Integrated design for cryogenic carbon capture and cold energy storage system

Due to continuous rise of greenhouse gases concentration in the atmosphere, global warming has become a universal issue. There is a need to do something to lessen the amount of CO2 entering into the environment, otherwise, the world will face severe impacts of environmental changes. Carbon capture, utilization and storage (CCUS) is thought to be a key innovation that can empower the industry to continue utilizing non-renewable energy source assets while limiting their impact on the environment. At the same time, with a continuous rise in the world population, there is an ever increase in the energy demand for industrial and domestics usage. In order to have a sustainable growth under the green and clean environment, there is a need to tackle the climate change and energy challenges. Presently, there are many CO2 capture technologies including amines, membranes, chemical looping, cryogenics and adsorption, at different level of maturity and scale of application. This project proposes to capture the CO2 cryogenically from the point sources, by utilizing the cold energy available from the natural gas fractionation (NGL) process. The cryogenic energy is stored in the liquefied CO2 that can be utilized later depending on the downstream process requirement. The proposed system will not only capture the CO2 from the flue gases but will also store the cold energy of captured CO2 that can be used to generate power using Rankine cycle or other thermodynamics cycles. The development of this novel design can play an important role in the economy of the Saudi Arabia. According to EIA statistics, Saudi Arabia has the worlds 5th largest proven natural gas reserves of over 294 TCF as of 2015. According to the Kingdoms vision 2030, Saudi Arabia plans to increase its natural gas production to double the current capacity by 2030 which will be used to cater the domestic energy demands. Currently, there are six natural gas processing plants across the Saudi Arabia and keeping the above expansion plans in view, the capacity of the natural gas processing plants have to be increased. The low temperatures at the NGL facilities can be used to cryogenically capture the CO2 and store the liquefied CO2 in the liquid state. The captured CO2 at cryogenic conditions acts as a thermal energy storage system. The cryogenic energy stored in the CO2 can be used afterwards to produce power using thermodynamic cycle or cool down other preprocess streams. The captured CO2 can be effectively used for enhanced oil recovery (EOR) purpose, which not only stores some amount of CO2 but also has an added benefit of an increased oil production. This integrated novel design can be valuable to the Saudi Arabia for implementing the CCS technology while improving energy efficiency of the whole NGL process.