Value-addition of wheat straw through acid treatment and pyrolysis of acid treated residues

Agricultural straw utilization has become a big concern in many countries with abundance of the production. While different comprehensive utilization methods have been used for the bio-oil production, complete uses of the waste biomass into useful products need to be examined to reduce the environmental burdens of agricultural straw disposal. By deploying value addition of straw biomass, this article evaluates the two process for the complete utilization of straw including acid treatment into carbohydrates rich compounds and acid treated residue pyrolysis to phenolic and ketonic rich compounds. Effects of intrinsic alkaline and alkaline earth metals on wheat straw pyrolysis behavior and product distribution investigated. Acid pickling was executed employing HCl, HF and HCl + HF solution. Pyrolysis products of acid treated wheat straw were investigated. Fixed bed reaction results showed that acid pickling is beneficial to the production of liquid, the yield of liquid increased from 37.48 wt% raw wheat straw to 42.24 wt% wheat straw-HCl, 48.03 wt% wheat straw -HF, and 47.20 wt% wheat straw-HCl + HF. The relative content of compounds identified by GC/MS in bio-oil changed significantly after acid pickling. Sugar increased from 1.43% wheat straw to 25.27% wheat straw-HCI, 19.00% wheat straw-HF and 19.78% wheat straw-HCl + HF. Particularly, D-Allose, which has been increased from 0.19% wheat straw to 22.18% wheat straw-HCl), 7.22% wheat straw-HF), and 7.89% wheat straw-HCl + HF. These results provide evidence that the straw biomass has good potential to increase bioenergy production. (C) 2020 Elsevier Ltd. All rights reserved.