TABLE 5.4 Fuel Costs and CO2 Emissions for Thermochemical Conversion of Coal and Biomass

 

Coal-to-Liquid FT

Coal-to-Liquid FT

Coal-to-Liquid MTG

Coal-and-Biomass-to-Liquid FT

Biomass-to-Liquid FT

Without CCS

With CCS

With CCS

With CCS

With CCS

Inputs:

 

 

 

 

 

Coal (tons per day as received)

26,700

26,700

23,200

3,030

0

Biomass (dry tons per day)

0

0

0

3,950

3,950

Biomass (mass %)

0

0

0

57

100

Biomass energy (%, low heating value)

0

0

0

42

100

Outputs:

 

 

 

 

 

Gasoline (bbl/d)

21,290

21,290

50,000

4,260

 

Diesel (bbl/d)

28,700

28,700

0

5,750

 

Total liquid fuels (bbl/d)

50,000

50,000

50,000

10,000

4,410

Economic metrics:

 

 

 

 

 

Specific total plant cost ($/bbl per day)

97,600

98,900

80,400

134,000

147,000

Total liquid fuels cost ($/gal of gasoline equivalent)

1.50

1.64

1.57

2.52

3.32

Break-even oil price ($/bbl)

56

68

51

103

139

Emissions relative to petroleum-derived fuels

2.18

1.03

1.17

−0.02

−1.35

Cost of avoided CO2 ($/tonne)a

11

10

15

20

Note: CCS = carbon capture and storage; FT = Fischer-Tropsch; MTG = methanol-to-gasoline.

aIncludes the costs of CO2 transport and geologic storage and is expressed as dollars per tonne of CO2 equivalent avoided.

10,000 bbl/d of fuels with close to zero CO2 emissions. Note that the case shown is for FT, but the economics would look similar if MTG were used. FT primarily produces diesel; MTG produces gasoline. The economics show that the capital costs of coal-and-biomass-to-liquid fuel plants are higher than the costs of coal-to-liquid fuel plants.

The CO2 emissions are near zero on a life-cycle basis because the biomass in the feedstock is a carbon sink, offsetting some of the coal carbon. The key assumption in this case is that biomass availability is limited to 4000 tons per day by regional harvesting and transportation considerations. In those sites where locally sustainable biomass densities are higher (see Figure 5.1), larger plants—perhaps as many as 100 nationwide—could be built at similar biomass-to-coal



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