Unveiling the role of potassium and calcium metal in biomass ash on the pyrolysis of corn stalk

Alkali and alkaline earth metals (AAEMs) in biomass ash significantly influence pyrolysis product characteristics. This study systematically investigates the catalytic effects of K and Ca on the pyrolysis of corn stalk, with metal concentrations ranging from 2% to 7% and pyrolysis temperatures from 400 to 600 °C. Results show that Ca, owing to its strong Lewis acidity, markedly promotes H₂ generation (from 5.67 to 32.49 vol%) and selectively enriches furans (from 2.89% to 65.88%) at 600 °C. In contrast, K exhibits concentration-dependent behavior: at low concentration (2%), it favors phenols (26.20%), whereas at higher concentrations (5-7%), it shifts selectivity toward ketones (12.76%) and acids (39.41%). Elevated pyrolysis temperatures synergize with both metals to enhance secondary cracking, reducing bio-char yield while increasing H₂ and CH₄ yields. These findings provide quantitative insights into the distinct catalytic roles of K and Ca and offer practical guidance for the targeted regulation of pyrolysis products through feedstock selection and process optimization. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.