Manufacture of acrylonitrile

Abstract

Processes for the production of acrylonitrile from acrolein and / or propylene and are disclosed. The acrolein feedstock is generated by the catalytic dehydration of glycerol. In various aspects, the invention integrates acrolein and its production by the dehydration of glycerol into the conventional manufacture of acrylonitrile and HCN and acetonitrile co-products by heterogeneous catalytic ammoxidation of propylene in the vapor phase with ammonia and air. Further, a component may be introduced into the ammoxidation reaction along with acrolein and / or olefin to increase the production of HCN and / or acetonitrile co-products, wherein the component is selected from the group consisting of an alcohol, a carboxylic acid or salt thereof, a ketone and mixtures thereof. The integrated processes provide desirable production flexibility and are capable of selectively generating bio-based acrylonitrile and / or bio-attributed acrylonitrile products along with bio-based and / or bi-attributed HCN and / or acetonitrile co-products.

Description

3523894.00080250178-PCT MANUFACTURE OF AC RYLONITRILEFIELD OF THE INVENTION

[0001] The invention generally relates to processes for the manufacture of acrylonitrile from propylene and glycerol starting materials and to associated process equipment and constructions for practicing the disclosed processes.BACKGROUND OF THE INVENTION

[0002] In the case of acrylonitrile, most of the commercially available product is produced by heterogeneous catalytic ammoxidation of propylene in the vapor phase with ammonia and air, for example, using the Sohio Process as described in U. S. Pat. Nos.3,222,422 in the name of L. A. Cohen; 3,278,642 and 3,346,520 both in the name of L. Lee; 3,442,981 in the name of O. L. Stafford, D. V. Wing and D. E. Stolsmark; and 3,509,238 in the name of N. E. Aubery and M. B. Jastrzebeski, which are incorporated herein by reference. Acrylonitrile is also produced by subjecting propane to vapor-phase catalytic ammoxidation with ammonia and air.

[0003] More recently, it has been proposed to manufacture acrylonitrile from renewable starting materials such as glycerol. For example, see US 2010 / 0048850 Al in the name of J. Dubois and WO 2023 / 105430 Al in the name of A. Liu, L. Schindler and C. Tyree. In such processes, the glycerol is converted directly to acrylonitrile by catalytic vapor phase reaction with ammonia and oxygen or by a two-step process in which the glycerol is first catalytically dehydrated to acrolein and the acrolein is subsequently reacted with ammonia and oxygen in the presence of an ammoxidation catalyst. Advantages of using such alternative processes are said to include a greener, more sustainable carbon footprint since a readily regenerable starting material is employed in place of a raw material such as propylene that is typically of fossil fuel origin; generation of fewer by-products and impurities; reduced exothermic heat during the ammoxidation reaction; and simplified separation and purification operations for the recovery of the acrylonitrile product.

[0004] However, despite these perceived advantages, alternative processes for the manufacture of acrylonitrile from renewable starting materials such as glycerol are not 1CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT commercially practiced to a significant extent and the global manufacture of acrylonitrile remains dominated by the Sohio Process utilizing petroleum-derived propylene feed material. Commercial implementation of these so-called greener processes for the production of acrylonitrile suffer from significant capital expenditures, and uncertainty regarding both technical feasibility and market demand and willingness to pay a premium for acrylonitrile produced from renewable starting materials. These hurdles, in the context of a well-developed commodity market, severely hampers more widespread development, acceptance, and commercial deployment of this technology.

[0005] Accordingly, there remains a need for processes capable of overcoming these uncertainties and realizing the benefits of acrylonitrile manufacture from renewable feedstocks such as glycerol while minimizing capital requirements, particularly when early adoption might not be sufficiently large scale to provide competitive economies of scale, further increasing the risk associated with investment.

[0006] It is therefore a general object of the present invention to provide processes for the manufacture of acrylonitrile from propylene and glycerol starting materials and to associated process equipment and constructions for practicing these processes that permit flexibility in light of the above-noted uncertainties and reduced capital requirements.Consequently, it is also a general objective to integrate glycerol-based technologies into preexisting plants and processes for the heterogeneous catalytic ammoxidation of propylene and / or propane in the vapor phase with ammonia and air to minimize the capital investment required to generate these new-to-market technologies.

[0007] Other objects and advantages of the invention will become apparent upon reading the following detailed description and appended claims.BRIEF SUMMARY OF THE INVENTION

[0008] The present invention is directed to various processes for the production of acrylonitrile and associated process equipment and plant constructions for practicing the disclosed processes.

[0009] In one embodiment, the process for the production of acrylonitrile comprises introducing acrolein and propylene into an ammoxidation reactor; reacting in the vapor 2CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT phase at an elevated temperature and pressure acrolein and propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst within the ammoxidation reactor to form a gaseous reaction effluent comprising acrylonitrile; contacting acrylonitrile obtained in the gaseous reactor effluent with an aqueous stream in an absorber to form a liquid absorption solution comprising acrylonitrile; and fractionating the liquid absorption solution in a purification section comprising one or more distillation columns to recover a product comprising acrylonitrile.

[0010] In accordance with another embodiment, the process for the production of acrylonitrile comprises, dehydrating glycerol contained in a dehydration feed stream to produce a dehydration reaction product comprising acrolein; introducing acrolein obtained in the dehydration reaction product and optionally propylene into one or more ammoxidation reactor units of an ammoxidation reactor system; reacting in the vapor phase at an elevated temperature and pressure acrolein and optionally propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst within the one or more ammoxidation reactor units of the ammoxidation reactor system to form a gaseous reaction effluent comprising acrylonitrile; contacting acrylonitrile obtained in the gaseous reactor effluent with an aqueous stream in an absorber to form a liquid absorption solution comprising acrylonitrile; and fractionating the liquid absorption solution in a purification section comprising one or more distillation columns to recover a product comprising acrylonitrile.

[0011] In accordance with a further embodiment, the process for the production of acrylonitrile comprises dehydrating glycerol contained in a dehydration feed stream to produce a dehydration reaction product comprising acrolein; introducing acrolein obtained in the dehydration reaction product into one or more ammoxidation reactor units of a first ammoxidation reactor system and reacting in the vapor phase at an elevated temperature and pressure acrolein with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst to form a first gaseous reaction effluent comprising bio-based acrylonitrile; introducing propylene into one or more ammoxidation reactor units of a second ammoxidation reactor system and reacting in the vapor phase at an elevated temperature and pressure propylene with a molecular oxygen containing gas and ammonia 3CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT in the presence of an ammoxidation catalyst to form a second gaseous reaction effluent comprising acrylonitrile; contacting bio-based acrylonitrile obtained in the first gaseous reactor effluent and acrylonitrile obtained in the second gaseous reactor effluent with an aqueous stream in an absorber to form a liquid absorption solution comprising bio-attributed acrylonitrile; and fractionating the liquid absorption solution in a purification section comprising one or more distillation columns to recover a product comprising bio-attributed acrylonitrile.

[0012] In accordance with another embodiment, the process for the production of acrylonitrile comprises dehydrating glycerol contained in a dehydration feed stream to produce a dehydration reaction product comprising acrolein; introducing acrolein obtained in the dehydration reaction product and optionally propylene into one or more ammoxidation reactor units of a first ammoxidation reactor system and reacting in the vapor phase at an elevated temperature and pressure acrolein and optionally propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst to form a first gaseous reaction effluent comprising bio-based acrylonitrile or bio-attributed acrylonitrile; introducing acrolein obtained in the dehydration reaction product into one or more ammoxidation reactor units of a second ammoxidation reactor system and reacting in the vapor phase at an elevated temperature and pressure acrolein with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst to form a second gaseous reaction effluent comprising bio-based acrylonitrile; contacting bio-based acrylonitrile or bio-attributed acrylonitrile obtained in the first gaseous reactor effluent and optionally at least a portion of the bio-based acrylonitrile obtained in the second gaseous reactor effluent with an aqueous stream in a first absorber to form a first liquid absorption solution comprising bio-based acrylonitrile or bio-attributed acrylonitrile; and fractionating the first liquid absorption solution in a first purification section comprising one or more distillation columns to recover a first product comprising bio-based acrylonitrile or bioattributed acrylonitrile. The process further optionally comprises contacting at least a portion of the bio-based acrylonitrile obtained in the second gaseous reactor effluent with an aqueous stream in a second absorber to form a second liquid absorption solution comprising bio-based acrylonitrile; and fractionating the second liquid absorption solution in a second 4CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT purification section comprising one or more distillation columns to recover a second product comprising bio-based acrylonitrile.

[0013] In accordance with a still further embodiment, the invention is directed to a process for the production of acrylonitrile and at least one co-product selected from the group consisting of acetonitrile and HCN. The process comprises dehydrating glycerol contained in a dehydration feed stream to produce a dehydration reaction product comprising acrolein; introducing acrolein obtained in the dehydration reaction product, a component selected to increase the production of the at least one co-product and optionally propylene into one or more ammoxidation reactor units of an ammoxidation reactor system, wherein the component selected to increase the production of the at least one co-product is selected from the group consisting of an alcohol, a carboxylic acid or salt thereof, a ketone and mixtures thereof; reacting in the vapor phase at an elevated temperature and pressure acrolein, the component selected to increase the production of the at least one co-product and optionally propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst within the one or more ammoxidation reactor units of the ammoxidation reactor system to form a gaseous reaction effluent comprising acrylonitrile and at least one co-product selected from the group consisting of acetonitrile and HCN; contacting acrylonitrile and at least one co-product obtained in the gaseous reactor effluent with an aqueous stream in an absorber to form a liquid absorption solution comprising acrylonitrile and at least one co-product selected from the group consisting of acetonitrile and HCN; and fractionating the liquid absorption solution in a purification section comprising one or more distillation columns to recover a product comprising acrylonitrile and at least one co-product selected from the group consisting of acetonitrile and HCN.

[0014] The present invention is also directed to a method for retrofitting a preexisting propylene-fed or propane-fed acrylonitrile production plant for the production of bio-based acrylonitrile or bio-attributed acrylonitrile. The pre-existing acrylonitrile production plant comprises an ammoxidation reactor system comprising one or more ammoxidation reactor units fed with a molecular oxygen containing gas, ammonia and propylene from a propylene source or propane from a propane source and containing an 5CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT ammoxidation catalyst to form one or more a gaseous reaction effluents comprising acrylonitrile; an absorber for contacting acrylonitrile obtained in the one or more gaseous reactor effluents with an aqueous stream to form a liquid absorption solution comprising acrylonitrile; and a purification section comprising one or more distillation columns to fractionate the liquid absorption solution and recover a product comprising acrylonitrile. The retrofit method comprises installing a glycerol dehydration unit containing a dehydration catalyst and fed with a dehydration feed stream comprising glycerol to produce a dehydration reaction product comprising acrolein; and an acrolein delivery system for receiving acrolein obtained in the dehydration reaction product, the acrolein delivery system being in fluid communication with at least one of the one or more ammoxidation reactor units of the ammoxidation reactor system for delivering acrolein obtained in the dehydration reaction product to at least one of the one or more ammoxidation reactor units, wherein acrolein obtained in the dehydration reaction product is reacted with a molecular oxygen containing gas and ammonia in the presence of the ammoxidation catalyst such that at least one of the gaseous reaction effluents comprises bio-based acrylonitrile or bio-attributed acrylonitrile.

[0015] Other objects and features will be in part apparent and in part pointed out hereinafter.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Fig. 1 is a schematic diagram depicting one embodiment of the process of the invention including integrated acrolein production by the dehydration of glycerol and coammoxidation of acrolein and propylene in the manufacture of bio-attributed acrylonitrile or bio-based acrylonitrile.

[0017] Fig. 2 is a schematic diagram depicting another embodiment of the process of the invention including integrated acrolein production by the dehydration of glycerol and production of bio-attributed acrylonitrile and / or bio-based acrylonitrile, with optional recovery of one or both products.6CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT

[0018] Dashed lines indicate optional equipment and process flows as described herein. Corresponding reference characters indicate corresponding parts throughout the drawings.DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention is directed to processes for the production of acrylonitrile from acrolein and / or propylene. The acrolein feedstock is generated by the catalytic dehydration of glycerol. In various aspects, the invention integrates acrolein and its production by the dehydration of glycerol into the conventional manufacture of acrylonitrile from propylene, for example, by the Sohio Process. Advantageously, the ammoxidation of acrolein and mixed acrolein-propylene feedstocks may be effectively catalyzed using the same heterogeneous catalyst conventionally employed in the ammoxidation of propylene. The integrated processes in accordance with the invention provide desirable production flexibility with respect to acrolein and / or propylene feedstocks and are capable of selectively generating bio-based acrylonitrile and / or bio-attributed acrylonitrile products.

[0020] In the context of the present invention, "bio-based acrylonitrile" means acrylonitrile produced by the catalytic ammoxidation of acrolein and / or propylene feedstock produced exclusively from materials other than from fossil fuels, including acrolein derived from glycerol and "bio-based propylene." In the context of the present invention, "bio-based propylene" means propylene produced exclusively from materials other than from fossil fuels, and which are bio-based, including propylene generated from CO2recovered or sequestered from sources other than those derived from fossil fuels and propylene generated from raw materials produced from CO2recovered or sequestered from sources other than those derived from fossil fuels. Non-limiting examples of bio-based propylene include, propylene produced from renewable materials such as in the cracking and refining of Tall Oil obtained from wood during the Kraft process for making paper and propylene produced from either ethanol or propanol. Similarly, in the context of the present invention, "biobased acetonitrile" and "bio-based HCN" mean co-products resulting from the catalytic ammoxidation of acrolein and / or propylene feedstock produced exclusively from materials7CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT other than from fossil fuels, including acrolein derived from glycerol and bio-based propylene.

[0021] Further, in the context of the present invention, "bio-attributed acrylonitrile" means acrylonitrile produced by the catalytic ammoxidation of acrolein and / or propylene feedstock wherein a portion, but not all, of the feedstock is produced from materials other than from fossil fuels. Similarly, in the context of the present invention, "bio-attributed acetonitrile" and "bio-attributed HCN" mean co-products resulting from the catalytic ammoxidation of acrolein and / or propylene feedstock wherein a portion, but not all, of the feedstock is produced from materials other than from fossil fuels. For example, a bioattributed acrylonitrile and bio-attributed acetonitrile and / or bio-attributed HCN co-products may be produced by the co-ammoxidation of acrolein derived from glycerol and petroleum-derived propylene from fossil fuels. Still further, in the context of the present invention, "bio-attributed propylene" means a portion, but not all, of the propylene feedstock is produced exclusively from materials other than from fossil fuels, and which are bio-based materials. For example, a bio-attributed propylene feedstock may include a mixture of biobased propylene and propylene produced from fossil fuels, including propylene generated from CO2recovered or sequestered from fossil fuel emissions.

[0022] In the practice of the invention, various types of ammonia may be used as a reactant in the ammoxidation reaction depending on the desired sustainability profile (i.e., carbon footprint) and market for the acrylonitrile product. These ammonia sources are designated by various colors recognized in the field that indicate the source of the hydrogen used in making the ammonia and / or the fate of the CO2generated. Non-limiting examples of commercially available ammonia sources include:

[0023] " Grey ammonia" designates that the hydrogen comes from reforming of methane (i.e., petroleum) based, and the generated CO2is emitted to the atmosphere.

[0024] " Blue ammonia" designates that the hydrogen comes from reforming of methane (i.e., petroleum) based, but the generated CO2is not emitted to the atmosphere and instead captured or reused. Blue ammonia has a lower carbon footprint than grey ammonia.8CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT

[0025] " Green ammonia" designates that the hydrogen is produced from the electrohydrolysis of water such that no carbon is directly involved or liberated as an emission.

[0026] While in general, the composition of these various types of ammonia are essentially identical (with slightly different impurity profiles with green vs grey / blue ammonia), each of these products is assigned a “Product Carbon Footprint (PCF),” where the PCF for grey ammonia > blue ammonia >green ammonia. As a result, a premium can be charged for acrylonitrile made using green ammonia because of its inherently lower PCF. Other ammonia sources with different color designations and associated PCF values are known in the art and are likewise suitably used in the practice of the present invention depending on the desired product sustainability profile.

[0027] Glycerol Dehydration

[0028] Processes for the catalytic dehydration of glycerol to acrolein are known in the art, including those described in the above-referenced US 2010 / 0048850 Al and WO 2023 / 105430 Al, the contents of which are incorporated by reference.

[0029] In the dehydration unit, glycerol is dehydrated in the presence of a dehydration catalyst to produce acrolein and water according to the following reaction:

[0030] (CH2OH)2CHOH → CH2=CH-CHO + 2 H2O

[0031] The glycerol feedstock may be pure or in the form of a concentrated or diluted aqueous feedstock and the concentration of glycerol can vary within wide limits (e.g., 5-90 wt.%). In accordance with one embodiment, the glycerol feedstock is generated from a biosource. For example, the glycerol feedstock may be derived from production of biodiesel by transesterification of vegetable oils and / or animal fats with an alcohol (e.g., methanol) in the presence of a catalyst. In accordance with another embodiment, the glycerol feedstock is produced from sugars derived from plant sources. In accordance with another embodiment, the glycerol feedstock is generated from CO2recovered or sequestered from various sources such as fossil fuel emissions.

[0032] The dehydration reaction is typically conducted in the gas phase at a temperature of at least about 250°C, for example from about 250°C to about 350°C and at a pressure of from about 100 kPa to about 500 kPa. In some embodiments, the catalyst bed 9CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT within the dehydration unit may be separated into a plurality of stages with intervening heat exchangers to provide heat as needed to maintain the desired temperature inside the catalyst during the endothermic dehydration reaction. The dehydration unit may also optionally include a preheater for heating the glycerol feedstock to the desired reaction temperature.

[0033] The dehydration catalyst may be any catalyst that is capable of converting glycerol to acrolein under the reaction conditions and include homogeneous as well as heterogeneous catalysts. Suitable examples of such catalysts are disclosed inUS 2010 / 0048850 Al, WO 2023 / 105430 Al, WO 2006 / 087083 A2 and WO 2013 / 017942 and include, for example, heterogeneous catalysts comprising porous carriers such as alumina (Al2O3), titanium oxide (TiO2), zirconia (ZrO2), tin oxide (SnO2), and silica (SiO2) impregnated with acidic functional groups such as sulfates, phosphates, tungstates and silicates. For example, in one embodiment, the heterogeneous dehydration catalyst comprises tungstenated zirconia or silica in pellet form having a diameter of about 1 mm to about 3 mm, and wherein a majority of pores in the porous carrier are in the meso pore size range (i.e., 2 nm to 50 nm).

[0034] The dehydration unit may comprise one or more dehydration reactors.Multiple dehydration reactors may be operated in parallel to permit continuous operation while one or more of the reactors are offline to permit regeneration of the dehydration catalyst. As described in WO 2023 / 105430 Al, the dehydration catalyst may be regenerated at temperatures below about 350°C while flushing the reactor with nitrogen followed by dosing air into the nitrogen stream at the reaction temperature until pure air level is reached.

[0035] The dehydration reaction product mixture comprises acrolein, unreacted glycerol, dehydration byproducts and water vapor (both from the glycerol feedstock and produced in the dehydration reaction). The dehydration unit may optionally further include acrolein purification / partial condensation operations to remove water, unconverted glycerol and heavy byproducts (e.g., phenol, hydroxypropanone, and the addition products of acrolein to glycerol (acetals), and products of the polycondensation of glycerol, cyclic or non-cyclic glycerol ethers, propionic acid, acrylic acid). For example, the dehydration reaction product from the dehydration reactor may be passed through a quenching chamber followed by feeding the cooled product into a distillation column where purified acrolein is 10CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT recovered from the top and a residual stream comprising unconverted glycerol, water and heavy dehydration byproducts is withdrawn from the bottom.

[0036] Ammoxidation Reaction

[0037] The acrolein obtained in the dehydration reaction product, optionally purified as described above, is subsequently converted in the presence of ammonia, oxygen and an ammoxidation catalyst to acrylonitrile according to the following reaction:

[0038] CH2=CH-CHO + 1 / 2 O2+ NH3→ CH2=CH-CN + 2 H2O

[0039] In an integrated process in accordance with the invention in which propylene is also subjected to ammoxidation, the propylene is converted in the presence of ammonia, oxygen and an ammoxidation catalyst to acrylonitrile according to the following reaction:

[0040] CH2=CH-CH3+ 3 / 2 O2+ NH3→ CH2=CH-CN + 3 H2O

[0041] Typically, the ammoxidation process is performed by contacting an ammoxidation feed mixture comprising acrolein, an olefin (e.g., propylene) and / or propane in the presence of ammonia and oxygen with an ammoxidation catalyst at an elevated temperature to produce the acrylonitrile.

[0042] Ammoxidation catalysts for use in the conversion of olefins such as propylene at elevated temperatures in the presence of ammonia and a source of molecular oxygen (e.g., air) in the manufacture acrylonitrile are well known and suitable for use in the practice of the present invention. Such catalysts typically contain mixed oxides of iron, bismuth and molybdenum, promoted with suitable elements. Non-limiting examples of suitable ammoxidation catalysts are described in U. S. Patent No. 8,350,075 andWO 2023 / 223295 Al, which are incorporated herein by reference. Advantageously, the ammoxidation of acrolein and mixed acrolein-propylene feedstocks may be effectively catalyzed using the same heterogeneous catalyst conventionally employed in the ammoxidation of propylene. Furthermore, the ammoxidation catalyst may comprise multiple catalysts of different composition or function to provide a catalyst system specifically tuned for improved ammoxidation of acrolein alone or mixed acrolein-propylene feedstocks.

[0043] In certain embodiments, the ammoxidation reaction is performed in a fluidized bed reactor. For example, the reactor design set forth in U. S. Pat. No. 3,230,246, herein incorporated by reference, is suitable. In another embodiment, other types of known 11CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT reactors, such as fixed-bed reactors or transport line reactors, may be used for the ammoxidation reaction. However, for best results, the ammoxidation process is carried out in an ammoxidation reactor system comprising one or more fluidized bed reactor units. Because of the high conversions obtained, a single pass system is typically satisfactory.

[0044] Approximately stoichiometric quantities of acrolein, olefin and / or propane, ammonia, and dioxygen are introduced into the ammoxidation reactor.

[0045] Any suitable source of oxygen may be employed. For economic reasons, however, it may be desirable to utilize air as the source of oxygen. In certain embodiments, the molar ratio of the oxygen to acrolein, olefin and / or propane in the feed is from about 0.5:1 to about 4:1, or from about 1: 1 to about 3:1. In general, the amount of oxygen necessary for the vapor phase ammoxidation of acrolein is approximately one-third less than that required for propylene and / or propane. In certain specific embodiments wherein propylene is fed to the ammoxidation reactor and the source of oxygen comprises air, the molar ratio of air to propylene is from about 5: 1 to about 20: 1, from about 5: 1 to about 15:1, from about 6:1 to about 12:1, from about 7:1 to about 15:1, from about 8:1 to about 15:1, from about 8:1 to about 14:1, from about 8:1 to about 13:1, or from about 8:1 to about 12:1. In other specific embodiments wherein acrolein is fed to the ammoxidation reactor and the source of oxygen comprises air, the molar ratio of air to acrolein is from about 2: 1 to about 16:1, from about from about 2: 1 to about 11:1, from about 2: 1 to about 9: 1, from about 3: 1 to about 11:1, from about 5: 1 to about 11:1; from about 5: 1 to about 10: 1, or from about 5: 1 to about 9:1. As recognized by those skilled in the art, in embodiments where the ammoxidation feed mixture comprises a mixture of propylene and / or propane and acrolein, the molar ratio of air (or other oxygen source) to propylene and / or propane and acrolein may be adjusted accordingly based on the specific composition of the feed mixture.

[0046] Generally, for economic reasons, the molar ratio of ammonia to acrolein, olefin and / or propane in the feed in the reaction is a ratio of about 2: 1 or less. For example, in certain embodiments, the molar ratio of ammonia to acrolein, olefin and / or propane in the feed in the reaction may vary from between 0.5:1 to 2: 1. For example, in one embodiment, the molar ratio of ammonia to acrolein, olefin and / or propane in the feed in the reaction is from about 0.5:1 to about 2:1, from about 0.5:1 to about 1.5:1, from about 0.5:1 to about 12CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT 1.4:1, from about 0.5:1 to about 1.3:1, from about 0.5:1 to about 1.2:1, from about 0.5:1 to about 1.1:1, from about 0.5:1 to about 1:1, or from about 0.75:1 to about 1:1.

[0047] The ammoxidation reaction may be carried out under "low ammonia conditions" while still providing high yields of acrylonitrile. For example, in certain embodiments, the molar ratio of ammonia to acrolein, olefin and / or propane is from about 0.9:1 to about 1.3:1, from about 0.9:1 to about 1.2:1, from about 0.9:1 to about 1.1:1, from about 1: 1 to about 1.1:1, or from about 1: 1 to about 1.05:1. These " low ammonia conditions" help to reduce unreacted ammonia in the reactor effluent, a condition known as "ammonia breakthrough", which subsequently helps to reduce process wastes. Specifically, unreacted ammonia must be removed from the reactor effluent prior to the recovery of the acrylonitrile. Unreacted ammonia is typically removed by contacting the reactor effluent with sulfuric acid to form ammonium sulfate, which results in a process waste stream to be treated and / or disposed. Further, as ammonia is a relatively expensive reagent, increasingly efficient utilization of ammonia further reduces the production costs.

[0048] Conditions for the ammoxidation reaction are described, for example, in U. S. Pat. Nos. 5,093,299; 4,863,891; 4,767,878; and 4,503,001, which are incorporated herein by reference.

[0049] Suitable ammoxidation reactor operating conditions include pressures in a range from about 3 to about 35 psig (20.7 to 241.4 kPa gage), more typically from about 5 to about 25 psig (34.5 to 172.4 kPa gage). Generally, temperatures are in a range from about 260° C to about 600° C, and typically in a range from about 350° C to about 480° C. Heat of reaction is removed by generation of steam to control the temperature and generating steam at temperatures of from about 300° to about 500° C at elevated pressure. The contact time, although not critical, is generally from about 0.1 to about 50 seconds. In certain embodiments, the contact time is from about 1 to about 15 seconds.

[0050] Typically, the oxidations are operated at the lowest temperature consistent with high conversion. Conversion increases with temperature; the selectivity generally decreases only with large increases in temperature. The life of the ammoxidation catalyst also decreases with increasing temperatures. Commercial ammoxidation catalysts are designed to give high performance over a range of operating conditions permitting gradual 13CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT increase of temperature over the operating life of the catalysts to maintain productivity and selectivity near the initial levels, thus compensating for gradual loss of catalyst activity.

[0051] Besides acrylonitrile, the gaseous ammoxidation product stream comprises smaller amounts of acetonitrile and other by-products such as hydrocyanic acid (HCN) and possibly unreacted ammonia.

[0052] Product Recovery and Purification

[0053] The products of the ammoxidation reaction may be recovered from the gaseous reactor effluent and purified by any known method.

[0054] For example, the ammoxidation reactor effluent stream may be subjected to cooling through a steam generator, and optionally an acid neutralization column to quench and remove any residual ammonia. Acrylonitrile and other by-products obtained in the gaseous reactor effluent are subsequently passed through an absorber to which cooled water or another appropriate solvent is supplied as an absorbent. At the bottom of the absorber a concentrated liquid absorption solution of acrylonitrile, water and other by-products is obtained, from which the acrylonitrile product may be separated by fractionating the liquid absorption solution in a purification section comprising one or more distillation columns and phase separation steps.

[0055] In one embodiment, the absorber is a counter-current absorption column in which effluent from the ammoxidation reactor is cooled and is scrubbed with water and from which off-gas, consisting chiefly of nitrogen, is vented. Organic products, primarily acrylonitrile, acetonitrile and HCN, are collected in the water to give up to about 8% aqueous acrylonitrile and co-products, typically from about 2.5% to about 7.5%, more typically from about 3% to about 7% of acrylonitrile and co-products in the liquid absorption solution.

[0056] For purposes of illustration, reference is made the product recovery and purification operations described in U. S. Patent No. 6,984,749, which is incorporated herein by reference. The liquid absorption solution of acrylonitrile and co-products is treated in an integrated system of distillation and phase separation steps by which organic products are recovered and at least acrylonitrile is refined. The liquid absorption solution is sent to the acrylonitrile recovery column, from which an overhead stream containing crude acrylonitrile 14CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT and HCN is recovered. A liquid side stream from the column is fractionated in a small column to the remove acetonitrile as a co-product or for disposal by incineration. Water is removed from the bottom of the acrylonitrile recovery column. Condensate from the overhead stream is separated, and the HCN removed in the overhead of the heads column. The acrylonitrile in the bottoms is further purified in the product column to obtain acrylonitrile product of the desired purity (e.g., fiber-grade acrylonitrile). The crude streams of HCN and acetonitrile that are generated are typically sent to further respective unit operations to purify HCN and acetonitrile, respectively.

[0057] Integrated Acrylonitrile Production from Acrolein and Propylene

[0058] Having described the glycerol hydration, ammoxidation reaction and product recovery and purification operations generally applicable in the practice of the present invention, detailed below are specific embodiments in which acrolein and its production by the dehydration of glycerol are advantageously integrated into the conventional manufacture of acrylonitrile from propylene. The integrated processes provide desirable production flexibility and are capable of selectively generating bio-based acrylonitrile and / or bioattributed acrylonitrile products as well as bio-based acetonitrile and or HCN and / or bioattributed acetonitrile and / or HCN co-products. In accordance with some embodiments, an alcohol selected from the group consisting of methanol, ethanol and mixtures thereof, a carboxylic acid or salt thereof and / or a ketone is introduced into one or more ammoxidation reactor units of the ammoxidation reactor system along with the acrolein, olefin and / or propane feedstock to increase the production of HCN and / or acetonitrile co-products.Further, in accordance with the invention, a pre-existing propylene-fed acrylonitrile production plant may be retrofitted for the production of bio-based acrylonitrile and coproducts and / or bio-attributed acrylonitrile and co-products. The processes disclosed herein are capable of flexibly matching production with the desired acrylonitrile product and coproducts based on market demand and costs.

[0059] With reference to Fig. 1, a process for the manufacture of bio-attributed acrylonitrile or bio-based acrylonitrile, including integrated acrolein production by the dehydration of glycerol and co-ammoxidation of acrolein and propylene, is schematically depicted.15CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT

[0060] A dehydration feed stream 1 comprising glycerol is introduced into a dehydration unit 2 comprising one or more dehydration reactors containing a dehydration catalyst for the gas phase dehydration of glycerol to acrolein. Dehydration of glycerol produces a dehydration reaction product comprising acrolein along with unreacted glycerol, various dehydration byproducts and water vapor. The dehydration unit may optionally further include acrolein purification / partial condensation operations as described above (not shown) to remove water and heavy byproducts. Acrolein obtained in the dehydration reaction product and optionally purified exits the dehydration unit as an acrolein product stream 3.

[0061] Acrolein product stream 3 and propylene 4 from a propylene source 5 are introduced into an ammoxidation reactor system 6 along with ammonia and molecular oxygen. The source of molecular oxygen is typically air and may be introduced as a component of the acrolein and / or propylene feeds to the ammoxidation reactor system. The source of ammonia may be selected from grey ammonia, blue ammonia, green ammonia and / or mixtures thereof. The ammoxidation reactor system comprises one or more ammoxidation reactor units containing an ammoxidation catalyst for the vapor phase reaction of acrolein and propylene with a molecular oxygen containing gas and ammonia to form a gaseous reaction effluent 8 comprising acrylonitrile exiting the ammoxidation reactor system.

[0062] The gaseous reaction effluent is directed to a product recovery and purification unit 9 to recover a product 10 comprising acrylonitrile. For example, the gaseous reaction effluent may be contacted with an aqueous stream in an absorber to form a liquid absorption solution comprising acrylonitrile and subsequently fractionating the liquid absorption solution in a purification section comprising one or more distillation columns and phase separation steps to recover the acrylonitrile product and optionally acetonitrile and / or HCN.

[0063] As shown in Fig. 1, acrolein in the acrolein product stream 3 may be blended with propylene 4 in a mixer 11 to form an ammoxidation feed mixture 12 introduced into the ammoxidation reactor system 6. As used herein, a mixer is generally a volume wherein components (e.g., acrolein and propylene) are combined upstream of the ammoxidation 16CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT reactor system and may be a conduit or may include static or active means to mix the components within the volume of the mixer. Alternatively, acrolein obtained in the dehydration reaction product and propylene may be introduced separately into one or more of the reactor units of the ammoxidation reactor system. Depending on the ratio of acrolein to propylene, the acrolein purification / partial condensation operations to remove water, unconverted glycerol and heavy byproducts may be reduced.

[0064] As further shown in Fig. 1, propylene source 5 may be supplied with bioattributed propylene or bio-based propylene 13 and petroleum-derived propylene 14 from conventional fossil fuel sources. Petroleum-derived propylene can contain up to about 15% of the corresponding alkane (propane), typically from about 1% or less to about 10%, and up to about 5% heavier hydrocarbon compounds, and typically less than about 1%. The propylene source is controlled to selectively direct bio-based propylene, petroleum-derived propylene or a mixture thereof to the ammoxidation reactor system depending on the desired sustainability profile and market for the acrylonitrile product. For example, in accordance with one embodiment, the propylene directed from the propylene source to the ammoxidation reactor system is exclusively bio-based propylene such that the recovered acrylonitrile product is exclusively bio-based acrylonitrile, optionally along with bio-based acetonitrile and / or bio-based HCN co-products. In accordance with another embodiment, the propylene directed from the propylene source to the ammoxidation reactor system is petroleum-derived propylene such that the recovered acrylonitrile product is bio-attributed acrylonitrile, optionally along with bio-attributed acetonitrile and / or bio-attributed HCN coproducts.

[0065] In accordance with some embodiments, an alcohol selected from the group consisting of methanol, ethanol and mixtures thereof is introduced into one or more ammoxidation reactor units of the ammoxidation reactor system along with acrolein and optionally propylene and / or propane to increase the production of HCN and / or acetonitrile co-products, respectively. U. S. Patent No. 6,204,407, which is incorporated herein by reference, discloses introducing an alcohol or a mixture of alcohols (e.g., Ci to C4 alcohols, such as methanol, ethanol and mixtures thereof) into the ammoxidation reaction of propylene and propane to produce acrylonitrile along with enhanced production of useful 17CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT nitrile co-products, such as HCN and acetonitrile. In accordance with one embodiment, a mixture of methanol and ethanol is employed and the relative amounts of hydrogen cyanide and acetonitrile co-products produced by the process is adjusted by adjusting the relative amounts of methanol compared to ethanol added to the ammoxidation reaction. If greater amounts of hydrogen cyanide are desired, the ratio of methanol to ethanol can be increased. Conversely, if less hydrogen cyanide is desired, the ratio can be reduced. While any grade of alcohol can be used, even highly pure methanol and / or ethanol, it is advantageous to use crude methanol and / or ethanol. In accordance with one embodiment, the alcohol or mixture thereof is generated from a biosource.

[0066] While alcohols such as methanol and ethanol are typically employed to increase the production of HCN and / or acetonitrile co-products, other molecules that increase the production of these desirable co-products can be included as a component of the ammoxidation reaction.

[0067] In accordance with some embodiments, a carboxylic acid or salt thereof is introduced into one or more ammoxidation reactor units of the ammoxidation reactor system along with acrolein and optionally propylene and / or propane to increase the production of acetonitrile co-product. U. S. Patent No. 6,982,242, which is incorporated herein by reference, discloses introducing a carboxylic acid (e.g., formic, acetic, propionic, butanoic, oxalic, acrylic, butenoic, maleic, succinic, adipic, benzoic, toluic and the like), salt thereof (e.g., ammonium salt) or mixtures thereof into the ammoxidation reaction of propylene and / or propane to produce acrylonitrile along with enhanced production of acetonitrile. The carboxylic acid may be in the form of a crude carboxylic acid mixture such as a crude mixture of formic, acetic and propionic acids obtained as a side product or waste stream generated in the manufacture of acetic acid. The relative amounts of acetonitrile can be controlled by adjusting the amount of carboxylic acid or salt thereof added to the ammoxidation reaction.

[0068] In accordance with some embodiments, a ketone is introduced into one or more ammoxidation reactor units of the ammoxidation reactor system along with acrolein and optionally propylene and / or propane to increase the production of HCN and / or acetonitrile co-products. U. S. Patent No. 6,413,485 which is incorporated herein by18CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT reference, discloses introducing a ketone (e.g., acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK) and the like), or mixture thereof into the ammoxidation reaction of propylene and / or propane to produce acrylonitrile along with enhanced production of HCN and / or acetonitrile. The ketone may be in the form of a crude mixture of at least two ketones and a diluent such as water. The ketone or mixture of ketones is converted into HCN and / or acetonitrile without substantially affecting the yield of acrylonitrile.

[0069] As shown in Fig. 1, an alcohol or a mixture of alcohols and / or a carboxylic acid or salt thereof and / or a ketone 20 may be co-fed into one or more ammoxidation reactor units of the ammoxidation reactor system by introducing the alcohol or mixture thereof and / or the carboxylic acid or salt thereof and / or the ketone into acrolein product stream 3. Although not shown in Fig. 1, other co-feeding arrangements may be employed. For example, the alcohol or mixture of alcohols and / or the carboxylic acid or salt thereof and / or the ketone may be co-fed by introduction into propylene stream 4. Alternatively, the alcohol or mixture of alcohols and / or the carboxylic acid or salt thereof and / or the ketone may be introduced into mixer 11 along with the acrolein product stream 3 and propylene 4 and blended therein to form ammoxidation feed mixture 12 introduced into the ammoxidation reactor system 6. Still further, one or more or each of the alcohol or a mixture thereof and / or the carboxylic acid or salt thereof and / or the ketone may be introduced directly into the ammoxidation reactor units of the ammoxidation reactor system.

[0070] With reference to Fig 2, a process for the manufacture of acrylonitrile, including integrated acrolein production by the dehydration of glycerol with selective production of bio-attributed acrylonitrile and / or bio-based acrylonitrile, and optional recovery of one or both products is schematically depicted.

[0071] A dehydration feed stream 1 comprising glycerol is introduced into a dehydration unit 2 comprising one or more dehydration reactors containing a dehydration catalyst for the dehydration of glycerol to acrolein. Acrolein obtained in the dehydration reaction product and optionally purified exits the dehydration unit as an acrolein product stream 3.

[0072] The process embodiment shown in Fig. 2, includes first and second ammoxidation reactor systems, each comprising one or more ammoxidation reactor units to 19CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT allow for the selective production and recovery of different acrylonitrile products, including bio-attributed acrylonitrile and / or bio-based acrylonitrile, as well as variable production capacity for the desired acrylonitrile products. In the illustrated embodiment, a first ammoxidation reactor system 6 comprises a plurality of ammoxidation reactor units 6a - 6c operated in parallel and a second ammoxidation reactor system 7 comprises ammoxidation reactor units 7a and 7b operated in parallel. The first ammoxidation reactor system is fed with an ammoxidation feed mixture 12 divided into feed streams 12a - 12c, one for each of the respective ammoxidation reactor units, to produce respective gaseous reaction effluents 8a - 8c that are combined in an effluent stream 8. The second ammoxidation reactor system is fed with an ammoxidation feed mixture 12' divided into feed streams 12d and 12e, one for each of the respective ammoxidation reactor units, to produce respective gaseous reaction effluents 8d and 8e that are combined in effluent stream 8'.

[0073] An acrolein delivery system generally designated 15 in Fig. 2 receives acrolein product stream 3 and is in fluid communication with at least one of the one or more ammoxidation reactor units of the first and optionally the second ammoxidation reactor systems for delivering acrolein to the respective ammoxidation reactor systems. In the embodiment illustrated in Fig. 2, acrolein delivery system 15 divides acrolein product stream 3 into stream 3a, directed to the first ammoxidation reactor system 6, and stream 3b, optionally directed to the second ammoxidation reactor system 7.

[0074] Propylene may optionally be delivered to at least one of the one or more ammoxidation reactor units in each of the respective ammoxidation reactor systems from a propylene source 5 via streams 4 and 4a.

[0075] As shown in Fig. 2, acrolein delivery system 15 optionally includes mixers 11 and 1 la for blending acrolein in streams 3a and 3b, respectively, with propylene in streams 4 and 4a, respectively, to produce ammoxidation feed mixtures 12 and 12' introduced into the first and second ammoxidation reactor systems. Alternatively, acrolein obtained in the dehydration reaction product and propylene may be introduced separately into the ammoxidation reactor units of the first and second ammoxidation reactor systems.

[0076] As also shown in Fig. 2, the acrolein delivery system further optionally includes an acrolein feed buffer tank 3 c in fluid communication with glycerol dehydration 20CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT unit 2 to receive acrolein obtained in the dehydration reaction product for delivery to at least one of the one or more ammoxidation reactor units of the first and optionally the second ammoxidation reactor systems. The acrolein feed buffer tank collects a supply of acrolein during operation of the glycerol dehydration unit and, along with the propylene source, allows the composition of the feedstock sent to the ammoxidation reactor systems to be adjusted during operation.

[0077] Acrolein and / or propylene introduced into the ammoxidation reactor systems are reacted in the vapor phase at an elevated temperature and pressure with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst to form a first gaseous reaction effluent 8 and optionally a second gaseous reaction effluent 8' comprising acrylonitrile. The source of ammonia may be selected from grey ammonia, blue ammonia, green ammonia and / or mixtures thereof.

[0078] As further shown in Fig. 2, propylene source 5 may be supplied with both bio-based propylene 13 and petroleum-derived propylene 14 from conventional fossil fuel sources. The propylene source is controlled to selectively direct bio-based propylene, petroleum-derived propylene or a mixture thereof to the first and second ammoxidation reactor systems depending on the desired sustainability profile and market for the acrylonitrile products.

[0079] In the embodiment illustrated in Fig. 2, gaseous reactor effluent 8 from the first ammoxidation reactor system and optionally at least a portion of gaseous reactor effluent 8' from the second ammoxidation reactor system are directed to a product recovery and purification unit 9 to recover a product 10 comprising acrylonitrile. For example, the gaseous reaction effluent or combined effluent may be contacted with an aqueous stream in an absorber to form a first liquid absorption solution comprising acrylonitrile and subsequently fractionating the liquid absorption solution in a purification section comprising one or more distillation columns and phase separation steps to recover the acrylonitrile product. During operation of the processes described herein and depending on the desired sustainability profile and market for the acrylonitrile products, at least a portion of gaseous reactor effluent 8' from the second ammoxidation reactor system may be continuously or intermittently directed to product recovery and purification unit 9.21CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT

[0080] Alternatively or in addition, all or a remaining portion of gaseous reactor effluent 8' is directed to a second product recovery and purification unit 9a to form a second liquid absorption solution in a second absorber and fractionating the second liquid absorption solution in a second purification section comprising one or more distillation columns and phase separation steps to recover a separate second product 10a comprising acrylonitrile.

[0081] If unreacted acrolein is present in the gaseous reactor effluent 8 from the first ammoxidation reactor system and / or gaseous reactor effluent 8' from the second ammoxidation reactor system, the first and / or second liquid absorption solution may be fractionated to produce a recovered acrolein fraction. The recovered acrolein may be recycled and introduced into the one or more ammoxidation reactor units of the first and / or second ammoxidation reactor system.

[0082] As described above with respect to the embodiment shown in Fig. 1, the process shown in Fig. 2 may also optionally include co-feeding a component (e.g. an alcohol or a mixture of alcohols and / or a carboxylic acid or salt thereof and / or a ketone) selected to increase the production of HCN and / or acetonitrile co-products into one or both of the ammoxidation reactor systems 6 and 7. Co-feeding such a component to the ammoxidation reaction allows the operator to meet demands or production obligations for HCN and acetonitrile co-products. Further, depending on the source of any olefin fed to the respective reactor systems and the recovery and purification operations employed, this practice can be utilized to increase the production of bio-based HCN and / or bio-based acetonitrile coproducts or bio-attributed HCN and / or bi-attributed acetonitrile co-products as desired.

[0083] As shown in Fig. 2, the alcohol or a mixture of alcohols and / or the carboxylic acid or salt thereof and / or the ketone 20 may be optionally introduced into acrolein streams 3a and / or 3b. Although not shown in Fig. 2, other co-feeding arrangements may be employed. For example,, the alcohol or mixture of alcohols and / or the carboxylic acid or salt thereof and / or the ketone may be co-fed by introduction into propylene stream 4 and / or 4a. Alternatively, the alcohol or mixture of alcohols and / or the carboxylic acid or salt thereof and / or the ketone may be introduced into mixer 11 and / or mixer 11a along with the acrolein and optionally propylene and blended therein to form ammoxidation feed mixture 12 and 12'22CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT introduced into ammoxidation reactor systems 6 and / or 7. Still further, one or more or each of the alcohol or a mixture thereof and / or the carboxylic acid or salt thereof and / or the ketone may be introduced directly into the ammoxidation reactor units of the ammoxidation reactor systems.

[0084] Advantageously, the process shown in Fig. 2 is capable of selectively manufacturing and recovering one or more acrylonitrile products, including simultaneously manufacturing and recovering bio-attributed acrylonitrile and / or bio-based acrylonitrile along with other valuable ammoxidation-co-products. The disclosed process is flexible with respect to the acrolein and / or olefin feedstock(s) fed to the first and second ammoxidation reactor systems and the ammoxidation products produced and recovered and allows operation to be optimized based on raw material (e.g., glycerol, bio-based propylene, petroleum-derived propylene, alcohol and ammonia source) costs and availability as well as the demand and price for different acrylonitrile products (e.g., bio-based acrylonitrile, bioattributed acrylonitrile and conventional acrylonitrile produced from petroleum-derived propylene) and ammoxidation co-products (e.g., bio-based acetonitrile, bio-based HCN, bioattributed acetonitrile and bio-attributed HCN, etc.).

[0085] For example, petroleum-derived propylene may optionally be co-fed with acrolein into one or both of the first and second ammoxidation reactor systems such that one or both of the recovered products 10 and 10a comprise bio-attributed acrylonitrile, optionally along with bio-attributed acetonitrile and / or bio-attributed HCN co-products. Similarly, bio-based propylene may be co-fed with acrolein into one or both of the first and second ammoxidation reactor systems such that one or both of the recovered products 10 and 10a comprise bio-based acrylonitrile, optionally along with bio-based acetonitrile and / or bio-based HCN co-products.

[0086] In accordance with one embodiment, the second ammoxidation reactor system may be fed with acrolein and / or bio-based propylene and all or a portion of gaseous reactor effluent 8' may be directed to second product recovery and purification unit 9a to recover bio-based acrylonitrile and bio-based acetonitrile and HCN co-products, while any remainder of the gaseous reactor effluent 8' may be directed to product recovery and purification unit 9 for recovery as bio-attributed or bio-based acrylonitrile, optionally along 23CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT with bio-attributed or bio-based acetonitrile and / or HCN co-products. In such an embodiment, selectively proportioning the gaseous reactor effluent 8' between first and second product recovery and purification units 9 and 9a allows the operator to control the production of bio-based acrylonitrile and co-products as desired.

[0087] Further, the process shown in Fig. 2 may be operated in campaigns to produce and recover desired acrylonitrile products (e.g., bio-based acrylonitrile, bioattributed acrylonitrile and / or conventional acrylonitrile produced from petroleum-derived propylene) and ammoxidation co-products (e.g., bio-based acetonitrile, bio-based HCN, bioattributed acetonitrile and / or bio-attributed HCN, etc.) during segregated periods of operation. For example, a campaign may include feeding one or both of the first and second ammoxidation reactor systems with acrolein from dehydration unit 2 and no propylene (optionally along with an alcohol or a mixture of alcohols) for a period of time to produce and recover an acrylonitrile product (e.g., bio-based acrylonitrile) and ammoxidation coproducts (e.g., bio-based acetonitrile and bio-based HCN); feeding one or both of the first and second ammoxidation reactor systems with propylene from propylene source 5 and no acrolein (optionally along with an alcohol or a mixture of alcohols) for a period of time to produce and recover an acrylonitrile product and ammoxidation co-products; and / or feeding one or both of the first and second ammoxidation reactor systems with acrolein and propylene (optionally along with an alcohol or a mixture of alcohols) for a period of time to produce and recover an acrylonitrile product (e.g., bio-attributed acrylonitrile) and ammoxidation co-products (e.g., bio-attributed acetonitrile, bio-attributed HCN).

[0088] In accordance with certain embodiments, the production capacities of the first and second ammoxidation reactor systems may differ (e.g., based on the number of ammoxidation reactor units contained in each system) and the process is controlled such that bio-attributed and bio-based acrylonitrile products (10 and 10a, or vice versa) are produced simultaneously at differing production rates as desired. Still further, it is possible that the feed directed to the first ammoxidation reactor system or to the second ammoxidation reactor system exclusively comprises all of the acrolein obtained in the dehydration product mixture and no propylene and the other ammoxidation reactor system is fed exclusively with petroleum-derived propylene and no acrolein such that acrylonitrile products 10 and 10a,24CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT comprise bio-based acrylonitrile and conventional acrylonitrile, respectively, or vice versa. Moreover, during various production campaigns, it is possible to idle one or more or all of the ammoxidation reactor units of the first or second ammoxidation reactor system.

[0089] In accordance with some embodiments and in order to take advantage of existing capital investments, the integrated processes described herein may be implemented by retrofitting a pre-existing acrylonitrile production plant fed with a hydrocarbon such as propylene and / or propane to allow for the selective production of bio-attributed acrylonitrile, bio-based acrylonitrile and / or acrylonitrile derived from petroleum.

[0090] Generally, a pre-existing propylene-fed acrylonitrile production plant comprises: an ammoxidation reactor system comprising one ammoxidation reactor unit or a plurality of ammoxidation reactor units operated in parallel and fed with a molecular oxygen containing gas, ammonia and propylene and containing an ammoxidation catalyst to form one or more a gaseous reaction effluents comprising acrylonitrile; a propylene source in fluid communication with the one or more ammoxidation reactor units; an absorber for contacting the one or more gaseous reactor effluents with an aqueous stream to form a liquid absorber solution comprising acrylonitrile; and a purification unit comprising one or more distillation columns to fractionate the liquid absorber solution and recover a product comprising acrylonitrile as described herein.

[0091] Acrylonitrile is also produced by subjecting propane to vapor-phase catalytic ammoxidation with ammonia and air. For example, see U. S. Pat. No. 7,919,430, which is incorporated herein by reference. A propane-fed acrylonitrile production plant comprises generally the same process equipment as a propylene-fed plant. Accordingly, the present invention and integration of acrolein production by the dehydration of glycerol is applicable to the manufacture of acrylonitrile from propane and also retrofitting a pre-existing propanefed acrylonitrile production plant for the selective production of bio-attributed acrylonitrile, bio-based acrylonitrile and / or acrylonitrile derived from petroleum.

[0092] With reference again to Fig. 2 and in accordance with one embodiment of the invention, retrofitting a pre-existing propylene-fed acrylonitrile production plant comprises installing additional equipment, including:25CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT

[0093] (1) glycerol dehydration unit 2 containing a dehydration catalyst and fed with a dehydration feed stream comprising glycerol to produce a dehydration reaction product comprising acrolein; and

[0094] (2) acrolein delivery system 15 for receiving acrolein obtained in the dehydration reaction product. The acrolein delivery system is in fluid communication with at least one of the one or more ammoxidation reactor units (e.g., each of a plurality of reactor units) of the first ammoxidation reactor system 6 and optionally the second ammoxidation reactor system 7 for selectively delivering acrolein obtained in the dehydration reaction product to at least one of the one or more ammoxidation reactor units such that at least one of the gaseous reaction effluents 8 and 8' comprises bio-based acrylonitrile or bio-attributed acrylonitrile.

[0095] Although the system illustrated in Fig. 2 is described as containing first and second ammoxidation reactor systems 6 and 7, it should be understood that if the preexisting acrylonitrile production plant comprises a single ammoxidation reactor system comprising a plurality of ammoxidation reactor units (e.g., 6a-6c, 7a and 7b) operated in parallel, in accordance with one embodiment, after retrofitting, the plurality of parallel ammoxidation reactor units are segregated in the retrofitted plant into first ammoxidation reactor system 6 fed with ammoxidation feed mixture 12 and second ammoxidation reactor system 7 optionally fed with ammoxidation feed mixture 12'. The compositions of ammoxidation feed mixtures 12 and 12' can be independently controlled by the acrolein delivery system 15, which is in separate fluid communication with the ammoxidation reactor units of the respective ammoxidation reactor systems.

[0096] In accordance with another embodiment, the pre-existing acrylonitrile production plant comprises a single ammoxidation reactor system 6 comprising one or more ammoxidation reactor units (e.g., a plurality of parallel ammoxidation reactor units 6a-6c) and the retrofit method further comprises installing one or more additional ammoxidation reactor units (e.g., a plurality of parallel ammoxidation reactor units 7a and 7b) to form second ammoxidation reactor system 7. In such an embodiment, the acrolein delivery system 15 selectively feeds acrolein obtained in the dehydration reaction product to the one or more newly installed ammoxidation reactor units (e.g., 7a and 7b), and some or all of the 26CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT gaseous reaction effluent 8' exiting the second ammoxidation reactor system 7 is directed to product recovery and purification unit 9 to recover bio-based acrylonitrile or bio-attributed acrylonitrile product 10. In accordance with another embodiment of the retrofit method, one or more of the ammoxidation reactor units of the pre-existing acrylonitrile production plant (e.g., parallel reactor units 6a-6c) are idled, decommissioned and / or torn down and replaced by installing one or more additional ammoxidation reactor units while retaining the product recovery and purification unit 9 associated with the pre-existing production plant.

[0097] The ammoxidation catalyst within the one or more newly installed ammoxidation reactor units of the second ammoxidation reactor system may be specifically tuned for improved acrolein ammoxidation in the retrofitted plant. Further, the size and capacity of the newly installed ammoxidation reactor unit or units can be advantageously matched to accommodate the desired production of bio-based acrylonitrile or bio-attributed acrylonitrile product 10 from acrolein obtained in the dehydration reaction product.

[0098] During operations of the retrofitted acrylonitrile production plant, one or more or all of the ammoxidation reactor units of the first or second reactor systems 6 or 7 may be idled, decommissioned and / or torn down.

[0099] As described above, the acrolein delivery system in the retrofitted plant may include a mixer 11 and / or 1 la for blending at least a portion of the acrolein obtained in the dehydration reaction product and propylene from the propylene source 5. In such an embodiment, the acrolein delivery system is adapted to deliver the mixed acrolein-propylene ammoxidation feed mixture to at least one and optionally both of ammoxidation reactor systems in the retrofitted plant. As further described above, the acrolein delivery system in the retrofitted plant may optionally further include an acrolein feed buffer tank 3 c in fluid communication with glycerol dehydration unit 2 to receive and collect acrolein obtained in the dehydration reaction product.

[0100] In order to selectively and simultaneously produce and recover different acrylonitrile products as described above (e.g., bio-based acrylonitrile and bio-attributed acrylonitrile) 10 and 10a, or vice versa, the retrofit method may further comprise installing a second product recovery and purification unit 9a comprising a second absorber and one or27CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT more distillation columns and phase separation steps to recover a second product comprising acrylonitrile.

[0101] In accordance with one embodiment, the second product recovery and purification unit 9a may be simplified as compared to that of the pre-existing propylene-fed acrylonitrile production plant. For example, such a unit may not include unit operations such as those typically employed in a pre-existing plant for subsequent purification of the crude HCN and acetonitrile streams that are generated. In such an embodiment, these crude streams may be fed to the appropriate unit operations (i.e., HCN purification section or the acetonitrile purification section) of the product recovery and purification unit 9 associated with the pre-existing production plant. In this manner, some of the capital costs associated with the recovery and purification of these ammoxidation co-products may be reduced.

[0102] After retrofitting, operation of the acrylonitrile production plant may be modified in various ways. For example, after retrofitting, operation of the acrylonitrile production plant may be further modified to include co-feeding an alcohol selected from the group consisting of methanol, ethanol and mixtures thereof into one or both of ammoxidation reactor systems 6 and 7 along with acrolein and / or propylene to increase the production of HCN and / or acetonitrile co-products, respectively. In accordance with one particular embodiment, the flow of propylene fed to one or more of the plurality of ammoxidation reactor units in one or both of the ammoxidation reactor systems 6 and 7 may be selectively discontinued. For example, the flow of propylene to the ammoxidation reactor units of both reactor systems 6 and 7 may be discontinued and the acrolein delivery system adapted to selectively deliver acrolein obtained in the dehydration reaction product (optionally along with an alcohol or a mixture of alcohols) to one or more of the ammoxidation reactor units of reactor system 6 to produce one or more gaseous reaction effluents comprising bio-based acrylonitrile and bio-based HCN and acetonitrile coproducts, while the ammoxidation reactor units of reactor system 7 are idled. Alternatively, ammoxidation feed mixture 12 fed to one or more of the ammoxidation reactor units of reactor system 6 may comprise both acrolein and petroleum-based propylene (optionally along with an alcohol or a mixture of alcohols) to produce one or more gaseous reaction effluents comprising bio-attributed acrylonitrile and bio-attributed HCN and acetonitrile co- 28CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT products. In a still further particular embodiment, after retrofitting, the flow of propylene to the ammoxidation reactor units of reactor systems 6 may be discontinued and the acrolein delivery system adapted to selectively deliver acrolein obtained in the dehydration reaction product (optionally along with an alcohol or a mixture of alcohols) to one or more of the ammoxidation reactor units of reactor system 6 to produce one or more gaseous reaction effluents comprising bio-based acrylonitrile and bio-based HCN and acetonitrile coproducts, while petroleum-based propylene is delivered to one or more of the ammoxidation reactor units of reactor system 7 to produce one or more gaseous reaction effluents comprising acrylonitrile along with HCN and acetonitrile co-products.

[0103] Given the reduced oxygen requirement for ammoxidation of acrolein as compared to propylene and propane, during operations after retrofitting when acrolein is supplied to one or more ammoxidation reactor units, it may be advantageous to increase the flow of nitrogen or other suitable ballast gas to the reactor system to ensure that the catalyst in fluidized bed reactors remains sufficiently fluidized. Further, after retrofitting, the ammoxidation catalyst within one or more of the ammoxidation reactor units of the first and / or second ammoxidation reactor systems may be exchanged with fresh catalyst tuned specifically for improved acrolein ammoxidation and / or ammoxidation of mixed acroleinpropylene feedstocks in the retrofitted plant.

[0104] When introducing elements of the invention or the embodiments(s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0105] In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

[0106] While the foregoing description and the above embodiments are typical for the practice of the instant invention, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of this description.Accordingly, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense and that all such alternatives,29CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT modifications and variations are embraced by and fall within the spirit and broad scope of the appended claims.CORE / 3523894.000802 / 238587898.1

Claims

3523894.00080250178-PCT CLAIMS:

1. A method for retrofitting a pre-existing propylene-fed or propane-fed acrylonitrile production plant for the production of bio-based acrylonitrile or bio-attributed acrylonitrile, the pre-existing acrylonitrile production plant comprising:an ammoxidation reactor system comprising one or more ammoxidation reactor units fed with a molecular oxygen containing gas, ammonia and propylene from a propylene source or propane from a propane source and containing an ammoxidation catalyst to form one or more a gaseous reaction effluents comprising acrylonitrile;an absorber for contacting acrylonitrile obtained in the one or more gaseous reactor effluents with an aqueous stream to form a liquid absorption solution comprising acrylonitrile; anda purification section comprising one or more distillation columns to fractionate the liquid absorption solution and recover a product comprising acrylonitrile, wherein the method comprises installing:a glycerol dehydration unit containing a dehydration catalyst and fed with a dehydration feed stream comprising glycerol to produce a dehydration reaction product comprising acrolein; andan acrolein delivery system for receiving acrolein obtained in the dehydration reaction product, the acrolein delivery system being in fluid communication with at least one of the one or more ammoxidation reactor units of the ammoxidation reactor system for delivering acrolein obtained in the dehydration reaction product to at least one of the one or more ammoxidation reactor units, wherein acrolein obtained in the dehydration reaction product is reacted with a molecular oxygen containing gas and ammonia in the presence of the ammoxidation catalyst such that at least one of the gaseous reaction effluents comprises bio-based acrylonitrile or bio-attributed acrylonitrile.

2. The retrofit method of claim 1, wherein the acrolein delivery system comprises a mixer for blending at least a portion of the acrolein obtained in the dehydration reaction product and propylene from the propylene source or propane from the propane source to form a mixed acrolein-propylene or acrolein-propane ammoxidation feed mixture and the31CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT acrolein delivery system delivers the mixed acrolein-propylene or acrolein-propane ammoxidation feed mixture to at least one of the one or more ammoxidation reactor units.

3. The retrofit method of claim 1, wherein the pre-existing acrylonitrile production plant comprises an ammoxidation reactor system comprising a plurality of parallel ammoxidation reactor units.

4. The retrofit method of claim 3, wherein the acrolein delivery system is in fluid communication with one or more of the plurality of parallel ammoxidation reactor units for delivering acrolein obtained in the dehydration reaction product to one or more of the plurality of ammoxidation reactor units.

5. The retrofit method of claim 3, wherein the acrolein delivery system is in fluid communication with each of the plurality of parallel ammoxidation reactor units for delivering acrolein obtained in the dehydration reaction product to each of the plurality of ammoxidation reactor units.

6. The retrofit method of any one of claims 3 to claim 5, further comprising discontinuing the flow of propylene fed to one or more of the plurality of ammoxidation reactor units.

7. The retrofit method of claim 6, wherein the acrolein delivery system is adapted to deliver acrolein obtained in the dehydration reaction product to the one or more of the plurality of ammoxidation reactor units from which the flow of propylene has been discontinued to produce one or more gaseous reaction effluents comprising bio-based acrylonitrile.

8. The retrofit method of claim 6 or claim 7, further comprising installing a second absorber and a second purification section comprising one or more distillation columns to recover a product comprising the bio-based acrylonitrile, wherein the second absorber receives and contacts bio-based acrylonitrile obtained in a gaseous reactor effluent generated by ammoxidation of acrolein obtained in the dehydration reaction product in one or more of the plurality of ammoxidation reactor units from which the flow of propylene has been discontinued with an aqueous stream to form a second liquid absorption solution comprising bio-based acrylonitrile, and the second purification section fractionates the second liquid absorption solution and generates the product comprising the bio-based acrylonitrile.32CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT 9. The retrofit method of claim 6, wherein one or more of the plurality of ammoxidation reactor units from which the flow of propylene has been discontinued is idled.

10. The retrofit method of any one of claims 1 to 8, wherein the acrolein delivery system further comprises an acrolein feed buffer tank in fluid communication with the glycerol dehydration unit to receive and collect acrolein obtained in the dehydration reaction product for delivery to at least one of the one or more ammoxidation reactor units.

11. The retrofit method of any one of claims 1 to 10, further comprising installing one or more additional ammoxidation reactor units to form a second ammoxidation reactor system, wherein the acrolein delivery system is in fluid communication with the least one or more ammoxidation reactor units of the second ammoxidation reactor system for delivering acrolein obtained in the dehydration reaction product to the at least one or more ammoxidation reactor units of the second ammoxidation reactor system, and wherein acrolein obtained in the dehydration reaction product is reacted with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst within the at least one or more ammoxidation reactor units of the second ammoxidation reactor system to produce a gaseous reaction effluent comprising bio-based acrylonitrile or bio-attributed acrylonitrile.

12. The retrofit method of claim 11, wherein a plurality of parallel ammoxidation reactor units are installed to form the second ammoxidation reactor system.

13. The retrofit method of claim 11 or 12, further comprising installing a second absorber and a second purification section comprising one or more distillation columns to recover a product comprising the bio-based acrylonitrile or bio-attributed acrylonitrile, wherein the second absorber receives and contacts bio-based acrylonitrile or bio-attributed acrylonitrile obtained in the gaseous reactor effluent generated by ammoxidation of acrolein obtained in the dehydration reaction product in one or more of the ammoxidation reactor units of the second ammoxidation reactor system with an aqueous stream to form a second liquid absorption solution comprising bio-based acrylonitrile or bio-attributed acrylonitrile, and the second purification section fractionates the second liquid absorption solution and generates the product comprising the bio-based acrylonitrile or bio-attributed acrylonitrile.33CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT 14. A process for the production of acrylonitrile, the process comprising:dehydrating glycerol contained in a dehydration feed stream to produce a dehydration reaction product comprising acrolein;introducing acrolein obtained in the dehydration reaction product into one or more ammoxidation reactor units of a first ammoxidation reactor system and reacting in the vapor phase at an elevated temperature and pressure acrolein with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst to form a first gaseous reaction effluent comprising bio-based acrylonitrile;introducing propylene into one or more ammoxidation reactor units of a second ammoxidation reactor system and reacting in the vapor phase at an elevated temperature and pressure propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst to form a second gaseous reaction effluent comprising acrylonitrile;contacting bio-based acrylonitrile obtained in the first gaseous reactor effluent and acrylonitrile obtained in the second gaseous reactor effluent with an aqueous stream in an absorber to form a liquid absorption solution comprising bio-attributed acrylonitrile; and fractionating the liquid absorption solution in a purification section comprising one or more distillation columns to recover a product comprising bio-attributed acrylonitrile.

15. A process for the production of acrylonitrile, the process comprising:dehydrating glycerol contained in a dehydration feed stream to produce a dehydration reaction product comprising acrolein;introducing acrolein obtained in the dehydration reaction product and optionally propylene into one or more ammoxidation reactor units of a first ammoxidation reactor system and reacting in the vapor phase at an elevated temperature and pressure acrolein and optionally propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst to form a first gaseous reaction effluent comprising bio-based acrylonitrile or bio-attributed acrylonitrile;introducing acrolein obtained in the dehydration reaction product into one or more ammoxidation reactor units of a second ammoxidation reactor system and reacting in the vapor phase at an elevated temperature and pressure acrolein with a molecular oxygen 34CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT containing gas and ammonia in the presence of an ammoxidation catalyst to form a second gaseous reaction effluent comprising bio-based acrylonitrile;contacting bio-based acrylonitrile or bio-attributed acrylonitrile obtained in the first gaseous reactor effluent and optionally at least a portion of bio-based acrylonitrile obtained in the second gaseous reactor effluent with an aqueous stream in a first absorber to form a first liquid absorption solution comprising bio-based acrylonitrile or bio-attributed acrylonitrile;fractionating the first liquid absorption solution in a first purification section comprising one or more distillation columns to recover a first product comprising bio-based acrylonitrile or bio-attributed acrylonitrile; andoptionallycontacting at least a portion of bio-based acrylonitrile obtained in the second gaseous reactor effluent with an aqueous stream in a second absorber to form a second liquid absorption solution comprising bio-based acrylonitrile; and fractionating the second liquid absorption solution in a second purification section comprising one or more distillation columns to recover a second product comprising bio-based acrylonitrile.

16. The process of claim 15, wherein at least a portion of the second gaseous reactor effluent comprising bio-based acrylonitrile is contacted with the aqueous stream in the second absorber to form the second liquid absorption solution comprising bio-based acrylonitrile; andthe second liquid absorption solution is fractionated in the second purification section to recover the second product comprising bio-based acrylonitrile.

17. The process of claims 15 or 16, wherein at least a portion of the second gaseous reactor effluent comprising bio-based acrylonitrile is contacted with the aqueous stream in the first absorber.

18. The process of claim 17, wherein at least a portion of the second gaseous reactor effluent comprising bio-based acrylonitrile is continuously blended with the first gaseous reactor effluent to form an absorber feed stream contacted with the aqueous stream in the first absorber.35CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT 19. The process of claim 17, wherein at least a portion of the second gaseous reactor effluent comprising bio-based acrylonitrile is intermittently blended with the first gaseous reactor effluent to form an absorber feed stream contacted with the aqueous stream in the first absorber.

20. The process of any one of claims 15 to 19, further comprising introducing bio-based propylene into the one or more ammoxidation reactor units of the second ammoxidation reactor system.

21. The process of any one of claims 15 to 20, wherein the ammonia fed to the one or more ammoxidation reactor units of the first ammoxidation reactor system is selected from the group consisting of grey ammonia, blue ammonia, green ammonia and mixtures thereof.

22. The process of any one of claims 15 to 21, wherein the ammonia fed to the one or more ammoxidation reactor units of the second ammoxidation reactor system is selected from the group consisting of blue ammonia, green ammonia and mixtures thereof.

23. The process of any one of claims 15 to 22, wherein the first gaseous reaction effluent further comprises unreacted acrolein and fractionating the first liquid absorption solution in the purification section produces a recovered acrolein fraction.

24. The process of claim 23, wherein at least a portion of the recovered acrolein fraction is recycled and introduced into the one or more ammoxidation reactor units of the first and / or second ammoxidation reactor system.

25. The process of any one of claims 15 to 24, wherein the second gaseous reaction effluent further comprises unreacted acrolein and fractionating the second liquid absorption solution in the second purification section produces a recovered acrolein fraction.

26. The process of claim 25, wherein at least a portion of the recovered acrolein fraction is recycled and introduced into the one or more ammoxidation reactor units of the first and / or second ammoxidation reactor system.

27. The process of any one of claims 14 to 26, wherein acrolein and optionally propylene is reacted with the molecular oxygen containing gas and ammonia within a fluidized bed comprising the ammoxidation catalyst.

28. A process for the production of acrylonitrile and at least one co-product selected from the group consisting of acetonitrile and HCN, the process comprising:36CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT dehydrating glycerol contained in a dehydration feed stream to produce a dehydration reaction product comprising acrolein;introducing acrolein obtained in the dehydration reaction product, a component selected to increase the production of the at least one co-product and optionally propylene into one or more ammoxidation reactor units of an ammoxidation reactor system, wherein the component selected to increase the production of the at least one co-product is selected from the group consisting of an alcohol, a carboxylic acid or salt thereof, a ketone and mixtures thereof;reacting in the vapor phase at an elevated temperature and pressure acrolein, the component selected to increase the production of the at least one co-product and optionally propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst within the one or more ammoxidation reactor units of the ammoxidation reactor system to form a gaseous reaction effluent comprising acrylonitrile and at least one co-product selected from the group consisting of acetonitrile and HCN; contacting acrylonitrile and at least one co-product obtained in the gaseous reactor effluent with an aqueous stream in an absorber to form a liquid absorption solution comprising acrylonitrile and at least one co-product selected from the group consisting of acetonitrile and HCN; andfractionating the liquid absorption solution in a purification section comprising one or more distillation columns to recover a product comprising acrylonitrile and at least one co-product selected from the group consisting of acetonitrile and HCN.

29. The process of claim 28, wherein the component selected to increase the production of the at least one co-product comprises an alcohol.

30. The process of claim 29, wherein the alcohol comprises ethanol to increase the production of and recovery of acetonitrile.

31. The process of claim 29, wherein the alcohol comprises methanol to increase the production and recovery HCN.

32. The process of any one of claims 29 to 31, wherein the alcohol is generated from a biosource.37CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT 33. The process of any one of claims 29 to 32, wherein acrolein obtained in the dehydration reaction product is blended with an alcohol selected from the group consisting of methanol, ethanol and mixtures thereof to form an ammoxidation feed mixture that does not comprise propylene and is introduced into the one or more ammoxidation reactor units of the ammoxidation reactor system to form the gaseous reaction effluent comprising biobased acrylonitrile and at least one co-product selected from the group consisting of biobased acetonitrile and bio-based HCN.

34. The process of claim 28, wherein the component selected to increase the production of the at least one co-product comprises a carboxylic acid or salt thereof to increase the production of acetonitrile.

35. The process of claim 34, wherein the carboxylic acid comprises acetic acid.

36. The process of claim 28, wherein the component selected to increase the production of the at least one co-product comprises a ketone.

37. The process of claim 36, wherein the ketone is selected from the group consisting of acetone, methyl ethyl ketone, methyl isobutyl ketone and mixtures thereof.

38. A process for the production of acrylonitrile, the process comprising: introducing acrolein and propylene into an ammoxidation reactor;reacting in the vapor phase at an elevated temperature and pressure acrolein and propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst within the ammoxidation reactor to form a gaseous reaction effluent comprising acrylonitrile;contacting acrylonitrile obtained in the gaseous reactor effluent with an aqueous stream in an absorber to form a liquid absorption solution comprising acrylonitrile; and fractionating the liquid absorption solution in a purification section comprising one or more distillation columns to recover a product comprising acrylonitrile.

39. A process for the production of acrylonitrile, the process comprising:dehydrating glycerol contained in a dehydration feed stream to produce a dehydration reaction product comprising acrolein;introducing acrolein obtained in the dehydration reaction product and optionally propylene into one or more ammoxidation reactor units of an ammoxidation reactor system;38CORE / 3523894.000802 / 238587898.13523894.00080250178-PCT reacting in the vapor phase at an elevated temperature and pressure acrolein and optionally propylene with a molecular oxygen containing gas and ammonia in the presence of an ammoxidation catalyst within the one or more ammoxidation reactor units of the ammoxidation reactor system to form a gaseous reaction effluent comprising acrylonitrile;contacting acrylonitrile obtained in the gaseous reactor effluent with an aqueous stream in an absorber to form a liquid absorption solution comprising acrylonitrile; and fractionating the liquid absorption solution in a purification section comprising one or more distillation columns to recover a product comprising acrylonitrile.

40. The process of claim 39, wherein acrolein obtained in the dehydration reaction product is blended with propylene to form an ammoxidation feed mixture and the ammoxidation feed mixture is introduced into the one or more ammoxidation reactor units of the ammoxidation reactor system.

41. The process of claim 40, wherein the propylene is selected from the group consisting of petroleum-derived propylene, bio-based propylene, and combinations thereof.

42. The process of claim 41, wherein the propylene is bio-based propylene generated from CO₂ recovered or sequestered from sources other than those derived from fossil fuels or CO₂ generated from raw materials produced from CO₂ recovered or sequestered from sources other than those derived from fossil fuels.

43. The process of any one of claims 38 to 42, wherein acrolein and optionally propylene is reacted with the molecular oxygen containing gas and ammonia within a fluidized bed comprising the ammoxidation catalyst.39CORE / 3523894.000802 / 238587898.1

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