Co-processing
Many refiners鈥� biofuels journeys will likely begin with co-processing up to 10% renewable feedstock (such as animal fats, used cooking oil and vegetable oil) in an existing hydrotreating unit for little or no capital expenditure. This can be a low to no capital cost response for producing hydrotreated vegetable oil (HVO), thereby potentially bridging the gap and complying with regulations before dedicated units are built for 100% biofeeds.
Co-processing can help mitigate the risks
In today鈥檚 new reality, with many refineries running below the severity that they were designed for, it could be straightforward to use this spare capacity to process renewable feeds.
However, it is important to be aware that adding a renewable feed can affect unit operation in several ways. Hydrogen consumption and heat release will increase, for example, and there are the risks of increased corrosion and fouling. Also, there may be greater difficulty with blending in the diesel pool because of degraded cold flow properties.
Some of these risks are new to hydroprocessing though not to other parts of Shell鈥檚 business. For example, the same corrosion mechanisms occur in its upstream assets, so Shell Catalysts & Technologies is able to draw on established tools and techniques to address them.
Consequently, our consultants are working with refiners around the world to help determine these risks and evaluate mitigation measures to minimise or eliminate them. These may include:
- Corrosion studies to evaluate carbonate cracking risks;
- Catalyst activity and life cycle assessments;
- Reactive hazard safeguarding analyses;
- Product quality impact reviews; and
- Heat integration and equipment assessments.