, Auto-Opstroom.com: Vision 21 - the Ultimate Power Plant Concept

Vision 21 - the Ultimate Power Plant Concept

Vision 21 - Artist Concept of a Futuristic Breed of Coal-Fired Power Plants

Program Performance Goal:
By 2015, develop the core modules for a fleet of fuel-flexible, multi-product energy plants that boost power efficiencies to 60+ percent, emit virtually no pollutants, and with carbon sequestration release minimal or no carbon emissions.


Vision 21 is a futuristic energy concept unlike any power plant that exists today.


TECHNOLOGY GOALS


Efficiencies

Emissions

Costs

Under development by the Department of Energy's Office of Fossil Energy, the concept envisions a virtually pollution-free energy plant. Unlike today's single purpose power plants that produce only electricity, a Vision 21 plant would produce multiple products - perhaps electricity in combination with liquid fuels and chemicals or hydrogen or industrial process heat. It also would not be restricted to a single fuel type; instead, it could process a wide variety of fuels such as coal, natural gas, biomass, petroleum coke (from oil refineries), and municipal waste. It would generate electricity at unprecedented efficiencies, and coupled with carbon sequestration technologies, it would emit little if any greenhouse gases into the atmosphere.

Vision 21, if successful, could revolutionize the power and fuels industry within the next 15 years.

The approach is to develop a suite of technology modules that can be interconnected in different configurations to produce selected products. These modular facilities will be capable of using a multiplicity of fuels to competitively produce a number of commodities at efficiencies greater than 60 percent for coal-based systems and 75 percent for natural gas-based systems with near-zero emissions.

Vision 21 builds on a portfolio of technologies already being developed, including low-polluting combustion, gasification, high efficiency furnaces and heat exchangers, advanced gas turbines, fuel cells, and fuels synthesis, and adds other critical technologies and system integration techniques. When coupled with carbon dioxide capture and recycling or sequestration, Vision 21 systems would release no net carbon dioxide emissions and have no adverse environmental impacts.

Many of the Vision 21 activities complement and extend focused activities to achieve intregated gasification combined cycle and other advanced high efficiency technologies. For example, hot gas particulate filtration, hot gas sulfur/alkali control, and air separation are critical elements to coal gasification. Vision 21 addresses gas separation and cleanup, but extends the development effort to:

  • increasingly efficient and cost-effective measures for particulate and sulfur/alkali control and air separation; and
  • measures dealing with a broader range of gases, such as hydrogen and carbon dioxide.

Advanced gas separation and cleanup are critical to achieving hybrid systems, fuel and product flexibility, and carbon sequestration. Hybrids and fuel and product flexibility offer the potential for major improvements in cost and performance. And effective carbon dioxide capture is a prerequisite to carbon sequestration.

A hybrid system showing great promise is integration of gasification with a fuel cell. Fuel cells offer very high efficiencies, with emerging fuel cells having 60 percent efficiency. These emerging fuel cells also produce very high-temperature exhaust gases that can either be used directly in combined-cycle or used to drive a gas turbine. Integrated gasification fuel cell hybrids have the potential to achieve up to 60 percent efficiency and near-zero emissions. Moreover, the concentration of carbon dioxide lends itself to removal by separation or other capture means. Such systems require that the syngas derived from gasification be free of contaminates for use in the fuel cell, or that the hydrogen be separated from the syngas (hydrogen is the fuel element for the fuel cell).

Fuel flexibility enables the use of low-cost indigenous fuels, renewables, and waste materials. Use of renewables and wastes contributes to solving environmental problems as well as reducing operating costs. The challenge is to develop effective feed mechanisms for these alternative fuels, establish effective operating parameters, and provide the means to achieve the operating parameters and to control any new pollutants that might be formed. For advanced, high-performance gas turbines, and hybrids incorporating advanced turbines/fuel cells, fuel flexibility requires research to address combustion of low-Btu gases and maintain low-NOx emissions at increasingly higher temperatures.

Product flexibility allows power suppliers to supplement revenues by designing plants to site- or region-specific markets for high-value by-products. Many chemical and fuel processes, however, require nearly contaminant-free syngas and warrant improvements to enhance product quality.

Carbon sequestration is the ultimate solution to stabilizing global carbon emissions. A prerequisite to carbon sequestration is carbon capture, which for power systems is carbon dioxide capture. Power system developments are moving toward higher efficiency to lower carbon dioxide emissions on a per-Btu basis and toward more concentrated carbon dioxide emission streams through oxygen-rather than air-based gasification and combustion. Air separation efforts support the move to oxygen-based systems. Ultimately, carbon dioxide must be captured either through chemical or physical separation methods.

Vision 21 is addressing the challenges outlined above through a cooperative effort involving industry, universities, and National Laboratories. It includes fundamental research in materials science, novel concept evaluation at bench-scale, and process verification at pilot-scale. Facilities such as the Power System Development Facility at Wilsonville, Alabama, along with industry/National Laboratory/university facilities, are being enlisted to address these challenges.