Economic and Sustainability Evaluations of Carbon Capture and Transformation Technologies

Abstract

Carbon dioxide is a major contributor to global warming, and there is an environmental benefit to capturing carbon dioxide from the atmosphere, oceans, or other sources. There is also economic value in refining or converting carbon dioxide into an economically valuable substance, such as carbon-based fuels. One barrier to the widespread implementation of existing technologies is that it is difficult to develop an economically viable system where the economic benefit of the product outweighs the costs of the capture/refinement processes. Additionally, many of these technologies require substantial inputs of energy and other resources including water and scarce materials (e.g., precious metal catalysts for chemical transformations) in order to function. There is a lack of knowledge on the comparative effectiveness of technologies that draw from on different sources of carbon dioxide capture, for example, air versus oceanic capture of CO2. This project establishes a holistic comparison of existing technologies with respect to the concentration of CO2 in the source stream, performance of capture and conversion technologies, operating costs and resource use. Information on costs and energy use for existing technologies were collected from data reported in the scientific literature. CO2 capture methods considered include: (a) thermochemical direct air capture, (b) amine scrubbing, and (c) electrochemical technologies. For the products I evaluate the value of making: (a) a pure stream of CO2; (b) methanol; and (c) thermoplastic polymers. Thermodynamic and data-driven analysis is performed to establish and identify combinations of sources, technologies, and products which are the most effective while being economically viable and sustainable. These learnings will provide guidance to shape ongoing research in electrochemical technologies, and to improve the future design of carbon capture and transformation technologies. This analysis showed that all carbon capture methods of producing these value-added products were less energy intensive than production by traditional methods. Additionally, all of the processes were economically profitable and amine scrubbing was found to be the least expensive and least energy intensive carbon capture method.