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In this work, the role of Brønsted acid for furfural production in biomass pyrolysis on supported sulfates catalysts was investigated. The introduction of Brønsted acid was shown to improve the degradation of polysaccharides to intermediates for furfural, which did not work well when only Lewis acids were used in the process. Experimental results showed that CuSO 4 /HZSM-5 catalyst exhibited the best performance for furfural (28% yield), which was much higher than individual HZSM-5 (5%) and CuSO 4 (6%). The optimum reaction conditions called for the mass ratio of CuSO 4 /HZSM-5 to be 0.4 and the catalyst/biomass mass ratio to be 0.5. The recycled catalyst exhibited low productivity (9%). Analysis of the catalysts by Py-IR revealed that the CuSO 4 /HZSM-5 owned a stronger Brønsted acid intensity than HZSM-5 or the recycled CuSO 4 /HZSM-5. Therefore, the existence of Brønsted acid is necessary to achieve a more productive degradation of biomass for furfural. [ABSTRACT FROM AUTHOR]

Undecylenic acid methyl ester (UAME) was continuously produced from methyl ricinoleate using a microwave-assisted pyrolysis system with atomization feeding. The UAME yield of 77 wt.% was obtained at 500 °C using SiC as the microwave absorbent and heating medium. The methyl ricinoleate conversion and UAME yield from microwave-assisted pyrolysis process were higher than those from conventional pyrolysis. The effect of temperature on the pyrolysis process was also investigated. The methyl ricinoleate conversion increased but the cracking liquid yield decreased when the temperature increased from 460 °C to 560 °C. The maximum UAME yield was obtained at the temperature of 500 °C. [ABSTRACT FROM AUTHOR]

• Sargassum horneri is utilized as catalyst for esterification reactions. • The successful grafting of –SO 3 H groups is confirmed by FT-IR and XPS. • The oleic acid conversion of >96% was obtained at optimal conditions. • The catalyst shows remarkable regenerability. A solid acid catalyst prepared by sulfonated Sargassum horneri carbon was utilized for the esterification reaction of oleic acid and methanol. The formed amorphous carbon layers during carbonization and the access of sulfonic acid groups during sulfonation can catalyze the esterification reaction for biodiesel preparation efficiently. The catalyst was characterized by various methods to investigate its physical and chemical properties. With carbonization at 300 °C for 2 h followed by sulfonation at 90 °C for 5 h, the catalyst reached acid density of 1.40 mmol/g. The catalyst dosage, methanol/oleic acid (molar ratio), reaction temperature, and reaction time were optimized to 10 wt%, 15:1, 70 °C, and 3 h, respectively. Under the optimal condition, the conversion of oleic acid reached 96.4%. Additionally, the catalyst was regenerated after four cycles, with the conversion of oleic acid still reaching 95.4%. [ABSTRACT FROM AUTHOR]