What is the most effective carbon capture and storage system for refineries?

In my experience, post-combustion capture is highly effective for refineries looking to reduce CO2 emissions without altering existing infrastructure significantly. It allows for the separation of CO2 from flue gases post-combustion using various technologies like chemical solvents or membranes. While advantageous for its retrofitting capability, it's important to note the energy demand and efficiency reduction it introduces to the refinery operations. Additionally, flue gas impurities pose challenges to capture equipment performance and longevity, necessitating thorough evaluation and management to ensure effectiveness and sustainability of the system.

In my experience, pre-combustion capture offers a significant advantage for carbon management in refineries by converting fossil fuels into hydrogen and CO2 before combustion. This method, which includes gasification or reforming, results in a high-purity CO2 stream that's easier to compress and transport, and the hydrogen produced can serve as a low-carbon fuel. Despite its benefits, the requirement for substantial changes to refinery infrastructure presents a challenge, involving complex modifications and substantial investment, highlighting the need for strategic planning and evaluation of long-term benefits versus initial costs.

Oxygen backed fuel combustion processes sound like a dream due to the virtual absence of notorious gases. We are yet to see this in full fledged action and having a better supply chain for pure oxygen might be a key driver to such initiatives. One such pilot project is Total's Lacq project which is the world's first integrated and industrial natural gas fired oxy-fuel plant. With the world's first pipeline injected oxy-fuel flue gas, they demonstrated that a technically feasible carbon capture scenario with re injection of carbon dioxide into a gas reservoir was possible. I'm still hoping that we all live long enough to see initiatives grow to an extent where elimination of re-injection to reservoirs happen. A very radical dream for now!

In my experience, oxy-fuel combustion capture, which involves burning fossil fuels in pure oxygen, significantly simplifies CO2 separation by producing a flue gas primarily composed of CO2 and water. This method enhances efficiency by eliminating the need for complex separation technologies and facilitates CO2 compression and transport due to reduced flue gas volume and pressure. However, the high oxygen demand presents economic and energy challenges, and the oxygen-enriched combustion environment introduces safety and operational considerations that require careful management.

In my experience, Enhanced Oil Recovery (EOR) utilizing CO2 injection not only extends the life of oil reservoirs but also presents an opportunity for carbon sequestration. This dual benefit makes EOR an attractive option for refineries interested in CCS technologies. It generates additional revenue through increased oil production while mitigating environmental impact by storing CO2 underground. However, its effectiveness and permanence are contingent on geological and infrastructural factors, highlighting the importance of thorough feasibility studies and monitoring to address potential CO2 leakage or migration issues.

Carbon sequestration is a proven technology which can be put to use by carbon emitters such as refineries to set aside the CO2 beneath the Earth’s surface. A proper site selection, efficient implementation, infrastructure development and MMV plan for long term can make a CCS project successful. One of the major hurdles is proximity to the correct site. In the US, Louisiana got primacy recently and Texas may get it soon. This will considerably reduce the time to get project approvals which was very long when EPA was the only authority controlling permits. With several US refineries along the gulf coast, the geology, regulation and deep technical expertise make gulf coast refineries a prime initiator of such projects.

In my experience, carbon sequestration offers a robust solution for the long-term disposal of CO2 from refineries, effectively mitigating its contribution to climate change. Leveraging deep geological formations, such as saline aquifers, for CO2 storage, utilizes existing oil and gas infrastructure, enhancing feasibility. Despite its potential, it's crucial to acknowledge the risks associated with leakage, induced seismicity, and groundwater contamination, necessitating comprehensive monitoring and regulatory frameworks to ensure its safety and effectiveness.

One of the measures to decarbonise refinery operations is carbon capture and storage (CCS) from existing combustion processes, such as process heaters and steam plants. CCS recovers carbon dioxide (CO2) and injects it deep into the subsurface ground (saline aquifers or depleted hydrocarbons) for long term storage. Many refiners will rely on CCS to achieve CO2 emissions reductions targets

Selecting the most effective CCS system for refineries is complex and requires a tailored approach. It involves considering factors like fuel type, refinery configuration, technology costs, environmental regulations, and acceptance by the market and society. It's crucial to assess each refinery's unique circumstances against these variables. Additionally, exploring other emission reduction strategies such as improving energy efficiency, switching fuels, or integrating renewable energy sources is essential. This holistic view ensures the chosen solution not only reduces emissions effectively but also aligns with broader sustainability goals and operational realities.