| 摘要 |
PURPOSE:To obtain isoprene in high yield, by reacting an isobutylene source with a formaldehyde source in the presence of both an acidic catalyst and water at low temperature to give an isoprene precursor, decomposing it in the presence of both an inert organic solvent and the above-mentioned catalyst at high temperature. CONSTITUTION:In preparing isoprene by subjecting continuously at least one isobutylene source selected from isobutylene, tertiary butanol, and an alkyl tertiary butyl ether, and a formaldehyde source to liquid-phase reaction in the presence of both an acidic catalyst and water, the isobutylene source is reacted with the formaldehyde source in the presence of water in a low-temperature reaction zone at 30-145 deg.C, especially 50-140 deg.C, to synthesize an isoprene precursor. The solution taken out from the reaction zone is fed to a high-temperature reaction zone at >=150 deg.C, preferably 150-230 deg.C, the precursor is decomposed in the presence of an inert organic solvent into isoprene, so that the compound is obtained in high selectivity in high yield. |
