catalysts Review Production of Levulinic Acid from Cellulose and Cellulosic Biomass in Different Catalytic Systems Chen Liu 1, Xuebin Lu 1,2,*, Zhihao Yu 1 , Jian Xiong 2, Hui Bai 1 and Rui Zhang 3,* 1 School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China;
[email protected] (C.L.);
[email protected] (Z.Y.);
[email protected] (H.B.) 2 Department of Chemistry & Environmental Science, School of Science, Tibet University, Lhasa 850000, China;
[email protected] 3 School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China * Correspondence:
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[email protected] (R.Z.) Received: 2 August 2020; Accepted: 17 August 2020; Published: 3 September 2020 Abstract: The reasonable and effective use of lignocellulosic biomass is an important way to solve the current energy crisis. Cellulose is abundant in nature and can be hydrolyzed to a variety of important energy substances and platform compounds—for instance, glucose, 5-hydroxymethylfurfural (HMF), levulinic acid (LA), etc. As a chemical linker between biomass and petroleum processing, LA has become an ideal feedstock for the formation of liquid fuels. At present, some problems such as low yield, high equipment requirements, difficult separation, and serious environmental pollution in the production of LA from cellulose have still not been solved. Thus, a more efficient and green catalytic system of this process for industrial production is highly desired. Herein, we focus on the reaction mechanism, pretreatment, and catalytic systems of LA from cellulose and cellulosic biomass, and a series of existing technologies for producing LA are reviewed.