|The ExxonMobil MTG process flow diagram. Source: EMRE. Click to enlarge.|
Sundrop Fuels, Inc., a gasification-based drop-in advanced biofuels company, finalized a licensing agreement to use ExxonMobil Research and Engineering Company’s methanol-to-gasoline (MTG) technology to be incorporated into a “green gasoline” production facility. Located near Alexandria, Louisiana, Sundrop Fuels plans to break ground late this year on its inaugural commercial plant, which will produce up to 50 million gallons of renewable gasoline annually. (Earlier post.)
The Sundrop Fuels installation represents the first commercial production of biofuels using the MTG process. The MTG technology was originally developed in the 1970s and was successfully commercialized for a large-scale natural gas to gasoline plant during the 1980s in New Zealand.
Sundrop Fuels will use a multi-phase process to convert sustainable forest waste into a bio-based drop-in gasoline for use in today’s combustion engines. A gasification process converts the forest waste combined with hydrogen from natural gas into a synthesis gas, which will then be converted into methanol and then into gasoline in a fixed bed reactor system via the MTG process.
|The MTG reaction path. Source: EMRE. Click to enlarge.|
The MTG process first dehydrates methanol to dimethylether (DME); an equilibrium mixture of methanol, DME and water is then converted to light olefins (C2-C4). A final step synthesizes higher olefins, n/iso-paraffins, aromatics and naphthenes. The shape-selective catalyst limits the synthesis reactions to 10 carbons.
MTG reactor product is separated into gas, raw gasoline and water. Raw gasoline is separated into LPG, light gasoline and heavy gasoline; heavy gasoline is hydro-treated to reduce durene content, then heavy and light gasoline are re-combined into finished MTG gasoline. The result is sulfur-free gasoline with a typical 92 Research Octane.
|MTG gasoline properties|
|Octane Number, RON||92.2||92.0-92.5|
|Octane Number, MON||82.6||82.2-83.0|
|Reid Vapor Pressure, kPa||85||82-90|
|Induction Period, min.||325||260-370|
|Durene Content, wt%||2||1.74-2.29|
|% Evaporation at 70° C||31.5||29.5-34.5|
|% Evaporation at 100° C||53.2||51.5-55.5|
|% Evaporation at 180° C||94.9||94-96.5|
|End Point, °C||204.5||196-209|
The gasoline yield represents 38% of the feed, and 87% of the hydrocarbon product. Water (H2O) represents 56% of the feed.
The company’s first facility will also provide an operational platform for Sundrop Fuels to begin field integration of its proprietary RP Reactor radiant particle heat transfer gasification technology. The super-efficient, ultra high-temperature process will drive Sundrop Fuels’ future massive-scale biofuels plants, planned to produce more than 300 million gallons of renewable, drop-in biofuels annually.
Plans are for Sundrop Fuels to achieve a combined production capacity of more than one billion gallons by 2020—a significant percentage of the cellulosic advanced biofuels goal set by the nation’s Renewable Fuels Standard (RFS).
Significant backing for Sundrop Fuels comes from Chesapeake Energy Corporation, the largest producer of natural gas in northern Louisiana’s Haynesville Shale Field and second-largest producer in the nation. Chesapeake invested $155 million in Sundrop Fuels in mid-2011. The company’s investors also include two of the world’s premier venture capital firms, Oak Investment Partners and Kleiner Perkins Caulfield & Byers.