Power production

Power production is responsible for the introduction of toxic chemicals into drinking water via several routes. These include petroleum production (drilling, pumping, transport, and refining), coal mining, petroleum combustion, and coal combustion. Nuclear reactors that produce electricity also pollute the water environment through the introduction of massive quantities of heat to surface waters. 

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Trends in commercial fuel, eg, fossd fuel, hydroelectric power, nuclear power, production and consumption in the United States and in the Organization of Economic Cooperation and Development (OECD) countries, are shown in Tables 2 and 3. These trends indicate (6,13) (/) a significant resurgence in the production and use of coal throughout the U.S. economy (2) a continued decline in the domestic U.S. production of cmde oil and natural gas lea ding to increased imports of these hydrocarbons (qv) and (J) a continued trend of energy conservation, expressed in terms of energy consumed per... 

Table 34. Biomass-Fueled Cogeneration and Small Power Production Capacities and Facilities, kW ...

X MW in 1986, of the power produced in the same year. Biomass-fueled electric capacity and generation was 19.2% (4.9 x 10 MW) and 21.2% (23.7 X 10 MWh) respectively, of total nonutiUty capacity and generation. Biomass-fueled capacity experienced a 16% increase in 1986 over 1985, the same as natural gas, but it was not possible to determine the percentage of the total power production that was sold to the electric utiUties and used on-site. Total production should be substantially more than the excess sold to the electric utiUties. Overall, the chemical, paper, and lumber industries accounted for over one-half of the total nonutiUty capacity in 1986, and three states accounted for 45% of total nonutiUty generation, ie, Texas, 26% of total California, 12% of total and Louisiana, 7% of total. There were 2449 nonutiUty producers with operating faciUties in 1986, a 15.8% increase over 1985 75% capacity was intercoimected to electric utiUty systems. 

Cmde gas leaves from the top of the gasifier at 288—593°C depending on the type of coal used. The composition of gas also depends on the type of coal and is notable for the relatively high methane content when contrasted to gases produced at lower pressures or higher temperatures. These gas products can be used as produced for electric power production or can be treated to remove carbon dioxide and hydrocarbons to provide synthesis gas for ammonia, methanol, and synthetic oil production. The gas is made suitable for methanation, to produce synthetic natural gas, by a partial shift and carbon dioxide and sulfur removal. 

The hot gases from the combustor, temperature controlled to 980°C by excess air, are expanded through the gas turbine, driving the air compressor and generating electricity. Sensible heat in the gas turbine exhaust is recovered in a waste heat boiler by generating steam for additional electrical power production. 

Methanol, a clean burning fuel relative to conventional industrial fuels other than natural gas, can be used advantageously in stationary turbines and boilers because of its low flame luminosity and combustion temperature. Low NO emissions and virtually no sulfur or particulate emissions have been observed (83). Methanol is also considered for dual fuel (methanol plus oil or natural gas) combustion power boilers (84) as well as to fuel gas turbines in combined methanol / electric power production plants using coal gasification (85) (see Power generation). 

Fig. 3. (a) General locations of hydrothemial power plants in the continental United States (6). Power is produced directiy from hydrothermal steam indicated by the steam plume at The Geysers in northern California. At all other locations, hot water resources are utilized for power production. In 1993, a hydrothermal power plant also came on line on the island of Hawaii, (b) Location of The Geysers steam-dominated hydrothermal field (D) in Lake and Sonoma counties, within the boundaries of the Cleadake—Geysers thermal anomaly (B). 

The price of lignite pet mined ton or pet heat unit is lower than that for higher rank coals. The market for all coals is primarily as boilet fuel for electric power production. Prices ate generally estabUshed by contracts between utiUty and suppHet before mining begins. 

OTSGs also experience deposition of material on the flow areas in the tube support plates which causes an increase in pressure drop and eventual reductions in plant power production. 

Weapons materials from production reactors were accumulated during the Cold War period as a part of the U.S. defense program. Prominent were tritium, ie, hydrogen-3, having a of 12.3 yr, and plutonium-239, 1/2 = 2.4 X lO" yr. The latter constitutes a waste both as a by-product of weapons fabrication in a waste material called transuranic waste (TRU), and as an excess fissionable material if not used for power production in a reactor. 

For insulators, Z is very small because p is very high, ie, there is Htde electrical conduction for metals, Z is very small because S is very low. Z peaks for semiconductors at - 10 cm charge carrier concentration, which is about three orders of magnitude less than for free electrons in metals. Thus for electrical power production or heat pump operation the optimum materials are heavily doped semiconductors. 

A low calorific value gas, which includes nitrogen from air, could be produced for boiler or turbine use in electric power production, or an intermediate calorific value gas containing no nitrogen for an industrial fuel gas, or synthesis gas for chemical and methane production could be provided. This approach which has been studied in Russia, Europe, Japan, and the United States, is stiU noncommercial in part because it is not economically competitive. 

The total annual value of products produced by electrochemical processing (see Table 1) is roughly 18 biUion. Electric power production in 1990 was 2908 x 10 kWh (9). Production of electric power increased about 2% in 1991 (4) although the economy was in a recession thus, electric power production in 1991 was about 2966 x 10 kWh. About 5% of the total electric power produced is used by the electrochemical process industries. PubHshed... 

The combined cycle is also appHcable to dedicated power production. When the steam from the waste heat boiler is fed to a condensing turbine, overall conversion efficiencies of fuel to electricity in excess of 50% can be achieved. A few pubHc utihty power plants use this cycle, but in general utihties have been slow to convert to gas turbines. Most electricity is generated by the cycle shown in Figures 5d and 6d. 

Banderson, Darryl (ed.), Plume Rise and Bouyancy Ejfects, Atmospheric Science and Power Production, DOE Beport DOE/TIC-27601, 1981. 

Bubbling AFBCs A simplified schematic of a bubbling AFBC is presented in Fig. 27-47. A demonstration plant generating 160 MWe, with a power production intensity of 1.49 MWe/m (1 MWe/16 ft ), began operation in 1988. Also operating is a 350-MWe unit that employs many of the same design features. 

Power production intensity is the power produced hy the hoiler per unit area of the plan section of the hed at a stated elevation. 

Basic to establishing whether power recovery is even feasible, let alone economical, are considerations of the flowing-fluid capacity available, the differential pressure available for the power recovery, and corrosive or erosive properties of the fluid stream. A further important consideration in feasibihty and economics is the probable physical location, with respect to each other, of fluid source, power-production point, and final fluid destination. In general, the tendency has been to locate the power-recoveiy driver and its driven unit where dictated by the driven-unit requirement and pipe the power-recoveiy fluid to and away from the driver. While early installations were in noncorrosive, nonerosive services such as rich-hydrocarbon absorption oil, the trend has been to put units into mildly severe seiwices such as amine plants, hot-carbonate units, and hydrocracker letdown. 

Nakhamkin, M. Increasing Gas Turbine or Combined Cycle Power Production with Compressed Air to Meet Peak Power Demands, ASME Paper No. 2000-GT-0596. 

The location of the plant is the principal determination of the type of plant best configured to meet its needs. Aero-derivatives are used on offshore platforms. Industrial turbines are mostly used in petrochemical applications, and the frame type units are used for large power production. 

The Magnox reactor concept owes its origins to a design study conducted at Harwell, U.K., diuing the early 1950s. The reactor was designed with the dual role of plutonium and power production, and was known by the code word PIPPA... 

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