Abstract: Pyrolysis processes comprise contacting a waste polyolefin with a solid catalyst at a pyrolysis temperature to form a pyrolysis product containing C1-C10 hydrocarbons. In some instances, the solid catalyst can be a silica-coated alumina, a fluorided silica-coated alumina, or a sulfated alumina, while in other instances, the solid catalyst can be any suitable solid oxide or chemically-treated solid oxide that is characterized by a d50 average particle size from 5 to 12 ?m and a particle size span from 0.7 to 1.7. Hydrocarbon compositions are formed from the pyrolysis of waste polyolefins with specific amounts of methane and higher carbon number hydrocarbons.

Abstract: Provided is a technique of producing isoprene from 3-methyl-1,3-butanediol or 1,3-butadiene from 1,3-butanediol by using a single catalyst. A catalyst produces a conjugated diene containing zirconium oxide and calcium oxide in order to produce isoprene by removing two water molecules from one 3-methyl-1,3-butanediol molecule or produce 1,3-butadiene by removing two water molecules from one 1,3-butanediol molecule. Furthermore, a method for producing a conjugated diene includes a step of obtaining a fluid containing a conjugated diene that is isoprene or 1,3-butadiene by bringing a fluid containing 3-methyl-1,3-butanediol or a fluid containing 1,3-butanediol into contact with the catalyst for producing a conjugated diene as a single catalyst so as to cause a dehydration reaction to proceed.

Abstract: The present invention discloses an integrated process and an apparatus for production of various alcohols and Oligomerization of Olefinic feed stocks comprising butylenes and mixture thereof. In this process the combined light olefinic hydrocarbon feedstock is divided into two streams and contacted in two different reaction zones, viz. hydration and oligomerization. The mixture of alcohols and oligomer product from hydration reaction is separated and the bottom stream from separator is routed to oligomerization reaction zone in a controlled quantity as selectivity enhancer. Both the reaction zones are operated at different conditions. The product from oligomerization zone is further separated in to lighter and heavier components. Each reaction zone may comprise series of reactors filled with acidic catalysts comprising ion exchange resins.

Abstract: Provided in one embodiment is a continuous process for converting waste plastic into recycle for polyethylene polymerization. The process comprises selecting waste plastics containing polyethylene and/or polypropylene, and passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into offgas, a pyrolysis oil and optionally pyrolysis wax comprising a naphtha/diesel fraction and heavy fraction, and char. The pyrolysis oil and wax is passed to a refinery FCC feed pretreater unit. A heavy fraction is recovered and sent to a refinery FCC unit, from which a C3 olefin/paraffin mixture fraction is recovered, which is passed to a steam cracker for ethylene production. In another embodiment, a propane fraction (C3) is recovered from a propane/propylene splitter and passed to the steam cracker.

Abstract: Isobutanol may be converted into predominantly C12+ olefin oligomers under specified conditions. Such methods may comprise: contacting a feed comprising isobutanol with a zeolite solid acid catalyst having a MWW framework under conditions effective to convert the isobutanol into a product comprising C4n olefin oligomers, wherein n is an integer having a value of two or greater and about 80 wt. % or greater of the C4n olefin oligomers are larger than C8.

Abstract: A method of producing a fuel additive includes: passing a first process stream comprising C4 hydrocarbons through a methyl tertiary butyl ether synthesis unit producing a first recycle stream; passing the first recycle stream through a hydration unit producing the fuel additive and a second recycle stream; passing the second recycle stream through a recycle hydrogenation unit and a deisobutanizer unit; and recycling the second recycle stream to the methyl tertiary butyl ether synthesis unit.

Abstract: Compositions can include mixtures having from about 2 wt % to about 40 wt % of C10-C20 linear paraffins based on the weight of the mixture, from about 60 wt % to about 98 wt % of C10-C20 branched saturated hydrocarbons based on the weight of the mixture, and less than or equal to about 30 wt % of C20+ saturated hydrocarbons based on the weight of the mixture. Methods to obtain these compositions can include the isomerization of one or more C10-C20 alpha olefins under skeletal isomerization conditions to obtain an isomerization mixture and the hydrotreating of the isomerization mixture.

Abstract: Systems and methods are provided for oligomerization of olefins to distillate boiling range products while also recycling naphtha boiling range olefins as part of the feed. By performing the olefin oligomerization while also recycling naphtha boiling range olefins, it has been discovered that the resulting distillate boiling range products can have an unexpected improvement in diesel combustion quality, such as an unexpected improvement in cetane rating. In order to manage coke formation and maintain consistent activity profile for the oligomerization catalyst, the reaction can be performed in a moving bed reactor. Additional temperature control can be maintained by the recycling of the naphtha boiling range portions of the oligomerization product back to the reactor.

Abstract: The present disclosure provides methods and systems for producing an olefin, such as ethylene and propylene. A method for producing an olefin can comprise injecting an oxidizing agent and methane into an oxidative coupling of methane (OCM) reactor to generate ethylene. The methane and/or additional feedstocks for the OCM reactor can be derived from a thermal cracking or fluidized catalytic cracking (FCC) process. The ethylene generated in the OCM reactor can be converted to propylene through a dimerization unit and metathesis unit.

Abstract: Catalytic conversion of ketoacids is disclosed, including methods for increasing the molecular weight of ketoacids. An exemlary method includes providing in a reactor a feedstock having at least one ketoacid. The feedstock is then subjected to one or more C—C-coupling reaction(s) in the presence of a catalyst system having a first metal oxide and a second metal oxide.

Abstract: The present invention provides a process for producing butadiene by oxidative dehydrogenation of butylene, comprising: a reaction stage, wherein a multi-stage adiabatic fixed bed in series is used, wherein butylene, oxygen-comprising gas and water are reacted in the presence of a catalyst in each stage of the adiabatic fixed bed with the first stage of the adiabatic fixed bed being further separately fed a diluent, being nitrogen and/or carbon dioxide, and the molar ratio between this separately fed diluents and the oxygen of all the oxygen-comprising gases fed in the subsequent stage(s) of the adiabatic fixed bed being controlled, wherein the oxygen-comprising gas is air, oxygen-enriched air or oxygen, and at least one of all the oxygen-comprising gases fed in the subsequent stage(s) of the adiabatic fixed bed is oxygen-enriched air having a specific oxygen concentration or oxygen; and a post treatment stage, wherein the effluent from the last stage of the adiabatic fixed bed is treated to obtain a product b

Abstract: The present disclosure is directed to producing zeolite structures, especially Zeolite SSZ-39, using organic structure directing agents (OSDAs). In particular, the OSDAs comprise isomeric mixtures of N,N-dialkyl piperidinium cations.

Abstract: Recycle of a stream comprising C8 oligomers to an oligomerization zone to be oligomerized with C4 olefins can produce diesel range oligomers. A diesel stream can be separated from a gasoline stream which can be recycled to the oligomerization zone.

Abstract: The present invention is concerned with a catalyst composition comprising titanium-, zirconium- and/or hafnium amidinate complexes and/or titanium-, zirconium- and/or hafnium guanidinate complexes and organo aluminium and/or organic zinc compounds, a coordinative chain transfer polymerization (CCTP) process employing the catalyst composition as well as long chain aluminium alkyls and subsequent alcohols obtained by such process.

Abstract: Processes for forming propylene from methanol are disclosed. The processes involve converting methanol to a product mixture comprising ethylene and propylene, separating the ethylene from the propylene, dimerizing a first portion of the ethylene to form a product mixture comprising 1-butylene, isomerizing the 1-butylene to form a mixture of cis and trans 2-butylene, and performing olefin metathesis on a second portion of the ethylene and the mixture of cis and trans 2-butylene. In one embodiment, the methanol is produced by converting syngas to methanol, and in one aspect of this embodiment, the syngas, or a portion thereof, is produced from renewable feedstocks. In this aspect, renewable propylene is produced. The propylene can be polymerized to form polypropylene or co- or terpolymers thereof, and when the propylene is made from renewable resources, the resulting polymer is a renewable polymer.

Abstract: The invention relates to methods and equipment for converting C3+ olefin to, e.g., one or more of di-C3+ olefin, oligomers and polymers of C3+ olefin, branched C4+-aldehydes, C4+-carboxylic acids, and C4+ oxygenates. The invention encompasses producing methyl tert-butyl ether and diisobutylene, and converting methyl tert-butyl ether to isobutylene.

Abstract: The invention provides a method and apparatus for creating plasma particles and applying the plasma particles to a liquid. Liquid feedstock (e.g., water and/or hydrocarbons mixed with biomass) is pumped through a pipeline; the single-phase stream is then transformed into a biphasic liquid-and-gas stream inside a chamber. The transformation is achieved by transitioning the stream from a high pressure zone to a lower-pressure zone. The pressure drop may occur when the stream further passes through a device for atomizing liquid. Inside the chamber, an electric field is generated with an intensity level that exceeds the threshold of breakdown voltage of the biphasic medium leading to a generation of a plasma state. Furthermore, the invention provides an energy-efficient highly adaptable and versatile method and apparatus for sanitizing water using plasma particles to inactivate biological agents contaminating water.

Abstract: An electrochemical conversion method for converting at least a portion of a first mixture comprising hydrocarbon to C2+ unsaturates by repeatedly applying an electric potential difference, V(?1), to a first electrode of an electrochemical cell during a first time interval ?1; and reducing the electric potential difference, V(?1), to a second electric potential difference, V(?2), for a second time interval ?2, wherein ?2??1. The method is beneficial, among other things, for reducing coke formation in the electrochemical production of C2+ unsaturates in an electrochemical cell. Accordingly, a method of reducing coke formation in the electrochemical conversion of such mixtures and a method for electrochemically converting carbon to C2+ unsaturates as well as an apparatus for such methods are also provided.

Abstract: The present invention relates to a process for removing oxygenate from an olefin stream comprising oxygenate, comprising providing to an oxygenate recovery zone the olefin stream comprising oxygenate and a solvent comprising propanol, treating the olefin stream comprising oxygenate with the solvent, and retrieving from the oxygenate recovery zone at least one oxygenate-depleted olefinic product stream comprising olefin and a spent solvent comprising at least part of the oxygenate.

Abstract: A process for producing a base for a fuel from a C2 ethanol feedstock, by a first stage for oligomerization of the feedstock into a hydrocarbon effluent that contains a mixture of olefins for the most part having between 4 and 30 carbons, and contains a C10-C24 fraction that has a mean linearity that is greater than 60%, in the presence of a homogeneous catalytic system that contains a metal precursor of titanium, zirconium, hafnium, nickel and/or iron, a second stage for oligomerization of a portion of the effluent that is obtained from stage a), into a hydrocarbon effluent that contains a mixture of olefins for the most part having between 4 and 30 carbon atoms, and containing a C10-C24 fraction that has a mean linearity that is less than 50%, in the presence of a homogeneous catalytic system.

Abstract: The invention provides an olefin oligomerization process comprising the steps of: i) reducing the level of nitriles in an olefin feed by contacting the feed with a guard bed comprising gamma alumina having a surface area greater than 250 m2/g; and ii) contacting the olefin feed obtained in step i) with an oligomerization catalyst under conditions suitable to oligomerize the olefins in the feed; wherein the gamma alumina used in step i) has been obtained from needle shaped boehmite

Abstract: A phosphorous modified zeolite (A) can be made by a process that includes selecting a zeolite, steaming the zeolite, leaching the zeolite, separating solids from liquid, and calcining. An olefin product can be made from an oxygen-containing, halogenide-containing or sulphur-containing organic feedstock by contacting the feedstock with the phosphorous modified zeolite (A) in an XTO reactor under conditions effective to convert at least a portion of the feedstock to olefin products. The XTO reactor effluent can include light olefins and a heavy hydrocarbon fraction. The light olefins can be separated from the heavy hydrocarbon fraction. The heavy hydrocarbon fraction can be contacted in an OCP reactor at conditions effective to convert at least a portion of the heavy hydrocarbon fraction to light olefins.

Abstract: In a feed clean-up process at least two adsorbents (2, 4) are installed in front of an oligomerization reactor (3). Olefin feed is sent over one adsorbent (2) and the nitrile poisons are adsorbed so that clean feed will enter the reactor (3). Before the adsorbent (2) will be saturated, the feed (1) is sent to the other, fresh adsorbent (4). At the same time oligomerization product from the reactor (3) is used to desorb nitriles from the spent adsorbent (2).

Abstract: A method of producing butene from an oxygenate-containing feedstock is described. The oxygenate-containing feedstock is converted to olefins and separated. The C4 isoolefins are then etherified and separated. The normal C4 olefins can be used to produce butadiene.

Abstract: The invention relates to a process for converting hydrocarbons into products containing aldehydes and/or alcohols. The invention also relates to producing olefins from the aldehyde and alcohol, to polymerizing the olefins, and to equipment useful for these processes.

Abstract: Disclosed is the use of a metal catalyst or catalyst precursor that catalyzes the isomerization of an unsaturated fatty acid, unsaturated fatty acid derivative, or an unsaturated triglyceride. Also disclosed is the use of a metal catalyst or catalyst precursor that catalyzes the decarboxylation of an unsaturated organic compound. Also disclosed is the use of a catalyst or catalyst precursor for the dual function isomerization and decarboxylation of an unsaturated fatty acid to an unsaturated organic compound.

Abstract: Methods are provided for oligomerizing a dilute ethylene feed to form oligomers suitable for use as fuels and/or lubricant base oils. The fuels and/or lubricant base oils are formed by oligomerization of impure dilute ethylene with a zeolitic catalyst, where the zeolitic catalyst is resistant to the presence of poisons such as sulfur and nitrogen in the ethylene feed. The oligomers can also be formed in presence of diluents such as light paraffins.

Abstract: The present invention provides an olefin oligomerization process comprising the steps of: i) reducing the level of acetonitrile in an olefin feed by contacting the feed with a non-zeolitic metal oxide; and ii) contacting the olefin feed with reduced level of acetonitrile with an olefin oligomerization catalyst under conditions suitable to oligomerize the olefin.

Abstract: The present invention relates to a process for removing oxygenate from an olefin stream comprising oxygenate, comprising providing to an oxygenate recovery zone the olefin stream comprising oxygenate and a solvent comprising propanol, treating the olefin stream comprising oxygenate with the solvent, and retrieving from the oxygenate recovery zone at least one oxygenate-depleted olefinic product stream comprising olefin and a spent solvent comprising at least part of the oxygenate.

Abstract: The present invention relates to a process for removing dimethylether from an olefin stream comprising dimethylether, comprising: (a) providing to an oxygenate recovery zone the olefin stream comprising dimethylether and a methanol-comprising solvent, treating the olefin stream comprising dimethylether with the methanol comprising solvent, and retrieving at least a dimethylether-depleted, methanol-comprising olefin stream; and (b) providing to the oxygenate recovery zone a non-aqueous C2 to C4 alcohol solvent and treating the dimethylether-depleted, methanol-comprising olefin stream with the non-aqueous C2 to C4 alcohol solvent, and retrieving from the oxygenate recovery zone at least an olefinic product that is depleted in dimethylether and methanol and a spent solvent comprising at least one C2 to C4 alcohol and methanol.

Abstract: The present invention discloses processes for oligomerizing a monomer containing internal olefins using a solid acid catalyst. Illustrative monomers can contain at least 50 wt. % C6 to C24 internal olefins.

Abstract: Integrated systems are provided for the production of higher hydrocarbon compositions, for example liquid hydrocarbon compositions, from methane using an oxidative coupling of methane system to convert methane to ethylene, followed by conversion of ethylene to selectable higher hydrocarbon products. Integrated systems and processes are provided that process methane through to these higher hydrocarbon products.

Abstract: Embodiments of an invention disclosed herein relate to processes utilizing solvent extraction to remove nitrogen containing compounds and optionally other components from feedstreams of olefins and paraffins.

Abstract: In a process for oligomerizing an olefinic hydrocarbon feedstock comprising at least 65 wt % olefins and/or sulfur-containing molecules, the feedstock is contacted under oligomerization conditions with (a) a first unidimensional 10-ring molecular sieve catalyst and (b) a second multidimensional crystalline molecular sieve catalyst. The first and second catalysts may be contained in separate reactors or as separate beds in a single reactor.

Abstract: A process for the production of jet and other heavy fuels from alcohols and mixture of alcohols is disclosed. The process may include contacting in a reaction zone at least one C2 to C11 alcohol with a solid catalyst having activity for the simultaneous dehydration of the alcohols to form olefins, isomerization of the olefins to form internal olefins, and oligomerization of the olefins produced in situ via the dehydration reaction to form an effluent comprising mono-olefinic hydrocarbons. Preferably, the alcohol feed is a mixture of alcohols, such as C2 to C7 alcohols or C4 and C6 alcohols, enabling the production of a mixture of branched hydrocarbons that may be used directly as a jet fuel without blending.

Abstract: A process for preparing oligomers by continuous oligomerization of butenes is described, wherein a) a feed stream 1) comprising 1-butene and 2-butene in a total concentration of from 10 to 70% by weight and from 10 to 60% by weight of isobutane is reacted until more than 60% by weight of the 1-butene comprised in the feed stream 1 but less than 50% by weight of the 2-butene comprised in feed stream 1 have been converted into oligomers. b) The oligomers obtained in a) are separated off and optionally passed to a further work-up and the remaining residual stream is fed to work-up by distillation. c) Isobutane is separated off by distillation from the residual stream, and d) the isobutane-depleted stream obtained after the work-up by distillation c) is reacted to form oligomers.

Abstract: Methods and systems are provided for converting methane in a feed stream to acetylene. The hydrocarbon stream is introduced into a supersonic reactor and pyrolyzed to convert at least a portion of the methane to acetylene. The reactor effluent stream is further processed to generate larger hydrocarbons in a second reactor. The reactor effluent stream can be processed before the second reactor to remove waste products such as carbon monoxide and nitrogen in the reactor effluent stream.

Abstract: A catalyst is described which comprises at least one IZM-2 zeolite, at least one matrix and at least one metal selected from metals from groups VIII, VIB and VIIB, said zeolite having a chemical composition expressed as the anhydrous base in terms of moles of oxides by the following general formula: XO2:aY2O3:bM2/nO, in which X represents at least one tetravalent element, Y represents at least one trivalent element and M is at least one alkali metal and/or alkaline-earth metal with valency n, a and b respectively representing the number of moles of Y2O3 and M2/nO; and a is in the range 0.001 to 0.5 and b is in the range 0 to 1.

Abstract: Natural gas and petrochemical processing systems including oxidative coupling of methane reactor systems that integrate process inputs and outputs to cooperatively utilize different inputs and outputs of the various systems in the production of higher hydrocarbons from natural gas and other hydrocarbon feedstocks.

Abstract: Feeds containing triglycerides are processed to produce an olefinic diesel fuel product and propylene. The olefinic diesel can optionally be oligomerized to form a lubricant base oil product. The olefinic diesel and propylene are generated by deoxygenating the triglyceride-containing feed using processing conditions that enhance preservation of olefins that are present in the triglycerides. The triglyceride-containing feed is processed in the presence of a catalyst containing a Group VI metal or a Group VIII metal and optionally a physical promoter metal.

Abstract: Feeds containing triglycerides are processed to produce an olefinic diesel fuel product. The olefinic diesel can optionally be oligomerized to form a lubricant base oil product. The olefinic diesel is generated by deoxygenating the triglyceride-containing feed using processing conditions that enhance preservation of olefins that are present in the triglycerides. The triglyceride-containing feed is processed in the presence of a catalyst containing a Group VI metal or a Group VIII metal and optionally a physical promoter metal.

Abstract: A mixture can include 0.01 to 30 weight % of a medium or large pore crystalline silicoaluminate, silicoaluminophosphate materials, or silicoaluminate mesoporous molecular sieves (A), and 99.99 to 70 weight % of a MeAPO molecular sieve. The mixture can be included in a catalyst. An XTO process can include contacting an oxygen-containing, halogenide-containing, or sulphur-containing organic feedstock with the catalyst under conditions effective to convert the organic feedstock to olefin products. A combined XTO and OCP process can include contacting the organic feedstock with the catalyst at conditions effective to convert at least a portion of the organic feedstock to form an XTO reactor effluent including light olefins and a heavy hydrocarbon fraction, separating the light olefins from the heavy hydrocarbon fraction, and contacting the heavy hydrocarbon fraction in an OCP reactor at conditions effective to convert at least a portion of the heavy hydrocarbon fraction to light olefins.

Abstract: The present invention is directed to providing a method of producing synthetic fuels and organic chemicals from atmospheric carbon dioxide. Carbon dioxide gas is extracted from the atmosphere, hydrogen gas is obtained by splitting water, a mixture of the carbon dioxide gas and the hydrogen gas (synthesis gas) is generated, and the synthesis gas is converted into synthetic fuels and/or organic products. The present invention is also directed to utilizing a nuclear power reactor to provide power for the method of the present invention.

Abstract: Isobutene, isoprene, and butadiene are obtained from mixtures of C4 and/or C5 olefins by dehydrogenation. The C4 and/or C5 olefins can be obtained by dehydration of C4 and C5 alcohols, for example, renewable C4 and C5 alcohols prepared from biomass by thermochemical or fermentation processes. Isoprene or butadiene can be polymerized to form polymers such as polyisoprene, polybutadiene, synthetic rubbers such as butyl rubber, etc. in addition, butadiene can be converted to monomers such as methyl methacrylate, adipic acid, adiponitrile, 1,4-butadiene, etc. which can then be polymerized to form nylons, polyesters, polymethylmethacrylate etc.

Abstract: The present invention provides a process for preparing ethylene and propylene and a butadiene-enriched product, comprising the steps of: a) providing a C4 hydrocarbon stream, comprising iso-olefins and butadiene. b) subjecting the C4 hydrocarbon stream to an etherification process, wherein the iso-olefins are converted with methanol and/or ethanol to an tert-alkyl ether in the presence of a catalyst, wherein the molar ratio of alcohol to iso-olefin is maintained above 1, and retrieving an etherification product stream; c) separating the etherification product stream into an ether-enriched stream and a butadiene-enriched product; d) converting the tert-alkyl ether in the ether-enriched stream to ethylene and/or propylene by contacting least part of the ether-enriched stream with a molecular sieve-comprising catalyst at a temperature in the range of from 350 to 1000° C. and retrieving an olefinic product comprising ethylene and/or propylene.

Abstract: The present invention provides a process preparing ethylene and propylene, comprising the step of: a) contacting a feed comprising a tert alkyl ether obtained from an etherification reaction between ethanol and a tertiary iso-olefin with a zeolite-comprising catalyst at a temperature in the range of from 350 to 1000° C. to obtain a olefinic product comprising ethylene and propylene.

Abstract: The present invention provides a process for preparing ethylene and/or propylene, comprising the steps of providing a hydrocarbon stream, comprising C4+ normal olefins and C4+ iso-olefins; converting C4+ isoolefins to tert-alkyl ether and separating the ethers from the hydrocarbon stream; isomersing the C4+ normal olefins to iso-olefins and converting C4+ isoolefins to tert-alkyl ether and separating the ethers from the hydrocarbon stream; converting the obtained tert-alkyl ether to ethylene and propylene by contacting the tert-alkyl ether with a molecular sieve-comprising catalyst and retrieving an olefinic product.

Abstract: The present invention provides a process for preparing ethylene and/or propylene, comprising the steps of: a) providing an oxygenate-comprising feedstock; b) contacting the oxygenate-comprising feedstock with a molecular sieve-comprising catalyst at a temperature in the range of from 450 to 700° C. and converting at least part of the oxygenate into an olefinic product comprising ethylene and/or propylene; and c) retrieving the olefinic product, wherein the oxygenate-comprising feedstock comprises in the range of from 1 to 97 wt % of at least one tert-alkyl ether selected from the group MTBE, ETBE, TAME and TAEE, based on the weight of the oxygenates in the oxygenate-comprising feedstock, and further comprises methanol and/or DME.

Abstract: The present invention relates to a process for making essentially ethylene and propylene comprising: a) providing an alcohol mixture (A) comprising about 20 w % to 100% isobutanol, b) introducing in a reactor (A) a stream comprising the mixture (A) mixed with methanol or dimethyl ether or mixture thereof, optionally water, optionally an inert component, c) contacting said stream with a catalyst (A1) in said reactor (A), the MTO reactor, at conditions effective to convert at least a part of the alcohol mixture (A) and at least a part of the methanol and/or dimethyl ether to olefins, d) recovering from said reactor (A) an effluent comprising: ethylene, propylene, butene, water, optionally unconverted alcohols, various hydrocarbons, and the optional inert component of step b), e) fractionating said effluent of step d) to produce at least an ethylene stream, a propylene stream, a fraction consisting essentially of hydrocarbons having 4 carbon atoms or more, water and the optional inert component of step a), op

Abstract: The present invention relates to a process for the conversion of an alcohols mixture (A) comprising about 20 w % to 100% isobutanol to make essentially propylene, comprising: a) introducing in a reactor (A) (also called the first reaction zone or low temperature reaction zone) a stream comprising the mixture (A), optionally water, optionally an inert component, b) contacting said stream with a catalyst (A1) in said reactor (A) at conditions effective to dehydrate: at least a portion of the isobutanol to essentially butenes, at least a portion of other alcohols, if any, to essentially olefins other than butene having the same carbon number as the alcohol precursor, c) recovering from said reactor (A) an effluent comprising: butenes, optionally olefins other than butene, water, optionally unconverted alcohols of the mixture (A), various hydrocarbons, and the optional inert component of step a), d) fractionating said effluent of step c) to remove a portion or all the water, unconverted alcohols, optionally th