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Catalytic Conversion of Lignocellulosic Biomass into Fuels and Value-Added Chemicals
Published in Sonil Nanda, Prakash Kumar Sarangi, Dai-Viet N. Vo, Fuel Processing and Energy Utilization, 2019
Shireen Quereshi, Suman Dutta, Tarun Kumar Naiya
Direct combustion is a technique in which biomass is burnt in the presence of oxygen to produce energy in the form of electricity. It is an exothermic reaction, which generates heat energy from the chemical energy stored in biomass for further application in boilers, furnaces, heat exchangers, steam turbines, and various industrial and household applications. On the contrary, thermochemical conversion is the process that utilizes the heat and chemicals to produce energy products in absence or presence of oxygen. In such processes, the solid biomass is transformed to gases, which are further modified to oil to produce various fuels and chemicals. The thermochemical conversion consists of pyrolysis, gasification, and liquefaction techniques (Mckendry 2002). However, the co-firing is the cost-effective technology usually used in power plants where biomass and coal are burnt to produce energy or biomass is gasified to produce clean fuel and that fuel is burnt with coal for power generation.
Distributed Generation, Clean Power and Renewable Energy
Published in Michael F. Hordeski, Emergency and Backup Power Sources:, 2020
Direct combustion of biomass is currently in use but improvements could be made to improve operating efficiencies. Co-firing will be used in more industrial facilities and includes fossil fuel replacement and reduced environmental effects. Co-firing provides near-term demand for biomass feedstocks that will help develop the infrastructure needed to produce stand-alone biomass electric generation facilities and integrated biorefineries.
Bio-resources Utilization in Fostering a Low-Carbon Renewable Energy–Based Economy
Published in Akinola Rasheed Popoola, Emeka Godfrey Nwoba, James Chukwuma Ogbonna, Charles Oluwaseun Adetunji, Nwadiuto (Diuto) Esiobu, Abdulrazak B. Ibrahim, Benjamin Ewa Ubi, Bioenergy and Environmental Biotechnology for Sustainable Development, 2022
Modupe Stella Ayilara, Oluwaseyi Samuel Olanrewaju, Olu Odeyemi, Mobolaji Adenike Titilawo
The energy could be produced through gasification, direct-firing, pyrolysis, torrefaction (thermal combustion of biomass to a temperature above 200°C) and co-firing (Goerndt et al., 2013). Gasification is done to produce syngas and slag by heating municipal solid waste to more than a temperature of 700°C using oxygen in a controlled manner. Slag is a molten liquid that has a resemblance to gas. It is used as a raw material to produce asphalt, cement and shingles. Syngas is made up of hydrogen and carbon monoxide without pollutants (e.g. sulfur) (Kang et al., 2020). It is used as a raw material to produce chemicals, fertilizers and biofuels or burned to produce electricity and heat. The biomass produced gets dried beyond spoilage, becomes black and is compressed to form briquettes. Biomass can be combusted with fossil fuel or briquette (co-firing) to produce energy. The co-firing helps to reduce the quantity of greenhouse gases emission. Pyrolysis is the process of combusting organic wastes in the absence of oxygen, thereby preventing carbon release. The process could generate heat above 200°C, and the end products include solid (biochar), liquid (pyrolysis oil) and gaseous (syngas) products which are used to produce energy. Biofuel can also be categorized as biomass energy, since they come from organic sources (living things). Biofuels are fuel energy obtained as a result of biological carbon fixation or the decomposition of previously living things (Rodionova et al., 2017). These could be photosynthetic organisms (vascular terrestrial plants and macro- and microalgae). Biofuels include biogas, syngas, bioalcohols, green diesel, biodiesels, algal fuel, bioethers and solid biofuels. Biogas is composed majorly of methane, and it is produced from anaerobic decomposition of organic materials with the aid of anaerobic bacteria. Biogas is used to cook, generate electricity and power vehicles (Odeyemi, 2014). Scarlat et al. (2018) reported that biogas production in the European Union (EU) countries was about 654 PJ (18 billion M3 methane) in 2015 which is about half of the biogas produced globally. Msimanga and Sebitosi (2014) reported China, Italy, India, the USA and Germany as the top five biogas-producing countries. They reported that out of the five countries, two are EU countries (Italy and Germany), and this indicates tremendous progress in the region which African and other developing nations should replicate.
An investigation into the use of CFD to model the co-firing of Jatropha curcas seed cake with coal
Published in International Journal of Green Energy, 2018
Buddhike Neminda Madanayake, Suyin Gan, Carol Eastwick, Hoon Kiat Ng
Figure 14a,b show the normalised NO emissions when the coal is co-fired with the untorrefied and torrefied biomass, respectively. Although the uncertainties in the model do not justify detailed conclusions being drawn, the overall trends indicate that co-firing reduces the NO emissions when compared to combusting only coal. The reduction in NO emissions when co-firing agrees with the results of another CFD study which reported that NO reduced proportionally with the biomass mass fraction in the mixed fuel during co-combustion of wheat straw with bituminuous coal (Ghenai and Janajreh 2010). Likewise, co-firing cardoon with lignite was demonstrated to reduce NOx emissions by up to 10% in a numerical study by Karampinis et al. (2012). Li et al. (2012) also reported that NOx emissions decreased significantly with increasing biomass substitution in coal co-firing. Nevertheless, it should be noted that only a small fraction of the coal has reacted in this work. If the coal and biomass combustion continues to a greater extent (for instance with a longer residence time), the results from the model are liable to change.
Combustion performance and kinetic modeling of lignite blended with torrefied biomass of different origin
Published in International Journal of Green Energy, 2022
D. Vamvuka, M. Diamantaki, S. Sfakiotakis
Co-combustion of biomass with coal is gaining increased interest recently, as the majority of existing power generation units around the world are coal-based, and therefore large investments in stand-alone biomass plants are not required. Co-firing can reduce emissions of SOx, NOx, and organic gases, but also the greenhouse gas CO2. This is based on the assumption that biomass is CO2-neutral because all the CO2 given off by its use was recently taken in from the atmosphere by photosynthesis. Thus, increased substitution of fossil fuels with biomass fuels, in a sustainable manner, would help reduce the potential of global warming, caused by increased atmospheric concentrations of CO2, and this is the main environmental benefit of biomass utilization for energy production. In many countries, co-firing is the most economic technology to achieve the target of CO2 reduction. However, although this process introduces environmental and economic advantages with respect to single coal combustion, or higher thermal efficiency and lower ash fouling with respect to new biomass plants (Roni et al. 2017; Vamvuka et al. 2020a; Vamvuka, Sfakiotakis, and Mpoumpouris 2018), it has to face some technical barriers arising from the diverse composition of biomass materials, which may affect negatively the overall efficiency. The lower grindability, density, and heating value of wastes on one hand and the high moisture and volatile contents on the other could make difficult the handling and feeding of materials and deteriorate ignition and flame stability during co-combustion (Drosatos et al. 2018; Guizani et al. 2016; Iroba, Baik, and Tabil 2017; Singh, Sarkar, and Prasad Chakraborty 2020; Vamvuka 2009; Vamvuka, Sfakiotakis, and Mpoumpouris 2018).
Investigation into torrefaction kinetics of biomass and combustion behaviors of raw, torrefied and char samples
Published in Biofuels, 2021
D.A. Granados, P. Basu, D. R. Nhuchhen, F. Chejne
Biomass co-firing is a promising technique for the reduction of greenhouse gas (GHG) emissions from existing coal-fired plants. With torrefied biomass one could potentially increase the share of biomass in a co-fired power plant to as much as 60–70%, thereby reducing GHG by that amount. However, only a limited number of works have studied the combustion characteristics of torrefied biomass [12, 21, 22, 42–46]. The present work therefore takes an additional step to examine the combustion behavior of the torrefied biomass.