Modelling and Simulation and Economic Evaluation of CO2 Capture Using Downflow Gas Contactor (DGC) Process
Why is this research needed?
By enacting the Net Zero Emission Law in 2019, the UK has set goals to achieve net-zero CO2 emissions by 2050 in order to comply with this binding agreement. Hence, significant reductions in CO2 emissions from the power sectors are required to reach this target. Carbon capture is considered as short to mid-term solution and is predicted to help deliver about 19% of the cumulative global CO2 emissions reduction from the power sector by 2050. The Paris Agreement cannot be met without carbon capture or the cost of doing so maybe about 70% more. However, post-combustion CO2 capture (PCC) and precombustion CO2 capture, the most matured carbon capture technology, is energy-intensive, typically > 4GJ/ton CO2 and require a huge solvent circulation rate at least 2 times the gas flowrate (w/w). The implication is a high cost of capture, >$48/ton CO2, and large process time inertia leading to a sluggish response characteristic with impact on the load following capability of their host power plants.
One way to address this challenge is to develop innovative methods such as downflow gas contactor. A survey of existing studies show that this innovative process could potentially:
(a) be used for gas absorption
(b) selective capture of CO2 from air or mixed gases
(c) upgrading of biogas by removal of CO2 and H2S
(d) this process has more applications such as effluent treatment; chemical reactions; stripping; air flotation.
What is this research investigating?
The main objectives of this research project are:
(a) experimental based screening of solvents
(b) laboratory testing of selected solvents
(c) modelling and validation of the complete DGC process
(d) sensitivity analysis of the process, and
(e) economic analysis of the complete DGC process
Novel contributions will include:
(a) Screening of candidate solvents for DGC process. Only a few solvents have been investigated in literature.
(b) Demonstration of CO2 capture in a complete DGC process through modelling and simulation. Only hydrodynamic aspects of the DGC have been modelled in existing studies and no study performed sensitivity analysis for DGC process.
(c) Economic analysis of complete DGC process with candidate solvents. No such study has been reported in the literature and there are very limited number of studies on this process.
What does the research hope to achieve?
This research will be beneficial to a wide range of academics including, but not limited to:
1) Researchers in CCUS – A novel method of CO2 capture is investigated in this study with modelling of the process and cost analysis. Other researchers will potentially benefit from a novel process for CO2 capture with different solvents. The scenarios and information on how the novel concepts developed in this project can be compared against conventional CO2 absorption using amines, and their environmental and economic performance. As the models developed during and the findings of this project will be made available, researchers in these fields will be able to build upon this research. The promising outcomes of this project could result in new collaborative projects, leading to further development of the proposed process. If the results of this project are published, it can be considered an alternative to absorption and adsorption processes.
2) Researchers in other disciplines, such as environmental, chemical and process engineering, will benefit from the outputs of this project as it will produce theoretical advances in the form of novel concepts that can potentially be adapted for the decarbonisation of industrial plants in the cement, lime, chemicals, hydrocarbon and steel industries, as well as providing feedstock for CO2 utilisation for chemicals and fuels production. Researchers in reliability engineering, in addition to those in process and chemical engineering, will benefit from the findings of this research through benchmarking of novel carbon capture processes against conventional systems with respect to the influence of uncertainty on process performance and reliability. The promising outcomes of this project could result in new collaborative projects, leading to the development of novel capture systems.
This research is ongoing. Outputs will be shared below as they become available.