Decarbonylation of Lactic Acid to Acetaldehyde over Aluminum Sulfate Catalyst

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• 作者：Zhanjie Zhai ; Xinli Li ; Congming Tang ; Jiansheng Peng ; Ning Jiang ; Wei Bai ; Hejun Gao ; Yunwen Liao
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：June 25, 2014
• 年：2014
• 卷：53
• 期：25
• 页码：10318-10327
• 全文大小：510K
• ISSN：1520-5045

文摘

Decarbonylation of lactic acid to acetaldehyde over several solid catalysts was investigated. Among the tested catalysts, aluminum sulfate has an excellent activity. In order to further understand the main reason which influenced the catalytic activity, NH₃-TPD was used to estimate the acidity of the catalyst. According to the total acid amount, aluminum sulfate has a moderate amount. Heteropolyacids have strong acidity which caused serious carbon deposition on the surface of catalysts, resulting in a rapid deactivation of catalysts. Besides, FT-IR, XRD, and SEM were also utilized to characterize the fresh catalysts and the used. As for the aluminum sulfate catalyst, an evident adsorption band occurs in 2970 cm^鈥?, suggesting a formation of poly lactate on the surface of the catalyst, and led to deactivation of the catalyst. Other parameters such as reaction temperature, lactic acid concentration, and LHSV (liquid hourly space velocity) were also discussed. Inspiringly, at high LHSV, lactic acid was efficiently converted to acetaldehyde via a decarbonylation reaction. As for stability and the recovery of aluminum sulfate, deactivation of the catalyst belongs to temporary deactivation caused by poly lactate covering the active sites of the catalyst, and only at simple calcination under the air atmosphere, the catalyst may be compeletely regenerated. Under the optimal reaction conditions, conversion of lactic acid achieved 100%, and the selectivity of acetaldehyde achieved 92.1% at 380 掳C over the aluminum sulfate catalyst.