Gas fired plants

From an economic standpoint, electricity production from a new natural gas plant versus a newly built coal-fired plant heavily favors natural gas, because natural gas-fired plants are cheaper to build. However, older coal-fired plants built 20 to 30 years ago are often more profitable than newly built gas plants, because — among other reasons — coal is cheaper than natural gas, and the older plants have long since paid for their capital investments through depreciation. 

We could argue that protecting the environment must take priority over financial savings. After all, investments into clean technologies, such as a gas-fired plant, have global environmental implications, so why shouldn t a utility owner/operator take a little less profit ... 

Classification of gas-fired plants using novel cycles... 

Chiesa and Con.sonni [1,3] have made detailed studies of how a CO2 tax would affect the economic viability of several of these cycles when a tax and CO2 removal are introduced. Fig. 8.27 shows their results on the cost of electricity for natural gas-fired plants plotted against the level of a carbon tax (in c/kg CO2 produced), for two of the novel cycles studied here, in comparison with an existing CCGT plant with natural gas firing. 

UK legislation referring to emissions from gas-fired plant is currently rather limited. The most important is The Health and Safety (Emissions into the Atmosphere) Regulations 1983 (SI No. 943, 1983). In Schedule 2 is listed substances deemed to be noxious, which include combustion products, dust, etc. 

For gas-fired plant large boilers and furnaces 50-700 MW thermal ... 

NB There is no limit for NOx for gas-fired plant. In practice, little or no such plant currently exists. The conditions for measurement of NOx are clearly defined.)... 

In the particular case of oxygen, valves shall be resistant to exposure for up to 12 h at all pressures up to 2 bar at 20° C. Requirements for non-return valves for oxygen are also discussed in the British Gas publication Guidance Notes on the Use of Oxygen in Industrial Gas Fired Plant and Working Flame Burners (lM/1). 

All gas-fired plant should be provided with operating instmctions for shutting down as well as starting up. Such instmctions will ensure that the correct sequence of operations is carried out to both avoid a hazard during the shutdown and to leave the plant in a safe condition. These procedures should also contain instmctions for actions to be carried out in emergencies. Such actions may differ from the normal shutdown. 

Under such circumstances, companies tend to choose relatively small generating units with low capital investment per unit of capacity, which are quick to build and have a short pay-out. These choices reduce the overall risk of an investment and are today available by choosing combined cycle gas fired plants if natural gas can be obtained at competitive prices. Compared to present nuclear power plants, such units have 1/3 of capital/kw, take two, rather than four to six years to build. Being more acceptable to the public, suitable sites for such plants are also far easier to find. 

It seems increasingly clear that the operating cost (operation and maintenance plus fuel costs) is very competitive with the same cost of its main competitors, coal-and gas fired plants. Therefore, the economic advantage of life extension is obvious, and also the clear trend to operate existing nuclear power plants on base load only. Even in France where there are too many nuclear plants to operate them all on base load, there is a trend to decrease the share of nuclear power in total production in view to operate eventually all... 

Power will be purchased from a nearby company. (One of the major reasons for locating here was the presence of low-cost, plentiful power.) A gas-fired plant for 125 psig steam will be built. This must be able to supply enough power to operate agitators and cooling-water pumps associated with the reactors when there is a power failure. Gas will be purchased from a local company. Drinking water will be purchased from the community of Martins Ferry, Ohio. Process and cooling water will be obtained from the Ohio River. Both will require treatment before they can be used in the plant. 

Note that in The Netherlands the share of non-carbon fuels in total power production is low and that power prices are usually set by carbon-fuelled installations, notably gas-fired plants. In countries where the share of non-carbon fuels is much higher or where power prices are set by either high carbon-fuelled (i.e. coal) installations or by a non-carbon fuelled generator, the windfall profit per MWh or allowance grandfathered may be substantially different than in The Netherlands. 

As basing phase II allocation on activities in phase I was discouraged by the EU Directive, some Member States update allocations using output-based fuel-specific benchmarks (FSB), where the benchmark is set higher for coal-fired plants than for gas-fired plants. Here, we assess the impact of this alternative updating method and compare with the output-based uniform benchmark approach. 

Mimura et al [1] found an effective amine solvent (KS-2) with a long lifetime and reported that the KS-2 solvent system could reduce the energy penalty by 20% compared with a MEA system. The power plant losses based on generator output power were calculated to be 5.4-5.8% for a natural gas-fired plant and 9.0% for a coal-fired plant at CO recovery of 90%. 

Power from a new coal-fired power plant will cost 5 to 6.4 cents per kWh and 4 to 5.7 cents per kWh for a gas-fired plant, and 4.6 to 6.5 cents per kWh for a nuclear plant, according to UNIPEDE, the European Utility Association. 

If the aggressive case relied on hydrogen produced by electrolysis from natural gas-fired plants, the demand for natural gas would increase 8% by 2030, 31% by 2040, and 43% by 2050. Again, these numbers are significantly higher than those for the reformation of natural gas due to the inefficiency of electrical generation. In terms of new generating facilities, this increased demand is the equivalent of 382 new 1000 MW nuclear or coal-fired plants by 2050. 

The theoretical advantage an IGCC plant has over a conventional coal plant is in the higher system efficiency of the combined cycle, a concept originally developed for natural gas-fired plants and used in many such plants for meeting intermediate and peak loads. 

H2 separation membrane WGS can, of course, also be adopted in natural gas fired plants to treat syngas from a steam reformer however, the benefits are expected to be smaller than those obtained by integrating the reformer and membrane directly. 

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