Analysis of Carbon Dioxide Integration as Raw Material in Existing Biomass Upgrading Processes for the Sustainable Production of High Value-Added Products

Carbon dioxide (CO2) emissions contribute to important impacts in climate change and global warming. The concentration of this gas has increased up to 400 ppm in the last years. The most contributing sectors to the CO2 accumulation in the atmosphere are the manufacturing and energy industries. The most important effect of CO2 releases is the constant increase of the global temperature of the Earth. The United Nations have stablished the Sustainable Development Goals (SDGs) as a strategy to improve the sustainability of society involving different issues such as poverty and human well-being, sustainable production and consumption, and natural resource use. Specifically, CO2 capture, storage, and utilization (CCSU) technologies contribute to the accomplishment of the SDG12 “Responsible consumption and production” and the SDG13 “Climate action”. International organizations have joined and are committed to measure greenhouse gases concentrations and to operate with neutral emissions according to the SDGs by avoiding the Earth warming and ocean acidification. Within the Carbon Capture and Storage (CCS) existing technologies to utilize CO2, post-combustion capture, pre-combustion capture, and oxyfuel combustion have been studied to achieve a clean production. The CO2 can be destined for valorization alternatives at different production scales to produce dimethyl carbonate (DMC), sodium bicarbonate (SB), and glycerol carbonate (GC). Moreover, the CO2 can also be destined as gasifying agent to obtain cold gas rich in carbon monoxide and methane. Regarding the emerging interest to capture and upgrade CO2 and the use of renewable resources (i.e., biomass) to obtain value-added products and energy vectors, this chapter aims to provide a review of the existing alternatives concerning to CO2 capture and utilization. In addition, this chapter analyzes the routes of CO2 transformation and the possible integration with existing biomass upgrading processes in the Colombian context. For this, two study cases are presented. The first study case involves the emitted CO2 upgrading after biogas obtaining and combustion in the starch extraction process using cassava as raw material. The second study case considers the emitted CO2 upgrading from molasses fermentation and sugarcane bagasse combustion in the bioethanol production process. Technical, economic, and environmental performance of the implementation of CO2 valorization to produce DMC and SB was assessed. The results for both study cases show that the obtaining of DMC by the direct synthesis of CO2 and methanol is the most suitable option to be implemented since this product has a high economic value, low capital investment, and high rate of return. As conclusions, post-combustion capture is the most straightforward technology for application in industrial plants. Besides that, the utilization of CO2 in integrated processes allows the mitigation of greenhouse gases emissions and contributes to an energetically viable production of high value-added products.