High-temperature dielectric properties and pyrolysis reduction characteristics of different biomass-pyrolusite mixtures in microwave field

Kangqiang Li; Guo Chen; Xiteng Li; Jinhui Peng; Roger Ruan; Mamdouh Omran; Jin Chen

doi:10.1016/j.biortech.2019.122217

High-temperature dielectric properties and pyrolysis reduction characteristics of different biomass-pyrolusite mixtures in microwave field

Bioresour Technol. 2019 Dec:294:122217. doi: 10.1016/j.biortech.2019.122217. Epub 2019 Sep 29.

Authors

Kangqiang Li¹, Guo Chen², Xiteng Li¹, Jinhui Peng², Roger Ruan³, Mamdouh Omran⁴, Jin Chen⁵

Affiliations

¹ Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China.
² Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China; Key Laboratory of Green-Chemistry Materials in University of Yunnan Province, Yunnan Minzu University, Kunming 650500, PR China.
³ Key Laboratory of Green-Chemistry Materials in University of Yunnan Province, Yunnan Minzu University, Kunming 650500, PR China; Center for Biorefining, Bioproducts and Biosystems Engineering Department, University of Minnesota, 1390 Eckles Ave., Saint Paul, MN 55108, USA.
⁴ Process Metallurgy Research Group, Faculty of Technology, University of Oulu, Finland.
⁵ Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China; Key Laboratory of Green-Chemistry Materials in University of Yunnan Province, Yunnan Minzu University, Kunming 650500, PR China. Electronic address: jinchen@kust.edu.cn.

PMID: 31606598
DOI: 10.1016/j.biortech.2019.122217

Abstract

Exploring the dielectric properties of mineral-biomass mixtures is fundamental to the coupled application with biomass pyrolysis and microwave technology to mineral reduction. In this work, the microwave dielectric properties of five pyrolusite-biomass mixtures were measured by resonant cavity perturbation technique and the pyrolysis reduction characteristics were systematically investigated, including poplar, pine, ageratina adenophora, rapeseed shell and walnut shell. Results indicated that the dielectric properties commonalities of five mixtures with temperature represented by increasing firstly, dropping intensely and finally rising slightly, with excellent responsiveness to microwaves; which the change trend was mainly attributed to the crystal transformation of amorphous MnO₂ and pyrolusite reduction reactions by biomass pyrolysis. Meanwhile, the heating characteristics successfully matched the dielectric properties of the mixtures, and the pyrolusite reduction process by biomass can be divided into two stages: biomass pyrolysis and pyrolusite reduction. The work highlights the universal feasibility of the novel coupled method for mineral reduction.

Keywords: Biomass pyrolysis; Dielectric properties; Heating characteristics; Low-grade pyrolusite; Microwave heating.

MeSH terms

Biomass
Manganese Compounds*
Microwaves*
Oxides
Pyrolysis
Temperature

Substances

Manganese Compounds
Oxides
manganese dioxide