Thermal characterization and pyrolysis kinetics of tropical biomass feedstocks for energy recovery
Introduction
The utilization of renewable energy sources is currently crucial to reach the changes required to reduce the increasing global warming impacts. Biomass represents a promising renewable energy with a large potential to substitute fossil fuels (McKendry, 2002a).
Biomass energy is widely used in the third world principally in rural regions where it is frequently the main energy source for cooking. Although the agricultural waste potential in many of these regions, few attentions are given to them.
Cameroon is a country in Middle Africa with about 20.03 million people (2011 census) and 50% of its population are below the national poverty line. Cameroon has the third major biomass potential in sub-Saharan Africa, with amount estimated at 6.3 billion tons (Ackom et al., 2013). Forest resources cover about 28 million ha and represent the three-quarters of the country's territory (Maesano et al., 2013). Wood fuel is the main energy source for cooking in both rural and urban Cameroonian areas. However, the unsustainable use of this resource (e.g. wood extraction-commercial, charcoal production and fuel wood) has led to important deforestation throughout the country (Mbatu, 2010).
This deforestation has encouraged research to identify and to use other biomass resources as a viable substitute of fuel wood. Since Cameroonian agriculture contributes to a great degree to the country's GDP, these generated residues may represent a promising alternative fuel (Ackom et al., 2013).
Soils and climate on the country's coast promote farming of oil palms, bananas and cocoa. The South Cameroon Plateau interior encourages cultivation of cash crops such as coffee, tobacco and sugar. Major agricultural produce in northern country includes cotton, corn, peanuts and rice.
These crops' cultivation as well as their transformation through agro-industrial processes generate in Cameroon a significant amount of residues. Hence, the palm oil extraction in the traditional mills mainly generates Palm Kernel Shells (PKS) and Mesocarp Fibres (PMF). Additionally, the coffee industry induces important amounts of Coffee Husk (CH) before the roasting coffee process. Furthermore, the maize and groundnut productions left certain amounts of Corn Cobs (CC) and Peanut shells (PNS). These valuable residues are usually cheap, widespread, and continuously produced. All these renewable energy resources have the potential to be widely used as source of energy both by the local populations (e.g., cooking and heating) and for industrial energy consumption.
In order to efficiently use them for energy production, various thermochemical conversion processes such as carbonization, combustion, gasification and liquefaction have been developed (McKendry, 2002b). However, these procedures involve pyrolysis because it is the primarily stage of biomass transformation (Yaman, 2004).
Kinetic studies of pyrolysis are usually conducted using a thermogravimetric analyser (Chouchene et al., 2012, Dorge et al., 2011, El may et al., 2012, Jeguirim et al., 2010, Jeong et al., 2014, Masnadi et al., 2014). The kinetic parameters include the activation energy, the frequency factor and the kinetic rate constant K. These parameters are required for the reactor designing since it is necessary to achieve an optimal conversion. Their usefulness with respect to modelling their respective thermochemical conversion processes is acknowledged. In fact, the data obtained from the thermal analysis are provided to kinetic models which use rate laws that follow the fundamental Arrhenius rate expression.
The main purpose of this investigation is to study the thermal characterization and the devolatilization kinetics of five Cameroonian biomass feedstocks: Palm Kernel Shells (PKS), Palm Mesocarp Fibres (PMF), Coffee Husk (CH), Corn Cobs (CC) and Peanut Shells (PNS) using thermogravimetric analysis data and the Coats and Redfern method. Comparison of thermal characteristics of the different biomasses is performed to assess the eventual utilization of the different biomasses for energy recovery.
Section snippets
Raw materials
Five types of Cameroonian biomass were studied: Palm Kernel Shells (PKS), Mesocarp Fibres (PMF), Coffee Husk (CH), Corn Cobs (CC) and Peanut Shells (PNS). PKS and PMF were obtained from the SOCAPALM palm oil mill in Douala. CC samples were provided by MAISCAM agro-industrial company in Ngaoundéré. PNS were provided from a farmer cooperative from the region of Garoua. CH samples were supplied by a farmer cooperative in Nkongsamba. All of these samples were dried naturally to reduce their
Raw material characterization
Elemental compositions as well as the “H/C” and “O/C” ratios of the different Cameroonian biomass species are listed in Table 2.
The analysis shows that elemental compositions of the different samples are in the range of typical composition values of biomass reported in literature (Cocozza et al., 2011, Wilson et al., 2011). Comparison of the different samples shows that CCs have the lowest carbon content, the highest oxygen content and therefore the highest O/C ratio. This characteristic was
Conclusion
Thermochemical conversion of five types of Cameroonian biomass, Palm Kernel Shells (PKS), Palm Mesocarp Fibre (PMF), Coffee Husk (CH), Corn Cob (CC) and Peanut Shell (PNS), was examined using thermogravimetric analysis under nitrogen atmosphere. Decomposition TG and DTG data were used to determine devolatilization kinetic parameters by applying diffusional and chemical reaction kinetic models.
Results show that the thermal degradation of Cameroonian biomass under nitrogen atmosphere could be
References (42)
- et al.
Non-isothermal kinetic analysis of the devolatilization of corn cobs and sugar cane bagasse in an inert atmosphere
Thermochim. Acta
(2011) - et al.
Modern bioenergy from agricultural and forestry residues in Cameroon: potential, challenges and the way forward
Energy Policy
(2013) On the use of the arrhenius equation to describe cellulose and wood pyrolysis
Thermochim. Acta
(1985)- et al.
How to determine consistent biomass pyrolysis kinetics in a parallel reaction scheme
Fuel
(2014) - et al.
Combustion of peanut shells in a cone-shaped bubbling fluidized-bed combustor using alumina as the bed material
Appl. Energy
(2012) - et al.
Energetic valorisation of olive mill wastewater impregnated on low cost absorbent: sawdust versus olive solid waste
Energy
(2012) - et al.
Chemical, physical and spectroscopic characterization of Posidonia oceanica (L.) Del. residues and their possible recycle
Biomass Bioenergy
(2011) - et al.
Study on the thermal behavior of different date palm residues: characterization and devolatilization kinetics under inert and oxidative atmospheres
Energy
(2012) - et al.
Thermal behaviour and kinetics of coal/biomass blends during co-combustion
Bioresour. Technol.
(2010) - et al.
Briquetting of palm fibre and shell from the processing of palm nuts to palm oil
Biomass Bioenergy
(2002)
Pyrolysis kinetics of coking coal mixed with biomass under non-isothermal and isothermal conditions
Bioresour. Technol.
Productivity and energy consumption in logging operation in a Cameroonian tropical forest
Ecol. Eng.
An alternative energy source from palm wastes industry for Malaysia and Indonesia
Energy Convers. Manag.
Fuel characterization and co-pyrolysis kinetics of biomass and fossil fuels
Fuel
Energy production from biomass (part 1): overview of biomass
Bioresour. Technol.
Energy production from biomass (part 2): conversion technologies
Bioresour. Technol.
Quantitative and kinetic TG–FTIR investigation on three kinds of biomass pyrolysis
J. Anal. Appl. Pyrolysis
Thermal degradation behavior and kinetic analysis of spruce glucomannan and its methylated derivatives
Carbohydr. Polym.
Thermal analysis and devolatilization kinetics of cotton stalk, sugar cane bagasse and shea meal under nitrogen and air atmospheres
Bioresour. Technol.
Pyrolysis kinetics of lignocellulosic materials—three independent reactions model
Fuel
Effects of pyrolysis temperature on changes in fuel characteristics of biomass char
Energy
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2021, Industrial Crops and ProductsCitation Excerpt :This was followed by the kinetic study of (Zhang et al., 2013) who analyzed the process using an Arrhenius type relation. Beginning 2014, several workers have investigated the thermo-chemical characteristics and pyrolytic behavior of PS using TG/DTG techniques (Bhavanam and Sastry, 2015; Braza and Crnkovic, 2014; Collins and Ghodke, 2018; Gurevich Messina et al., 2017a; Jeguirim et al., 2014; Mohammed et al., 2017; Ren et al., 2018; Yao et al., 2016; Yuan et al., 2015; Márquez-Montesino et al., 2015; Zhu et al., 2014). The microwave energy has also been used to pyrolyze PS (Wang et al., 2015).