Diesel & Other Fischer-Tropsch Liquids

Discover how to make clean diesel and other liquid fuels using FastOx gasification.


Sierra Energy produces diesel and gasoline products using Fischer-Tropsch (FT) systems on the back end of our FastOx gasifiers. FT systems convert syngas through a series of chemical reactions over a catalysts (typically cobalt and iron) to produce sulfur-free and aromatic-free renewable diesel. The diesel we generate is twenty times cleaner than even the ultra-low sulfur diesel standards in California.

The catalytic conversions sequester carbon from carbon monoxide and string them into long carbon chains. They then attach Hydrogen molecules to the carbon chains to create hydrocarbons. By varying the catalyst composition and adjusting the process conditions (pressure and temperature), it is possible to control the polymerization chain growth reactions of these hydrocarbon chains. This enables the production of a range of products including light hydrocarbons, liquefied petroleum gas, naphtha, diesel, and wax fractions. Typical operating conditions for FT synthesis of long-chain products, such as renewable diesel, are 200–250°C (390-480°F) and pressures of 25–60 bar.

The discharge of the FT reactor contains byproduct water (pressurized to stay in the liquid form), low molecular weight hydrocarbons (gases), and a wide range of liquid hydrocarbons that can include naphtha, diesel, and wax cuts. These can be separated by use of a three-phase separator. The tail-gas can be recycled to the FastOx gasifier or used to generate additional electricity on site. The purified water is cooled and used within the plant and the liquid hydrocarbons continue on to a fractionator. The fractionator, as the name implies, separates appropriate fractions of the liquid hydrocarbons to produce the final desired product in the proper quantities.

Sierra Energy partners with industry experts to deliver FT systems that convert syngas into these liquid products.



Diesel produced using FastOx gasification has a very low sulfur content. As a consequence, using the diesel created from our gasification plant to generate electricity produces very low amounts of sulfur dioxide emissions, one of the most common and toxic pollutants emitted from burning fossil fuel. With our gasification system, the environmental benefits are twofold in that they reduce waste and produce a clean diesel with significantly less pollutants than conventional forms.

The exact nature of diesel production depends on many factors such as the feedstock being converted, system configuration, and other plant specifics. For a system processing post-recycled municipal solid waste, FastOx gasifiers would produce approximately 29 to 39 gallons per metric ton of feedstock for small scale projects.

Use our online calculator to see diesel outputs for different waste materials and various capacities.



The exact nature of equipment required to run a Fischer-Tropsch back-end system varies with the type of fuel desired. All FT production systems will require some combination of the following:

  • Catalysts
  • Fractionator
  • FT Reactor
  • Compressors
  • Pumps
  • Heat Exchangers

To learn more about generating diesel through FastOx gasification, please contact us.