Patent RU-2374215-C2 (RU)
Inventor: KEHLNEZ TOM NEL SON
IPC: C07C11/06
Filed: 2005-08-01
Granted: 2009-11-27
Abstract: FIELD: chemistry. ^ SUBSTANCE: invention relates to a continuous method of selective conversion of C1-C6 aliphatic alcohol oxygenate to propylene, involving the following stages: a) bringing incoming material into contact with an acid etherification catalyst in the first reaction zone under etherification conditions, effective for formation of an outgoing flow containing ether and moving not less than 10% exothermal reaction heat, released when incoming material is converted to propylene, with the next propylene synthesis stage at that etherification stage, that way heating the ether-containing outgoing flow to approximately 250 to 450C, and obtaining a by-product in form of water in amount not less than 0.5 mole per mole of converted C1-C6 aliphatic alcohol oxygenate; b) increasing temperature of the formed ether-containing outgoing flow to approximately 375 and 525C and addition of a diluent to obtain heated mixture of ether, unreacted C1-C6 aliphatic alcohol oxygenate and diluent; c) reacting the formed heated mixture with particles of a double-acting catalyst which contains a molecular sieve, which is capable of converting contained oxygenates to C3 olefins and mutually converting C2 and C4Çè+ olefins to C3 olefin in the second reaction zone, containing not less than one reactor with a moving bed, where the reaction zone works in oxygenate conversion conditions, effective for converting oxygenates contained in the mixture to propylene and with speed of circulating the catalyst through the second reaction zone chosen such that, the operation cycle time of the catalyst is 300 hours or less so as to obtain propylene contained in the outgoing stream, containing the bulk of C3 olefin product and water, less quantity of C2 olefin, C4Çè+ olefins and C1-C4Çè+ saturated hydrocarbons and minor quantities unreacted oxygenate, oxygenate by-product and aromatic hydrocarbons; d) passing the propylene-containing outgoing stream in a separation zone where the outgoing flow is cooled and separated into a vapour fraction rich in C3 olefin, an aqueous fraction containing unreacted oxygenates and oxygenate by-product and a fraction of liquid hydrocarbons, containing heavier olefins, heavier saturated hydrocarbons and small quantities of aromatic hydrocarbons; e) repeated use of part of the aqueous fraction obtained at stage d) and b) to provide for at least part of the diluent used at that stage; f) division of the vapour fraction into a fraction rich in C2 olefin, a fraction of a product rich in C3 olefin, and a fraction rich in C4Çè+ olefin; g) repeated use of part of the fraction rich in C2 or C4Çè+ olefin, or a mixture of these fractions at state c); and h) removal of particles of the double-acting catalyst particles containing coke from the second reaction zone, oxidative regeneration of the removed catalyst particles in the regeneration zone and returning the stream of regenerated catalyst particles to the second reaction zone. ^ EFFECT: use of this method improves mean output of propylene in the operation cycle of the catalyst. ^ 10 cl, 1 dwg