Sunday, September 25, 2011

Primus' Biomass-to-Gasoline Process to Cost $1.95/Gallon

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More information on Primus
GCC article about Primus' plans
Primus’s process is based on a proprietary variant of the ExxonMobil Methanol-to-Gasoline process, simplified to produce standard gasoline without need for separation or further treatment, the company says. The Primus process consists of three main steps:

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). _GCC

The biomass is pelletised, then gasified. The syngas is converted to methanol, and the methanol is converted directly to gasoline, via Exxon Mobil's highly efficient MTG process -- as modified by Primus. More on MTG:
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. _GCC

This is an entirely renewable biomass to gasoline process which is likely to impact the fossil fuels markets in good time. Perhaps the main obstacle to a large scale adoption of biomass to liquid fuels, is the current very cheap price of natural gas.

Taken from a previous article at Al Fin Potpourri

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