• Gasification of biomass (feedstock flexible) to produce a syngas;

• CO₂ separation and scrubbing of the syngas; and

• catalytic liquid fuel synthesis using a four-stage catalytic system (the MTG variant).

Primus says that its gasoline is cost-competitive with fossil fuels without subsidies, utilizing carbon-efficient and high fuel-yielding non-agricultural biomass that does not compete with foodstocks.

A February 2011 report from the US Department of Energy’s National Renewable Energy Laboratory (NREL) conclude that gasoline produced via the methanol-to-gasoline (MTG) route (earlier post) using syngas from a 2,000 dry metric tonne/day (2,205 US ton/day) biomass-fed facility could have a plant gate price (PGP) of $1.95/gallon US ($0.52/liter). (Earlier post.)

Very broadly, the biomass-to-gasoline (BTG) process assessed in the NREL report gasifies biomass to produce a syngas rich in hydrogen and carbon monoxide. This syngas is cleaned and conditioned and then catalytically converted into methanol for use in the MTG process.

In the MTG process, dimethylether (DME), the dehydrated derivative of methanol, is reacted over a ZSM-5 zeolite catalyst, on which the chain growth of molecules is sterically hindered, thus allowing only production of gasoline and lighter material. The gasoline product from the MTG process has more than 51 compounds, similar to straight-run gasoline in a petroleum refinery.

This mixture is then separated using a process similar to that used in a gasoline refinery. The design utilized in the NREL model utilizes five distillation columns to separate the remaining gas, LPG, light gasoline, and heavy gasoline. The remaining gas is sent to the fuel combustor. The light gasoline continues without further treatment. The heavy gasoline could proceed through a durene isomerizer in order to eliminate the presence of the 1,2,4,5-tetramethylbenzenes by converting them to 1,2,3,5-tetramethylbenzenes. This stream would then be merged with the light gasoline. The two product streams are LPG and gasoline.

As noted above, Primus claims to have simplified the MTG process, reducing the need for separation or end treatment.

Primus says it plans to build its first commercial facility in Pennsylvania. The company will leverage the benefits of its partnerships with local farms for agricultural land and EcoTherm for biomass feedstock to support Primus’ plans for continued production scale up and operational growth. The commercial facility will have a processing capacity of 40,000 tonnes of biomass per year, thereby generating 3.2 million gallons of high-octane gasoline each year.

The company’s thermochemical conversion process can be applied to the production of other fuels. Primus has a technology and engineering cooperation and teaming agreement with Lockheed Martin to develop bio-jet fuel.