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Novel CO2 condensation and separation in supersonic flows contributing to carbon capture and storage (CCS)

Periodic Reporting for period 1 - NOCO2 (Novel CO2 condensation and separation in supersonic flows contributing to carbon capture and storage (CCS))

Reporting period: 2019-01-01 to 2020-12-31

The clean utilization of fossil energy has been recognised as one of the most promising measures to improve sustainable development. This project proposes a novel carbon dioxide (CO2) separation in supersonic flows, which provides a great opportunity for the clean utilization and sustainable development of natural gas. The aim of this project is to achieve the fundamental and experimental understanding on the thermo-physical phenomena of CO2 supersonic separation, with the goal of developing a mathematical model capable of predicting the condensation flows and achieving experimental evidence of capturing the supersonic phenomenon. This unique project not only clearly reduces the European emissions from fossil fuels, but also enables the clean utilization of natural gas, which contributes to the sustainable development of Europe society and growth.
The proposed project will understand the fundamentals governing the flow and thermo-physical phenomena within a supersonic separator for CO2 removal from natural gas, culminating in a mathematical model capable of predicting the condensation and separation flows. This newly developed CFD technique will play a key role in achieving this objective. Incorporation of nucleation process, droplet growth and heat transfer into such a model will allow the prediction of the thermal history of gas/liquid in a supersonic separator. Developments in this direction will produce a mathematical model to establish a comprehensive understanding of the phenomena involved at a molecular scale. The resulting information, in terms of constitutive equations or other suitable forms (e.g. gas properties description with real gas model), can be incorporated into a continuum-based computer model for process engineering application.

We have developed a computational fluid dynamics (CFD) model to predict the CO2 condensing flow in a supersonic nozzle. Adding two transport equations to describe the liquid fraction and droplet number, the detailed numerical model can describe the heat and mass transfer characteristics during the CO2 phase change process under the supersonic expansion conditions. A comparative study is performed to evaluate the effect of CO2 condensation using the condensation model and dry gas assumption. The results show that the developed CFD model predicts accurately the distribution of the static temperature contrary to the dry gas assumption. Furthermore, the condensing flow model predicts a CO2 liquid fraction up to 18.6% of the total mass, which leads to the release of the latent heat to the vapour phase. The investigation performed in this study suggests that the CO2 condensation in supersonic flows provides an efficient and eco-friendly way to mitigate the CO2 emissions to the environment.
The EU has played an active role throughout the process and is committed to implementing the 2030 Agenda for Sustainable Development within the EU and in development cooperation with partner countries. The clean utilization of natural gas is one of the most important sustainable developments of fossil energy. This project focuses on understanding the complicated condensation phenomena in supersonic flows by developing advanced computational models. This novel technology overcomes some of the disadvantages of conventional technologies, such as high capital expenditures, high energy consumption, large plant. More specifically, the proposed project can contribute to several facets of the research and society, including: a) Develop novel CFD models to further understand the nucleation and condensation mechanism of CO2; b) Present a novel technical process for clean utilization of natural gas, especially for offshore and subsea uses; c) Provide significant cost savings at the liquefaction department for its compact tubular design; d) Propose an environmental-friendly facility by eliminating the need for chemicals and associated regeneration systems.
Novel CO2 capture