Study on product distribution, physicochemical structure evolution, and energy flow in concentrated solar pyrolysis of walnut shells

作者：Hanjian Li, xiaoxuan Lyu, Shichen Ding, Ying Zhao, Shagali Abdulmajid Abdullahi, Yi Wang, Sheng Su, Song Hu, Jun Xiang, Huanying Chi · 发表于：Fuel Processing Technology · 年份：2026 · DOI：10.1016/j.fuproc.2026.108396 · 被引用次数：3 · 研究领域：Solar Thermal and Photovoltaic Systems、Solar Energy Systems and Technologies、Thermochemical Biomass Conversion Processes

The present study explores the concentrated solar-driven pyrolysis of walnut shells to characterize the product distribution, physicochemical structural evolution, and energy flow. The experiments were conducted using a custom-built Confocal Elliptical-Streamline Concentrating Photothermal (CESCP) system, which implements a furnace lamp with a spectral output closely approximating natural sunlight. This setup provides a controlled simulation of genuine high-flux solar radiation and achieves an ultra-fast heating rate of 1000 °C/min. Across the temperature range of 500–1000 °C, the gas yield was notably high and increased significantly from 13.4% to 54.3%, among which syngas (H 2 + CO) exhibited the most substantial increase from 40.99 vol% to 70.5 vol%. For solid phase products, as the pyrolysis reaction proceeded, the specific surface area significantly increased by 314 times from 0.354 m 2 /g to 111.459 m 2 /g, the amorphous carbon progressively transformed into defective polycyclic aromatic hydrocarbons, and the oxygen-containing functional groups (such as hydroxyl and C-O bonds) exhibited higher activity. Crucially, at the pyrolysis temperature of 1000 °C, the sum of the higher heating value and the latent heat of vaporization of the products reached 17,207 J, representing an increase of 199 J compared to the raw biomass material. This data provides direct quantitative evidence for the storage of solar energy in the form of chemical energy. The findings of this study can ...