, .or are highly soluble, and not subject to rapid vaporization, when dissolved in a liquid with a boiling point below 21 degrees Celsius (70 Fahrenheit).

The stream of product gases and vapors exiting the top of the ﬂuidized bed therefore contains hydrogen, water vapor, C0, C02, and entrained solid particles. It also ns hydrocarbon products of hydropyrolysis of the ock, including e, ethane, propane, butane, and a variety of other hydrocarbon les with atmospheric-pressure boiling points conforming to those of gasoline, kerosene, and diesel fuel. Some hydrocarbons, with oxygen in their molecular ure, and/or other heteroatoms such as nitrogen, sulfur and phosphorus, may also be present in the vapor stream leaving the ﬂuidized bed. Other of the vapors, such as H28 and ammonia may also be present, ing on the ition feedstock. However, the product vapors are sufﬁciently chemically stable that they can be effectively separated from the ned solid particles by ﬁltration, inertial, or electrostatic means, without plugging or otherwise impairing the separation devices through which they pass.

In the present invention, the product vapor stream emanating from the top of the ﬂuidized-bed reactor vessel 100, is kept hot enough to prevent condensation of any liquid product, and then conveyed to one or more particle separation devices 110, 120. In one red ment, inertial separation and ion are employed in series and occur ﬁrst in a, primary separation system 110 (e.g. a cyclone or virtual or), which removes larger particles consisting primarily of char and ash. The gases and vapors are then ed to a hot ion system 120 (for e, a porous barrier "ﬁlter that may or may not be enhanced with a magnetic separation step) which removes all remaining entrained solid particles, and may e a solid stream consisting primarily of catalyst ﬁnes from the ﬂuidized bed. However, any other effective means by which the char can be removed from the stream of hot process gases and vapor may be applied.

The product vapor stream can then be cooled in order to condense the water and condensable liquid hydrocarbon product, or the t vapor stream can be directed to another reactor for further processing. If the products of hydropyrolysis are cooled to condense liquid products, and transferred to an environment where the pressure is at or near ambient pressure, and the temperature is at or near 21 degrees Celsius (70 degrees Fahrenheit) two liquid phases are recovered. One phase ﬂoats on top of the other, and this 4% upper phase comprises hydrophobic hydrocarbons, and contains less than approximately by weight of oxygen. The lower phase comprises primarily water, as well as any water- e species produced by the process. The hydrocarbon. phase comprises primarily hydrocarbons with properties consistent with those of ne, kerosene, and diesel ﬁlel.

In accordance with one embodiment of this invention, the feedstock subjected to hydropyrolysis comprises primarily of a type of biomass, such as certain species of algae, - containing a signiﬁcant fraction of lipids. When subjected to hydropyrolysis, this type of feedstock will yield signiﬁcant quantities of deoxygenated diesel oil, which could otherwise be made from lipids extracted from the algae. In addition, hydropyrolysis of algae containing 2012/030386 a signiﬁcant fraction of lipids will also yield onal gasoline and diesel hydrocarbons 'which are produced as a result of hydropyrolysis of non-lipid fractions of the algae (cell walls, etc.). This is ularly attractive because lipid extraction from algae, via, for example, -based solvent-stripping, is expensive. It should also be noted that conventional fast pyrolysis of algae biomass Would be very unattractive because the uncontrolled thermal reactions that occur during fast pyrolysis would degrade the lipids in the algae feedstock. Thus, the process of the present invention is ideal for algae conversion because it can be carried out on algae feedstocks, which are usually only partially dewatered, and still produce high y diesel and gasoline arbons as a resulting product.

The process of this invention provides several distinct advantages over conventional fast-pyrolysis—based processes in that it produces a liquid hydrocarbon product that contains low or ible amounts of solid char, very little oxygen, is chemically stable, and is hydrophobic. Hot ﬁltration of solid char from the product vapor stream is generally not possible with yrolysis vapors, particularly when biomass is used as the feedstock.

However, hot ﬁltration ofsolid char is readily applied to biomass hydropyrolysis product vapor streams in accordance with the s of the present invention. In addition, fast pyrolysis of biomass feedstocks does not yield a stream of hydrophobic, deoxygenated liquid product, meaning that recovery of a useable liquid hydrocarbon fuel, from liquids produced via fast pyrolysis of biomass ts a signiﬁcant technical challenge. r, recovery of a useable stream of liquid hydrocarbon fuel from hydropyrolysis of biomass, via the process of the t invention, is straightforward, as described above.

Because the liquid hydrocarbon fuels produced in the process of the present invention possess an inherently low oxygen content, the water—based (aqueous) liquid product stream produced by this process remains relatively free of dissolved. hydrocarbons and will likely contain less than 5% by mass dissolved total c carbon (TOC). Due to this relatively low > TOC concentration, the stream of aqueous liquid product can be handled and disposed of with relativeease. The stream of aqueous liquid product will also contain a tration of dissolved ammonia that will depend on the amount of nitrogen initially present in the ock.

The hydropyrolysis process of the present invention produces primary streams of such as methane, ethane and propane, and . char, water, steam, hydrogen, hydrocarbon gases liquid hydrocarbon fuels. These can be integrated with other processes that produce s or fuels from related renewable feeds. In addition, secondary streams of nutrients can be obtained from the hydropyrolysis process of the present invention, which may be useful in promoting biomass growth. Ammonia is one such nutrient, which can be recovered from the process of the present invention, and can be used as a fertilizer, in order to promote biomass growth. Char obtained from the process can also be used as a soil amendment to improve the cultivation of crops such as corn and sugar cane. Biomass feedstocks amenable to production in a process integrated with the process of the present invention include, but are not limited to, algae, jatropha, corn stover, wood, bagasse, grass, miscanthus, and nuts (or nut ' husks and shells). Processes. producing high-value nutraceutical products, obtained from plants or other crops, can also be integrated with the process of the t invention. rmore, the embodiment of the hydropyrolysis process of the present invention that converts corn stover to liquid transportation fuel can be integrated into ties which produce l from corn. The water and steam produced by hydropyrolysis of corn stover could ﬁnd use in the tion of corn l, which typically requires both energy and water as inputs. Wastes from the corn ethanol production can likewise be utilized as feeds for the hydropyrolysis process.

The biomass hydropyrolysis process also can be integrated into a petroleum reﬁnery.

The char from the hydropyrolysis process can be burned to produce energy in reﬁnery furnaces y ng reﬁnery greenhouse gas emissions, since C02 emissions from renewable sources do not count as ouse gas emissions. The hydrocarbon liquids from the hydropyrolysis process can go directly to the reﬁnery hydrotreating units for further upgrading and are fully compatible. The C1—C3 hydrocarbon gases from the hydropyrolysis unit can go to the hydrogen plant to make the hydrogen required for the hydropyrolysis.

PREFERRED CATALYST TERISTICS In order for hydropyrolysis to be carried out ively in the ﬂuidized-bed reactor, as described in the process of the present invention, the catalyst ably includes several characteristics: 1. The particles of catalyst must be approximately-spherical, with particle diameters signiﬁcantly greater than the diameter of solid feedstock residues formed during hydropyrolysis. Catalyst particle densities of approximately 0.5 to 2 kilograms per liter are necessary, so that the catalyst will be effectively ed in the bed while char and other small particles (which have much lower particle densities and aerodynamic diameters than the catalyst) are elutriated from the bed. 2. The particles of catalyst must provide sufﬁcient catalytic activity to allow the hydropyrolysis process of the present invention, described above, to proceed under the conditions speciﬁed above. 3. The particles of catalyst must effectively ze the deoxygenation reactions of the process of the t invention, without catalyzing reactions that would form excessive amounts of solid carbonaceous residue (coke) on the catalytically-active es of the catalyst. 4. The particles of catalyst must be resistant to attrition, so that the amount of catalyst attritted per day, week, month, or year of operation is low enough to be easily replaced, without mising the economic ity of the process.

Generally, the use of spherical catalyst les (as opposed to other shapes) will produce the lowest rate of attrition.

As described above, the hydropyrolysis catalyst of the present invention is disposed within a ﬂuidized-bed reactor, and the bed of catalyst has an L/D ratio signiﬁcantly greater than 2. ng of the bed, during operation, is avoided via the use of an lugging insert or other anti-slugging modiﬁcation of the reactor (described in r detail below). The size of the catalyst le is determined by the smallest size to which solid particles in the feedstock stream can be reduced, without compromising the practicality or commercial viability of the process. Generally, if particles of a solid feedstock, such as s, are reduced below approximately 2800 s in a commercial operation, the cost of grinding and preparation of the feedstock can signiﬁcantly rise. In order for the solid residue produced from solid particles of feedstock that are approximately 2800 microns in diameter, to rise easily through the bed, and eventually be elutriated from the bed, without a concomitant loss of catalyst, a particle size of 3200 microns or more is generally speciﬁed for the catalysts in accordance with the process of the present invention. In cases where smaller feedstock particles can be applied in practice, the catalyst particle size may then be reduced, providing that the catalyst particles remain large enough to be effectively ed in the ed bed while the solid residues of hydropyrolysis are elutriated.

The process requires an active catalyst that ively deoxygenates and chemically stabilizes the hydropyrolysis vapors, but that is not so catalytically active that it rapidly cokes. The catalyst in the ﬂuidized bed of the present invention can be any highly active deoxygenation catalyst which reduces the collective oxygen content of produced hydrocarbon 2012/030386 vapors with more than four carbons in their molecular structure (C4+ hydrocarbons) to less than 4% oxygen. Preferably, the catalyst in the ed bed must meet the requirements outlined above, and carry out the requisite reactions at a VHSV of greater than 1 hr'l. A . variety of catalysts may be employed in the ed hydropyrolysis bed of the present invention; r, catalysts generally in accordance with preferred ments of this invention are as follows: In one preferred embodiment, the catalyst comprises spherical particles of porous alumina or some other appropriate support, which have been impregnated with catalytic al consisting .of Nickel and Molybdenum (NiMo) or Cobalt and Molybdenum (COMO), and have then been sulﬁded. Catalysts comprising sulﬁded NiMo or CoMo on a porous alumina support material have been shown to be good sts for hydropyrolysis and exhibit good enation activity in experimental testing. As described above, spherical catalyst les are required in ﬂuidized beds to minimize attrition. If catalysts are not spherical they will quickly attrit, and excess-catalyst losses will occur that can threaten the - economic viability of the process.

In another embodiment of the process of the present invention, the catalyst comprises cal particles of porous alumina or some other appropriate support impregnated with nickel, or cobalt, or iron, or other metals which can be used for hydrotreating. Any metal or combination of metals, impregnated into an appropriate t, which is appropriate for use in hydrotreating, can also be used as a hydropyrolysis catalyst in the process of the present invention, as long as the resulting material displays sufﬁcient catalytic activity to reduce the collective oxygen content of the C4+ arbon vapors present in the hydropyrolysis product stream to less than 4% by mass, while releasing enough exothermic heat of reaction to maintain a stable ﬂuidized bed temperature in the hydropyrolysis reactor.

In one preferred embodiment of the present invention, the feedstock comprises solid biomass particles comprising a bulk density of approximately 0.2 to 0.4 kilograms per liter, and the catalyst particles comprise a bulk density of approximately 0.7 to 1.2 kilograms per liter. The difference in the bulk density of the ock and catalyst in this embodiment s that the solid residue (char) of biomass hydropyrolysis is rapidly conveyed through the ﬂuidized bed and elutriated.

PREFERRED INSERT CHARACTERISTICS As discussed above, the ﬂuidized bed of catalyst particles of the present invention is deep. enough that it is prone to ng. In order to ensure that slugging does not occur, an anti-slugging insert or other anti-slugging modiﬁcation of the reactor vessel is employed.

There are severalstrategies that can be employed to mitigate slugging in ﬂuidized beds, that do not involve the insertion of obstructions, obstacles, or constrictions into the bed. However, these cannot be usefully d in the case of the present invention. Two of these other anti- slugging strategies are: l. ed Bed. Inclining the reactor has been shown to ate ng, and to increase axial mixing in a ﬂuidized bed under certain conditions. However, the radial distribution and velocity of the gas ﬂow increases in non-uniformity as the angle of inclination is increased. This creates a condition wherein the majority of ﬂuidizing gas and process vapors can bypass the catalyst in the bed, and the d hydropyrolysis reactions cannot be carried out. 2. d nical Bed. It is also possible to build a conical reactor vessel, one which is wider at the top than at the bottom. This arrangement is often ed to as a spouted bed. The slope of the reactor wall, in this case, can interrupt the formation and propagation of a slug to some extent. r, it is much more difﬁcult to manufacture a conical reactor vessel than it is to manufacture a reactor vessel with straight, vertical sides. Moreover, the velocity of ﬂuidizing gas in the reactor is much higher near the bottom of a conical reactor, where the cross-sectional area of the cone is smallest, than near the top. This effect generally creates a space near the base of the cone where there is no bed material at all, because the velocity of the ﬂuidizing gas is so high that the bed material is lifted out of this space. The high ﬂuidizing gas velocity in this region can also create ive catalyst attrition.

Inserts and Vessel Modifications Featuring Lateral Obstacles or Obstructions Because inclined and conical beds do not provide a practical means by which slugging can be controlled in the hydropyrolysis s of the present invention, a different approach is employed. According to a preferred embodiment of the present invention, one or more s 130, such as that shown schematically in Fig. 1, are included and/or installed in 2012/030386 the ﬂuidized-bed reactor 100, preventing the formation of slugs, and enabling rapid, uniform axial and radial mixing in deep beds. In the present invention, this approach is applied in a hydropyrolysis reactor, where unusually deep ﬂuidized beds 140, composed of large particles, are employed.

Figure 2 shows a reactor having a vessel wall 230 deﬁning a ﬂuidized bed 240 into which feedstock particles 260 are fed along with a ﬂuidizing gas stream 250. Process vapors 220 are schematically shown leaving the ﬂuidized bed 240. In one embodiment of the present invention, slugging is minimized or prevented via the installation of lateral obstructions 200 installed on a central support rod, as shown in Figure 2A. The obstructions 200 extend at least part of the way from the centerline of the reactor to the reactor wall 230, on at least one side of the center line. In a preferred embodiment, the obstructions extend all the way across the reactor, and, at their longest point, have a length that is equal to the reactor diameter, D. The width of the obstruction, W, is such that“ the obstruction covers approximately 40% of the cross-sectional area of the reactor; The obstructions 200 are installed at r axial intervals, H, equivalent in length to approximately one to two diameters of the bed. The orientations (shown in Figure 2B as l, 2, 3) of the obstructions 200 are ed so that the axis of each obstruction is separated by 60 degrees of rotation from the axis of the obstructions above and below it, as shown in the wn view in Figure 2B.

This ement ensures that a coherent slug of bed particles, ing the full diameter of the reactor, cannot form, and cannot propagate along the axis of the reactor. In order to prevent slugging throughout the entire bed, the obstructions should be installed in such a way that they extend along the full height of the ﬂuidized bed, L, once the bed is fully ﬂuidized.

The top of the ed bed should extend less than one r diameter, D, past the top of the uppermost ction.

In other embodiments of the present invention, a wide range of obstruction geometries can be applied to disrupt the formation of slugs in the bed, including rectangular tabs, obstructions with triangular cross sections, obstructions with d-shaped cross-sections, obstructions with oval cross-sections, gratings, etc. Open areas in the obstructions, or open areas of the reactor cross section, are ably not aligned with each other, and should overlap as little as possible, when seen from above.

Dead spots in the ﬂuidized bed 240 may form on the upper e of obstructions 200, if the obstructions are not ed correctly. In a dead spot, solid particles come to rest on the upper surface of the obstruction, and do not move around in the ﬂuidized bed. In order WO 45123 2012/030386 to prevent this effect, the upper surface of the obstructions should be sloped, peaked, or rounded, so that bed material cannot rest on the top surface of the obstruction.

Another approach to suppress the formation of dead spots is to employ a porous insert or insert that employs a porous upper portion so that hydrogen, for example, can be made ﬂow through the central support 210 and be conveyed-to the porous or partially porous slug- ng cylindrical obstructions deployed along the length of the central support 210.

In some cases, it may be advantageous to allow limited ng, or cyclical expansions of the ﬂuidized bed 240 that do not fully meet the deﬁnition of slugging, in the ost part of the bed. This may be necessary in order to more effectively grind up large particles of solid hydropyrolysis residue into smaller sizes that can be elutriated from the bed 240. If this effect is desired, a portion at the top of the expanded bed 240 can remain unobstructed, in which case, this n of the bed will tend to slug (if it s for a sufﬁcient distance) or may begin to oscillate up and down in a periodic manner, without displaying the coherent bed motion that is characteristic of slugging.

The type of obstruction 200 shown in Figure 2 can be used to prevent slugging in beds with very large length to depth (L/D) ratios, e a slug tends to require an unobstructed path of axial travel equal to approximately 1 to 2 bed diameters to form, and the installation of these obstructions interrupts the slug just as it would begin to become coherent. Since the obstructions are placed at intervals of approximately one to two diameters, D, there is no section of the ﬂuidized bed 240 within which a coherent slug can form.

The action of the bed 240 will tend to abrade the material of the obstructions 200, and limit the useful lifetime of the ctions 200. In one embodiment, which can be may employed in situations where this is a concern, the insert may be constructed in such a way that it is easily removed and replaced.

In another embodiment, the obstructions and central support of the insert can be made to be highly abrasion-resistant, by, for example, making them from a ceramic or glass- ceramic material or from a ceramic-coated material. A combination of materials could also be used, where, for example, those ents likely to see the most wear are made of an extremely hard material, and other components, such as the central support rod 210, are made of metal.

In another embodiment, the surfaces of the insert and the vessel walls 230 can be ‘ formulated so that they are also catalytically active, and contribute to the tic activity needed to complete the process chemistry in the reactor.

In another embodiment, the lateral ctions 200 are equipped with means by which they can be heated or , and/or are equipped with instrumentation allowing the local temperature of the ﬂuidized bed 240 to be measured and/or regulated.

In r embodiment, the lateral obstructions 200 are not attached to a central support, but are ed to, or installed directly upon, the reactor vessel wall 230. If this embodiment is applied, the obstructions cannot be easily removed from the reactor, and replaced, as part of a single coherent insert. However, this embodiment allows access to the interior of each obstruction, through the location at the vessel wall where the obstruction is ed. Means of heat transfer, instrumentation, and/or steam generation can then be applied within each obstruction 200, through the locations where the obstructions 200 are attached to the vessel wall 230.

Inserts and Vessel Modiﬁcations Featuring Constrictions Constrictions 300 of the bed diameter, such as those shown schematically in Figure 3, can have the same slug-breaking effect created by lateral obstacles or obstructions 200.

According to this embodiment of the present invention, one or more inserts 130, such as that shown schematically in Figure 1, are included and/or installed in the ﬂuidized—bed r 100, preventing the formation of slugs, and enabling rapid, uniform axial and radial mixing in deep beds. As bed above, this approach is applied in a hydropyrolysis reactor, where lly deep ﬂuidized beds 140, composed of large les, are employed.

Figure 3 shows a reactor having a vessel wall 330 deﬁning a ﬂuidized bed 340 into which feedstock particles 360 are fed along with a ﬂuidizing gas stream 350. Process vapors 320 are tically shown leaving the ed bed 340. In one embodiment of the present invention, slugging is minimized or prevented via the lation of constrictions of the reactor cross-section, 300 installed on a circumferential support, as shown in Figure 3.

The cross-sectional area, A, of the. constriction 300 is such that the constriction covers imately 40% of the cross-sectional area of the reactor. The constrictions 300 are installed at r axial intervals, H, equivalent in length to approximately 'one to 'two diameters of the bed. The orientation of the constrictions 300 is adjusted so that the centerline of the open area of each constriction is separated by 120 degrees of rotation from the centerline of the open area of the constrictions above and below it, as shown in the top-down view in Figure 3B. This arrangement ensures that a coherent slug of bed particles, occupying the full diameter of the reactor, cannot form, and cannot propagate along the axis of the reactor. In order to prevent slugging throughout the entire bed, the constrictions should be installed in such a way that they extend along the full height of the ﬂuidized bed, L, once the bed is fully ﬂuidized. The top of the ﬂuidized bed should extend less than one reactor diameter, D, past the top of the uppermost constriction.

In other embodiments of the present invention, a wide range of constriction geometries can be d to disrupt the formation of slugs in the bed, including constrictions with multiple openings, rounded contours, irregular contours, etc. Open areas in the constrictions, oropen areas of the reactor cross n not blocked by the constrictions, are preferably not d with each other, and should overlap as little as possible, when seen from above.

As is the case when obstructions or obstacles are installed in the bed, dead spots in the ﬂuidized bed 340 may form on the upper surface of constrictions 300, if the constrictions are not designed correctly. In order to prevent this effect, the upper surface of the constriction should be sloped, peaked, or rounded, so that bed material cannot rest on the top surface of the obstruction.

Another approach to suppress the formation of dead spots is to employ a porous constriction or constriction that s a porous upper portion so that hydrogen, for example, can be made to ﬂow through tubes ed along the ferential support 310 and be ed to the porous or partially porous slug-breaking cylindrical obstructions deployed along the length of the central support 310.

In some cases, it may be advantageous to allow d slugging, or cyclical expansions of the ﬂuidized bed 340 that do not ﬁJlly meet the deﬁnition of slugging, in the uppermost part of the bed. This may be necessary in order to more ively grind up large particles of solid hydropyrolysis residue into smaller sizes that can be elutriated from the bed 340. If this effect is desired, a portion at the top of the expanded bed 340 can remain unobstructed, in which case, this section of the bed will tend to slug (if it extends for a sufﬁcient distance) or may begin to oscillate up and down in a periodic manner, without displaying the coherent bed motion that is characteristic of ng.

The type of constriction 300 shown in Figure 3 can be used to prevent slugging in beds with very large length to depth (L/D) ratios, because .a slug tends to e an unobstructed path of axial travel equal to approximately 1 to 2 bed diameters to form, and the installation of these constrictions interrupts the slug just as it would begin to become coherent. Since the constrictions are placed at intervals of approximately one to two 2012/030386 diameters, D, there is no section of the ﬂuidized bed 340 within which a coherent slug can form.

The action of the bed 340 will tend to abrade the material of the constrictions 300, and may limit the useful lifetime of the constrictions 300. In one embodiment, which can be employed in ions where this is a concern, the insert may be constructed in such a way that it is easily removed and replaced.

In another embodiment, the constrictions and circumferential support of the insert can be made to be highly abrasion-resistant, by, for example, making them from a ceramic or glass-ceramic material, or from a ceramic-coated material. A combination of materials could also be used, where, for example, those components likely to see the most wear are made of an extremely hard material, and other components are made of metal.

In another embodiment, the surfaces of the insert and the vessel walls 330 can be formulated so that they are also catalytically active, and contribute to the catalytic ty needed to complete the process chemistry in the reactor.

In another ment, the constrictions are equipped with means by which they can be heated or cooled, and/or are equipped with mentation allowing the local temperature of the ﬂuidized bed 340 to be measured and/or regulated.

In another embodiment, theconstrictions 300 are not attached to a removable support, but are. attached to, or led directly upon, the reactor vessel wall 330. If this embodiment is applied, the constrictions cannot be easily removed from the reactor, and replaced, as part of a single coherent insert. However, this embodiment allows access to the interior of each iction, through the location at the vessel wall where the iction is attached. Means of heat transfer, mentation, and/or steam generation can then be applied within each constriction 300, through the locations where the constrictions 300 are attached to the vessel wall 330. l ation on lugging Obstructions and Constrictions Each type of slug-breaking obstacle can be installed either on a central support, extending along the axis of the reactor, or on a circumferential support, extending around the exterior of the reactor. There is no requirement that a particular type of slug-breaking feature be installed on a particular type of support in‘order for it to be effective.

The vertical cross-section of a slug—breaking feature may be contoured to remove or accentuate sharp . More rounded contours will be more esistant, while more sharp-edged contours may break slugs more ively.

In ﬂuidized-bed reactors that are lined with a molded or cast tory material, the refractory can be molded or cast in such a way that the slug-breaking features are integral to the reactor lining. ations of obstructions and constrictions of different shapes, or alternating obstructions (attached to a central support) and constrictions (projecting into the bed from the circumference of the reactor) may provide optimal bed motion.

Obstructions and constrictions need not be installed horizontally across the r and can be installed at some angle other than 90 degrees relative to the central axis of the bed.

Obstructions can be circular or rounded in cross section, when seen from the top of the reactor.

If desired, obstructions can project from a l support on only one side of the centerline of the reactor, extending outward toward the wall of the reactor. As long as obstructions of this type are properly arranged, the formation of slugs may be effectively disrupted.

In general, the obstructions or ictions at each location in the reactor should create a pressure drop equal to about 10-20% of the total pressure drop that the entire ed bed would create if there were no obstructions or constrictions present.

Finally, obstructions or ictions deployed within the ﬂuidized bed can incorporate heat exchangers so that they can perform the dualfunction of mitigating slug formation and managing bed ature increases associated with the exothermic nature of the present invention. These heat exchangers can be used to create process steam (e.g. converting liquid water to steam) or to use liquids to reﬁne temperature distributions within the bed that may be caused by deploying catalysts of differing activity that will stratify and segregate into distinct layers within the bed by choice of density, aerodynamic diameter, or both.

EXAMPLES zed Bed Mixing Studies without Insert Experiments were d out in order to study slugging in bubbling ﬂuidized beds, consisting of relatively large, spherical solid particles similar to the catalyst used in the hydropyrolysis process of the present invention. The bed material consisted of porous alumina spheres, with a mean diameter of 1800 microns. The diameters of the particles of bed material were all within plus or minus 200 microns of the mean diameter. The bulk density of the bed material was 0.75 kilograms per liter.

Fluidized beds expand as ﬂuidizing gas is passed h them, so they are most readily compared on an unexpanded basis. In this case, the unexpanded depth of the bed is the depth of the bed when no ﬂuidizing gas is passing through it.

Beds with an unexpanded L/D near 6 were studied in two clear plastic tubes. One tube had an inner diameter of 3.33 centimeters, and the other had an inner diameter of 7.62 eters. The smaller tube had a grid at its base for distribution of ﬂuidizing gas. The tube with the larger diameter had an inverted conical base, with a 90 degree included angle in the described cone, and a central gas jet at the apex of the cone. Beds of the alumina spheres above, were found to require a characteristic minimum fluidization velocity (Uf) of approximately 0.61 meters/second to 0.76 meters per second. The minimum ﬂuidization ty, Uf, is the velocity at which the pressure drop across the bed ceases to rise with sing superﬁcial gas velocity through the bed, but at which no motion is observed in the bed. Once the ﬂow of gas through the bed in each clear plastic tube was raised above Uf, the bed expanded until its volume d approximately 1.5 times the unexpanded volume, and then bulk motion began. Slugging in both tubes was observed when the unexpanded L/D was 6 and bulk motion ed in the bed.

Slugging in both tubes could only be avoided if the nded L/D ratio of the bed was less than 1.5. The phenomena affecting bulk motion in the bed did not appear to be inﬂuenced either by the er of the tube in which each test was carried out, or by the in the very different ﬂow distribution methods associated with each tube (the sparging grid case of the tube with the r diameter, and the spouted base in the case of the tube with the larger diameter). The tendency of the bed to slug was therefore found to occur whenever the bed of porous alumina spheres had an unexpanded L/D greater than 1.5, and the phenomena responsible for the onset and propagation of slugging were not found to be sensitive to the diameter of the test apparatus, or the means used to introduce the ﬂuidizing gas into the bottom of the bed.

Fluidized Bed Mixing s with Insert Further studies were d out in the larger plastic tube, in order to examine the effect on slugging of introducing lateral obstructions, attached to an insert. The insert consisted of a metal rod, located at the centerline of the tube, with various obstructions and obstacles installed on it in order to break up the nt slug of alumina spheres.

Near the bottom of the tube, three steel washers were installed at intervals of 7.62 centimeters. The lowest of these .washers was installed at an ion of 7.62 centimeters (or one tube diameter, D) above the bottom of the tube. The diameter of each washer was about 2.54 centimeters, meaning that the washer obstructed about 10% of the sectional area of the tube. The circular obstructions (washers) increased the gas ty as the gas passed around the obstruction, visibly interrupting the formation and propagation of slugs in the bed.

However, it was observed during initial trials that the bed above the last washer displayed a nced tendency to slug, and the addition of further washers above this level had little to no effect on the slugging; Circular obstacles around the centerline were therefore found to provide little beneﬁt at unexpanded bed depths greater than L/D = 2 (with the ed bed, after ﬂuidization occupying a depth with an L/D ratio of approximately 3).

During this work it was noted that the integrity of the slug was important in the development of slugging. Within the slug, either the entire bed has to move as a single body, or the slug begins to collapse immediately. In order to make the slug collapse, and eliminate the problem of ng, rectangular tabs were cut and drilled so they could be installed on the same metal rod. The outer edge of each tab was rounded so as to conform to the interior wall of the tube. Three tabs were prepared with a width of 2.54 centimeters and a length of 3.18 centimeters. Each tab obstructed approximately 20% of the cross-sectional area of the tube, and reached from the central rod to the reactor wall, meaning that the ing gas had to accelerate as it passed each tab, and the bed particles in the slug had to rearrange themselves in order to pass around this obstacle. The tabs were installed at axial intervals of 7.62 centimeters, with the lowest tab located 7.62 eters above the base of the tube.

When a slug of bed material began to form and encountered the obstruction created by the tabs, the obstruction created enough motion within the slug that the slug's cohesion was disrupted. Open gas passages formed around the tab, and particles d out of the slug _ and down toward lower levels ofthe bed.

Two arrangements of tabs were examined: In one, the tabs were placed on alternating sides of the reactor with the orientation of each tab separated from that of the next in line by 180 degrees; in the other, they were arranged so that each tab was oriented 120 degrees from the tab above and below.

A systematic effort was then made to study slugging in the clear plastic tube with the ' internal diameter of 7.62 centimeters, using beds of alumina s with an nded L/D of 3, and a superﬁcial ﬂuidizing gas velocity of 0.91 meters per second. A population of s in the general bed, with diameters slightly less than 1700 microns, was identiﬁed, separated by sieving, and dyed red. The rest of the bed was white. The red spheres could be mixed into the bed, and readily recovered. The motion and distribution of red spheres in the bed provided a means by which mixing and particle distribution in the bed could be ed directly, and quantiﬁed.

A protocol to examine the rate of mixing was ped, which involved depositing a layer of red spheres on top of the white spheres in the bed, and then starting a stopwatch at the same time that the ﬂuidizing gas ﬂow was sent through the bed. When red balls ﬁrst became visible at the very bottom of the bed, the stopwatch was stopped, and this was then referred to as the characteristic mixing time ed for the bed, under a given set of experimental conditions.

The characteristic mixing time of the bed, in the absence of any slug-breaking insert, was found to be: seconds. Slugging was observed to occur.

The insert conﬁgurations described above (tabs separated by 180 s and tabs separated by 120 degrees) were then tested.

The characteristic mixing time obtained with tabs arranged at 180 degrees was found to be: .3 seconds. Slugging was not observed to occur. .

The characteristic mixing time obtained with tabs arranged at 120 degrees was found to be: .0 seconds. ng was served to occur.

Slugging was not observed when either insert was employed within the 7.62 centimeter clear plastic tube. The mixing times obtained with the inserts were both shorter than the shortest mixing time observed when the reactor had no insert. The 120 degree tab- separation angle ement is particularly effective, since the ﬂowing gas can never ﬁnd a single clear, ructed route to the top of the bed, and has to change its path each time it encounters a tab. While some cyclical bubble formation was still observed, the bubbles could not occupy the entire tube diameter, and could not travel up the entire length of the bed.

Mechanisms that would have caused the bed to slug were thereby defeated.

Finally, a deeper bed, with an unexpanded L/D of 5.5, was tested. When expanded, this bed had an L/D of approximately 7.5.

With the gree-tab-separation-angle insert in the bed, the deeper L[D = 5.5 bed was found to mix rapidly and uniformly. However, a portion of the expanded bed extended above the uppermost tab, and slugging occurred in this uppermost portion of the bed. This result indicates that tabs need to be positioned at axial intervals of approximately 1 to 2 bed diameters, throughout the entire expanded depth of the ng ﬂuidized bed, in order to prevent slugging from occurring. If this methodology is followed, it appears that in the absence of other limitations there is no upper limit to the depth of the bed; one could accommodate as many tabs as necessary in order to create a bed with'any desired depth, and no ng would occur at any point in the bed.

The examples bed above were conducted with obstructions (washers, tabs) located at axial intervals of one tube er. ctions installed at intervals that are larger or smaller than this will also break slugs. An l ement and spacing of obstructions exists for any given bed. Axial spacings greater than 2 diameters, however, are not likely to yield optimal longitudinal mixing, as a coherent slug may be able to form between obstructions if the obstructions are too far apart. Likewise, spacings that are too tight (obstructions too close together) will slow the return of bed material to the bottom of the reactor, increase the mixing time, and introduce non-uniformities into the» axial temperature proﬁle of the bed.

The upper, rectangular obstructions (tabs) that were tested in the apparatus above obstructed about 20% of the open area of the bed. These obstructions need not be rectangular; a wide variety of other shapes could be considered (triangular, oval, diamond, etc). cantly, based on the tests described above that were carried out with a bed of unexpanded L/D =5.5, it appears that a bed of essentially unlimited depth could be ﬂuidized, without slugging, while maintaining rapid longitudinal mixing, if properly oriented obstructions or constrictions are placed at riate intervals along the axis of the bed. If 2012/030386 the entire bed were enclosed in an isothermal environment (such as a long, multi-zone furnace, in which each zone is maintained at the same temperature) the entire bed would stay at ially the same temperature. Alternatively, in a very long, deep bed (very large L/D ratio) axial variations in bed temperature could be induced by ng the local ature around the reactor, since the rate of heat exchange along the axis of the bed is ﬁnite.

Experimental Process Demonstration The table below compares experimental results obtained during trations of the of the art of pyrolysis process of the present invention with processes representing the state and hydropyrolysis. As is clear from the table, the process of the t invention differs signiﬁcantly from the state of the art, and employs a much lower partial pressure of hydrogen to remove much more oxygen from the ﬁnished liquid hydrocarbon product. Results from two experimental demonstrations of the process of the present invention are presented. These are referred to as Case 1 and Case 2. The same feedstock (wood) was used in both cases. The experiments in both cases were carried out at the same hydrogen partial pressure of 325 psig (23 bar absolute). Catalyst particles consisting of a nickel-impregnated porous alumina material were used in Case 1 yst A). Catalyst particles consisting of a porous alumina support, nated with a sulﬁded cobalt-molybdenum material were used in Case 2 yst B). The ﬂuidized bed in Case 1 was kept at a slightly different temperature than in Case 2.

Further ation is presented in Figure 4 which presents a graph that relates oxygen content in liquid hydrocarbon products to the partial pressure of hydrogen used during processing. As is clear from the plot, processes described by the present state of the art are able to produce hydrocarbon products with low oxygen content only if very high partial of 325 pressures of hydrogen are utilized during processing. The hydrogen partial pressure psig (23 bar absolute) applied during processing of biomass in Cases 1, and 2 would be expected to yield a liquid product containing approximately 22% , by mass. Instead, the process of the present invention, as demonstrated in Cases 1, and 2, produced cant yields of liquid arbon products with oxygen contents lower than 4% by mass.

While in the foregoing speciﬁcation this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to WO 45123 2012/030386 additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

Process Mohan, Rocha, et al. Rocha, et a1. Present Present Characteristic et al. (1) (4) (4) Invention Invention Case 1 Case 2 3/9/11 2/25/10 Feedstock stems Process Fast Hydro- Hydro— Hydro- Hydro- Hydro- Hydro- Pyrolysi sis pyrolysis pyrolysis pyrolysis pyrolysis pyrolysis Fluidized Bed Y 5 Yes . .

Used - (bar absolute) - ~ Catalyst F Catalyst A Catalyst B Solvent Y N Heatin_ DegreesC - Residence s 1.25 hours 55min Seconds Seconds Seconds Seconds Liquid 0% 0% 0% 0% 0% 24% 26% hydrocarbon yield with less than 4% ox en % oxygen in ~38 7.6 9.7 11.5 22 2.6 0.68% liquid product Sources: 1. Mohan, Pittman, and Steele, “Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review,” in Energy & fuels, Volume 20, pp. 848-889, 2006 2. Meier, Jakobi and Faix, “Catalytic Hydroliquefaction of Spruce Wood,” in l of Wood Chemistry and logy, Vol. 8, No. 4, pp. 523-542, 1988 3. Meier and Faix, “Solvent-Free Hydroliquefaction of of Pine Wood and Miscanthus Stems,” in Proceedings of the International Conference on Biomass for Energy and Industry, Lisbon, Portugal, October 9—13, 1989 4. Rocha, Luengo, and Snape, “The Scope for Generating Bio-Oils with Relatively Low Oxygen ts via Hydropyrolysis,” in Organic Geochemistry, Vol. 30, pp. 1527— 1534, 1999 —

Claims

We claim:

1. A method of hydropyrolysis sing: a. introducing an oxygenated organic ock into a fluidized bed reactor, wherein said feedstock is rapidly heated from ambient temperature to the temperature of the fluidized bed, and is thereby devolatilized; b. introducing a stream of fluidizing gas comprising mostly molecular hydrogen into the fluidized bed reactor, creating conditions under which rapid mixing and heat transfer occur throughout the zed bed; c. maintaining a deep bed of solid particles of catalyst, the depth of which is significantly greater than2 reactor diameters, in a state of us motion, to promote reactions resulting in deoxygenation and chemical stabilization of vapors produced when the feedstock is devolatilized; d. removing solid residues, remaining after devolatilization and hydropyrolysis of the feedstock, from the fluidized bed r via nment in the stream of fluidizing gas and t vapors exiting the fluidized bed reactor; e. removing attritted residues of catalyst, but not intact particles of catalyst, or particles of catalyst that have been minimally attritted, from the fluidized bed reactor via nment in the stream of fluidizing gas and product vapors exiting the fluidized bed reactor; f. separating the solid residues, entrained in the stream of fluidizing gas and product vapors exiting the fluidized bed reactor, from the stream of fluidizing gas and product vapors exiting the fluidized bed reactor; g. recovering a product stream of hydrocarbon vapors comprising hydrocarbon species with atmospheric-pressure boiling points, consistent with those of at least one of ne, kerosene and diesel fuel, from the hydropyrolysis process as condensed liquid; h. releasing enough rmic heat from the deoxygenation reactions occurring during hydropyrolysis of the feedstock to supply process heat required by ermic 10720680 processes occurring during hydropyrolysis of the ock, including chemical reactions, heating of feedstock, and evaporation of liquids; and i. dispersing one or more modifications to an interior of the r vessel in such a manner that slugging does not occur within the fluidized bed reactor.

2. The method of claim 1 wherein the fluidized-bed r is maintained at a partial pressure of en of about 13.8 barg to about 41.4 barg.

3. The method of claim 1 or 2 wherein the recovered stream of condensed liquid contains less than 4% by mass of oxygen.

4. The method of any one of claims 1 to 3 wherein the temperature of the fluidized bed reactor is between approximately 343 degrees Celsius (650 s Fahrenheit) and approximately 593 degrees Celsius (1100 degrees Fahrenheit).

5. The method of any one of claims 1 to 4 wherein the relationship between a volumetric feed rate of solid ock les and a volume of the fluidized bed reactor is such that the Volume Hourly Space Velocity (VHSV) of the reactor is between approximately 1 and approximately 40.

6. The method of any one of claims 1 to 5 wherein a density of particles of catalyst is in the range of approximately 0.5 kilograms per liter to 2 kilograms per liter.

7. The method of any one of claims 1 to 6 n the feedstock is prepared in such a way that solid residues, remaining after hydropyrolysis of the feedstock, are substantially smaller, in their largest dimension, than the solid catalyst particles that form the zed bed.

8. The method of any one of claims 1 to 7 wherein the feedstock contains no water.

9. The method of any one of claims 1 to 7 wherein the feedstock is only partly dewatered, and contains some water.

10. The method of any one of claims 1 to 9 wherein the feedstock comprises particles of solid biomass. 10720680

11. The method of any one of claims 1 to 10 wherein the feedstock comprises solid particles of an oxygenated polymer.

12. The method of any one of claims 1 to 11 wherein the feedstock comprises a wholly or partially dewatered biomass feedstock that is high in lipid content.

13. The method of any one of claims 1 to 12 wherein the feedstock comprises organic material of an aquatic .

14. The method of any one of claims 1 to 13 wherein the feedstock comprises materials manufactured or otherwise obtained from biomass.

15. The method of any one of claims 1 to 14 wherein the feedstock comprises organic material of animal origin.

16. The method of any one of claims 1 to 15 wherein the feedstock comprises waste organic al of animal origin.

17. The method of any one of claims 1 to 16 wherein the feedstock is introduced to the reactor as a stream comprising solid particles entrained in a rapidly-moving transport gas stream, and wherein the transport of ock into the fluidized bed is accomplished ily via the action of the ort gas on solid particles of feedstock.

18. The method of any one of claims 1 to 17 wherein the feedstock comprises a slurry of solid les, suspended in a carrier liquid that evaporates when it is introduced into the reactor.

19. The method of any one of claims 1 to 18 wherein the feedstock comprises an oxygenated organic , which oes hydropyrolysis in the hydropyrolysis process.

20. The method of any one of claims 1 to 19 wherein a icial velocity of fluidizing gas passing through the fluidized bed reactor, is sufficient to create a state consistent with that of a bubbling fluidized bed. 10720680

21. The method of any one of claims 1 to 20 wherein a superficial velocity of fluidizing gas passing through the fluidized bed reactor is no higher than the minimum needed to create a state consistent with that of a bubbling fluidized bed.

22. The method of any one of claims 1 to 21 wherein the solid particles of catalyst are spherical.

23. The method of any one of claims 1 to 22 wherein the solid particles of catalyst are ionresistant.

24. The method of any one of claims 1 to 23 wherein the solid particles of catalyst are porous and include a large internal surface area within the outer surface of the particle.

25. The method of any one of claims 1 to 24 wherein the solid les of catalyst have properties consistent with those of a highly active reating catalyst.

26. The method of any one of claims 1 to 25 wherein the solid particles of catalyst comprise an alumina-based substrate, impregnated with a sulfided nickel-molybdenum catalyst or sulfided cobalt-molybdenum catalyst.

27. The method of any one of claims 1 to 26 n the solid particles of catalyst comprise an a-based substrate, impregnated with a metal active for hydrotreating.

28. The method of any one of claims 1 to 27 wherein the solid particles of catalyst comprise an aluminiosilicate-based substrate, impregnated with a metal active for hydrotreating.

29. The method of any one of claims 1 to 28 wherein the solid particles of st comprise a ceramic-based substrate, impregnated with a metal active for hydrotreating.

30. The method of any one of claims 1 to 29 wherein the solid particles of catalyst comprise two or more catalysts which differ by at least one of density, aerodynamic size and aerodynamic diameter but are otherwise physically similar, and are disposed hout the fluidized bubbling bed and by virtue of having different properties tend to segregate and stratify, becoming vertically ordered by property so as to create regions within the bed that differ in tic activity. 10720680

31. The method of any one of claims 1 to 30 wherein a mean diameter of catalyst particles is greater than approximately 3200 microns (3.2 millimeters).

32. The method of any one of claims 1 to 31 further sing ting metallic catalyst fines from char, the separation effected with a r filter that incorporates a remotely energized and de-energized magnetic field to retain magnetic catalyst particles until they can be discharged by backpulsing when the magnetic field is de-energized.

33. The method of claim 32 wherein char can be separated from the product stream and removed by backpulsing while the magnetic field remains zed and ic material is retained on a filtering surface of the barrier .

34. The method of any one of claims 1 to 33 further comprising separating metallic catalyst fines from char, wherein the separation is effected by a virtual impactor that diverts a stream of heavier catalyst fines to a downstream collection stage.

35. The method of claim 34 wherein the downstream collection stage is a barrier filter that can be cleaned by periodic backpulsing.

36. The method of claim 34 or 35 wherein the downstream collection stage is a barrier filter that incorporates a remotely energized magnetic field to retain magnetic catalyst particles until they can be discharged when the magnetic field is deenergized and the filter is cleaned by backpulsing.

37. The method of any one of claims 1 to 36 wherein the modifications se ent incorporating lateral obstructions, les, or constrictions, an axis or line of the equipment intersecting a centerline of the fluidized bed reactor.

38. The method of claim 37 wherein a cross-sectional area of the obstructions, obstacles, or constrictions, when seen from a top of the fluidized-bed reactor, is equal to imately 40% of the cross-sectional area of the fluidized bed reactor.

39. The method of claim 37 or 38 wherein the obstructions, obstacles, or constrictions, are equipped with at least one of temperature-sensing means and means by which heat may be removed from or added to the fluidized bed, in such a manner that the temperature of the 10720680 fluidized bed around the obstructions, obstacles, or constrictions can be monitored and/or ted.

40. The method of any one of claims 37 to 39 wherein the obstructions, obstacles, or constrictions, are installed at vertical locations along the fluidized bed reactor that are separated from one another by one to two reactor diameters.

41. The method of any one of claims 37 to 40 wherein the orientations of the obstructions, obstacles, or constrictions, are , when seen from a top of the reactor, so that a single, open passage, running the length of the reactor for a distance of more than two reactor diameters, is not present.

42. The method of any one of claims 37 to 41 wherein upper surfaces of the obstructions, obstacles, or constrictions, are at least one of rounded, peaked and sloped in order to prevent bed al from coming to rest on said surfaces.

43. The method of any one of claims 37 to 42 n the upper surfaces of the obstructions, obstacles, or constrictions, are porous and constructed so that gas can pass through the upper part of the obstructions, obstacles, or ictions in order to prevent bed material from coming to rest on said surfaces.

44. The method of any one of claims 37 to 43 wherein the upper surfaces of the obstructions, obstacles, or constrictions, are uniformly porous and constructed of a highly abrasionresistant sintered glass ceramic material so that gas can pass through the exterior of the obstructions, obstacles, or constrictions in order to prevent bed material from coming to rest on said surfaces.

45. The method of any one of claims 37 to 44 wherein the ent is highly-abrasion resistant.

46. The method of any one of claims 37 to 45 wherein the equipment is at least partially ucted of an extremely hard ceramic or glass-ceramic material. 10720680

47. The method of any one of claims 37 to 46 wherein the equipment is at least partially coated with one of a highly on-resistant coating and an extremely hard ceramic or glassceramic material.

48. The method of any one of claims 37 to 47 wherein surfaces of the equipment are catalytically active, and facilitate hydropyrolysis reactions.

49. The method of any one of claims 37 to 48 wherein the equipment comprises an insert with a centrally located support, g along the central axis of the fluidized bed reactor, to which the obstructions, obstacles, or constrictions, are attached.

50. The method of any one of claims 37 to 48 wherein the equipment comprises an insert with a circumferential support, disposed around the circumference of the fluidized bed reactor, to which the obstructions, les, or constrictions, are ed.

51. The method of any one of claims 37 to 48 wherein the equipment comprises an insert with a ferential support, disposed around the circumference of the fluidized-bed reactor, with gas paths available to connect with locations to where porous obstructions, obstacles, or constrictions are attached.

52. The method of any one of claims 37 to 51 wherein the equipment comprises obstructions, obstacles, or constrictions that are directly ed to, supported by, and in communication with the wall of the fluidized bed r.

53. The method of any one of claims 37 to 51 wherein the ent comprises obstructions, obstacles, or constrictions that are molded or cast into a molded or cast refractory lining of the zed bed reactor.

54. The method of any one of claims 1 to 53 wherein the modifications that control slugging in the fluidized bed reactor incorporate internal xchanging flow pathways connected to external piping that is isolated from the internal environment of the r through which liquids and gases can be passed to extract heat from the reactor.

55. The method of any one of claims 1 to 54 wherein all required process heat is supplied from the deoxygenation reactions occurring during hydropyrolysis of the feedstock. 10720680

56. The method of claim 11, wherein the oxygenated polymer is hylene terephthalate.

57. The method of claim 12, wherein the wholly or partially red biomass feedstock is high lipid algae.

58. The method of claim 13, wherein the organic material of an aquatic origin is selected from the group consisting of fish, fish parts, wastes from fish processing, and mixtures thereof.

59. The method of claim 14, wherein the materials manufactured or otherwise obtained from biomass are ed from the group consisting of paper products, residues rejected as waste s by paper mills, and mixtures thereof.

60. The method of claim 15, wherein the organic material of animal origin is selected from the group consisting of offal, fats, greases, tissues, and mixtures thereof.

61. The method of claim 16, wherein the waste organic material of animal origin is selected from the group consisting of manure, sewage sludge, and mixtures thereof.

62. The method of claim 27, wherein the metal is selected from the group consisting of nickel, cobalt, iron, and mixtures f.

63. The method of claim 28, wherein the metal is selected from the group ting of nickel, cobalt, iron, and mixtures thereof.

64. The method of claim 29, wherein the metal is selected from the group consisting of nickel, cobalt, iron, and mixtures thereof.