May-2024

Electrification as a pathway towards a green refinery

To maximise and optimise electrification benefits, refineries should develop a scalable, individualised electrification strategy.

Damien Feral
Schneider Electric

Article Summary

Despite widespread decarbonisation efforts, CO2 emissions, the main driver of global warming, are at a record high (Forster, et al., 2023). While all industries are under pressure to reduce their carbon footprint, the oil and gas (O&G) sector’s efforts are under particularly intense scrutiny. According to the World Economic Forum (WEF), O&G is one of the industries that must be decarbonised to reach global climate goals (Ashraf & Bocca, 2022). The sector accounts for 15% of total energy-related emissions, while oil refining alone represents 4% of worldwide greenhouse gas (GHG) emissions (1.59 gigatons of emissions) (Ma, et al., 2022).

Regulatory policies, financial incentives, and environmental, social, and governance (ESG) considerations are key drivers of the sector’s decarbonisation. However, above all, the industry must make rapid and strategic changes to survive in a changing energy landscape with decreasing fuels’ demand. All these drivers have a role in a complex decarbonisation equation that no silver-bullet solution can solve. Instead, there are a number of different decarbonisation strategies that oil refineries implement in their pathway to a green refinery.

This article explores how electrifying refining and downstream processes can accelerate the journey towards decarbonised operations. It highlights why electrification is an effective decarbonisation solution, where refineries can electrify, and the potential challenges to overcome.

Pathways to a green refinery
Oil refining is a complex process that requires a high quantity of energy (a typical medium-complexity refinery with an average crude capacity of 150 kbbl/d needs about 700-900 MW of thermal power and sometimes more than 50 MW of electricity, depending on its exact configuration) (Schneider Electric, 2024). The majority of its CO2 emissions, typically more than 1 million tons of CO2 (Scope 1 and 2) per year for an average refinery, come from the combustion of fossil fuels required for industrial heat (process heating and steam generation). In addition, direct process emissions are linked to specific processes, such as hydrogen production or coke burning in a fluid catalytic cracking unit (FCC).

Refineries have a number of different decarbonisation initiatives that can be incorporated into their green strategy. However, there is no single best method for improving sustainability. Refineries’ decarbonisation strategies should be crafted based on factors such as their size, configuration, and the specific regulations they must meet.

They can benefit from technologies that enhance their energy efficiency in the long run. For example, advanced digital solutions can help optimise their design and operations, as can more energy-efficient processes and equipment, such as new types of heat exchangers, electric process heaters and boilers, variable speed drives, and heat recovery systems.

Low-carbon hydrogen will play a key role in producing lower carbon fuels when used as a chemical feedstock for refineries’ catalytic units or future synthetic fuels production with captured CO2. ‘Green hydrogen’ produced by low-carbon electricity via electrolysers is also an indirect way to electrify the processes’ energy demand by switching the combustible fuel in existing or revamped fired heaters to hydrogen.

Carbon capture, utilisation and storage (CCUS) solutions are progressively scaling up and will allow the capture of hard-to-abate and/or process emissions. Besides the typical amine process to capture CO2 molecules, CCUS solutions also require low-carbon electrical power to address the compression and transport needs of the molecules at the lowest carbon intensity.

Eventually, it may be mutually financially beneficial for industries in a cluster to work together on large-scale projects that meet their common objectives and challenges. For example, they could share the development and infrastructure costs of creating large-scale solutions like renewables, green hydrogen, or other decarbonisation projects. They may also share physical infrastructure, such as a large network of hydrogen.

Electrification as an accelerator for reducing refineries’ CO2 emissions
Process electrification – using low-carbon electricity to meet process energy needs that have traditionally been met with fossil fuels – is an effective solution for reducing the oil and gas industry’s GHG emissions. A recent study from the Oil and Gas Climate Initiative’s (OGCI) Energy Efficiency workstream has found that it is possible to decarbonise the majority of refineries’ Scope 1 and 2 emissions by powering some equipment with electricity (generated from low-carbon sources), rather than fossil fuels (OGCI, 2021). OGCI represents 12 of the world’s largest O&G companies (collectively accounting for around 30% of global O&G production) to help guide the industry’s response to climate change.

Electrification allows refineries to incorporate more renewable energy into their energy mix (for example, from solar, wind, or biogas) produced on-site or remotely (via power purchasing agreements, PPA). They can also participate in electrical grids’ stability or flexibility mechanisms.

In addition, refineries can potentially lower emissions by replacing gas combustion processes with electrically powered ones. This change can make a positive environmental impact because the actual share of electricity in the energy mix of an average refinery is around 5% to 10%, and sometimes more than 20% of natural gas is imported to complement the internally generated fuel gas (Concawe, 2019).

Electrification is already central to many industries’ climate change mitigation strategies. For example, the steel industry has adopted electric arc furnaces. O&G companies are electrifying their operations on floating production storage and offloading (FPSO), offshore, and downstream assets by making changes like replacing gas turbines with motors and using electric boilers instead of gas-fired ones. The concept of all-electric LNG plants that can minimise emissions and increase energy efficiency is also gaining interest.

Many refinery processes can be electrified
A typical refinery’s electrification potential is dependent on multiple components, including its internal energy mix, fuel gas and steam balance, process configuration, and electricity supply and distribution.

For instance, some types of equipment that usually need steam to operate, such as steam ejectors that generate vacuum or steam turbines that drive compressors, can be electrified respectively using vacuum pumps and motors controlled with variable speed drives (VSD). Generally, an electric motor with a VSD is much more energy efficient (around 90-95%) than a condensing-type steam turbine or open-cycle gas turbine (sometimes as low as 25% energy).