Chapter 8 - Life-cycle assessment on sequestration of greenhouse gases for the production of biofuels and biomaterials

Abstract

As one of the greenhouse gas (GHG) mitigation strategies, CO2 sequestration introduces various environmental benefits. It appears that carbon capture and storage is the most promising method to reduce CO2 emissions, and is in fact suitable for a wide range of anthropogenic CO2 sources. Captured CO2 is kept in natural storage for future use or converted into valuable products. Additional systems are developed, which produce sequestrating results such as more energy and other practical resources. Without storage, captured CO2 can be utilized directly or applied in the production of biomaterials and biofuels. Results from various life-cycle assessment (LCA) case studies show the potential of using sequestered CO2 for different purposes. The prospects and challenges on climate change are analyzed through the GHG contribution of the products. The production of biomaterials using carbon sequestrating microorganisms can help reduce GHG emissions in comparison to petroleum-based feedstock. The reason for this is the increase in CO2 credits during a crop cultivation period. Microbial biofuels do not conflict with the crop, but their poorer efficiency and higher environmental challenges than other types of biofuels prevent them from being the perfect substitute for gasoline. Biomaterials from CO2 sequestration are comparable to petrochemical materials, but their impacts on global warming potential and nonrenewable energy consumption are still high. High production costs constitute one of the major limitations of the commercialization of microbial diesel due to a variety of factors. A reasonable price for a high-quality product can be achieved by implementing a detailed techno-economic analysis. Each phase of the production process has its role to play in the cost; improvement of technology should be considered for economic benefit.