1. Title: Coal Cowboy Duration: 00:12:51 Link: http://coe-jaguar. engr

2. Conversion of Coal to Liquid (CTL) Fuels
Several very old processes… since WWII
Same general theme: increase H/C ratio
Can make a wide variety of hydrocarbon products (e.g. synthetic crude or synfuel)
Two basic methods: direct and indirect

3. Advantages of Coal To Liquid
(CTL) Fuels
• CTL Improves national and economic security
• Lessens dependence on foreign oil
• Uses domestic resources and produces more
jobs for Americans
• Provides environmental benefits
- Cleaner fuels that reduce NOx and particulate emissions
- Enables use of higher efficiency engines
• Is capable of capturing CO2 emissions
• Provides geographic diversity as energy source

4. Coal Liquefaction Very expensive
Liquefaction attractive for transportation fuel
Indirect liquefaction commercially proven (>50 yrs)
Acid gas removal by amines (CO2, H2S)
S removal by Claus Process
H2S + O2 = H2O + SO2
H2S + SO2 = S + H2O

5. Direct Liquefaction of Coal Attractive Because of
Low transportation cost
Less chemical transformation required
Higher efficiency than high Btu gas production
Easy to store
Less water required for manufacture
However, processing slurries at high temperature and pressure presents difficulties with equipment life and solid/liquid separation (still not commercial)

6. SASOL in South Africa Indirect Coal liquefaction is proven technology
• South Africa’s SASOL Co. developed a commercial
coal liquids industry (fuel plus chemicals)
• The plant produces about 150,000 barrels daily at
its second plant

7. Coal To Liquids in China
Concerned about increasing dependence on oil imports and its impact on economic growth and national security, China is making a massive $6 billion investment in new coal liquefaction plants.
Planned $2 billion Shenhua facility will eventually produce 50,000 barrels daily of diesel fuel and gasoline.

8. Two Basic Approaches To Convert Coal To A Liquid Fuel
1. Direct Liquefaction:
• Dissolves coal in a solvent at elevated temperature and pressure
• Combined with hydrogen gas and a catalyst
2. Indirect Liquefaction:
• Involves first gasifying coal, followed by reacting carbon monoxide and hydrogen together
nCO + (2n+1)H2 = CnH2n+2 + nH2O

9. Comparison of Processes
DIRECT
LIQUEFACTION
INDIRECT
LIQUEFACTION
Adds hydrogen to break down the coal
Dissolves in a solvent followed by hydrocracking
Operates at 450 C and 170 bars
Light products are distilled
Medium and heavy distillates obtained from vacuum distillation
Liquid yields of 70% of the dry weight of coal feed
Further upgrade is needed for use as transportation fuels
Complete breakdown of coal with steam and oxygen
Sulfur is removed from the syngas
Syngas reacted over catalyst at
300 C and 20 bars
Produces a lighter suite of products; high quality gasoline and petrochemicals
Oxygenated chemicals

10. Indirect Liquefaction
• Fischer-Tropsch Indirect Liquefaction Process
- Yields high quality transportation fuels plus other
products

11. Schematic diagram of different coal liquefaction processes.

18. CTL Costs
• Coal-based liquid fuel becomes viable when the per-barrel price of oil is expected to exceed the $ range for 20+ years • CTL has high front-end capital cost - A 50,000 barrel-a-day plant would cost over $3 billion to construct • The product refinement process is three to four times more expensive than refining an equivalent amount of oil • The cost of sequestering the captured CO2 would increase the price of the end product by $10-20 a barrel. • The imposition of a carbon cap and trade policy would also raise the cost of fuel produced with CTL technology

20. CTL is Very Water-Intensive
CTL requires ~7:1 water to fuel ratio
~7 gallons of water per gallon of fuel produced
Water scarcity can be a limiting factor for CTL plant permitting
Conventional gasoline
1-2.5 gallons of water per gallon of fuel produced
Irrigated Biofuels
1000 gallons of water per gallon of fuel

21. Liquids Fuels Summary….
Proven technologies
All processes require adding hydrogen
All processes remove sulfur and ash
Product include liquid, gas, and combustible solid(char)
Several long-standing commercial processes (e.g., S. Africa - SASOL)
So far no large-scale use without government support

22. Coal to Liquids Summary….
Good promise because of very large coal deposits in the world
Numerous processes that can generate a wide variety of products
Environmental issues include some hazardous wastes and byproducts
Does not yet effectively compete with natural gas or oil production … requires some form of subsidy