Simulation and modelling study of a chemical absorption plant to evaluate capture effectiveness when treating high CO2 content iron and steel industry emissions
Year: 2024
Type: article
Abstract: Humanity needs to decarbonise to prevent climate disaster associated with CO2 and other greenhouse gases. The iron and steel industry contribute significantly to global CO2, with 70% of emissions from an integrated steel plant arising from the blast furnace. Replacement of blast furnaces with direct reduced iron reactors using green hydrogen is still in development. A stepping-stone intermediate solution is required to begin the decarbonisation journey. Chemical absorption via amine solvents is a proven carbon capture technology, theoretically ideal for use with flue gas CO2 concentrations and conditions that are typical of iron and steel making industrial processes.A representative simulation of the Translational Energy Research Centre (TERC) pilot-scale amine capture plant (ACP) was created in Aspen Plus V11.0 and identified conditions to minimise the specific reboiler duty (SRD) for representative gases of the iron and steel industry. This work predicted operating conditions and trends across a range of flue gas CO2 concentrations up to 25 mol% CO2, including: gas volumetric flow rate, solvent mass flow rate, liquid to gas (L/G) ratio, column temperature profiles, stripping column pressure, capture efficiency and reboiler duty.The results demonstrated that for a set CO2 concentration the optimal L/G ratio to achieve 90% capture efficiency was independent of the gas volumetric flow rate with the optimal L/G ratio increased by approximately 0.7 for each 5 mol% increase of CO2 concentration. At optimal L/G ratios for higher flue gas CO2 concentrations of 20 and 25 mol% the lean solvent loadings were predicted to be within a narrow range between 0.250 to 0.260 mol·CO2/mol·MEA. Temperature profiles identified operational modes of the absorbing and stripping columns. Stripping column pressure was identified as a multi-variable problem where the L/G ratio, incoming CO2 concentration, system heat integration and desired capture efficiency influence the ideal conditions, identified as 1.2 to 1.4 bara.The results provide useful trends for further studies on CO2 capture from the iron and steel industry, providing initial setpoint conditions and considerations for optimisation, with future experimental work planned to verify the simulation predictions. Model accuracy would be enhanced by calibrating to experimental results.
Source: Fuel
Authors: Jack Wells, Andy Heeley, Muhammad Akram, Kevin J. Hughes, Derek B. Ingham, Mohamed Pourkashanian
Institution: University of Sheffield
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,200
OpenAlex ID: W4402629696