Selective Conversion of Scenedesmus into Lactic Acid over Amine-Modified Sn-β

Amine-modified Sn-beta was synthesized to improve the yield of lactic acid produced from Scenedesmus. After studying the growth of Scenedesmus, we selected Scenedesmus with the highest sugar content of 46.7% after 8 days of culture as the reaction substrate. The results showed that the yield of lactic acid from Scenedesmus was greatly increased after being catalyzed by 3-aminopropyltrimethoxysilane (APTMS)-modified Sn-beta. After the pretreatment of Scenedesmus in an ice bath ultrasound, under the optimal reaction conditions (190 degrees C and 5 h), the yield of lactic acid reached the highest (37%). The acid-base characterization results of the catalyst confirmed that there are both Lewis acidic sites and medium-strength basic sites in the catalyst. Both of these sites can promote the hydrolysis of Scenedesmus, while the Lewis acidic sites can promote the production of lactic acid and the basic sites can effectively inhibit the production of the byproduct 5-hydroxymethylfurfural (HMF). This study proved that this amination catalyst is a useful strategy to increase the yield of lactic acid.

Automated summary

The utilization of amine-modified Sn-beta catalyst significantly increased the yield of lactic acid produced from Scenedesmus, achieving a maximum yield of 37%. The catalyst contains both Lewis acidic and medium-strength basic sites, which promote the hydrolysis of Scenedesmus and inhibit the production of the byproduct HMF.