Making next-generation renewable biofuels competitive

Biofuels are expected to play an important role in reducing our carbon footprint and make us independent of fossil fuel sources such as coal, oil and gas in the future. To make the change, it is crucial that we are able to produce sustainable renewable fuels at a price that can compete with that of fossil fuels. Exactly that is the goal of a very interesting research project, Haldor Topsoe is engaged in.

The 'Bio-crude Production and Upgrading to Renewable Diesel project' will investigate innovative approaches to optimize an integrated, advanced biofuels process in order to produce sustainable renewable diesel at an attractive cost.

The chosen process is catalytic biomass pyrolysis integrated with a hydroprocessing unit. This type of process is generally considered an attractive route towards sustainable renewable fuels. It uses cellulosic feedstocks such as woody biomass, energy crops and agricultural and other wastes, making it a next generation technology.

The focus of the project is to:

1. maximize biocrude (also known as pyrolysis oil) yields in catalytic biomass pyrolysis by optimizing the physical and chemical characteristics of cellulosic biomass feedstock, in a commercially viable manner;
2. improve efficiency of the upgrading of biocrude to renewable diesel blendstock by splitting the liquid intermediate in fractions that are hydroprocessed individually.

By extraction and distillation, the biocrude is separated into three different streams of similar functionalities; a less polar aromatic fraction (light cycle oil – LCO), a pyrolytic lignin fraction, and a water-soluble fraction. The separation process as well as the proposed upgrading strategy is shown in the figure below.

Topsoe’s main contribution is to optimize the hydroprocessing steps shown in the blue squares.

The project takes an important next step in the commercialization of the technology by upscaling the catalytic biomass pyrolysis process, integrating it with a hydroprocessing unit, and demonstrating the long-term operation and performance of the integrated process.

Topsoe collaborates with RTI International who is developing the advanced biofuels technology that integrates catalytic biomass pyrolysis and hydrotreating to produce hydrocarbon-based biofuels. Idaho National Laboratory, National Renewable Laboratory, and Forest Concepts, LLC, are also involved as project partners. The project is funded by the US Department of Energy, Office of Energy Efficiency and Renewable Energy

Topsoe already offers the HydroFlex™ process that is in commercial operation at refineries producing renewable diesel from vegetable oils, animal fats, and tall oil. The result is identical to fossil diesel on the molecular level. This means that the renewable diesel produced from the HydroFlex™ process can be used as a drop-in diesel without modification of standard car engines.

Click to read more about unconventional feeds.