Ethyl Lactate Synthesis by Catalytic Membranes in a Pervaporation‐Assisted Membrane Reactor

Abstract

A poly(styrenesulfonic acid)‐carboxymethylcellulose (PSSA‐CMC) blend catalytic membrane was prepared for ethyl lactate production in a pervaporation‐aided membrane reactor. The effects of PSSA/CMC concentration, initial molar ratio, and temperature on acid conversion were evaluated. Additionally, the separation performance of membrane was investigated as a function of flux and separation factor. Increasing the temperature enhanced lactic acid conversion at constant alcohol:acid ratio.

Green and Efficient Esterification Method Using Dried Dowex H+/NaI Approach

“…It was also quite difficult to isolate compound 30 for the same reasons; however, we were able to obtain a 40% yield. Malic acid (11) was chosen to be one of the starting materials in our esterification experiments because it is a dicarboxylic acid and it has two different kinds of carboxylic acid groups, primary and secondary. The dimethyl ester of malic acid (33) was effectively synthesized by stirring at room temperature for 24 h. Amino acids are very important compounds for all life on Earth, but in addition, their structures were very interesting for the esterification experiments presented here because of αamino groups and different side chains.…”

“…For the reasons mentioned earlier, DL-malic acid (11) was considered an interesting compound for selective esterification experiments. Malic acid is an important compound in biochemistry, produced by all living organisms, and it is part of the earlier mentioned citric acid cycle; 28 it also confers the sour taste to fruits.…”

“…10 Even though the literature is replete with methods for esterifications, novel approaches have been reported recently. Here are only a few examples: synthesis of ethyl lactate, 11 aryl carboxylates, 12 vinyl ether-containing esters, 13 and lipase-catalyzed alkyl valerates. 14 In addition, the use of triphenylphosphine oxide and oxalyl chloride [(COCl) 2 ] coupling reagents to achieve esterification at room temperature has been reported as a novel method.…”

Kimyasal Reaksiyonlarda Katalitik Membran Kullanımının İncelenmesi

“…Sabit alkol/asit oranında sıcaklığın artmasının laktik asit dönüşümünü arttırdığı tespit edilmiştir. Katalitik membran aktivitesini kaybetmeden 6 kez kullanılmıştır [17]. Ünlü Üretilen katalitik membranda SSA hem katalizör hem de çapraz bağlayıcı görevi görmüştür.…”