Our team provided front-end engineering services for a renewable diesel project at a refinery. The project objective was to use existing, available hydrotreater capacity to produce renewable diesel from edible soybean oil. We worked with the refiner and the renewable diesel technology provider to identify the scope required to convert two hydrotreater units to renewable diesel service. Our team defined the outside battery limits (OSBL) scope associated with the project. Additionally, we developed a cost estimate for the option of constructing a grassroots renewable diesel unit.
FEL1 engineering feasibility studies
FEL1 revamp cost estimates
FEL0 grassroots cost estimate
The scope of this project was to evaluate hydrotreating of edible soybean oil within existing jet and diesel hydrotreater units to produce renewable diesel in compliance with the California Air Resources Board Low Carbon Fuel Standard (CARB LCFS) program. A project objective was to limit capital expenditure and utilize as much existing infrastructure as possible. Separate FEL1 studies were completed on each existing unit. An FEL0 scope definition study was completed for a new 7 MBPD grassroots renewable diesel plant.
The capacities of the two hydrotreater conversion projects were 5 MBPD and 4.5 MBPD, limited by compressor and reactor loop capacities. Addition of reactor capacity was included for isomerization. Block mode operation between jet hydrotreating and renewable diesel mode was evaluated, and scope was included for handling of the transmix generated while switching operating modes.
Hydrotreating of edible soybean oil has several unique attributes that were considered as part of the project. Examples include high pour and cloud points of the feedstock and un-isomerized product, high reaction exotherm, metallurgy upgrades and reaction byproducts.
Evaluation of the impacts of renewable diesel operation on upstream and downstream units were a key part of the engineering studies. The systems studied include hydrogen supply, sour water handling, fuel gas systems and downstream gas plants.
The OSBL scope included refurbishment of an existing rail loading rack, significant new heat tracing infrastructure and new tankage.
Conversion of hydrotreater units to renewable diesel units
Grassroots renewable diesel plant
Import of edible soybean oil from barges to the refinery
Revamp of existing rail facilities to export renewable diesel