CHEMICAL ENGINEERING TRANSACTIONS VOL. 78, 2020 A publication of The Italian Association of Chemical Engineering Online at www.cetjournal.it Guest Editors: Jeng Shiun Lim, Nor Alafiza Yunus, Jiří Jaromír Klemeš Copyright © 2020, AIDIC Servizi S.r.l. ISBN 978-88-95608-76-1; ISSN 2283-9216 Pyrolysing Horse Manure via Microwave-Induced Heating for Bioenergy Recovery Guo Ren Mong a , Cheng Tung Chong b, *, Jo-Han Ng c , Su Shiung Lam d , William Woei Fong Chong a , Farid Nasir Ani a a School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia. b China-UK Low Carbon College, Shanghai Jiao Tong University, Lingang, Shanghai 201306, China. c Faculty of Engineering and Physical Sciences, University of Southampton Malaysia (UoSM), 79200 Iskandar Puteri, Johor, Malaysia. d Eastern Corridor Renewable Energy Group (ECRE), Environmental Technology Programme, School of Ocean Engineering, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia. ctchong@sjtu.edu.cn Transforming waste to energy is essential in view of the need to search for greener and more sustainable energy sources. Such transformation of energy is also aligned with the aim of reducing excessive waste generation whilst creating potential biofuel pathways for power generation. In the present study, animal waste in the form of horse manure is being used as feedstock to undergo microwave-induced pyrolysis via a fixed- bed pyrolysis rig. The relationship of the pyrolysis parameters such as pyrolysis temperature of 350 and 550 °C, carrier gas flow rate of 0.5 and 1.5 L/min and ratio of horse manure to activated carbon blend of 1:2 and 1:1, with the yield of pyrolysed products is studied. The derived pyrolysis products in the form of solid, liquid and gaseous are characterised and quantified. Result shows that the highest yield of solid, liquid and gaseous products obtained are 78.8 wt%, 24.7 wt% and 34.2 wt%. Solid yield is observed to decrease with increasing pyrolysis temperature while gaseous yield shows a reverse trend. Higher carrier gas flow rate is observed to lower the generation of gaseous and liquid yield while increasing the solid yield. Higher amount of activated carbon within the feedstock is seen to lower the solid yield but increase the gaseous and liquid yields. The liquid yield is found to contain 55.78 wt% of phenolic compounds while gaseous product consists of up to 55 vol% of syngas. The control of the operating conditions in pyrolysis rig enables the production of pyrolysis end products in different phases, generating useful bioenergy and biofertilizer products in the context of circular economy. 1. Introduction A joint study by the U.S Department of Energy and Agriculture in 2005 shows an approximate 35 M dry t of dry animal manure is produced from the agricultural land. From an energy point of view, these manures consist of 0.4310 18 J worth of equivalent energy, which amounts to 15 % of the total biomass energy consumed annually in the U.S (Perlack et al., 2005). The land and water pollution from illegal dumping or unsystematic disposal of animal waste have also raised concerns among the public. Effective methods to process these animal waste for safe disposal or upgrade them into higher value end products are in demand. Thermochemical conversion technologies present a viable solution that could achieve both the needs of waste disposal and waste utilisation. Thermochemical conversion refers to a process where a sample is heated to elevated temperature in an oxidative or inert environment to produce end products in the forms of solid (biochar), liquid (bio-oil) or gas (biogas). In general, such thermochemical conversion technologies are effective due to short processing time, capable of killing pathogens and producing minimal amount of nonbiodegradable sludge (Ro et al., 2010). One of the promising thermochemical conversional processes is pyrolysis which could be applied to animal manure. Various types of animal manure, such as swine manure (Ro et al., 2009), poultry manure (Isemin et al., 2019) and cattle manure (Yuan et al., 2017) have been DOI: 10.3303/CET2078024 Paper Received: 14/04/2019; Revised: 01/09/2019; Accepted: 16/09/2019 Please cite this article as: Mong G.R., Chong C.T., Ng J.-H., Lam S.S., Chong W.W.F., Ani F.N., 2020, Pyrolysing Horse Manure via Microwave- Induced Heating for Bioenergy Recovery, Chemical Engineering Transactions, 78, 139-144 DOI:10.3303/CET2078024 139