Metric for Evaluating Non-Geologic CO2 Utilization Options

Abstract

Carbon Dioxide Utilization (CDU) has been proposed as a means of converting carbon dioxide that would otherwise be emitted to the atmosphere into a useable or storable product. This work proposes a rapid, standardized methodology for assessing the performance, status, and potential impact of a wide range of CDU technologies. These components are used to develop a multi-dimensional metric for evaluating CDU options. The intended use of the metric is for rapid evaluation of CDU technologies to understand their performance and potential impact if deployed at scale. To support the assessment, a companion spreadsheet is made available for performing energetic and lifecycle analysis of different CDU processes based on major inputs and outputs. This spreadsheet is populated with common reactants and products of carbon utilization and can be modified by the user to include additional reactants or products. Carbon dioxide is a stable molecule that requires energy to be converted into alternate forms. This conversion energy takes the form of thermal, electrical, chemical, or solar energy. Each of these energetic inputs and their associated greenhouse gas emissions are compared to the energetic and greenhouse gas emissions of the product(s) displaced by the CDU synthesis route. The overall impact of the technology is defined as the net difference between the current method of production and the proposed production route via carbon conversion.