The dehydration of lactic acid to produce acrylic acid is a renewable alternative to the mostly used production of acrylic acid from propene. In this review, the recent developments and state of the art for the dehydration of lactic acid to acrylic acid are presented and critically commented. The most recent publications on the topic are discussed inetail with respect to the observed catalysts and process performance data. Among the different catalysts developed, three main groups can be distinguished: zeolites, sulphates, and phosphates. The latter, especially hydroxyapatites, have recently attracted the attention of academics in particular. The three families of catalysts are discussed and the recent developments and technical drawbacks in the gas phase dehydration are reported.

中文翻译：

---

乳酸脱水：最新技术

乳酸脱水生产丙烯酸是一种可再生的替代方法，可替代从丙烯中最常用的丙烯酸生产方法。在这篇综述中，提出了乳酸脱水为丙烯酸的最新进展和技术发展并进行了评论。关于所观察到的催化剂和工艺性能数据，没有必要讨论有关该主题的最新出版物。在开发的不同催化剂中，可以区分出三大类：沸石，硫酸盐和磷酸盐。后者，尤其是羟基磷灰石，最近特别引起了学者的关注。讨论了这三类催化剂，并报道了气相脱水中的最新进展和技术缺陷。