Mechanism of the effect of temperature on the characteristics of microwave hydrothermal products of dead pig model compounds

Abstract

Microwave hydrothermal treatment is a promising technology for the environmentally friendly disposal and resource utilization of dead pigs. However, the hydrothermal transformation mechanism of animal-based biomass is unclear, impeding the regulated conversion of target products. To address this, bovine serum albumin, glycerol-oleic acid, and glucose were selected as model compounds for protein (P), lipid (L), and carbohydrate (C), respectively. In this paper, the product distribution and related properties of single, binary, and ternary model compounds at different microwave hydrothermal temperatures (120–240 °C) were investigated, and the essential reaction pathway of the dead pig model compounds during microwave hydrothermal treatment was proposed. The results showed that lipids dominated the formation of bio-oil. L&C and L&P showed a slight synergistic effect on bio-oil yield at 240 ℃, while exhibited antagonistic effects at other temperatures. L&P&C showed antagonistic effects on bio-oil yield at all temperatures. The participation of glucose was more conducive to the formation of carbonized solid products. The model compounds of dead pigs underwent a series of reactions such as dehydration, decarboxylation, deamination and condensation during microwave hydrothermal treatment. To a certain extent, lipids promoted the Maillard reaction of protein and carbohydrate, while glucose promoted the esterification reaction of fatty acids.