Environment:
CTL fuels for a cleaner environment
Beyond its capability to strengthen national security, liquefied coal fuels can also help satisfy demands for reduced emissions and cleaner air. This is because coal gasification, the initial stage of the liquefaction process, removes impurities from coal and enables the U.S. to use its unrivalled coal reserves — the world's largest — in an environmentally responsible way.
The low particulate, low mercury and almost zero sulfur emission profile of these fuels means reduced tailpipe emissions, cleaner running mass transit systems in urban communities, no measurable toxic pollutants and lower emissions from fuel production. The result is a fuel that burns much cleaner than conventional diesels and cleaner than gasoline in use today.
CTL Plants Issues related to plant siting will be addressed in strict accordance with applicable requirements, including the Clean Air Act criteria governing all major plant construction and operations. Air emissions of conventional pollutants and mercury will be minimized in accordance with the new Clean Air Interstate Rule and a first-ever requirement for reduced mercury emissions from power plants.
Process Emissions Because coal is gasified as in an IGCC plant, CTL plants allow for relatively easy extraction through scrubbing of impurities in the gas stream such as heavy metals and mercury. Post gasification treatment of the syngas removes virtually all of the particulate matter and any residual metals. The result is a near zero-sulfur fuel and lower NOx emissions because the fuel itself does not contribute to NOx formation in engine cylinders. The process also yields virtually no measurable amounts of acids or hazardous air pollutants.
Greenhouse Gas Reduction The coal gasification process can also reduce greenhouse gas emissions suspected of contributing to climate change. Because coal gasification reduces the cost and energy required to remove carbon, CTL can capture carbon dioxide (CO2) through the gasification and Fischer-Tropsch (F-T) processes for use in enhanced oil and coal bed methane recovery or for safe storage deep underground. Considered on a life-cycle basis, the resulting coal-derived diesel fuel would have a greenhouse gas profile comparable to that of petroleum diesel.
CTL is therefore consistent with existing policies and programs designed to lower greenhouse gas emissions — including the carbon sequestration goals embodied in The Energy Policy Act of 2005, the administration's Climate Vision program promoting voluntary industry initiatives for reducing greenhouse gases, and the FutureGen program designed to capture carbon from the world's first coal-based hydrogen fuel plant with near zero emissions.
Clean Byproducts The gasification and subsequent liquefaction process also produces valuable by-products. Elemental sulfur has industrial uses while other would be treated and contained as in any modern coal plant, such as an IGCC facility.
Biodegradable Fuels Liquefied coal fuels are more biodegradable than conventional diesel thanks to its molecular structure and the absence of aromatics following the F-T process. This process liquefies the fuel from syngas rather than through a refining separation process.
Coal Mining Oversight Supplies of additional coal for feedstock will be mined domestically under the most comprehensive environmental and safety laws in the world. Coal mining operations are subject to the following federal environmental and safety laws:
- National Environmental Policy Act
- Surface Mining Control and Reclamation Act
- Clean Water Act
- Clean Air Act
- Endangered Species Act
- Safe Drinking Water Act
- Mine Safety and Health Act
- National Historic Preservation Act
- Toxic Substances Control Act
- Migratory Bird Treaty Act
- BLM and Forest Service Regulations
- Wilderness Act