40 percent (higher heating value [HHV]), and cost in excess of $2,000/kW (1999 dollars), which is less than the cost of analogous coal-fueled plants (Brkic and Cooperberg, 1999; Collodi, 1999; de Graaf et al., 1999; Farina and Collodi, 1999). Four heavy-oil and coke-fueled gasification plants have been started up or will be started up by the end of 2000; several additional plants are scheduled for start-up in the next few years. These plants range in cost from $1,400 to $2,000/kW (1999 dollars) (Brkic and Cooperberg, 1999; Collodi, 1999; de Graaf et al., 1999; Farina and Collodi, 1999), which is less than the $2,000/kW (1999 dollars) cost for analogous coal-fueled gasification demonstration plants. All of these plants have required (or will require) investments that far exceed the Vision 21 Program goal of about $800/kW. These non-coal plants are important to the Vision 21 Program because several subsystems, including syngas purification, solids feeding, and syngas combustion, are being demonstrated at full commercial scale. Real-time demonstrations of new technologies are vital to private sector acceptance and will be necessary for the realization of commercially operable Vision 21 plants. Virtual demonstration alone will not provide a transition of Vision 21 plants and technologies to commercialization.
Third, because of the likelihood of future regulations limiting carbon dioxide emissions from power production plants, the production of a concentrated carbon dioxide stream will be an advantage for competitive power production. Gasification technologies produce a very concentrated stream of carbon dioxide (typically 42 percent concentration), which can be separated from plant exhaust gases at lower cost and with less reduction in overall efficiency than the less concentrated carbon dioxide stream (typically 12 percent) produced by combustion processes.
Finally, meeting the Vision 21 goal of competitive power generation by reducing the investment cost of the direct syngas production section of the plant from $850/kW to less than $550/kW (in 1999 dollars) to compete with plants that use natural gas in the same types of fuel-flexible gas turbines, will require innovative, high-risk R&D. The committee encourages DOE to investigate new ideas relating to novel, as well as existing, gasification processes. Existing gasification plants in the United States could be studied to determine what improvements might be achieved. Based on current DOE programs and suggestions in the literature, a very aggressive R&D program could conceivably meet the Vision 21 goal. Promising approaches involve improvements in coal feeding, heat recovery, and cycle integration (van der Burgt, 1998).
Coal-gasification systems produce syngas (a mixture of carbon monoxide and hydrogen) that can be converted into electricity by IGCCs, fuel cells, or gas-turbine/fuel-cell hybrid systems at high electrical conversion efficiencies. These are the only combinations of coal-conversion technology and energy-conversion technology with the potential to achieve the 60-percent efficiency target of the Vision 21 Program. Coal-gasification systems can also be configured to produce a concentrated carbon dioxide stream that minimizes the costs of carbon dioxide capture, converts essentially all of the sulfur in the coal to elemental sulfur,