FIELD: chemistry.
SUBSTANCE: invention relates to a method of converting methanol material to olefins. The method involves: reacting the methanol material in a first conversion zone with a catalyst in reaction conditions effective to produce a first reaction zone effluent containing dimethyl ether (DME), unreacted methanol and water; cooling the first reaction zone effluent to separate DME as a first gaseous product from the first reaction zone effluent and to form a first aqueous stream containing water, unreacted methanol, soluble DME and oxygenates; further reacting the first gaseous product in a second conversion zone with a catalyst in reaction conditions effective to produce a second reaction zone effluent containing light olefins, unreacted DME, water and oxygenates; cooling the second reaction zone effluent to separate the light olefins and the unreacted DME as a second gaseous product from the second reaction zone effluent and to form a second aqueous stream containing water, soluble DME and oxygenates; compressing the unreacted DME and the light olefins; separating DME from the light olefins with an aqueous absorbing liquid to produce virtually DME free olefin product and a third aqueous stream containing the absorbing liquid, absorbed DME, soluble oxygenates and hydrocarbons; feeding at least a portion of the first, second and/or third aqueous streams into a stripper of a fractionation tower and stripping and recovering the methanol, DME, soluble oxygenates and hydrocarbons as an overhead gaseous product and a fourth aqueous stream containing substantially clean water as a bottom liquid product; and recycling at least a portion of the overhead gaseous product to the first conversion zone and/or to the second conversion zone.
EFFECT: use of the present method enables to minimise formation of reaction by-products which cannot be recycled or used in other processes.
10 cl, 1 dwg
