Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman Pyrolysis characteristics and kinetic studies of horse manure using thermogravimetric analysis Cheng Tung Chong a, ⁎ , Guo Ren Mong b , Jo-Han Ng c,d , William Woei Fong Chong b,d , Farid Nasir Ani b , Su Shiung Lam e , Hwai Chyuan Ong f a China-UK Low Carbon College, Shanghai Jiao Tong University, Lingang, Shanghai 201306, China b School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia c Faculty of Engineering and Physical Sciences, University of Southampton Malaysia (UoSM), 79200 Iskandar Puteri, Johor, Malaysia d UTM Centre for Low Carbon Transport in Cooperation with Imperial College London, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia e Pyrolysis Technology Research Group, Eastern Corridor Renewable Energy Group, School of Ocean Engineering, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia f Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia ARTICLE INFO Keywords: Pyrolysis Horse manure Thermogravimetric analysis Kinetic analysis Isoconversional method ABSTRACT Horse manure is a biowaste with bioenergy recovery potential for heat and power generation. However, there is no kinetics data in literature to date. In this work, a kinetic study of the pyrolysis process of horse manure is investigated through the use of thermogravimetric analyses. The samples were heated over a range of tem- perature from 298 to 927 K with four different heating rates of 1, 2, 5 and 10 K/min. The weight loss was measured by a thermogravimetric analyser in an inert atmosphere. The differential thermal gravimetric (DTG) thermogram shows that the highest reaction rate occurred at between 290.2 and 329.6 °C where the devolati- lisation process was initiated to overcome the activation energy barrier of the manure. The activation energy and pre-exponential factor obtained by the Kissinger method, assumed to be constant throughout the whole pyrolysis process are 149 kJ/mol and 3.3 × 10 12 s -1 , respectively. The activation energy calculated from the non-iso- thermal Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Friedman methods are 199.3, 200.2 and 194.6 kJ/mol, whereas the pre-exponential values are 9.3 × 10 18 , 1.8 × 10 19 and 3.6 × 10 20 s -1 , respectively. The kinetic parameters determined based on interval conversional fraction shows good agreement. The high volatile and low ash content in horse manure indicates the potential for bioenergy recovery. The results of the kinetic study can be used for modelling devolatilisation and designing thermochemical conversion processes. 1. Introduction The over-dependency on fossil fuels for power generation has led to the alarming decline in oil reserve and contributes directly to global warming. According to the study by the International Energy Association, half of the global crude oil reserve will be depleted by 2040 [1]. The insatiable appetite for fossil fuel also causes serious environ- mental concerns, such as water pollution from oil spillage and global warming from excessive emissions of carbon dioxides by burning fossil fuel. These factors have prompted the research and development of alternative fuels that are sustainable and environmental friendly. Bio- mass and biowastes have been explored extensively by researchers as potential carbon neutral fuels [2–4]. One of the biowastes is manures from livestocks, as animal excrement contains energy that can be har- nessed through various types of thermochemical processes [5]. Although manures have traditionally been used as fertilisers or land- filled as wastes, stricter environmental regulation calls for alternative disposal method to reduce land and water pollutions [6]. Some re- searchers have attempted to recover energy from manure waste, such as developing techniques to produce methane-rich biogas through anae- robic digestion [7] or gasification [8], bio-oil through pyrolysis [9] or hydrothermal liquefaction [10] and bio-char through pyrolysis [11]. Horse manure presents an attraction option as a source biomass waste for production of energy. According to the Food and Agriculture Organization of the United Nations, the global population of horses is estimated to be at 58 million. Although horse population is much lower compared to the most common livestock – cow (1 billion), the daily amount of manure produced by horse is comparable to those produced by cow. A typical adult horse weighing 450 kg produces about 16.8 kg of manure on a daily basis, while a cow of the same weight produces https://doi.org/10.1016/j.enconman.2018.11.071 Received 7 September 2018; Accepted 27 November 2018 ⁎ Corresponding author. E-mail address: ctchong@sjtu.edu.cn (C.T. Chong). Energy Conversion and Management 180 (2019) 1260–1267 0196-8904/ © 2018 Elsevier Ltd. All rights reserved. T