Main content area

Physicochemical characteristics and pyrolysis performance of corn stalk torrefied in aqueous ammonia by microwave heating

Hu, Jun, Jiang, Bingxing, Wang, Jing, Qiao, Yiheng, Zuo, Tianyi, Sun, Yahui, Jiang, Xiaoxiang
Bioresource technology 2019 v.274 pp. 83-88
acids, aldehydes, ammonia, ash content, corn stover, crystal structure, esters, furans, gas chromatography-mass spectrometry, hemicellulose, ketones, microwave treatment, moieties, phenols, physicochemical properties, pyrolysis, torrefaction
The physicochemical characteristics and pyrolysis performance of corn stalk (CS) torrefied in water and aqueous ammonia by microwave heating were investigated. Physicochemical characterization revealed that both microwave water torrefied CS (MCS) and microwave ammonia torrefied CS (MACS) showed low hemicellulose content, disrupted macrostructure, improved porous properties, and low ash content. MACS exhibited a significantly lower crystallinity degree of 44.34% than CS (79.55%) and MCS (89.50%). MACS also showed increased methyl/methylene groups intensity, and complete acetyl groups disrupture. Pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) revealed that compared with CS and MCS, MACS exhibited higher peak areas for ketones, aldehydes, furans and esters, and significantly lower peak areas for acids and phenols. A possible mechanism was proposed for the effects of wet torrefaction with aqueous ammonia on changes in physicochemical structure and pyrolysis behavior of corn stalk.