This paper reports on the investigation of the gasification from biomass using a laboratory scale fluidized bed gasifier. Main influencing factors, such as the temperature, steam flow rate and CaO to biomass mass ratio were studied. A model was developed for hydrogen-rich gas production from biomass via using ASPEN PLUS software. Sawdust was used as raw material for this study. Different operating conditions were considered and the model was verified. The results showed that the production of H₂ and CO₂ increased while the production of CO and CH₄ decreased with increasing temperature. When the steam was used as the gasifying agent at different temperatures, the production of H₂ increased significantly and its growth rate was ~48%. The increase of CaO to biomass mass ratio from 0% to 50% resulted in hydrogen content increasing from 40% to 68%. Simulation results showed that the model was suitable for biomass gasification process, which could provide some reference value for further biomass gasification experiment.

The stability of biocrude oil is a significant challenge for its storage, transportation, and refining. In this investigation, the thermal and oxidative stability of Spirulina-biocrude oil derived from a plug-flow continuous hydrothermal reactor was systematically studied. The biocrude oil was stored at three temperatures to simulate the winter (4 °C), spring and autumn (15 °C), and summer (35 °C) seasons, and in two atmospheres (air and N₂) to simulate the conditions of a storage tank being sealed or kept open. Results demonstrated that the physicochemical properties of biocrude oil were highly influenced by the storage environment. The viscosity of biocrude oil increased with increasing storage temperature and time. The maximum viscosity (17,577 mPa·s) was observed when biocrude oil was stored at 35 °C and in an air condition over 84 days, 145% higher than fresh biocrude oil (7164.2 mPa·s). The viscosity increased by 10.9% when biocrude oil was sorted at 4 °C in an N₂ atmosphere after being stored for 28 days. After long-term storage, biocrude oil still exhibited comparable characteristics to petroleum, with a slight decrease in HHV (31.36–33.97 MJ·kg⁻¹) and the nitrogen-to-carbon ratio (0.087–0.092). This study indicated that the viscosity and HHV of the biocrude oil derived from a continuous reactor stored at 4 °C in an N₂ atmosphere condition remained relatively unchanged, which enables the scheduling of oil refining production.

Chemical composition evaluation and pyrolysis behavior of biomass tar: Pyrolysis experiment and kinetic studies

With the acceleration of urbanization, while the amount of fertilizers used in agricultural production is increasing rapidly in industrial development, heavy metal pollution is also becoming more severe. Excessive use of fertilizers can lead to soil acidification, compaction, and degradation, while the sharp increase in heavy metal pollution observed also has adverse effects on soil quality and crop quality. Therefore, to prevent the loss of phosphorus from soil, improve the utilization rate of nitrogen in soil, and control cadmium pollution, the effects of biochar on the adsorption of nitrogen, phosphorus, and cadmium in soil were explored in this study. The following four experimental treatments were conducted: no biochar application, straw charcoal application, fruit shell charcoal application, and coconut shell charcoal application. Samples were collected from different soil depths (0 cm and 10 cm) after both 14 days and 28 days. The contents of total nitrogen, phosphorus, and cadmium were compared. The research findings indicate that these three types of biochar exhibit significant adsorption effects on nitrogen and phosphorus elements. Nevertheless, the adsorption effect on cadmium is not pronounced, potentially due to the stability of the biochar, the activity of microorganisms in the soil, and the alteration of cadmium speciation, which consequently results in an increase in cadmium content.