Contents lists available at ScienceDirect Bioresource Technology journal homepage: www.elsevier.com/locate/biortech Applying microwave vacuum pyrolysis to design moisture retention and pH neutralizing palm kernel shell biochar for mushroom production Wan Adibah Wan Mahari a,b,1 , Wai Lun Nam b,1 , Christian Sonne c,1 , Wanxi Peng a,1 , Xue Yee Phang b , Rock Keey Liew d , Peter Nai Yuh Yek b,e , Xie Yi Lee b , Ou Wei Wen f , Pau Loke Show g , Wei-Hsin Chen h,i,j , Jo-Shu Chang i,k , Su Shiung Lam b,a, ⁎ a Henan Province Engineering Research Center for Biomass Value-added Products, Henan Agricultural University, Zhengzhou 450002, China b Pyrolysis Technology Research Group, Institute of Tropical Aquaculture and Fisheries (Akuatrop), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia c Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark d NV WESTERN PLT, No. 208B, Jalan Macalister, Georgetown, Pulau Pinang 10400, Malaysia e University College of Technology Sarawak, Department of Engineering, 96000 Sibu, Sarawak, Malaysia f Siong Hoong Agro Organic Farm, Jalan Tanggul, Kg Bukit Kuan, 21040 Marang, Terengganu, Malaysia g Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia h Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan 701, Taiwan i Department of Chemical and Materials Engineering, College of Engineering, Tunghai University, Taichung 407, Taiwan j Department of Mechanical Engineering, National Chin-Yi University of Technology, Taichung 411, Taiwan k Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan GRAPHICAL ABSTRACT ARTICLE INFO Keywords: Biochar Vacuum Pyrolysis Oyster mushroom Mushroom cultivation ABSTRACT Microwave vacuum pyrolysis of palm kernel shell was examined to produce engineered biochar for application as additive in agriculture application. The pyrolysis approach, performed at 750 W of microwave power, pro- duced higher yield of porous biochar (28 wt%) with high surface area (270 cm 2 /g) compared to the yield obtained by conventional approach (< 23 wt%). Addition of the porous biochar in mushroom substrate showed increased moisture content (99%) compared to the substrate without biochar (96%). The mushroom substrate added with biochar (150 g) was optimal in shortening formation, growth, and full colonization of the mycelium https://doi.org/10.1016/j.biortech.2020.123572 Received 21 April 2020; Received in revised form 19 May 2020; Accepted 21 May 2020 ⁎ Corresponding author. E-mail address: lam@umt.edu.my (S.S. Lam). 1 Co-first authors with equal contribution to this work. Bioresource Technology 312 (2020) 123572 Available online 23 May 2020 0960-8524/ © 2020 Elsevier Ltd. All rights reserved. T