Catalytic co-pyrolysis of microwave pretreated chili straw and polypropylene to produce hydrocarbons-rich bio-oil.

In this work, the kinetic behavior and products of the co-pyrolysis of chili straw (CS) and polypropylene (PP) of distinguishing conditions (blending ratios, addition of catalysts, and microwave pretreatment at different power) had been investigated. Co-pyrolysis effectively reduced the proportion of oxygenated composition in CS, and the Oxygenated composition of 5CS5PP decreased by 76.69% compared to CS. When HZSM-5 was added, the aromatic hydrocarbons in the product increased from 4.46% to 17.34%, and the final residual mass decreased from 12.75% to 7.71%, illustrating that HZSM-5 had a positive effect on co-pyrolysis. Compared with P0HZSM-5, the microwave pretreatment at a higher power level of 567 W reduced the oxygenated composition from 17.41% to 13.09%, and the weight loss peak in the first stage increased from -18.11%/min to -19.94%/min. At the same time, the activation energy decreased from 271.25 kJ/mol to 231.13 kJ/mol.

Hydrothermal liquefaction of Chlorella pyrenoidosa and effect of emulsification on upgrading the bio-oil.

This work studied the hydrothermal liquefaction of Chlorella pyrenoidosa and effect of emulsification on upgrading the bio-oil. The fuel properties and storage stability characteristics of emulsion fuels were explored. The combustion characteristic analysis showed that the ignition temperatures of emulsion fuels (139.6-151.3 °C) were lower than that of bio-oil (176.9 °C). Besides, emulsion fuels had higher comprehensive combustion indexes (7.24-14.08 × 10-6 × min-2 × C-3) than bio-oil (1.51 × 10-6 × min-2 × C-3), indicating that emulsion fuels had better combustion performance. The kinetic analysis showed that emulsification could effectively reduce the activation energy, resulting in less energy input for combustion. Based on chemical composition evolution during the storage process, a possible stability mechanism was proposed. The storage stability analysis indicated that the diesel-solvable fractions in bio-oil had better stability. Overall, this work provides a feasible way for bio-oil upgrading through emulsification. In addition, a better understanding of the stability property of emulsion fuel was provided.