Electricity from coal

Converting coal to electric power appears, on paper, to be a relatively simple process. In most coal-fired power plants, coal is crushed into fine powder and fed into a combnstion nnit where it is burned. Heat from the burning coal is nsed to generate steam that is nsed to spin one or more turbines to generate electricity. 

One-quarter of the world s coal reserves are found within the United States, and the energy content of the US coal resources exceeds that of all the world s known recoverable oil. Coal is also the workhorse of the nation s electric power indnstry, supplying more than half the electricity consnmed by Americans. 

However, much of the world is becoming increasingly electrified and currently, in the United States, more than half of the electricity generated comes from coal. In the foreseeable future, coal will continue to be the dominant fuel used for electric power production. The low cost and abundance of coal is one of the primary reasons why consumers in the United States benefit from some of the lowest electricity rates of any free-market economy. 

Coal combustion technology is a mature technology with potentially increasing the efficiency in progress of advanced materials. In the short term and medium term, it will play an important role in the world energy section. In the long term, the role of coal may be reduced but coal will be difficult to replace. 

Power plants for electricity generation are defined by functional type (1) base load, (2) peak load, and (3) combined cycle—each has advantages and disadvantages. 

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The poor efficiencies of coal-fired power plants in 1896 (2.6 percent on average compared with over forty percent one hundred years later) prompted W. W. Jacques to invent the high temperature (500°C to 600°C [900°F to 1100°F]) fuel cell, and then build a lOO-cell battery to produce electricity from coal combustion. The battery operated intermittently for six months, but with diminishing performance, the carbon dioxide generated and present in the air reacted with and consumed its molten potassium hydroxide electrolyte. In 1910, E. Bauer substituted molten salts (e.g., carbonates, silicates, and borates) and used molten silver as the oxygen electrode. Numerous molten salt batteiy systems have since evolved to handle peak loads in electric power plants, and for electric vehicle propulsion. Of particular note is the sodium and nickel chloride couple in a molten chloroalumi-nate salt electrolyte for electric vehicle propulsion. One special feature is the use of a semi-permeable aluminum oxide ceramic separator to prevent lithium ions from diffusing to the sodium electrode, but still allow the opposing flow of sodium ions. 

Another special situation arises when one resource has its origin in two different processes. For instance, when a process uses the electricity provided by an energy company, it is possible that this electricity is generated partly by burning coal and partly by burning natural gas. In this case, the process should be considered to use two different types of electricity electricity from coal and electricity from natural gas. Both types of electricity then have their own derived depletion time and, based on how much they contribute to the total amount of electricity supplied, their own exergy flow. 

Can cogeneration of hydrogen and electricity from coal, coupled with co2 extraction, be made into an affordable and practical system for cost-effectively generating both energy carriers ... 

Power for industrial operations is supplied at present by electricity from coal, natural gas, and oil, working heat engines at overall efficiencies of < 35%. All can be replaced by fuel cells of various kinds operating for the next two to three decades on hydrogen from re-formed fossil fuels and as soon as possible by hydrogen from photovoltaics and the decomposition of water.20... 

Using electricity from coal-fired power plants, for example, could increase C02 emissions by a factor of 2-4. But, as long as efficient technology is employed we would not expect significant changes in C02 emissions in the coming decades. 

Greenhouse Gas Savings Relative to Electricity from Coal... 

ZECA [Zero Emission Coal Alliance] A process for making electricity from coal. The coal is reacted with steam and hydrogen to produce methane, which is reformed to produce pure hydrogen, which is used in a solid oxide fuel cell to produce electricity. Developed from 1999 by Los Alamos National Laboratory and an alliance of industrial research laboratories, now organized as the ZECA Corporation. 

The combination of high value outputs, scale-effects and flexibility in general, may lead to a very efficient, cost-effective and clean overall system. Cost-effective means that the electricity produced has to compete with electricity from coal. For fair comparison the cost of clean electricity generation must be considered with a similarly low environmental burden. For instance, costs for removal or storage of the emitted carbon dioxide from coal plants have to be included. For electricity this inches an allowable cost price of 0.05 Euro/kWh. This value is the EU strategic goal and seems achievable for large advanced systems [5] where electrical efficiencies between 50 and 60% can be obtained [6]. In the case of the produced liquid fuels, cost-effective means that the cost price must correspond to the cost prices of fossil fuels, which will be used in the future in cars with low or very low emissions. For the liquid fuels FT diesel is taken as example and the cost price would have to be 0.34 Euro/litre (of diesel). 

Howard HC. Direct Generation of Electricity from Coal and Gas (Fuel cells). New York Wiley 1945. 

De Lorenzo L, Kreutz TG, Chiesa P, Williams RH (2008) Carbon-free hydrogen and electricity from coal options for syngas cooling in systems using a hydrogen separation membrane reactor. J Eng Gas Turbines Power 130 031401-1... 

Any continuing use of fossil fuels should use clean and efficient technology. Power-stations generating electricity from coal and oil (fossil fuel) release a lot of CO2 in the generating process. New-build power-stations must now be fitted with carbon capture filters to reduce the bad environmental effects. 

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