Apr-2023

Co-hydroprocessing renewable feedstocks through hydrocrackers

A wider variety of feedstocks are being processed through hydrocracking units. These units were primarily designed to process heavy crude oil or vacuum gas oil (VGO) feedstocks to produce higher-value products, including diesel fuel and jet fuel.

Rene Gonzalez
Editor, PTQ

Article Summary

However, with changes higher demand for cleaner and more sustainable energy sources, refineries are now using a wider variety of feedstocks in their hydrocracking units, such as renewable feedstocks that include vegetable oils and animal fats.

In terms of variety, refineries are also using lighter feedstocks, such as shale oil and tight oil, as well as unconventional feedstocks like bitumen and heavy oil sands. Furthermore, hydrocracking units are being used to upgrade lower-value products, such as atmospheric gas oil (AGO), into higher-value products, such as diesel fuel and lubricating oil. This has enabled refineries to remain competitive in the face of changing market dynamics.

Hydrocracking is a key process for upgrading renewable feedstocks such as vegetable oils and animal fats into high-quality biodiesel and renewable diesel. Against this backdrop, co-hydroprocessing waste cooking oil (WCO) and VGO in a hydrocracker can create several margins opportunities:

·  Improved yield of high-quality diesel with lower sulphur content, higher cetane number, and better lubricity, resulting in better fuel efficiency and lower emissions. This can lead to increased profits through improved product quality and reduced environmental compliance costs

·  WCO is often cheaper than traditional petroleum-based feedstocks, and its use can help diversify the feedstock portfolio, reducing exposure to fluctuations in crude oil prices

· -hydroprocessing WCO and VGO can increase hydrocracking unit utilization, resulting in increased throughput and higher plant utilization rates. This can lead to increased profits through higher production levels and reduced fixed costs per unit of output

·  Processing WCO feedstock can help reduce carbon emissions by diverting waste from landfills or incineration, and its co-hydroprocessing can reduce the final product sulphur content, resulting in reduced emissions of sulphur dioxide (SO2), leading to increased profits through access to carbon credits and other sustainability incentives.

A recently published study found that co-hydroprocessing WCO with VGO through a hydrocracker could result in profits of around $430 per ton of feedstock, assuming a WCO price of $0.36 per pound and a VGO price of $2.25 per gallon. However, it should be noted that this estimate is based on a specific set of assumptions and market conditions, and actual margins can vary depending on a range of factors specific to each refinery operating conditions.

In addition to the hydrocracker, other insertion points for the co-processing of renewable-based feedstocks such as animal fats, plant-based feeds, WCO, etc., include FCCUs, diesel hydrotreaters and kerosene hydrotreaters. However, processing these types of feedstocks through catalytic conversion units designed to process petroleum-based feeds don’t come without a wide range of problems, such as the requirement for higher amounts of hydrogen compared to petroleum-based feedstocks.

For example, high levels of oxygen in biofeedstocks can lead to the formation of water and other undesirable products. High oxygen content in biofeedstocks requires higher operating temperatures and pressures, which can increase the risk of corrosion and require more frequent maintenance. But in those instances involving the co-hydroprocessing of WCO and VGO in hydrocracker, the opportunities cannot be overlooked, including improved product quality, lower feedstock costs, increased plant utilization, and enhanced environmental sustainability.