Investigation on Catalytic Effects of Aromatic Sulfonic Acids in Thermochemical Conversion of Agricultural Wastes to Valuable Chemicals
Project no. 20794 · Status: Kapanmış · 2019
Summary
<p>Nearly 97% of the lignocellulosic biomass produced annually worldwide is not utilized. Intensive studies are being conducted on a laboratory and pilot scale to extract liquid and gaseous fuels and various chemicals from this large potential using chemical and biochemical methods. In 2004, a list of 12 leading chemicals (building blocks) that can be produced from lignocellulosic biomass was published. These chemicals will form the basis for biorefineries to replace petrochemical refineries in the near future. One of these 12 chemicals is LEVULINIC ACID (LA). In this study, the conditions for the formation of LA using an autoclave reactor system in the presence of aromatic sulfonic acid catalysts from biomass waste were studied, which are important for our country. Production of levulinic acid (LA) from safflower stalk using aromatic sulfonic acids as environmentally friendly catalysts was also investigated. A Taguchi experimental design was used to determine the conditions for the highest product yield, and the variations of valuable by-products such as 5-HMF, formic acid, and acetic acid as a function of reaction conditions were also analyzed. Optimum conditions for maximum LA yield were found using para-toluenesulfonic acid (PTSA) with concentration of 0.3 M, solvent/biomass ratio as 20 at a temperature of 200°C. Comparison experiments were performed with sulfuric acid (H2SO4) under optimum conditions, and it was concluded that PTSA could be an alternative catalyst to H2SO4 in terms of LA yield. In the experiments with different biomasses under optimal conditions, the highest yield was found for corn cobs. Experiments were also performed to confirm the optimum LA yield found using analysis of variance (ANOVA). The reaction constants were determined in kinetic studies performed under optimum conditions. The yields of levulinic acid calculated with these constants and determined experimentally were found to fit the 3rd degree polynomial model.</p>