Integrated process for the production of vinyl acetate from acetic acid via acetaldehyde
申请人:Johnston Victor J.
公开号:US20100168466A1
公开(公告)日:2010-07-01
This invention provides an integrated multistep economical process for the production of vinyl acetate monomer (VAM) from acetic acid in the vapor phase. First, acetic acid is selectively hydrogenated over a hydrogenating catalyst composition to form acetaldehyde. Acetaldehyde so formed can be converted to ethylidene diacetate via reaction with acetic anhydride. In a subsequent step so formed ethylidene diacetate is thermally decomposed to form VAM and acetic acid. Alternatively, acetaldehyde formed in the first step can selectively be reacted with ketene to form VAM. In an embodiment of this invention reaction of acetic acid and hydrogen over platinum and iron supported on silica selectively produces acetaldehyde in a vapor phase at a temperature of about 300° C., which is selectively hydrogenated over platinum supported catalyst to form ethanol and dehydrated over NAFION catalyst to form ethylene at a temperature of about 185° C., which is mixed with molecular oxygen, acetic acid and reacted over a palladium/gold/potassium catalyst supported on titania to form VAM at a temperature of about 150° C. to 170° C.
这项发明提供了一种集成多步骤经济过程,用于从醋酸在蒸汽相中生产乙烯醋酸酯单体(VAM)。首先,醋酸经过氢化催化剂组合物的选择性加氢,形成乙醛。所形成的乙醛可以通过与醋酸酐反应转化为乙烯二醋酸酯。在随后的步骤中,所形成的乙烯二醋酸酯经热分解形成VAM和醋酸。另外,第一步中形成的乙醛可以选择性地与酮烯反应形成VAM。在这项发明的实施例中,醋酸和氢在铂和铁负载在二氧化硅上的催化剂上反应,选择性地在约300°C的温度下产生乙醛,然后在铂负载的催化剂上加氢形成乙醇,再在NAFION催化剂上脱水形成乙烯,温度约为185°C,然后与分子氧混合,醋酸反应,使用负载在钛白粉上的钯/金/钾催化剂形成VAM,温度约为150°C至170°C。