In a study published in Case Studies in Chemical and Environmental Engineering, Unsomsri et al., explored a method to mitigate air pollution from open-field rice straw burning. The research focused on optimizing biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More production using an integrated biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More gasifier and burner (BGB) system. This innovative approach not only offers a sustainable alternative to traditional burning practices but also significantly reduces greenhouse gas emissions and total suspended particulates.  

Rice straw, an abundant byproduct of rice production, often ends up being burned in open fields, causing significant environmental damage. This burning releases harmful pollutants into the atmosphere, including PM2.5, and contributes to soil degradation and poor air quality. To combat these issues, the study explored the production of biochar, a carbon-rich material made from biomass pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More, as a sustainable alternative.  

The authors optimized biochar production at 550°C for 4 hours, achieving a biochar product with 61% carbon content and a 0.92 stability factor. Each batch of biochar retained 4.382 kg of carbon, equivalent to 16.07 kg of CO2, with an annual sequestration potential of 5.863 tons of CO2 equivalent. The BGB system proved effective in significantly reducing environmental pollutants: greenhouse gas emissions were reduced by 65%, and total suspended particulates decreased by 89%.  

This study demonstrates that biochar production offers a promising strategy for mitigating climate change and providing a sustainable alternative to open-field burning for farmers.  

SOURCE: Unsomsri, N., Koedthong, P., Tawkaew, S., Wiriyasart, S., & Kaewluan, S. (2025). Mitigating dust and air pollution from open-field rice straw burning through biochar production using an integrated biomass gasifier and burner. Case Studies in Chemical and Environmental Engineering, 11, 101222.