Hydrogenation-derived renewable diesel (HDRD) is the product of fats or vegetable oils, alone or blended with petroleum, that have been refined in an oil refinery.  This involves hydrogenation of triglycerides using an existing refinery infrastructure.  HDRD produced in this manner is sometimes called a 'second-generation biodiesel.'  Although largely unproven, it is expected that HDRD will substitute directly for or blend in any proportion with petroleum-based diesel, without modification to vehicle engines or fueling infrastructure. [1]  HDRD's ultra-low sulfur content and high cetane number (a measure of the combustion quality of diesel fuel) likely will provide vehicle performance and emissions benefits.  HDRD is not widely available at present, but it is likely to become fully commercialized in the near future.  A number of manufacturers around the world are developing HDRD refining processes and testing them in commercial trials. 

For example, ConocoPhillips is producing HDRD at its Whitegate refinery in Cork, Ireland.  The primary renewable feedstock is soybean oil, but other vegetable oils and animal fats and oils could be used as well.  HDRD is being produced using existing refinery equipment and is blended and transported with petroleum-based diesel.  Initial production is 1,000 barrels per day.

ConocoPhillips was also partnering with Tyson Foods to produce HDRD using animal fat, beginning in 2007.[2]  Though, due to a substantial cut in tax incentives, the project was deemed to be no longer profitable and was cancelled shortly after reaching the commercial market.  However, it is worth noting that the HDRD product from the animal fat feedstock, as a product, was a viable alternative fuel option and the product itself was not the cause of the cancellation.