Microwave-assisted catalytic pyrolysis of switchgrass for improving bio-oil and biochar properties

Badr A Mohamed; Chang Soo Kim; Naoko Ellis; Xiaotao Bi

doi:10.1016/j.biortech.2015.10.096

Microwave-assisted catalytic pyrolysis of switchgrass for improving bio-oil and biochar properties

Bioresour Technol. 2016 Feb:201:121-32. doi: 10.1016/j.biortech.2015.10.096. Epub 2015 Nov 5.

Authors

Badr A Mohamed¹, Chang Soo Kim², Naoko Ellis³, Xiaotao Bi⁴

Affiliations

¹ Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Agricultural Engineering Department, Cairo University, Giza, Egypt.
² Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Clean Energy Research Center, Korea Institute of Science and Technology, 14 gil 5 Hwarang-no Seongbuk-gu, Seoul 136-791, Republic of Korea.
³ Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
⁴ Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada. Electronic address: tony.bi@ubc.ca.

PMID: 26642217
DOI: 10.1016/j.biortech.2015.10.096

Abstract

Solid additives were used as a microwave absorber to improve the low microwave absorption rate of switchgrass going through pyrolysis, and as a catalyst to improve the bio-oil and biochar characteristics. The synergistic effects were manifested in the presence of a mixture of K3PO4 and clinoptilolite or bentonite compared with single catalyst, resulting in increased microwave absorption rate, and improved bio-oil and biochar quality. The sample of microwave heating switchgrass with 10wt.% K3PO4+10wt.% bentonite reached 400°C after 2.8min, compared with 28.8min through conventional heating, producing biochar with increase in BET surface area from 0.33m(2)/g to 76.3m(2)/g compared with conventional heating. Furthermore, water content of the bio-oil reduced from 22.7 to 15.0wt.% compared with biomass mixed with 20wt.% SiC, a chemically-inert microwave absorbing material used to increase microwave heating. Introducing catalysts showed a great potential for accelerating microwave heating and improving bio-oil and biochar qualities.

Keywords: Bentonite; Catalytic microwave pyrolysis; Clinoptilolite; K(3)PO(4); Synergistic effects.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bentonite / chemistry
Biofuels*
Catalysis
Charcoal / chemistry*
Heating / methods
Microwaves
Panicum / chemistry*
Phosphates / chemistry
Potassium Compounds / chemistry
Zeolites / chemistry

Substances

Biofuels
Phosphates
Potassium Compounds
biochar
clinoptilolite
Bentonite
Zeolites
Charcoal
potassium phosphate