Biotechnological Processes as Part of a Carbon Capture and Utilisation Strategy in the Oil and Gas Sector: A Case Study in a Natural Gas Treatment Plant in Libya

Abstract

While the rapid deployment of renewable energy generation technologies is a critical priority, predictions of future global energy demand indicate that fossil fuels will continue to meet over 50% of global energy demand beyond 2050. Every effort should, therefore, be made to limit the climate impacts of the extraction and processing of these fossil fuels. This study investigates the environmental burdens and benefits of integrating biotechnology-based approaches to utilising carbon dioxide currently emitted by a natural gas treatment plant, particularly in the context of the oil and gas sector in Libya, through a gate-to-gate life cycle assessment.

The work quantifies that for a natural gas treatment plant processing 1,166,694 kg/h of raw gas, 273.82 t/h of carbon dioxide is emitted from the sour gas removal plant. This recoverable CO₂ could be combined with renewable hydrogen in biological processes to produce approximately 2,090, 4033, and 826 t/d of synthesis methane, acetic acid, and polymers, respectively. These processes could add up to 13% of methane gas to the natural gas product stream or acetic acid, and polyhydroxyalkanoates (PHA) could be added as low-carbon products to the natural gas treatment facility. The three approaches could reduce the emitted CO₂ across the natural gas treatment plant resulting in up to 97% of carbon entering the facility in raw gas being exported in products.

The gate-to-gate life cycle assessment of environmental burdens shows that integrating the synthesis methane, acetic acid, and PHA production systems into the natural gas treatment plant (reference case) has reduced the global warming impact by approximately 56%, 63%, and 8%, respectively.

However, while global warming is being reduced, there is also an increase in all other categories of environmental damage. The impacts are increased mainly due to the extensive infrastructure of renewable energy technologies, such as wind turbines and H₂ electrolysers, and different biological systems. This analysis highlights a significant shift in environmental impacts: although renewable energy technologies helped decrease global warming potential, the resources used in renewable energy construction increased consequences in other environmental categories; this suggests a shifting of environmental burdens rather than eradication.

Date of Award	2024
Original language	English
Sponsors	National Oil Corporation
Supervisor	Tim Patterson (Supervisor) & Sandra Esteves (Supervisor)