APPARATUS AND METHOD RELATED TO USE OF SYNGAS IN OLEFIN

PRODUCTION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. provisional application 62/537,771, filed on July 27, 2017, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] Syngas (mixtures of H ₂ and CO), also known as synthesis gas, can be readily produced from a carbon source, such as either coal or methane (natural gas) by methods well known in the art and widely commercially practiced around the world. A number of well-known industrial processes use syngas for producing various hydrocarbons and oxygenated organic chemicals.

[0003] The Fischer-Tropsch catalytic process for catalytically producing hydrocarbons from syngas was initially discovered and developed in the 1920's, and was used in South Africa for many years to produce gasoline range hydrocarbons as automotive fuels. The catalysts typically comprised iron or cobalt supported on alumina or titania, and promoters were sometimes used with cobalt catalysts to improve various aspects of catalytic performance. The products were typically gasoline-range hydrocarbon liquids having six or more carbon atoms, along with other heavier hydrocarbon products.

[0004] Today lower molecular weight C2-C4 hydrocarbons are desired and can be obtained from syngas via the Fischer-Tropsch catalytic process. However, appreciable amounts of undesirable by-products such as methane, ethane and propane can be produced in the Fisher- Tropsch reaction synthesis, thereby reducing yield and efficiency of the process.

[0005] Furthermore, the composition of synthesis gas used in the Fisher-Tropsch olefin production is an important consideration. It is known that the synthesis gas produced from processes where solid feedstocks are used is usually deficient in hydrogen. Thus, there is a need to enrich the synthesis gas in hydrogen. Conventionally, this short fall in hydrogen is compensated by subjecting at least a portion of the gasification derived synthesis gas to CO Shift process. However, this process can result in the unwanted formation of CO ₂ and use of excess steam.

[0006] Accordingly, there remains a long-term market need for a new and improved apparatus and method that do not require a use of CO shift process to enrich synthesis gas in hydrogen. Furthermore, there remains a long-term market need for a new and improved apparatus and method that allows synthesis gas enrichment in hydrogen and utilizing energy and by-products from the Fischer-Tropsch process to improve the energy efficiency and yield of olefin production. Such an apparatus and method are described herein.

SUMMARY OF THE INVENTION

[0007] Disclosed herein is a method comprising the steps of: a) converting a first synthesis gas to a product stream comprising methane, ethane and propane, wherein the converting comprises a Fisher Tropsch synthesis reaction; b) separating the product stream to produce a tail gas comprising methane, a tail gas comprising ethane, and a tail gas comprising propane; c) subjecting the tail gas comprising methane to a sufficient heat in a first heat exchange reformer, wherein the first heat exchange reformer is configured to receive a feed of a second synthesis gas having a temperature of at least 900 °C, and wherein the sufficient heat is provided by heat exchange with the second synthesis gas, thereby producing from the tail gas comprising methane a reformed gas comprising synthesis gas and whereby cooling of the second synthesis gas produces a third synthesis gas having a temperature from about 500 °C to about 900 °C; d) subjecting the tail gas comprising ethane and the tail gas comprising propane to a sufficient heat in a second heat exchange pre-reformer, wherein the second heat exchange pre-reformer is configured to receive a feed of the third synthesis gas, and wherein the sufficient heat is provided by heat exchange with the third synthesis gas, thereby producing from the tail gas comprising ethane and the tail gas comprising propane a pre-reformed gas comprising methane and whereby cooling of the third synthesis gas produces a fourth synthesis gas having a temperature from about 350 °C to about 500 °C; and e) introducing the pre- reformed gas comprising methane to the first heat exchange reformer.

[0008] Also disclosed herein is an apparatus comprising: a) synthesis gas generation unit; b) a first heat exchange reformer, wherein the first heat exchange reformer is in fluid

communication with the synthesis gas generation unit; c) a second heat exchange pre-reformer, wherein the second heat exchange pre-reformer is in fluid communication with the first heat exchange reformer and/or a third heat exchanger unit, wherein the second heat exchange pre- reformer is configured in series to the first heat exchange reformer and/or the third heat exchanger unit; d) the third heat exchanger unit, wherein the third heat exchanger unit is in fluid communication with the second heat exchange pre-reformer and/or the first heat exchange reformer, and wherein the third heat exchanger unit is configured in series to the second heat exchange pre-reformer and/or the first heat exchange reformer; and e) a Fischer- Tropsch reactor, wherein the reactor is in fluid communication with the third heat exchanger unit or the second heat exchange pre-reformer, and wherein the apparatus does not comprise a CO shift reaction unit.

[0009] Additional advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or can be learned by practice of the aspects described below. The advantages described below will be realized and attained by means of the chemical compositions, methods, and combinations thereof particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

DESCRIPTION OF THE FIGURES

[0010] The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects, and together with the description, serve to explain the principles of the invention.

[0011] FIG. 1A and IB show exemplary flow diagrams of an apparatus and a method described herein.

[0012] FIG. 2 shows schematics of a first heat exchanger.

[0013] The present invention can be understood more readily by reference to the following detailed description of the invention.

DETAILED DESCRIPTION

[0014] Disclosed herein are materials, compounds, compositions, and components that can be used for, can be used in conjunction with, can be used in preparation for, or are products of the disclosed method and compositions. It is to be understood that when combinations, subsets, interactions, groups, etc. of these materials are disclosed that while specific reference of each various individual and collective combinations and permutation of these compounds cannot be explicitly disclosed, each is specifically contemplated and described herein. This concept applies to all aspects of this disclosure including, but not limited to, steps in methods of making and using the disclosed compositions. Thus, if there are a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific aspect or combination of aspects of the disclosed methods, and that each such combination is specifically contemplated and should be considered disclosed.

[0015] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.

1. DEFINITIONS

[0016] In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:

[0017] As used in the specification and in the claims, the term "comprising" can include the aspects "consisting of and "consisting essentially of." Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined herein.

[0018] As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a hydrocarbon" includes mixtures of two or more hydrocarbons.

[0019] As used herein, the terms "about" and "at or about" mean that the amount or value in question can be the value designated some other value approximately or about the same. It is generally understood, as used herein, that it is the nominal value indicated ±10% variation unless otherwise indicated or inferred. The term is intended to convey that similar values promote equivalent results or effects recited in the claims. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art.

[0020] Ranges can be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as "about" that particular value in addition to the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0021] The terms "first," "first synthesis gas," "second," "second synthesis gas," and the like, where used herein, do not denote any order, quantity, or importance, and are used to distinguish one element from another, unless specifically stated otherwise.

[0022] As used herein, the terms "optional" or "optionally" means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0023] References in the specification and concluding claims to parts by weight, of a particular element or component in a composition or article, denote the weight relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a compound containing 2 parts by weight of component X and 5 parts by weight of component Y, X and Y are present at a weight ratio of 2:5, and are present in such a ratio regardless of whether additional components are contained in the compound.

[0024] A weight percent ("wt %") of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included. For example, if a particular element or component in a composition or article is said to have about 80% by weight, it is understood that this percentage is relative to a total compositional percentage of 100% by weight.

[0025] As used herein, the terms "syngas" or "synthesis gas" are used interchangeably herein.

[0026] Moreover, it is to be understood that unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including:

matters of logic with respect to arrangement of steps or operational flow; plain meaning derived from grammatical organization or punctuation; and the number or type of aspects described in the specification.

2. APPARATUS

[0001] Synthesis gas derived from gasification of solid materials is usually deficient in hydrogen and thus not directly suitable for Fischer-Tropsch synthesis. This is especially so when the synthesis gas is derived from a gas generator where the syngas exits at a high temperature, a temperature not less than 900 °C. The syngas ratio (H ₂ /CO) in the syngas derived from these high temperature gas generators may vary between 0.3 and 1.0. In order to increase the syngas ratio to a value suitable for Fischer-Tropsch synthesis (1.5 to 2.0), the syngas is processed in a CO Shift unit. In a CO Shift unit, the syngas is reacted with steam over a catalyst producing H ₂ and CO ₂ . This process has several disadvantages since CO ₂ is produced and usually excess steam (more than the stoichiometric requirement) is required in the CO Shift unit.

[0002] In a hydrocarbon production process using Fischer-Tropsch synthesis, a range of hydrocarbons are produced. The distribution of the range of hydrocarbons produced in a Fischer Tropsch reaction follows the Anderson Schultz Flury product distribution. The hydrocarbons produced include, for example, C1-C3 paraffins, such as methane, ethane and propane, C2-C3 olefins (ethylene and propylene), C4+ hydrocarbons, and wax (i.e. C20+ hydrocarbons). The light paraffins, such as methane, ethane and propane, are conventionally routed to a fuel system, which results in an overall low yield of ethylene and propylene. [0003] Disclosed herein are an apparatus and a method that utilize a Fischer-Tropsch based process to maximize the production of ethylene and propylene by reducing or substantially eliminating a need for CO shift unit, by utilization of byproducts such as methane, ethane and propane in an energy efficient manner and increasing the yield of desired product such as ethylene and propylene. The apparatus and a method disclosed herein also have the capabilities of simultaneously reforming methane to synthesis gas in an energy efficient manner.

[0004] Conventionally ethylene and propylene are produced by steam cracking of ethane, propane, and naphtha. Other feedstocks have been sought for, for the production of ethylene and propylene. These include natural gas, coal, biomass and liquid hydrocarbon feedstocks. A manner to convert these feedstocks to ethylene and propylene is via Fischer Tropsch synthesis. In this process the carbonaceous feed is first converted into synthesis gas. After cooling and cleaning of the synthesis gas, CO and H ₂ are converted to hydrocarbons via Fischer Tropsch synthesis. The desired hydrocarbons (ethylene and propylene) are then recovered from the Fischer Tropsch synthesis products. The synthesis gas produced from processes where solid feedstocks are used are usually deficient in hydrogen. In order to make this gas suitable for FT synthesis, a CO Shift process is used. This results in the unwanted formation of CO ₂ and use of excess steam.

[0005] Methane, ethane and propane are amongst the products formed via the Fischer Tropsch reaction and separated when ethylene and propylene are recovered. The apparatus and methods disclosed herein utilize methane, ethane and propane to produce reformed gas comprising syngas and pre-reformed gas comprising methane in an energy efficient manner and thus increase the desired ethylene and propylene product yield, when the reformed gas comprising synthesis gas is converted to products, including ethylene and propylene, in a Fischer Tropsch reaction.

[0006] The feed of carbonaceous containing material is converted to synthesis gas at a temperature above at least about 900 °C. The resulting synthesis gas also has a temperature above at least 900 °C. This synthesis gas needs to be cooled before it is used in a Fischer- Tropsch reaction, which usually operates at a temperature from about 220 °C to about 380 °C, such as for example from about 220 °C to about 270 °C. In a conventional syngas generation unit, the synthesis gas with a temperature above at least about 900 °C is cooled in a steam generating unit, which produces steam that can be used in various processes.

[0007] The apparatus and method disclosed herein can also simultaneously utilize the heat from the synthesis gas with a temperature above at least about 900 °C to drive the reformation process of methane to produce new synthesis gas, which in turn can be used to produce more ethylene and propylene in a Fischer Tropsch reaction. Accordingly, the synthesis gas can be cooled by converting methane to synthesis gas and by converting by converting ethane and propane to a mixture of methane and syngas.

[0008] Thus, the apparatus and method disclosed herein are more energy efficient than a conventional syngas process, since the energy in the synthesis gas having a temperature above at least about 900 °C is used to drive chemical reactions instead of only generating steam.

[0009] Disclosed herein is an apparatus comprising: a) synthesis gas generation unit; b) a first heat exchange reformer, wherein the first heat exchange reformer is in fluid communication with the synthesis gas generation unit; c) a second heat exchange pre-reformer, wherein the second heat exchange pre-reformer is in fluid communication with the first heat exchange reformer and/or a third heat exchanger unit, wherein the second heat exchange pre-reformer is configured in series to the first heat exchange reformer and/or the third heat exchanger unit; d) the third heat exchanger unit, wherein the third heat exchanger unit is in fluid communication with the second heat exchange pre-reformer and/or the first heat exchange reformer, and wherein the third heat exchanger unit is configured in series to the second heat exchange pre- reformer and/or the first heat exchange reformer; and e) a Fischer-Tropsch reactor, wherein the reactor is in fluid communication with the third heat exchanger unit or the second heat exchange pre-reformer, and wherein the apparatus does not comprise a CO shift reaction unit.

[0010] In further aspects, the Fisher Tropsch reactor of the disclosed apparatus is in fluid communication with the first and the second heat exchange pre-reformers. The heat exchanger units are known in the art. In some aspects, any of the heat exchanger units disclosed herein can comprise one or more heat exchanger units. In other aspects, any of the heat exchanger units disclosed herein can comprise at least two heat exchanger units. It is further understood that the term "heat exchanger unit," as used herein, refers to any unit built for efficient heat transfer from one medium to another. In some aspects, the media can be separated by a solid wall to prevent mixing. In other aspects, the media can be in direct contact. It is understood that any known in the art heat exchanger units can be used in the method disclosed herein. It is further understood that the heat exchanger units can be classified according to their flow arrangements. In the aspects, where two fluids enter the exchanger at the same end, and travel in parallel to one another to the other side, the heat exchanger unit is classified as parallel-flow heat exchanger. In the aspects, where two fluids enter the exchanger from opposite ends is classified as a counter-flow heat exchanger unit. In the aspects, wherein two fluids travel perpendicular to one another through the exchange, the heat exchanger unit is classified as a cross-flow heat exchanger.

[0011] In some aspects, at least one of the first heat exchange reformer and the second heat exchange pre-reformer comprises a catalyst. In some aspects, the first heat exchange reformer comprises a catalyst. In yet other aspects, the second heat exchange pre-reformer comprises a catalyst.

[0012] In still further aspects, the third heat exchanger unit is a heat recovery and a steam generation unit. It is understood that the heat recovery and a steam generation units are known in the art, and any applicable unit can be utilized in this disclosure.

[0013] In still further aspects, the third heat exchanger unit can be positioned downstream from the first heat exchange reformer and upstream from the second heat exchange pre-reformer.

[0014] In further aspects, the third heat exchanger unit is in further fluid communication with an acid gas removal unit. In certain aspects, the acid gas removal unit is utilized to remove CO2 gas and sulfur from the synthesis gas entering the Fisher-Tropsch reactor. It is understood that the acid gas removal units are known in the art, and any applicable unit can be utilized in this disclosure.

[0015] In still further aspects, the acid gas removal unit is in further fluid communication with the Fisher Tropsch reactor.

[0016] In the further aspects, the apparatus comprises a syngas generation unit that can convert a solid feedstock to syngas. It is understood that any units known in the art capable of generating a synthesis gas (syngas) can be used in this disclosure.

[0017] The syngas generation unit is configured to receive a solid carbon source that can be converted to syngas in the syngas generation unit. It is understood that the syngas can be generated from a variety of different materials that contain carbon. In some aspects, the syngas can be generated from biomass, plastics, coal, or municipal waste, or any combination thereof. In some aspects, the syngas is generated by steam reforming.

[0018] It is further understood that any known in the art Fischer-Tropsch reactor can be used. In some aspects, isothermal and/or adiabatic fixed bed reactors can be used as a Fischer- Tropsch reactor, which can carry out the Fischer-Tropsch process. The Fischer-Tropsch reactor can comprise a catalyst, such as, for example, one or more Fischer-Tropsch catalysts. Fischer-Tropsch catalysts are known in the art and can, for example, be Fe based catalysts and/or Co based catalysts and/or Ru based catalysts. In one aspect, the reactor comprises a Co/Mn catalyst or a Co/Mo catalyst, or a combination thereof. For example, U.S. patent 9,416,067 discloses a promoted Co/Mn catalyst for use in a Fischer-Tropsch process, which is hereby incorporated in its entirety, specifically for its disclosure of a promoted Co/Mn catalyst. For example, U.S. patent 9,381,499 discloses a supported Co/Mo catalyst for use in a Fischer- Tropsch process, which is hereby incorporated in its entirety, specifically for its disclosure of a supported Co/Mo catalyst.

[0019] Optionally, in various aspects, the disclosed system can be operated or configured on an industrial scale. In one aspect, the reactors described herein can each be an industrial size reactor. For example the syngas generation unit can be an industrial size reactor. In yet another example, the Fischer-Tropsch reactor can be an industrial size reactor. For example, the first heat exchange reformer, the second heat exchange pre-reformer, and/or the third heat exchanger unit can be an industrial size reactor.

[0020] The reactors, units, and vessels disclosed herein can have a volume of at least about 1,000 liters, about 2,000 liters, about 5,000 liters, or about 20,000 liters. For example, the reactor can have a volume from about 1,000 liter to about 100,000 liters.

[0021] In one aspect, the syngas generation unit can have a volume of at least about 1,000 liters, about 2,000 liters, about 5,000 liters, or about 20,000 liters. For example, the syngas generation unit can have a volume from about 1,000 liter to about 100,000 liters.

[0022] In one aspect, the Fischer-Tropsch reactor can have a volume of at least about 1,000 liters, about 2,000 liters, about 5,000 liters, or about 20,000 liters. For example, the Fischer- Tropsch reactor can have a volume from about 1,000 liter to about 100,000 liters. [0023] In one aspect, the first heat exchange reformer, the second heat exchange pre-reformer, and/or the third heat exchanger unit can have a volume of at least about 1,000 liters, about 2,000 liters, about 5,000 liters, or about 20,000 liters. For example, the first heat exchange reformer, the second heat exchange pre-reformer, and/or the third heat exchanger unit can have a volume from about 1,000 liter to about 100,000 liters.

[0024] Now referring to FIGs. 1A and IB, which show non-limiting exemplary aspects of the apparatus and method disclosed herein. FIG. 1A and IB show an apparatus 100. The apparatus has a Fisher Tropsch synthesis reaction unit 102 for production and separation of olefins. The Fisher Tropsch (FT) synthesis reaction unit 102 comprises a FT reactor 134 is in fluid communication with an acid gas removal unit 128, a FT Gas CO ₂ removal and FT Gas Dryer unit 136, and Olefin Rich Gas dryer unit 138. The FT reactor 134 is in further fluid communication with Olefin conversion unit 140.The FT reactor 134 is further in fluid communication with the first heat exchange reformer 112, the second heat exchange pre- reformer 120, and the third heat exchanger unit 126. The FT gas CO ₂ removal and FT gas dryer unit 136 and Olefin Rich Gas dryer unit 138 are in fluid communication with the Light Ends Recovery 130 and Pressure Swing Absorption unit 130. The Light Ends Recovery unit 130 separates methane and forming a tail gas comprising methane 106. The Light Ends Recovery 130 and Pressure Swing Absorption unit 130 is further in fluid communication with a product separation unit 144 where a product stream comprising ethylene and propylene is formed and a product stream comprising a tail gas comprising ethane 110 and a tail gas comprising propane 108 are formed. The olefin conversion unit 140 is in fluid communication with an aromatics extraction unit 142. The first heat exchange reformer 112 is in fluid communication with a synthesis gas formation unit, for example a coal gasifier unit 148. The first heat exchange reformer 112 is in further fluid communication with an incoming feed of the tail gas comprising methane 106, an incoming feed of a pre-reformed gas comprising methane 122, and an outgoing feed of a reformed gas comprising synthesis gas 116. The first heat exchange reformer 112 is also in fluid communication with the second heat exchange pre- reformer 120. The first heat exchange reformer 112 is also in fluid communication with the third heat exchanger unit 126. The second heat exchange pre-reformer 120 is in fluid communication with an incoming feed of the tail gas comprising ethane 110 and the tail gas comprising propane 108. The second heat exchange pre-reformer 120 is in further communication with an outgoing feed of pre-reformed gas comprising methane 122. The second heat exchange pre-reformer 120 is in further communication with the third heat exchanger unit 126. The third heat exchanger unit 126 is in fluid communication with an incoming feed of the reformed gas comprising synthesis gas 116. The third heat exchanger unit 126 is in optional fluid communication with a CO shift unit 146. The third heat exchanger unit is in further fluid communication with an acid gas removal unit 128.

3. METHODS

[0025] Disclosed herein is a method comprising the steps of: a) converting a first synthesis gas to a product stream comprising methane, ethane and propane, wherein the converting comprises a Fisher Tropsch synthesis reaction; b) separating the product stream to produce a tail gas comprising methane, a tail gas comprising ethane, and a tail gas comprising propane; c) subjecting the tail gas comprising methane to a sufficient heat in a first heat exchange reformer, wherein the first heat exchange reformer is configured to receive a feed of a second synthesis gas having a temperature of at least 900 °C, and wherein the sufficient heat is provided by heat exchange with the second synthesis gas, thereby producing from the tail gas comprising methane a reformed gas comprising synthesis gas and whereby cooling of the second synthesis gas produces a third synthesis gas having a temperature from about 500 °C to about 900 °C; d) subjecting the tail gas comprising ethane and the tail gas comprising propane to a sufficient heat in a second heat exchange pre-reformer, wherein the second heat exchange pre-reformer is configured to receive a feed of the third synthesis gas, and wherein the sufficient heat is provided by heat exchange with the third synthesis gas, thereby producing from the tail gas comprising ethane and the tail gas comprising propane a pre-reformed gas comprising methane and whereby cooling of the third synthesis gas produces a fourth synthesis gas having a temperature from about 350 to about 500 °C; and e) introducing the pre-reformed gas comprising methane to the first heat exchange reformer .

[0026] In the exemplary aspect, the method disclosed herein is schematically illustrated in FIG. 1A and IB. In one aspect, the first syngas 104 is converted to a product stream comprising methane, ethane and propane in the Fischer Tropsch synthesis reaction unit 102. It is understood that the Fisher Tropsch synthesis reaction unit 102 can comprise a Fisher Tropsch (FT) reactor 134, a FT CO ₂ removal and a FT gas dryer 136, an olefin rich gas dryer 138, a unit for a Light Ends Recovery 130 and pressure swing absorption, an Olefin Conversion Unit 140, an aromatics extraction unit 142, a product separation unit 144 and the like.

[0027] The Fischer-Tropsch catalytic process for producing hydrocarbons from syngas is known in the art. Several reactions can take place in a Fischer-Tropsch process, such as, a Fischer-Tropsch (FT) reaction, a water gas shift reaction, and a hydrogen methanation, as shown in Scheme 1.

Scheme 1

FT rea km: » CO + 2» ~* iC _z ) -i i¾

ats? Gss Shsf R®acli©« fWGS CO + JirO → CO* ~h ¾

Mettanatioii CO i ¾ →€H« - ¾0

[0028] A Fischer-Tropsch process that targets the production of light olefins (C2-C8 olefins) is desired and such process can produce a significant amount of C2-C4 hydrocarbons. In other aspects, the FT process can further comprise a product stream comprising C2-C4, C4+ olefins, or any combination thereof. It is further understood that the product stream comprising methane, ethane and propane is also formed. In other aspects, the desirable olefins are separated and the tail gases comprising methane, ethane and propane are formed. In some exemplary aspects, the product stream is separated to produce a tail gas comprising methane 104, a tail gas comprising ethane 110, and a tail gas comprising propane 108.

[0029] In other aspects, the tail gas comprising methane 104 is conveyed by any known in the art means to a first heat exchange reformer 112. In the first heat exchange reformer the tail gas comprising methane is subjected to a sufficient heat. The first heat exchange reformer is further configured to receive a feed of a second synthesis gas 114 having a temperature of at least about 900 °C, at least about 950 °C, at least about 1,000 °C, at least about 1,100 °C, at least about 1,200 °C, at least about 1,300 °C, at least about 1,400 °C, or at least about 1,500 °C. For example the second synthesis gas can have a temperature from about 900 °C to about 1,600 °C.

[0030] In some exemplary aspects, the second synthesis gas is generated from a solid carbon containing feed. It is understood that the second syngas can be generated from a variety of different sources that contain carbon. In some aspects, the syngas can be generated from solid feedstock, for example, biomass, plastics, coal, or municipal waste, or any combination thereof.

[0031] In some aspects, the sufficient heat used to heat the tail gas comprising methane is provided by heat exchange with the second synthesis gas in the first heat exchange reformer, thereby producing from the tail gas comprising methane a reformed gas comprising synthesis gas 116 and a third synthesis gas 118 having a temperature from about 500 °C to about 900 °C. In some aspects, the third synthesis gas can have a temperature of about 550 °C, about 600 °C, about 650 °C, about 700 °C, about 750 °C, about 800 °C, or about 850 °C.

[0032] In some other aspects, the step of producing the reformed gas comprising synthesis gas from the tail gas comprising methane can be based on steam reforming. In some aspects, the heat exchange with the second synthesis gas in the first heat exchange reformer drives endothermic steam methane reforming reactions, thereby producing the third synthesis gas having a temperature lower than the second synthesis gas and the reform gas.

[0033] In one aspect, the tail gas comprising ethane and the tail gas comprising propane can be combined into one stream.

[0034] In some aspects, the exemplary first heat exchange reformer is schematically illustrated in FIG. 2. The second synthesis gas (hot syngas) and the tail gas comprising methane

(methane) enter the first heat exchange reformer 112. The first heat exchange reformer 112 comprises a plurality of catalyst filled tubes. It is understood that the catalyst used in the reforming of the tail gas comprising methane can be any catalyst known in the art. In some aspects, the catalyst is a nickel based catalyst. In other aspects, the catalyst is a cobalt based catalyst. In still further aspects, the catalyst is an alloy metal based catalyst. In certain aspects, the catalyst is non-metallic catalyst. It is further understood that the shape of the catalyst pellets can be optimized to achieve maximum activity with minimum increase in a pressure drop. In certain aspects, the pressure drop can depend on the void fraction of the packed bed and decrease with increasing particle size. The reformed gas comprising synthesis gas (reformed gas) 116 (FIG. 1A and IB) and the third synthesis gas (warm syngas) 118 (FIG. 1A and IB) exists the first heat exchange unit for further processing.

[0035] In still further aspects, the tail gas comprising ethane 110 and propane 108 are conveyed by any means known in the art to a second heat exchange pre-reformer 120. In some aspects, the tail gas comprising ethane and the tail gas comprising propane are subjected to a sufficient heat in the second heat exchange pre-reformer. In certain aspects, the second heat exchange pre-reformer is configured to receive a feed of the third synthesis gas. In certain aspects, the sufficient heat is provided by heat exchange with the third synthesis gas, thereby producing from the tail gas comprising ethane and the tail gas comprising propane a pre- reformed gas comprising methane and whereby cooling of the third synthesis gas produces a fourth synthesis gas. In certain aspects, the step of subjecting the tail gas comprising ethane and the tail gas comprising propane to a sufficient heat comprises heating the tail gas comprising ethane and the tail gas comprising propane to a temperature form about 350 °C to about 550 °C, for example, form about 400 °C to about 500 °C, including exemplary values of about 410 °C, about 420 °C, about 430 °C, about 440 °C, about 450 °C, about 460 °C, about 470 °C, about 480 °C, and about 490 °C.

[0036] In some aspects, the fourth synthesis gas can have a temperature from about 350 °C to about 550 °C, including exemplary values of about 410 °C, about 420 °C, about 430 °C, about 440 °C, about 450 °C, about 460 °C, about 470 °C, about 480 °C, and about 490 °C.

[0037] The third synthesis gas (warm syngas) and the tail gas comprising ethane and propane (ethane and propane) enter the second heat exchange pre-reformer 120. The second heat exchange pre-reformer 120 comprises a plurality of catalyst filled tubes. It is understood that the catalyst used in the forming of the pre-reform gas from the tail gas comprising ethane and from the tail gas comprising propane can be any catalyst known in the art. In some aspects, the catalyst is a nickel based catalyst. In other aspects, the catalyst is a cobalt based catalyst. In still further aspects, the catalyst is an alloy metal based catalyst. In certain aspects, the catalyst is non-metallic catalyst. In some aspects, the pre-reformed gas comprising methane is formed from the tail gas comprising ethane and from the tail gas comprising propane in an adiabatic catalytic reaction. In still further aspects, the pre-reformed gas comprising methane (122, FIGs. 1A and IB) and the fourth syngas (warm syngas) (124, FIG. 1A and IB) leave the second heat exchanger for further processing.

[0038] In still further aspects, the pre-reformed gas comprising methane 122 (FIG. 1A and IB) is further introduced to the first heat exchange reformer 112. In certain aspects, the pre- reformed gas comprising methane is subjected to a sufficient heat in the first exchanger unit to further form the reformed gas comprising synthesis gas 116. In certain aspects, the heat is provided by a heat exchange with the second synthesis gas.

[0039] As one of ordinary skill in the art would readily appreciate the efficiency of the Fisher- Tropsch synthesis reaction depends on the synthesis gas composition. In some aspects, the second synthesis gas, the third synthesis gas and the fourth synthesis gas have a ratio of ¾ to CO from about 0.3 to about 1.0, including exemplary values of about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, and about 0.9.

[0040] In yet other aspects, the composition of the reform gas comprises a ratio of H ₂ to CO from about 2.7 to about 6.0, including exemplary values of about 2.8, about 2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about 5.7, about 5.8, and about 5.9.

[0041] In still further aspects, the reformed gas comprising synthesis gas 116 (FIGs. 1A and IB) is further introduced to a third heat exchanger unit 126, where it can be cooled by heat exchange to assist in the production of steam or by heat exchange with other process streams. In certain aspects, the third exchanger unit 126 is further configured to receive a feed of the fourth synthesis gas 124. In the third heat exchanger unit 126 the fourth synthesis gas 124 can be cooled by heat exchange to assist in the production of steam or by heat exchange with other process streams, thereby producing the first synthesis gas 104. It is understood that in some aspects, the reformed gas comprising synthesis gas is provided separately from the feed of the fourth synthesis gas. It is further understood that in certain aspects, the reformed gas comprising synthesis gas comprises substantially no impurities. In yet other aspects, the reformed gas comprising synthesis gas comprises substantially no sulfur. In still further aspects, the reformed gas comprising synthesis gas is substantially free of sulfur.

[0042] In certain aspects, the third heat exchanger unit 126 is a heat recovery and steam generation unit. In these aspects, the steam generated in the third heat exchanger unit 126 can be fed back to the first heat exchange reformer 112 and the second heat exchange pre-reformer 120. In yet other aspects, the steam formed in the third heat exchanger unit and fed back to the first and the second heat exchange pre-reformers is used as a reactant in reforming of the tail gas comprising methane and pre-reforming the tail gas comprising ethane and the tail gas comprising propane. In the further aspects, the reformed gas comprising synthesis gas is cooled in the third heat exchanger unit by generation of steam.

[0043] In further aspects, the first synthesis gas is produced by mixing the reformed gas comprising synthesis gas exiting the third heat exchanger unit with unreacted syngas 132 generated in the Light Ends Recovery (LER) unit 130, and a cooled in the third exchanger unit the fourth synthesis gas to form the first synthesis gas that is fed to a Fischer Tropsch synthesis reactor 134. In certain aspects, the cooled fourth synthesis gas existing the third heat exchanger unit has a temperature from about 30 °C to about 270 °C, such as from about 30 °C to about 100 °C, or from about 150 °C to about 270 °C.

[0044] In some aspects, the first synthesis gas has a composition comprising a ratio of H ₂ to CO from about 1.0 to about 2.0, including exemplary values of about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, and about 1.9. In yet other aspects, the first synthesis gas has a temperature from about 220 °C to about 380 °C, such as from about 220 °C to about 270 °C, including exemplary values of about 230 °C, about 240 °C, about 250 °C, and about 260 °C.

[0045] In some aspects, the inventive method does not comprise a CO shift reaction unit. The CO shift reaction unit is commonly used to increase hydrogen composition in the synthesis gas. It is understood that the inventive method allows increase of the hydrogen composition without presence of the CO shift unit. However, in some aspects, where further enrichment of the synthesis gas with the hydrogen is required, the method can further comprise a CO shift reaction unit 146. In the aspects, where the CO shift unit is optionally present the cooled fourth synthesis gas is processed in the CO shift unit prior to the mixing with the reform gas.

[0046] In some aspects, the method further comprises removing an acid gas prior to the mixing with the reform gas in the acid gas removal unit 128. In some aspects, the acid gas removal unit is used to remove carbon dioxide and sulfur from the synthesis gas prior to combining it with the reformed gas comprising synthesis gas and recycle synthesis gas to form a firth synthesis gas that is fed into FT reactor. The acid gas units are known in the art and can comprise one or more units depending on a desirable application.

[0047] In some exemplary aspects, the first syngas is converted to hydrocarbons in the FT synthesis reactor 104. In other aspects, within the FT synthesis reactor, the FT product gas is cooled yielding several streams. In some aspects, the first product stream is wax, the second is FT water, the third is FT condensate and the last is FT gas. In still further aspects, the FT gas is then processed in a carbon dioxide removal unit 136. Carbon dioxide is removed from the FT gas since it will freeze in the separation unit where low temperatures are prevalent in order to achieve separation and recovery of the ethylene and propylene. In yet other aspects, downstream of the FT gas carbon dioxide removal unit 136, the FT gas is dried before it is processed in the Light Ends Recovery (LER) unit 130.

[0048] In still further exemplary aspects, the FT water stream is distilled to separate dissolved oxygenates from the water. In further aspects, the oxygenates and FT condensate are routed to the Olefin Conversion Unit (OCU) 140 where they are catalytically cracked to ethylene and propylene.

[0049] In some aspects, in the OCU 140 a catalytic cracker is employed which converts the hydrocarbon condensate (FT condensate) and oxygenates from the FT unit into to ethylene and propylene. In other aspects, the olefin rich gas from the OCU is then processed in a dryer before separation takes place.

[0050] In still further aspects, both the dried FT gas and olefin rich gas are processed in the LER unit 130. In the LER unit 130 light gases such as CO, H ₂ , N ₂ , Ar and methane are separated from the C2+ hydrocarbons. Also within the LER 130 unit methane is separated from a mixture of CO, ¾, N ₂ and Ar to form a tail gas comprising methane 106. This tail gas comprising methane 106 is fed to the first heat exchange reformer 112 as described above (methane reformer). In yet other aspects, a portion of the syngas with inert gases is recycled to the FT synthesis unit 134. Another portion of syngas with inert gases is processed in a Pressure Swing Absorption (PSA) unit 130 to produce hydrogen. Also the off gas from the PSA is vented to the fuel gas system to reduce the buildup of inert gases in the syngas recycle loop. C2+ hydrocarbons are further processed in the Product Separation Unit (PSU) 144 where ethane, propane, ethylene, propylene and C4+ hydrocarbons are obtained as separate product streams. The C4+ hydrocarbons are recycled to the OCU where the C4+ hydrocarbons are catalytically cracked to ethylene and propylene. The tail gases comprising ethane 110 and propane 108 are fed to the second heat exchange unit 120 as described herein, where they are heated and then pre-reformed to methane and syngas. [0051] The apparatus and method disclosed herein have several benefits, including a lower capital cost, decrease in volumetric flow of gases to the reactor, decrease in compressor duty, and decrease in steam consumption. The reforming of methane and pre-reforming of ethane and propane in these disclosed heat exchanger units also has the advantage of being more energy efficient than the use of a standalone steam reformer and pre-reformer. These benefits are achieved by eliminating an external sources of heat used in the standalone steam reformers to drive the endothermic chemical reactions.

[0052] A Fischer-Tropsch reactor that targets the production of light olefins (C2-C8 olefins) is desired and such process can produce a significant amount of C2-C3 hydrocarbons, and methane. In some exemplary aspects, the first product can comprise hydrogen, CO, CO ₂ , methane, ethylene, ethane, propylene, propane, butene, butane, mixture of nitrogen and argon, C2-C7 hydrocarbons, or any combination thereof. An exemplary non-limiting composition of the first product is shown in Table 1. The values shown in Table 1 were simulated using Aspen HYSYS V8.4. The values in Table 1 of the first product were calculated after removal of CO ₂ and upgrade of C4-C9 hydrocarbons (olefins) via a catalytic conversion unit before being integrated with the remainder of the apparatus disclosed herein.

TABLE 1

4. ASPECTS

[0053] In view of the described catalyst and catalyst compositions and methods and variations thereof, herein below are described certain more particularly described aspects of the inventions. These particularly recited aspects should not however be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein, or that the "particular" aspects are somehow limited in some way other than the inherent meanings of the language and formulas literally used therein.

[0054] Aspect 1 : A method comprising the steps of: a) converting a first synthesis gas to a product stream comprising methane, ethane and propane, wherein the converting comprises a Fisher Tropsch synthesis reaction; b) separating the product stream to produce a tail gas comprising methane, a tail gas comprising ethane, and a tail gas comprising propane; c) subjecting the tail gas comprising methane to a sufficient heat in a first heat exchange reformer, wherein the first heat exchange reformer is configured to receive a feed of a second synthesis gas having a temperature of at least about 900 °C, and wherein the sufficient heat is provided by heat exchange with the second synthesis gas, thereby producing from the tail gas comprising methane a reformed gas comprising synthesis gas and whereby cooling of the second synthesis gas produces a third synthesis gas having a temperature from about 500 °C to about 900 °C; d) subjecting the tail gas comprising ethane and the tail gas comprising propane to a sufficient heat in a second heat exchange pre-reformer, wherein the second heat exchange pre-reformer is configured to receive a feed of the third synthesis gas, and wherein the sufficient heat is provided by heat exchange with the third synthesis gas, thereby producing from the tail gas comprising ethane and the tail gas comprising propane a pre-reformed gas comprising methane and whereby cooling of the third synthesis gas produces a fourth synthesis gas having a temperature from about 350 °C to about 550 °C; and e) introducing the pre- reformed gas comprising methane to the first heat exchange reformer.

[0055] Aspect 2: The method of aspect 1, wherein the pre-reformed gas comprising methane is further subjected to a sufficient heat in the first heat exchange reformer to form the reformed gas comprising synthesis gas, and wherein the heat is provided by a heat exchange with the second synthesis gas.

[0056] Aspect 3: The method of aspects 1 or 2, wherein the reformed gas comprising synthesis gas is cooled in a third heat exchanger unit, wherein the third heat exchanger unit is configured to receive a feed of the fourth synthesis gas, and wherein the fourth synthesis gas cooled in a third heat exchanger unit, thereby producing the first synthesis gas. [0057] Aspect 4: The method of any one of aspects 1-3, wherein the second, the third and the fourth synthesis gas comprises H ₂ and CO in a ratio of H ₂ :CO from about 0.3 to about 1.0.

[0058] Aspect 5: The method of any one of aspects 1-4, wherein the reformed gas comprises ¾ and CO at the ratio of H2:CO from about 2.7 to about 6.0.

[0059] Aspect 6: The method of any one of aspects 1-5, wherein the first synthesis gas comprises H ₂ and CO at the ratio of H ₂ :CO from about 1.0 to about 2.0.

[0060] Aspect 7: The method of any one of aspects 1-6, wherein the tail gas comprising ethane and the tail gas comprising propane are combined into one stream and provided as one stream.

[0061] Aspect 8: The method of any one of aspects 1-7, wherein the step of subjecting the tail gas comprising ethane and the tail gas comprising propane to a sufficient heat comprises heating the tail gas comprising ethane and the tail gas comprising propane to a temperature from about 350 °C to about 500 °C.

[0062] Aspect 9: The method of any one of aspects 1-8, wherein the method does not comprise a CO shift reaction.

[0063] Aspect 10: The method of any one of aspects 1-9, wherein the first heat exchange reformer comprises a catalyst.

[0064] Aspect 11 : The method of any one of aspects 1-10, wherein the second heat exchange pre-reformer comprises a catalyst.

[0065] Aspect 12: The method of any one of aspects 1-11, wherein the step of converting the tail gas comprising ethane and the tail gas comprising propane to the pre-reformed gas comprising methane comprises an adiabatic catalytic reaction.

[0066] Aspect 13: The method of any one of aspects 1-12, wherein the third exchanger unit is a heat recovery and steam generation unit.

[0067] Aspect 14: The method of any one of aspects 1-13, wherein a Fisher Tropsch synthesis reaction further comprises formation of a product stream comprising C2-C4 olefins, C4+ olefins, or any combination thereof.

[0068] Aspect 15: The method of any one of aspects 1-14, wherein the method further comprises removing acid gas prior to forming the first synthesis gas. [0069] Aspect 16: An apparatus comprising: a) synthesis gas generation unit; b) a first heat exchange reformer, wherein the first heat exchange reformer is in fluid communication with the synthesis gas generation unit; c) a second heat exchange pre-reformer, wherein the second heat exchange pre-reformer is in fluid communication with the first heat exchange reformer and/or a third heat exchanger unit, wherein the second heat exchange pre-reformer is configured in series to the first heat exchange reformer and/or the third heat exchanger unit; d) the third heat exchanger unit, wherein the third heat exchanger unit is in fluid communication with the second heat exchange pre-reformer and/or the first heat exchange reformer, and wherein the third heat exchanger unit is configured in series to the second heat exchange pre- reformer and/or the first heat exchange reformer; and e) a Fischer-Tropsch reactor, wherein the reactor is in fluid communication with the third heat exchanger unit or the second heat exchange pre-reformer, and wherein the apparatus does not comprise a CO shift reaction unit.

[0070] Aspect 17: The apparatus of aspect 16, wherein the Fisher Tropsch reactor is in fluid communication with the first and the second heat exchange pre-reformers.

[0071] Aspect 18: The apparatus of aspects 16 or 17, wherein the third heat exchanger units is a heat recovery and a steam generation unit.

[0072] Aspect 19: The apparatus of any one of aspects 16-18, wherein the third heat exchanger unit is in further fluid communication with an acid gas removal unit.

[0073] Aspect 20: The apparatus of aspect 19, wherein the acid gas removal unit is in further fluid communication with the Fisher Tropsch reactor.

[0074] Various modifications and variations can be made to the compounds, composites, kits, articles, devices, compositions, and methods described herein. Other aspects of the compounds, composites, kits, articles, devices, compositions, and methods described herein will be apparent from consideration of the specification and practice of the compounds, composites, kits, articles, devices, compositions, and methods disclosed herein. It is intended that the specification and examples be considered as exemplary.