Evaluation of CO2 Purification Requirements and Techno-Economic Evaluation of Processes for Impurities Deep Removal from the CO2 Product Stream

  • Zeina Abbas

Student thesis: Master's Thesis

Abstract

Carbon Capture and Storage (CCS) technology has become known as a very effective and immediate means of cutting down carbon emissions in the atmosphere. It basically separates carbon dioxide gas from flue gas and then transports it to geological formations, either for storage or other purposes. There are three major capture routes, namely: pre-combustion, post-combustion and oxy-fuel combustion. Depending on the applied capture technology, the reference power plant and the type of fuel, the CO2 product stream will contain several impurities which may have negative impacts on pipeline transportation, geological storage and/or Enhanced Oil Recovery (EOR) applications. All negative impacts require setting stringent quality standards for each application and purifying the CO2 stream prior to exposing it to any of these applications. In this research, the CO2 streams specifications and impurities from the major CO2 capture technologies were assessed. Furthermore, the CO2 restricted purification requirements for pipeline transportation, EOR and geological storage were evaluated. Upon the comparison of the levels of impurities present in the CO2 streams and their restricted targets, it was found that the two major impurities which entail deep removal, due to operational concerns, are oxygen and water. After evaluating different technological options for oxygen and water removal, it was found that catalytic oxidation of hydrogen and refrigeration and condensation are the best technologies for oxygen and water removals, respectively. Last but not least, detailed process modeling, design and a techno-economic evaluation were performed on these two technologies. Both selected technologies proved their potential by achieving the required targets with a total cost of treating and compressing one ton of CO2 of $14.37 for the coal-fired power plant reference case and $23.37 for the NGCC reference process. Moreover, compression was deduced to be the most energy intensive part of the whole process with a cost of approximately $10.33 per ton of CO2 for the coal-fired case. This means that adding the purification technologies to the coal fired case will increase the cost of CO2 compression by around 40% and the overall capture cost by 4-6%.
Date of Award2012
Original languageAmerican English
SupervisorMohammad Abu Zahra (Supervisor)

Keywords

  • Carbon Dioxide -Recycling
  • Carbon Dioxide-Economic Aspects

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