Abstract:
Levulinic acid is a C5-chemical with a ketone and a carboxylic group which can used to produce value-added product. It can be produced from lignocellulose by using pretreatment process and chemical reaction. Giant sensitive plant (Mimosa pigra L.), a woody tropical weed containing high cellulose content which can be utilized as a substrate for levulinic acid production, was used in this research. The aims of this study are to investigate the feasibility of the pretreatment of wood from giant sensitive plant and to produce levulinic acid from pretreated wood. The wood was pretreated with 3 pretreatment methods and it was found that (1) the optimum condition for the thermo-chemical pretreatment was pretreatment with microwave-assisted NaOH at 10 % w/v, for 10 min, which could increase the cellulose content of wood up to 65.37 % (w/w), (2) the optimum condition for the biological pretreatment was pretreatment with Phanerochaete sordida SK7 at ration 6:1 mg culture/g wood , for 30 days, which could increase the cellulose content of wood up to 53.83 % (w/w), and (3) the optimum condition for the biological pretreatment combined with thermo-chemical pretreatment was pretreatment with the optimum condition of biological pretreatment and followed by the optimum condition of thermo-chemical pretreatment, which could increase the cellulose content of wood up to 70.15 % (w/w). The pretreated wood from each method under optimum condition was used to produce levulinic acid via hydrothermolysis process using ZSM-5 and Al-SBA-15 as catalysts. The highest levulinic acid yields was 5.68 % (w/w) (pretreated wood with biological pretreatment combined with thermo-chemical pretreatment) using ZSM-5 as the catalyst.