| 摘要 |
PURPOSE:To produce isoprene from an isobutylene source and a formaldehyde source, economically, under specific condition, by using inexpensive spent BB fraction as the isobutylene source, and subjecting the source to the low-temperature reaction step, 4C compound removal step, high-temperature reaction step and purification step. CONSTITUTION:An isobutylene source is made to react with a formaldehyde source continuously in a liquid phase in the presence of an acidic catalyst and water to obtain isoprene. In the above process, the butane-butene fraction containing isobutylene and produced as a by-product of the catalytic cracking of petroleum is used as the isobutylene source, and is subjected to (1) the low-temperature reaction step 4 comprising the synthesis of isoprene precursor by reacting with a formaldehyde source at 50-140 deg.C, (2) the 4C compound removal step 13 to remove the 4C hydrocarbon from the liquid obtained by the step (1), (3) the high-temperature reaction step 16 to decompose the isoprene precursor in the liquid obtained by the step (2) to isoprene at 145-230 deg.C, and (4) the purification step 23 to purify the produced isoprene. Isoprene can be produced efficiently from an inexpensive raw material with a simple apparatus. |
