TABLE 5.3 Comparison of Costs (in 2007 Dollars) for Three Scenarios That Represent Low, Medium, and High Levels of Improvements in Technology and Process Efficiency in a Biorefinery Using the Woody Biomass Poplar

 

Level of Improvement

Cost at Higher Capacity and Medium Improvement

Poplar Low

Poplar Medium

Poplar High

Plant capacity (million gallons)

40

40

40

100

Total capital ($ million)

223

194

174

349

Total capital ($ per annual gallon)

5.65

4.85

4.34

3.49

Total capital ($ per barrel per day)

87,000

75,000

67,000

61,000

Biomass used (dry tons)

593,000

514,000

461,000

1,286,000

Yield (gallons per ton)

67

78

87

78

Ethanol operating cost ($ per gallon)

1.95

1.40

0.90

1.30

Ethanol production cost ($ per gallon)

2.70

2.00

1.50

1.82

Facility-dependent fraction of cost (percent)

34

39

48

36

Raw material-dependent fraction of cost (percent)

57

51

40

57

fraction of cost”) is a significant component of ethanol production costs. But with significant evolutionary improvement of the technology and scaling up of the operation, the process economics can be improved.

Ethanol has 66 percent as much energy as gasoline does. Ethanol is also hygroscopic and cannot be transported in existing fuel-infrastructure pipelines because of its affinity for water. It also is corrosive and can damage seals, gaskets, and other equipment and induce stress-corrosion cracking in high-stress areas. Ethanol is currently shipped by rail or barge. If ethanol is to be used in a fuel at concentrations higher than 20 percent ethanol (for example, in E85, which is a blend of 85 percent ethanol and 15 percent gasoline), the number of refueling stations will have to be increased. If ethanol is to replace a substantial volume of transportation gasoline, an expanded infrastructure will be required for its distribution. (The transport and distribution of synthetic diesel and gasoline produced from thermochemical conversion are less challenging because they are compatible with the existing infrastructure for petroleum-based fuels.)



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