Synthetic Liquid Fuels
Synthetic fuel typically is produced in a heat and chemical reaction called Fischer-Tropsch. The product is a liquid hydrocarbon, like crude or diesel, which is cleaner burning than traditional fossil fuels; it causes less wear and tear on parts, saving money and commanding a premium on the market. Synthetic fuel is predictable and can make high-quality petro-chemicals and plastics.
Turning coal into a liquid fuel may sound like an innocuous process, something akin to melting blocks of ice. However, it is a highly energy intensive and carbon dioxide laden process.
The first step in converting coal to liquid fuel is to gasify the coal producing a methane-like syngas that can be used like natural gas in power generation, heating, and feed stock for chemical manufacturers like Agrium in Nikiski. Agrium had plans in 2008 to start a coal gasifier, called Blue Sky, to replace the dwindling Cook Inlet NG feedstock.
Traditional coal liquefaction comes with all the inherent drawbacks of traditional coal energy — namely, mining, transportation and carbon and toxic pollution. Underground Coal Gasification (where the Fischer-Tropsch process is done completely underground in the coal seam) could alleviate some of these concerns. However, there are still many questions concerning this technique.
While coal liquefaction can take several forms natural gas liquefaction typically uses the Fischer-Tropsch process. Fischer–Tropsch is operated in the temperature range of 150–300 °C (302–572 °F). The process converts the coal to gas and uses a catalyst to convert the gas into liquid. The catalyst is often a metal, like cobalt, however much research is going into finding new and more efficient catalyst materials.
Using Usibelli coal from Healy Alaska would technically be called Brown Coal to Liquids BCTL. Since Usibelli’s coal is sub-bituminus or Lignite, would need an extra drying process to remove water. This research was done by Japan in early 1990s. The process fell out of favor due to cheap oil.
Though liquefied gas is traditionally thought of as compressed and refrigerated gas shipped in large quantities over long distances, traditional LNG is far too unwieldy to use as an everyday fuel source. Instead, to make liquid fuel you can handle at room temperature and atmospheric pressures, one that can burn clean in existing transportation fleets, it needs to be liquefied through Fischer-Tropsch.
Though natural gas is a source of carbon dioxide pollution and its exploration and extraction have an impact on Alaska’s invaluable environment, natural gas is the best option to bridge between our current heavy reliance on fossil fuels to 2025 when at least half of our energy can come from renewable energy systems.
Alaska Legislators have introduced a bill to incentivize the development of a synthetic fuels market in Alaska. SB228 Tax Incentive for Gas-to-Liquids an Act providing for an industrial incentive investment tax credit and including a gas-to-liquids facility as an eligible investment; and providing for a production tax limit on gas used as a raw material for producing liquids or petrochemicals from gas in the state
While the bill language does include natural gas liquefaction, the gas in Gas-to-Liquids can come from coal, biomass or other feedstock.
The bill is sponsored by Senators Lesil McGuire, Bill Wielechowski and Johnny Ellis. It was referred to (S) Resources then (S) Finance.
The Department of Defense plans to use synthetic fuels 50 percent of its aviation fuel use. Coal liquefaction was the initial favorite technology.
However, new procurement rules require that the synfuel be less carbon-intensive than traditional fossil fuel refinement processes. Even including carbon capture and sequestration or biomass blending (feeding CO2 to algae etc.), coal liquefaction may have trouble meeting this mark. Natural Gas liquefaction could meet the requirements of the Dept. of Defense while at the same time incentivizing in-state natural gas development.
Synthetic fuel manufacture is not a new technology. Coal liquefaction was used by Germany in WWII and by South Africa due to sanctions related to apartheid. The patent for the Fischer Tropsch process was published in 1930. However, there have been recent advances in direct liquefaction processes and advances in catalyst technology, which might include carbon nano-tubes to increase the surface area for reactions.
The newest Direct to Liquids technology can be found in China. Invented in 1990 or 1991, the Chinese perfected the process from 2002 to 2009 for around $2 billion.
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