Carbon pump - a reinterpretation model for energy efficiency of CO2 capture

The major barrier to a widespread adoption of CO2 capture is that imposed energy penalty commonly leads to at least 20% reduction in net output of retrofitted power plant. Such considerable energy requirement limits a scale-up development of near-term CO2 capture technologies. In contrary to the feasibility study on material and process in laboratory, the performance study on energy efficiency of various capture technologies should focus more on the scale of system by using specialized evaluation tools. However, the existing studies on such research field cannot present a satisfied performance "map" with a clear framework of energy efficiency for various CO2 capture technologies, so that three questions shown below cannot be directly answered: 1. What are the performance "windows" of energy efficiency for typical technologies in CCS industrial field? That is actually a "top ceiling" problem about the performance limitation of energy efficiency for various CCS technologies. 2. How to carry out a performance comparison of these typical technologies on a fair and clear platform of energy efficiency? The key to this problem is providing a standard methodology of performance evaluation which includes indicator, method and tool. 3. How to precisely indicate an effective pathway or possible directions for various CCS technologies to achieve energy-saving? This paper presents a rethink on the methodology of energy-efficient analysis of CO2 capture using classical thermodynamic tools. A carbon pump model, which can be considered as an analogy from heat pump, was proposed with related principles, equation, and calculation method, based on the thermodynamic theory. Various aspects of possible applications of carbon pump model, especially on the performance evaluation, are discussed as well. In addition, several case studies on performance analysis are presented as a preliminary answer to above-mentioned three questions.