| 摘要 |
A process comprises: (a) charging a mixt. of methanol and tert. butyl alcohol in molar ratios 0.5-4:1 to an etherification reaction zone contg. a bed of an etherification catalyst under reaction conditions including pressure 30-500 psia, temp. 90-140 deg C and flow rate 0.5-20 vol. feed mixt. per vol. etherification catalyst per hour to thus form a reaction prod. comprising unreacted methanol, unreacted tert. butyl alcohol, water, isobutylene, DME and methyl tert. butyl ether (MTBE); (b) charging the reaction prod. to first MTBE recovery distn. zone and sepg. it into first lower boiling fraction contg. isobutylene, DME, methanol, water and MTBE and a second heavier fraction contg. methanol, tert. butyl alcohol and water; (c) charging the first fraction to methanol solvent extn. zone and countercurrently contacting it with water in vol. ratio 1-10:1 under extraction conditions including temp. 20-60 deg C and pressure 50-500 psia to provide overhead extract contg. isobutylene, DME, water and MTBE and a raffinate contg. methanol, MTBE, isobutylene, DME and water; (d) charging the extract to second MTBE purificn. distillation zone and separating it into second lower boiling fraction contg. isobutylene, DME and water and a second heavier fraction contg. MTBE; (e) charging the second lighter fraction to decantation sepn. zone and separating it into isobutylene fraction and water fraction; (f) charging at least part of the isobutylene fraction and added methanol to an isobutylene conversion reaction zone in molar ratio 0.3-0.8:1 methanol:isobutylene and contacting with a solid resin etherification catalyst under conditions including temp. 35-100 deg C, pressure 150-250 psia and flow rate 0.5-10 vol. per vol. catalyst per hour to convert the methanol and part of the isobutylene to MTBE and form isobutylene conversion prod. contg. MTBE, unreacted isobutylene, less than 0.5 wt.% methanol, DME, tert. butyl alcohol and water; and (g) recycling the isobutylene conversion prod. to the second MTBE purificn. distillation zone. |
