Electricity 9%
Electricity 9%
Other emissions 4%
Other emissions 4%
FCC 17%
FCC 17%
Can be o set by WSA 9%
Furnaces and boilers 61%
H via SMR 9%
H via SMR 9%
Furnaces and boilers 52%
Figure 4 Example: shares of Scope 1 and Scope 2 GHG emissions of a refinery in Europe (left) and the theoretical offset of Scope 1 GHG emissions via the acid route (right)
However, the solution outlined above provides refineries with a viable pathway to decarbonisation without compro- mising profitability, offering a compelling addition to more capital-intensive options such as carbon capture, utilisa- tion, and storage. Path forward GHG emissions from furnaces and boilers and electricity in hydroskimming refineries account for 66.2% and 26.5%, respectively, of total GHG emissions.7 This highlights the significant contribution of these processes to the refin - ing sector’s carbon footprint. In the top 20 countries with the largest GHG emissions of oil refining, these processes contributed 30.1-43.5%⁸ of total cumulative refinery GHG emissions from 2000 to 2021. Conversely, this proportion rises to 47.0-67.2% in the lowest-emitting from the refin - ing sector countries.⁹ The typical refinery from our example processing 10 MTA of crude oil and emitting 2 Mt of Scope 1 and 2 CO₂ emis - sions can potentially offset approximately 1.5% of its total carbon footprint through steam generation within the Claus process. However, to expedite decarbonisation efforts, refineries may strategically allocate a part of their acid gas stream to sulphuric acid production. This strategic shift enables the harnessing of HP steam, thereby reducing the demand for steam from refinery boilers and consequently reducing direct Scope 1 CO₂ emissions from the stack. A complete transition from sulphur production to acid production within this typical refinery could theoretically offset up to 9% of its overall CO₂ emissions by capitalising on the energy output from the WSA process. The quality of WSA-generated superheated HP steam also presents opportunities for integration with steam turbines to pro - duce electricity. This integration can unlock additional value through carbon credit programmes or by offsetting Scope 2 CO₂ emissions, provided the refinery utilises the gener - ated electricity rather than purchasing it from the grid (see Figure 4 ). Exploring opportunities to enhance overall energy effi - ciency, revamp, or replace existing Claus-based SRUs with WSA units presents a promising avenue for accelerat - ing emissions reduction efforts in the refining industry. A
gradual carbon footprint reduction of 2-3% per Claus line replaced by WSA SRU offers a financially viable and stra - tegic pathway to achieving industry decarbonisation goals. While the transition to acid production introduces new con - siderations, the potential benefits of product diversification and the global demand for sulphuric acid make it a com - pelling proposition for refineries seeking to optimise their operations and environmental performance. Disclaimer: This article incorporates data and insights from various pub - lished studies and reports. While every effort has been made to accu - rately represent the information, readers are encouraged to consult the original sources for further details. Certain sections of this article may draw upon the work of other authors, whose contributions are acknowl - edged and appreciated. References 1 Decarbonizing Chemicals and Refining – Pathways to Commercial Liftoff (energy.gov). 2 Global oil refining’s contribution to greenhouse gas emissions from 2000 to 2021: The Innovation (cell.com). 3 Emission factor, natural gas 0.068 kg CO₂eq/MJ. 4 Carbon intensity 200 gCO₂eq/kWh. 5 Henceforth, the information regarding the Claus SRU case will be sourced from: www.hydrocarbonprocessing.com/magazine/2023/jan - uary-2023/process-optimization/new-state-of-the-art-in-sulfur-recov - ery-part-2-environmental-benefits 6 New state of the art in sulfur recovery, part 1, Hydrocarbon Processing , December 2022. 7 Global oil refining’s contribution to greenhouse gas emissions from 2000 to 2021: The Innovation (cell.com). 8 GHG emissions based on process units. 9 GHG emission composition of process units in the 20 countries with the lowest GHG emissions from the refining industry. Igor Yu Kostromin is a chemical engineer with more than a decade of experience in the field of clean air and clean fuel technologies. Holding a master’s degree in chemical engineering, he has held various roles at Topsoe, specialising in the development and implementation of clean air solutions. With a strong background in sulphur recovery technolo - gies, encompassing engineering, start-up, and technical service roles at Topsoe, he brings a wealth of expertise to the analysis of decarbonisa - tion strategies within the industry.
39
Revamps 2024
www.digitalrefining.com
Powered by FlippingBook