Achieving Fit for 55 emission reduction targets by 2030
Options available to oil refineries in reducing CO2 emissions while providing a clearer vision on possible roadmaps.
Fred Baars and Samiya Parvez
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Emissions reduction protocols
Numerous governments and companies around the world have committed to reducing their CO2 footprint to ultimately achieve net-zero emissions. The European Commission (EC) has set a target to reduce CO2 emissions by 55% by 2030 (relative to 1990) with a 2050 ‘net-zero’ target.
CO2 emissions are generally classified as Scope 1, 2 or 3. The Green House Gas protocol1 refers to Scope 1-3 emissions for greenhouse gases in general. For the purposes of this discussion, only CO2 emissions are considered. As far as oil refineries are concerned, Scope 1 emissions relate to the amount of CO2 that a refinery emits to produce saleable products. Scope 2 are the emissions related to the imported utilities that the refinery consumes, while Scope 3 emissions result from all the goods/services that the refinery purchases, sells, or disposes of.
Oil refinery Scope 1 CO2 emissions result from the burning of refinery fuel (fuel gas and or natural gas) or from certain processes such as hydrogen manufacturing via steam methane reforming (SMR). CO2 emissions can be reduced by improving the energy efficiency of various process units, by replacing refinery fuels (natural gas, electricity), by CO2 neutral sources such as green electricity or green hydrogen (fuel substitution), by replacing crude oil feedstock, for example with vegetable oil or mixed plastic waste (MPW, feedstock substitution), or by capturing CO2 from process streams and/or stacks and utilising or storing the CO2. Fuel substitution also includes 'electrification' such as switching gas/steam turbines to electric motors and using e-boilers/furnaces. Some measures may only affect the Scope 1 emissions, while others may impact Scope 1, 2 and 3 emissions shown in Table 1.
Feedstock substitution and most CO2 utilisation measures make the greatest contribution to Scope 3 emission reduction. Feedstock substitution may increase Scope 1 and 2 emissions depending on the source of the supplemental utilities required, if any.
The individual measures can be combined in various ways to arrive at a refinery decarbonisation programme. Such a programme includes:
Å’ A set of CO2 abatement curves showing cumulative CO2 removal against the cost of the individual measures, considering synergies or improvement opportunities when combining measures.
Â A roadmap which will picture how decarbonisation could develop with time, considering the duration of the implementation of the various solutions (taking into account permitting, turnaround sequence, and construction time) and/or expected time for technologies to have matured to an acceptable technical readiness level.
Å½ Full economic analyses of the roadmap, also including CO2 credits/taxes.
In addition to presenting various options available to oil refineries in the reduction of CO2 emissions, elaboration on what a potential roadmap would look like is forthcoming. Assessing the full impact and potential of the options being considered is a complex exercise. The true potential of various decarbonisation programmes will require a full life cycle (ensuring a seamless evaluation of the consecutive steps in the process without gaps or overlaps) and economic analysis, which is outside the scope of this article.
Our reference case is a typical European refinery processing 10 MTA of crude oil, producing motor fuels and having a delayed coker and hydrocracker as its main conversion units. The refinery will continue to produce motor fuels in the immediate future. The breakdown of Scope 1, 2 and 3 emissions is shown in Table 2.
Scope 2 emissions relate to electricity import. Scope 3 emissions represent emissions related to the combustion of motor fuels only, ignoring other contributors. Scope 3 emissions can be drastically reduced if a greater fraction of the refinery products is worked up to petrochemicals.
CO2 abatement measures
Improved energy efficiency
Improving energy efficiency has a direct impact on Scope 1 and possibly Scope 2 emissions. While it has always been the goal of a refinery operator to reduce fuel consumption, the enforcement of a CO2 tax gives further impetus to this. Techniques previously regarded as uneconomical may now prove to be attractive.
Energy efficiency can be improved by operational and technical means. Operational means include operating distillation columns at their lowest possible pressure, minimising furnace excess air, avoiding reprocessing of streams, avoiding cooling and subsequent reheating of streams, minimising tank heating, use of more efficient catalysts that allow operating temperature or pressure to be reduced, preventive maintenance/cleaning, and so on. Technical means include installing additional or more efficient heat exchangers, implementing variable speed drives on pumps, applying heat pumps, swapping steam-driven ejectors for liquid-driven ejectors, and/or additional instrumentation to monitor key variables and maintain them at optimum values.2, 3
Operational and technical measures often go together, such as installing instrumentation to measure furnace flue gas Oâ‚‚ content and ensuring this information is used to adjust the air rate to the burners. Energy efficiency improvement projects reduce CO2 emissions, have a positive payback, and a negative CO2 avoidance cost.
A comprehensive review was carried out to determine the cost/benefits of revamping/replacing several stand-alone furnaces/boilers to achieve a 90% thermal efficiency. In preparing a hypothetical case, the refinery has a few furnaces with efficiencies as low as 60%, which will need to be replaced. A number of other, higher-duty furnaces with efficiencies of around 80% will be revamped (for example, by installing air preheaters).
For the hypothetical case, the total investment amounts to 97 Mâ‚¬. The 44 MW reduction in natural gas firing duty reduces Scope 1 CO2 emissions by 74 KTA (4% of the original Scope 1 emissions). Without CO2 tax, this project would, assuming 10% disbursement per year and a natural gas price of 375 â‚¬/t, have a payback time of close to 10 years and would not qualify for project sanctioning. The cost per ton of CO2 avoided is -4 â‚¬/t, dropping to -44 â‚¬/t at a 30% higher natural gas price. The cost per ton of CO2 avoided takes into account investment disbursement and changes in operating cost between the as-is situation and the future situation also considering any changes in Scope 3 emissions where relevant.
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