Thermo-chemical pretreatment of rice straw for further processing for levulinic acid production

Rice straw as a feedstock for biofuels: Availability, recalcitrance, and chemical properties

“…SEM micrographs of the rice straw before and after AP pre‐treatment showed that the smooth, intact and ordered structure of native rice straw gets modified into a rough and defibrillated material . Elumalai et al . found that after AP, rice straw swelled and became spongy like material with high porosity and accessibility .…”

“…FTIR analysis indicated that removal and aromatic deformation of lignin along with carbohydrate depolymerization (Table 21). 43,78,79,127 GPC analysis showed that molecular weight and polydispersity index of rice straw lignin was reduced to 2320 g mol −1 and 1.45, respectively, from 2910 g mol −1 and 1.87 present in native rice straw aft er AP. 124 Similarly, He et al 128 reported that lignin polydispersity was reduced from 3.53 to 1.03 along with its molecular weight aft er AP.…”

“…128 SEM micrographs of the rice straw before and aft er AP pre-treatment showed that the smooth, intact and ordered structure of native rice 203 204 152 n.d., not determined straw gets modifi ed into a rough and defi brillated material. 129 Elumalai et al 127 found that aft er AP, rice straw swelled and became spongy like material with high porosity and accessibility. 130 Khaleghian et al 131 also suggested that that the packed structure of native rice straw was opened up and outer silica layer was removed aft er pre-treatment which is believed to improve the enzyme accessibility.…”

Making Levulinic Acid and Ethyl Levulinate Economically Viable: A Worldwide Technoeconomic and Environmental Assessment of Possible Routes

“…The use of rice husks is also an object of study, and investigators optimized conditions for a pressurized acid hydrolysis by using hydrochloric and sulfuric acid (Table ) . The use of rice straw as a feedstock was also evaluated by other investigators, which included the assessment of different pretreatment options with NaOH, H 2 SO 4 , NaClO 2 , and NaClO; HCl was always used as the catalyst for the final conversion of the post‐pretreated fiber to LA . Wheat, which is one of the most cultivated grains in the world, also creates an idle flow of biomass residue in the market that could be used in the production of LA .…”

“…[89] Theu se of rice straw as af eedstock wasa lso evaluated by otheri nvestigators,w hich included the assessmento fd ifferent pretreatment options with NaOH, H 2 SO 4 ,N aClO 2 ,a nd NaClO;H Cl was always used as the catalyst for the final conversion of the post-pretreated fiber to LA. [90] Wheat, which is one of the most cultivated grainsi nt he world, also creates an idle flow of biomass residuei nt he market that could be used in the productiono fL A. [91] Investigators determined the optimal conditions for LA production from wheat straw,w hich are presented in Table 1.…”