In-depth physiochemical characterization and detailed thermo-kinetic study of biomass wastes to analyze its energy potential Hammad Siddiqi a, * , Manisha Bal a , Usha Kumari a , B.C. Meikap a, b, c a Department of Chemical Engineering, Indian Institute of Technology (IIT) Kharagpur, West Bengal, 721302, India b Department of Chemical Engineering, School of Engineering, Howard College, University of Kwazulu-Natal, Durban, 4041, South Africa c School of Safety Science and Engineering, Henan Polytechnic University, 2001 Century Avenue, Jiaozuo, Henan, P.R. China article info Article history: Received 23 April 2019 Received in revised form 24 October 2019 Accepted 29 October 2019 Available online xxx Keywords: Alternate energy Biofuel Pyrolysis Reaction kinetics Thermodynamic parameters abstract The present work focuses on to determine the feasibility of alternate energy generation from waste biomass as a feedstock. Five different wastes namely coconut shell, corn cob, sugarcane bagasse, Shorea Robusta and Citrus limetta have been thoroughly characterized to analyze their energy potential. Coconut shell with highest heating value of 16.8 MJ/kg among all the samples and bulk density of 590.85 kg/m 3 has been selected for further detailed kinetic analysis. Highest overall volatile conversion of 57.17% is obtained in the active zone for heating rate 40  C/min. Different differential and integral based models have been discussed and implemented for the calculation of activation energy and its average value for coconut shell sample is found to be 109.90 kJ/mol with pre-exponential factor as 4.37х10 9 s 1 . Moreover, the reaction model was predicted by comparing various theoretical and experimental z (a) master plots. Also, the model fitting method is also used to obtain the reaction model f(a) ¼ (1-a) 4.6654 [-ln (1-a)] 0.2 which shows order based nucleation mechanism. Change in enthalpy, entropy and Gibbs free energy has also been determined to access the thermodynamic stability of the system. The kinetic parameters and thermodynamic results suggest highly reactive system initially which decreases with the extent of conversion. © 2019 Elsevier Ltd. All rights reserved. 1. Introduction Energy utilization in the world is rising intensely as economic growth and industrialization of any nation depends on its energy reserves. Increasing development activities have accelerated the energy demand, and population growth with urbanization are making the scenario even worst [1 ,2]. According to International Energy Agency (IEA), the total energy consumption will increase from 12,000 to 16,800 Mtoe (million tons of oil equivalent) be- tween 2007 and 2030 at the rate of 1.5% per year [3]. Today the primary energy dependence is on fossil fuels like coal and petro- leum etc., whose reserves are finite and also CO 2 emissions from these fuels give rise to global warming and greenhouse gas effect. As estimated by IPCC (Intergovernmental panel on climate change) fossil fuels will give around 27.2 Gt (Giga tones) of GHG (Green- house gas) emissions which accounts for 56.6% of the total GHG emissions. Due to these concerns, the UN climate panel is trying to reduce nearly 50% of GHG emissions by 2050 [4]. Rapid depletion of fossil fuel is also associated with the price rise of petroleum products. Therefore, a long-term renewable alternative is needed that is abundantly available, easily accessible and also have positive footprints on the environment along with its economic feasibility [5e7]. Another major challenge which is also a consequence of increased population growth and industrialization is waste man- agement. An accumulated waste will not only affect the public health and environment but also hamper the industrial and socio- economic growth [8]. An ideal scenario will be such that if both these problems can be handled simultaneously and the energy crisis can be resolved by utilizing the various wastes. There are different types of wastes ranging from MSW (Municipal solid waste), agricultural waste, industrial waste, biomedical waste, plastic waste etc. [9, 10]. Waste biomass is considered a prominent solution to this energy crisis mainly because of its carbon neutrality feature. It is the abundantly available dry plant matter which is regarded as a source of renewable energy. The amount of CO 2 released due to the combustion of biomass based fuel will be offset by CO 2 utilized during plant growth needed to supply that * Corresponding author. E-mail address: hsiddiqi@iitkgp.ac.in (H. Siddiqi). Contents lists available at ScienceDirect Renewable Energy journal homepage: www.elsevier.com/locate/renene https://doi.org/10.1016/j.renene.2019.10.162 0960-1481/© 2019 Elsevier Ltd. All rights reserved. Renewable Energy xxx (xxxx) xxx Please cite this article as: H. Siddiqi et al., In-depth physiochemical characterization and detailed thermo-kinetic study of biomass wastes to analyze its energy potential, Renewable Energy, https://doi.org/10.1016/j.renene.2019.10.162