Technologies for Biogas Upgrading to Biomethane: A Review

Abstract

The environmental impacts and high long-term costs of poor waste disposal have pushed the industry to realize the potential of turning this problem into an economic and sustainable initiative. Anaerobic digestion and the production of biogas can provide an efficient means of meeting several objectives concerning energy, environmental, and waste management policy. Biogas contains methane (60%) and carbon dioxide (40%) as its principal constituent. Excluding methane, other gasses contained in biogas are considered as contaminants. Removal of these impurities, especially carbon dioxide, will increase the biogas quality for further use. Integrating biological processes into the bio-refinery that effectively consume carbon dioxide will become increasingly important. Such process integration could significantly improve the sustainability of the overall bio-refinery process. The biogas upgrading by utilization of carbon dioxide rather than removal of it is a suitable strategy in this direction. The present work is a critical review that summarizes state-of-the-art technologies for biogas upgrading with particular attention to the emerging biological methanation processes. It also discusses the future perspectives for overcoming the challenges associated with upgradation. While biogas offers a good substitution for fossil fuels, it still not a perfect solution for global greenhouse gas emissions and further research still needs to be conducted.

Beyond Sugar and Ethanol Production: Value Generation Opportunities Through Sugarcane Residues

“…While the core product of AD is biogas, the process can also be partially steered toward the production of carboxylates as discussed above. Biogas can directly be utilized for electricity and heat production by using combined heat and power (CHP) units or it can be upgraded to high-quality biomethane (more than 98% purity) by various technologies reviewed elsewhere (Angelidaki et al, 2018;Adnan et al, 2019). Such high-quality methane can be injected into a natural gas grid, if available in close vicinity, or it can be utilized for residential and industrial applications.…”

Waste management and bioenergy recovery from açaí processing in the Brazilian Amazonian region: a perspective for a circular economy

“…The biogas can undergo a purification process to eliminate sulfur compounds and carbon dioxide. 32,33 This process is necessary to avoid corrosion in the motor generator and to reduce the density of the gas. 32,33 After purification, more than 95% methane is obtained, and the biomethane can be injected directly into existing natural gas networks.…”

“…32,33 This process is necessary to avoid corrosion in the motor generator and to reduce the density of the gas. 32,33 After purification, more than 95% methane is obtained, and the biomethane can be injected directly into existing natural gas networks. 34 From an environmental perspective, beyond reducing the content of organic matter in a waste, AD produces clean energy, a value-added product.…”

Green Dairy Plant: Process Simulation and Economic Analysis of Biogas Use in Milk Drying

“…Desulphurized biogas can be used directly for combustion. To be used as biomethane and as transportation fuel, its methane content has to be further increased by additional upgrading techniques such as pressure swing adsorption, cryogenic separation, membrane separation, methanation, and so forth [4][5][6]. For example, in order to inject biogas into the natural gas grid in European countries, methane volumetric content from at least 85% to more than 97% is required [3].…”