Fuel Cell Emissions

Comparison of emissions from diesel, gas turbine and petrol engines with fuel cell. (Adapted from Nolan, G. Applications for Fuel cells. By Gerry Nolan, Silicon Chips, Issue 166, Published July 6, 2002. Available at http //www.siliconchip.com.au/cms/A 30527/article.html, accessed March 28, 2013.) 

This corresponds to lower CO2 and CO2 emissions. Fuel cell power plants also have longer life expectancies and lower maintenance costs than their alternatives. 

A fuel cell power generation system consists of several components besides the fuel cell such as a fuel processor and a power conditioner/inverter. The fuel processor is the first step of the conversion of fuel into an electrical current Typically, a fuel processor utilizes a combination of steam reforming (SR) and partial oxidation (POX) methods to convert hydrocarbons (methane, natural gas) into the pure hydrogen necessary as input to the fuel processor. During this process, the fuel processor also should strip the input gas of its pollutants such as carbon and carbon monoxide. The fuel processor is one of the areas in which the greatest environmental threat can occur because of this. There are a number of other considerations to be taken into account when examining the environmental impact and life cycle assessment of fuel cell power generation system such as axillary equipment and their economic and environmental impact (Kordesch and Simader 1995 van Rooijen 2006 Tromp 2002). 

Though fuel cell cars have more efficient energy use in the vehicles than conventional internal combustion engines, the use of alternative fuels require additional conversion stages onboard the vehicles. These fuels, except bioenergy carriers, can only be extracted and produced with a higher use of energy than for conventional fuels, so the additional conversion processes 

Used Emission Factors for Fuel Cell Compact Fieat and Power Production Installations and Conventional Installations 

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Another important potential appHcation for fuel cells is in transportation (qv). Buses and cars powered by fuel cells or fuel cell—battery hybrids are being developed in North America and in Europe to meet 2ero-emission legislation introduced in California. The most promising type of fuel cell for this appHcation is the SPEC, which uses platinum-on-carbon electrodes attached to a soHd polymeric electrolyte. 

Fuel cells, which rely on electrochemical generation of electric power, could be used for nonpolluting sources of power for motor vehicles. Since fuel cells are not heat engines, they offer the potential for extremely low emissions with a higher thermal effidency than internal combustion engines. Their lack of adoption by mobile systems has been due to their cost, large size, weight, lack of operational flexibility, and poor transient response. It has been stated that these problems could keep fuel cells from the mass-produced automobile market until after the year 2010 (5). 

See also Batteries Capacitors and Ultracapacitors Electric Motor Systems Emission Control, Vehicle Environmental Problems and Energy Use Flywheels Fuel Cells Fuel Cell Vehicles Flybrid Vehicles Materials Transportation, Evolution ofEnergy Use and. 

Transportation accounts for about one-fourth of the primary energy consumption in the United States. And unlike other sectors of the economy that can easily switch to cleaner natural gas or electricity, automobiles, trucks, nonroad vehicles, and buses are powered by internal-combustion engines burning petroleum products that produce carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons. Efforts are under way to accelerate the introduction of electric, fuel-cell, and hybrid (electric and fuel) vehicles to replace sonic of these vehicles in both the retail marketplace and in commercial, government, public transit, and private fleets. These vehicles dramatically reduce harmful pollutants and reduce carbon dioxide emissions by as much as 50 percent or more compared to gasoline-powered vehicles. 

Howard, P. E. (1996). The Ballard Zero-Emission Fuel Cell Engine. Prese. At Commercializing Fuel Cell Vehicles, InterTech Conference (September). 

Hydrogen can be used with vei y little or no pollution for energy applications. When hydrogen is burned in air, the main combustion product is water, with traces of nitrogen oxides. Wlien hydrogen is used to produce electricity in a fuel cell, the only emission is water vapor. 

While hydrogen engines have some advantages over natural-gas engines, the hydrogen fuel cell offers a true quantum leap in both emissions and efficiency. 

If hydrogen is made from decarbonized fossil fuels, fuel-cycle emissions can be cut by up to 80 percent. With renewable energy sources such as biomass, solar, or wind, the fuel cycle greenhouse gas emissions are virtually eliminated. It is possible to envision a future energy system based on hydrogen and fuel cells with little or no emissions of pollutants or greenhouse gases in fuel production, distribution, or use. 

In the longer term, more exotic technologies, such as fuel cells powered by hydrogen, may be feasible. These technologies are fai from being economically feasible, but rapid progress is being made. However, as conventional vehicles become cleaner, the relative emissions-reduction benefits from alternative fuels declines. 

Catalyst in fuel cells and automobile emission control. 

Air pollution from exhaust emissions NO t and particulate matter from exhaust emissions causing air pollution are -1% at present. By adoption of better combustion control technology, better quality fuels (or even fuel cell-based motor vehicles), and more efficient catalytic converters, researchers aim to mitigate this problem. 

Imagine an automobile thatmns in silence and without polluting emissions. Such an automobile, long a dream of the environmentally conscious, has recently become a reality. The power source is a fuel cell, an electrochemical cell that uses a combustion reaction to produce electricity. Hydrocarbons such as natural gas and propane can be used in fuel cells, but the cleanest fuel is molecular hydrogen. 

Today s society asks for technology that has a minimum impact on the environment. Ideally, chemical processes should be clean in that harmful byproducts or waste are avoided. Moreover, the products, e.g. fuels, should not generate environmental problems when they are used. The hydrogen fuel cell (Chapter 8) and the hydrodesulfurization process (Chapter 9) are good examples of such technologies where catalysts play an essential role. However, harmful emissions cannot always be avoided, e.g. in power generation and automotive traffic, and here catalytic clean-up technology helps to abate environmental pollution. This is the subject of this chapter. 

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