A reactor within a refinery can have a lifetime of decades if properly maintained. Predicting the valuable uses for such a reactor during that time period, however, is difficult at best. Changes in customer demand can make it desirable to produce alternative products. Regulatory changes can also impact the desired output for a refinery, due to tightening of allowed limits for contaminants and/or requirements to incorporate new types of materials into petroleum products.
Regulations related to renewable fuels provide an example of how product requirements can change over time. During the next decade, the United States, Canada, and the European Union have decided to increase and/or are likely to increase the required amount of product from renewable sources that is contained in transportation fuels. Based on such regulatory requirements, fuels for vegetable, animal, or algae sources such as “biodiesel” will become increasingly important as a refinery product. As a result, methods are needed that will allow existing refinery equipment to produce suitable transportation fuels that incorporate increasing amounts of renewable components.
U.S. Patent Application Publication No. 2010/00307052 describes an integrated biofuel process for converting a lignocellulosic material into an energy source. A reactor suitable for the conversion is described as having concentric tubes. The tubes can be packed with a suitable catalyst. An initial feedstock and hydrogen can be introduced at the top of the interior tube. The bottom of the interior tube is in fluid communication with the bottom of the exterior tube. Excess hydrogen and desired fuel gases can exit from the top of the exterior tube.
U.S. Patent Application Publication No. 2009/0166256 describes a method for staged co-processing of biocomponent feeds. A mineral hydrocarbon feed, such as a vacuum gas oil, can be hydroprocessed in a first reaction stage. A biocomponent feed can be added after the first reaction stage for co-processing in a second hydroprocessing reaction stage. The method can al low for deoxygenation of the biocomponent feed in an existing reactor while still allowing for desulfurization of a mineral feed to a desired level.