This analysis developed detailed process flow diagrams and an Aspen Plus® model, evaluated energy flows including a pinch analysis, obtained process equipment and operating costs, and performed an economic evaluation of two process designs based on the syngas clean up and conditioning work being performed at NREL. One design, the current design, attempts to define today's state of the technology. The other design, the goal design, is a target design that attempts to show the effect of meeting specific research goals.

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Executive Summary/ConclusionsIn principle, syngas (primarily consisting of CO and H 2 ) can be produced from any hydrocarbon feedstock, including: natural gas, naphtha, residual oil, petroleum coke, coal, and biomass. The lowest cost routes for syngas production, however, are based on natural gas, the cheapest option being remote or stranded reserves. Economic considerations dictate that the current production of liquid fuels from syngas translates into the use of natural gas as the hydrocarbon source. Nevertheless, the syngas production operation in a gas-to-liquids plant amounts to greater than half of the capital cost of the plant. The choice of technology for syngas production also depends on the scale of the synthesis operation. Syngas production from solid fuels can require an even greater capital investment with the addition of feedstock handling and more complex syngas purification operations. The greatest impact on improving the economics of gasto liquids plants is through 1) decreasing capital costs associated with syngas production and 2) improving the thermal efficiency with better heat integration and utilization. Improved thermal efficiency can be obtained by combining the gas-to-liquids plant with a power generation plant to take advantage of the availability of low-pressure steam.

Prepared under Task No. BP911030 Excluding the consumption of fossil fuels by the power plant, the external energy efficiency and external energy ratio indicate that upstream processes are large consumers of energy. In fact, two operations, those related to flue gas clean-up and coal transportation, account for between 3.8% and 4.2% of the total system energy consumption, and between 67.4% and 70.5% of the non-coal energy. Processes involved in the gas clean-up operations include the production, transport, and use of limestone and lime in the Average and NSPS systems, and the production, distribution, and combustion of natural gas in the LEBS system. These operations consume between 35.3% and 38.5% of the non-coal energy, and between 2.0% and 2.4% of the total energy of the systems. Transportation of the coal uses similar amounts: between 30.1% and 32.2% of non-coal, and 1.8% of total system energy. As expected, the amount of resources consumed, emissions produced, and energy used, are small for the mine mouth transportation case. It was found that the transportation distance has a significant effect on the oil consumption, a few of the systems emissions, and the energy consumption, whereas the mode of transportation has virtually no effect on the results. Although energy consumption is significant, transportation required fewer resources and had lower air, water, and solid waste emissions than either the mining or electricity generation subsystems. Appendices Appendix A: Graphical Representation of the LCA System in TEAM ® Appendix B: Additional Results Tables Appendix C: Additional Figures Units of Measure Metric units of measure are used in this report. Therefore, material consumption is reported in units based on the gram (e.g., kilogram or megagram), energy consumption based on the joule (e.g., kilojoule or megajoule), and distance based on the meter (e.g., kilometer). When it can contribute to the understanding of the analysis, the English system equivalent is stated in parenthesis. The metric units used for each parameter are given below, with the corresponding conversion to English units. Mass: kilogram (kg) = 2.205 pounds megagram (Mg) = metric tonne (T) = 1 x 10 g = 1.102 ton (t) 6 Distance: kilometer (km) = 0.62 mile = 3,281 feet Area: hectare (ha) = 10,000 m = 2.47 acres 2 Volume: cubic meter (m) = 264.17 gallons 3 Pressure: kilopascals (kPa) = 0.145 pounds per square inch Energy: gigajoule (GJ) = 0.9488 MMBtu (million Btu) kilowatt-hour (kWh) = 3,414.7 Btu gigawatt-hour (GWh) = 3.4 x 10 Btu 9

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