REGULATION MECHANISM OF BIOMASS ASH FUSION CHARACTERISTICS THROUGH AAEMs MIGRATION AND TRANSFORMATION IN CO2-MEDIATED TORREFACTION

Wang Weishu; Qin Yuhong; Wang Yuefeng; Gao Songping; Guo Shugang

doi:10.19912/j.0254-0096.tynxb.2025-0496

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Acta Energiae Solaris Sinica ›› 2026, Vol. 47 ›› Issue (8) : 1-8. DOI: 10.19912/j.0254-0096.tynxb.2025-0496

REGULATION MECHANISM OF BIOMASS ASH FUSION CHARACTERISTICS THROUGH AAEMs MIGRATION AND TRANSFORMATION IN CO₂-MEDIATED TORREFACTION

Wang Weishu¹, Qin Yuhong¹, Wang Yuefeng¹, Gao Songping², Guo Shugang³

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Abstract

This study focuses on walnut shell（WS） and vinegar residue （VR） as research subjects, investigating the effects of torrefaction pretreatment on biomass ash fusion characteristics in both CO₂ and N₂ atmospheres within a fixed-bed reactor. Chemical fractionation and inductively coupled plasma mass spectrometry （ICP-MS） were adopted to quantify the occurrence modes and contents of AAEMs, respectively. The results reveal that compared with N₂ atmosphere, torrefaction under CO₂ atmosphere elevates the mass loss rate and ash yield of biomass, and significantly increases four ash melting characteristic temperatures of torrefied biomass, namely deformation temperature （DT）, softening temperature （ST）, hemisphere temperature （HT） and flow temperature （FT）. At the torrefaction temperature of 300 ℃ under CO₂ atmosphere, the ST of WS ash rises by 251 ℃, while the ST of VR ash increases by 117 ℃. Chemical fractionation results demonstrate that CO₂ atmosphere facilitates the growth of HCl-soluble and insoluble AAEM fractions in torrefied biomass. Further X-ray diffraction （XRD） characterization verifies the rise in relative content of high-melting-point alkaline earth metal aluminosilicates in ash. In summary, torrefaction in CO₂ atmosphere can more effectively mitigate ash deposition and slagging during biomass thermal conversion.

Key words

biomass / alkali metal elements / alkaline earth metal elements / torrefaction pretreatment / ash fusion characteristics

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Wang Weishu, Qin Yuhong, Wang Yuefeng, Gao Songping, Guo Shugang. REGULATION MECHANISM OF BIOMASS ASH FUSION CHARACTERISTICS THROUGH AAEMs MIGRATION AND TRANSFORMATION IN CO₂-MEDIATED TORREFACTION[J]. Acta Energiae Solaris Sinica. 2026, 47(8): 1-8 https://doi.org/10.19912/j.0254-0096.tynxb.2025-0496

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