Influence of acid-washed pretreatment on the pyrolysis of corn straw: A study on characteristics, kinetics and bio-oil composition

Corn straw was washed using hydrochloric acid in this study. The properties of biomass and pyrolysis charac-teristics and the bio-oil components were examined systemically. The results showed acid washing removed the most metals in corn straw, improved the contents of cellulose and hemicellulose and reduced the activation energy of pyrolysis process. FTIR (Fourier transform infrared) spectra displayed some differences in peak transmittances between the original and pretreated corn straw. The GC-MS (Gas chromatography-mass spec-trometer) analysis showed the major oxygenated components in bio-oil including furans, ketones, acids, phenols and aldehydes were efficiently destroyed by hydrochloric acid pretreatment, while the alcohols and sugars content increased significantly. A significant decrease of furans content was observed, especially the benzofuran, 2,3-dihydro-, from 7.23 % to 0%. D-allose and D-Erythro-Pentose, 2-deoxy-have been found in pretreated corn straw, which implied that more value-added chemicals could be obtained by hydrochloric acid washing.

Automated summary

The study found that hydrochloric acid washing could effectively remove metals in corn straw, increase cellulose and hemicellulose content, and reduce the activation energy of the pyrolysis process. GC-MS analysis showed that oxygenated components in bio-oil were efficiently destroyed by hydrochloric acid pretreatment while alcohols and sugars content increased significantly.