Coal Gasification/Repowering: A Means of Increasing Plant Capacity While Reducing Oil Consumption

1980 ◽  
Author(s):  
S. J. Lehman ◽  
A. J. Giramonti ◽  
R. H. Meyer
Keyword(s):  
Power Plants ◽  
Coal Gasification ◽  
Waste Heat ◽  
Time Frame ◽  
Combined Cycle ◽  
Heat Recovery Boiler ◽  
Steam Boiler ◽  
Oil Consumption ◽  
Fuel Gas ◽  
Coal Gasifier

An exploratory study was carried out by the United Technologies Research Center and Northeast Utilities Service Company to identify the performance characteristics of power plants based upon the repowering of several existing steam plants. In steam station repowering, an advanced, high temperature gas turbine fired by coal-derived, low-Btu fuel gas would generate power and exhaust to a new waste-heat recovery boiler that replaces the old oil-fired steam boiler. Steam from the new boiler drives the existing steam turbine. Computer models were assembled to simulate the integration of molten salt and Texaco coal gasification systems with combustion turbomachinery representative of the 1990 time frame. The results of this study indicated that either coal gasifier in a combined-cycle repowering application appears attractive as a means of replacing oil-fired systems with coal.

scholarly journals Combined Cycles Permit the Most Environmentally Benign Conversion of Fossil Fuels to Electricity

1990 ◽  
Author(s):  
Guenther Haupt ◽  
John S. Joyce ◽  
Konrad Kuenstle
Keyword(s):  
Environmental Impact ◽  
Power Plants ◽  
Fossil Fuels ◽  
Coal Gasification ◽  
High Efficiency ◽  
Waste Heat ◽  
Primary Energy ◽  
Combined Cycle ◽  
Point Of View ◽  
Steam Boiler

The environmental impact of unfired combined-cycle blocks of the GUD® type is compared with that of equivalent reheat steam boiler/turbine units. The outstandingly high efficiency of GUD blocks not only conserves primary-energy resources, but also commensurately reduces undesirable emissions and unavoidable heat rejection to the surroundings. In addition to conventional gas or oil-fired GUD blocks, integrated coal-gasification combined-cycle (ICG-GUD) blocks are investigated from an ecological point of view so as to cover the whole range of available fossil fuels. For each fuel and corresponding type of GUD power plant the most appropriate conventional steam-generating unit of most modern design is selected for comparison purposes. In each case the relative environmental impact is stated in the form of quantified emissions, effluents and waste heat, as well as of useful byproducts and disposable solid wastes. GUD blocks possess the advantage that they allow primary measures to be taken to minimize the production of NOx and SOx, whereas both have to be removed from the flue gases of conventional steam stations by less effective and desirable, albeit more expensive secondary techniques, e.g. flue-gas desulfurization and DENOX systems. In particular, the comparison of CO2 release reveals a significantly lower contribution by GUD blocks to the greenhouse effect than by other fossil-fired power plants.

Overall Performance of Advanced H2/Air Cycle Power Plants Based on Coal Decarbonisation

2005 ◽  
Author(s):  
M. Gambini ◽  
M. Vellini
Keyword(s):  
Power Plant ◽  
Hydrogen Production ◽  
Power Plants ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Fuel Gas ◽  
Production Section ◽  
Pinch Technology ◽  
Energy Economy ◽  
Overall Performance

In this paper the overall performance of a new advanced mixed cycle (AMC), fed by hydrogen-rich fuel gas, has been evaluated. Obviously, hydrogen must be produced and here we have chosen the coal gasification for its production, quantifying all the thermal and electric requirements. At first, a simple combination between hydrogen production section and power section is performed. In fact, the heat loads of the first section can be satisfied by using the various raw syngas cooling, without using some material streams taken from the power section, but also without using part of heat, available in the production section and rejected into the environment, in the power section. The final result is very poor: over 34%. Then, by using the Pinch Technology, a more efficient, even if more complex, solution can be conceived: in this case the overall efficiency is very interesting: 39%. These results are very similar to those of a combined cycle power plant, equipped with the same systems and analyzed under the same hypotheses. The final result is very important because the “clean” use of coal in new power plant types must be properly investigated: in fact coal is the most abundant and the cheapest fossil fuel available on earth; moreover, hydrogen production, by using coal, is an interesting outlook because hydrogen has the potential to become the main energy carrier in a future sustainable energy economy.

Comparative Evaluation of Power Plants With Regard to Technical, Ecological and Economical Aspects

2001 ◽  
Author(s):  
Alex Lezuo ◽  
Robert Taud
Keyword(s):  
Life Cycle Cost ◽  
Power Plants ◽  
Coal Gasification ◽  
Time Frame ◽  
Combined Cycle ◽  
Fluidized Bed Combustion ◽  
Ecological Data ◽  
Economical Analysis ◽  
Generation Costs ◽  
Steam Parameters

The development of efficiency of gas turbine based combined cycle plants has been very fast during the last 10 years and has reached now a value of close to 60 %. This value is well above that of coal power plants or other technologies. Even though development has been going on in these fields as well. For a fairly comprehensive reorientation and status evaluation with the time frame of 2005 in focus, a comparative study with equal boundary conditions has been performed considering coal steam plants with various steam parameters, fluidized bed combustion, coal gasification and natural gas fired combined cycle plants. Besides investment also technical differences and ecological data are given. The final evaluation of power generation technologies is based however mainly on its electricity generation costs or life cycle cost. Considering today’s fuel prices and price development projections over the plant life times, an economical analysis has been performed and will be presented, serving also as framework for project and investment decisions.

scholarly journals Thermal Efficiency of Combined Cycle Power Plant

2018 ◽  
Vol 8 (3) ◽  
Author(s):  
R. Rajesh ◽  
P. S. Kishore
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Waste Heat ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Heat Recovery Boiler ◽  
Brayton Cycle ◽  
Single Cycle ◽  
Working Medium ◽  
Temperature And Pressure

Now a day’s power generation is most important for every country. This power is generated by some thermal cycles. But single cycle cannot be attain complete power requirements and its efficiency also very low so that to fulfill this requirements to combine two or more cycles in a single power plant then we can increase the efficiency of the power plant. Its increased efficiency is more than that of if the plant operated on single cycle. In which we are using two different cycles and these two cycles are operated by means of different working mediums. These type of power plants we can called them like combined cycle power plants. In combined cycle power plants above cycle is known as topping cycle and below cycle is known as bottoming cycle. The above cycle generally brayton cycle which uses air as a working medium. When the power generation was completed the exhaust gas will passes in to the waste heat recovery boiler. Another cycle also involved in bottoming cycle. This cycle works on the basis on rankine cycle. In which steam is used as working medium. The main component in bottoming cycle is waste heat recovery boiler. It will receive exhaust heat from the gas turbine and converts water in to steam. The steam used for generating power by expansion on steam turbine. Combined cycle power plants are mostly used in commercial power plants.In this paper we are analyzing one practical combined cycle power plant. In practical conditions due to some losses it can not be generates complete power. So that we are invistigated why it is not give that much of power and the effect of various operating parameters such as maximum temperature and pressure of rankine cycle, gas turbine inlet temperature and pressure ratio of Brayton cycle on the net output work and thermal efficiency of the combine cycle power plant.The outcome of this work can be utilized in order to facilitate the design of a combined cycle with higher efficiency and output work. Mathematical calculations and simple graphs in ms excel, and auto cad has been carried out to study the effects and influences of the above mentioned parameters on the efficiency and work output.

The Development of Integrated Coal-Gasification Power Plants With Clean Combustion in Germany

1985 ◽  
Author(s):  
H. H. Finckh ◽  
R. Mueller
Keyword(s):  
Capital Investment ◽  
Power Plants ◽  
Coal Gasification ◽  
Modular Design ◽  
Low Cost ◽  
Electrical Energy ◽  
Gas Production ◽  
Combined Cycle ◽  
Fuel Gas ◽  
Electrical Energy Production

As advances are made in flue-gas clean-up systems, such as electrostatic precipitators, wet and dry desulfurization techniques and deNOX catalysers, the environmental impact of conventional steam turbine power plants fired with pulverized coal can be reduced at great expense in the form of additional capital investment and lowered station efficiency. The clean fuel gas obtainable from various coal-gasification processes, however, can be used to generate electricity with excellent efficiency and low-pollution emissions in low-cost unfired combined-cycle power plants of modular design. These are termed GUD power plants from the German designation “Gas und Dampf” meaning gas and steam. The overall efficiency is appreciably enhanced by closely integrating the gas-production process with the power generating cycle. Such an integrated coal-gasification combined-cycle installation should thus allow China to exploit its vast coal reserves for electrical energy production in both the most economical and environmentally acceptable way.

scholarly journals Design and Test of a Low-NOx Advanced Rich-Lean Combustor for LBG Fueled 1300°C-Class Gas Turbine

1992 ◽  
Author(s):  
T. Nakata ◽  
M. Sato ◽  
T. Ninomiya ◽  
T. Yoshine ◽  
M. Yamada
Keyword(s):  
Gas Turbine ◽  
Coal Gasification ◽  
Combustion Process ◽  
Calorific Value ◽  
Ammonia Concentration ◽  
Combined Cycle ◽  
Combustion Stability ◽  
Fuel Gas ◽  
Gas Cleaning ◽  
Coal Gasifier

Research and development of an IGCC (Integrated Coal Gasification Combined Cycle) power generation system is being carried out as one of the advanced coal utilization technology in Japan. The coal gasified fuel, which is produced in a coal gasifier of air-blown entrained-flow type has calorific value as low as 1/10 of LNG. Furthermore, the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. The authors have designed and made an 1300°C-class advanced rich-lean combustor mainly designed for achieving low fuel-NOx combustion. By testing it under atmospheric pressure conditions, we have successfully reduced the NOx emissions (to 60 ppm corrected at 16 percent O2) by more than half the level previously achieved when the ammonia concentration was 1000 ppm. Combustion stability was adequate even when the calorific value of the fuel decreased to 2700 kJ/m3N.

Advanced H2/Air Cycles Based on Coal Gasification

2004 ◽  
Author(s):  
M. Gambini ◽  
G. L. Guizzi ◽  
M. Vellini
Keyword(s):  
Hydrogen Production ◽  
Carbon Dioxide Emissions ◽  
Power Plants ◽  
Coal Gasification ◽  
H2 Production ◽  
Combined Cycle ◽  
Fuel Gas ◽  
Energy Flows ◽  
Energy Economy ◽  
Overall Performance

In this paper the overall performance of a new advanced mixed cycle (AMC), fed by hydrogen-rich fuel gas, has been evaluated. Obviously, hydrogen must be produced and here we have chosen the coal gasification for its production, quantifying all the thermal and electric requirements. At first, the thermodynamic performance of this cycle has been investigated in comparison with that attainable by combined cycle power plants (CC). Then, the power plants have been integrated with the fuel production system. Including all the material and energy flows, the overall performance has been evaluated. The main result of the performed investigation is that the two power plants attain the same efficiency level with and without H2 production requirements (over 60% and over 34% without and with hydrogen production respectively). The final carbon dioxide emissions are about 0.123 kg/kWh both for AMC and CC. It is important to underline that the “clean” use of coal in new power plant types must be properly investigated because it is the most abundant and the cheapest fossil fuel available on earth; moreover, hydrogen production, by using coal, is an interesting prospect because hydrogen has the potential to become the main energy carrier in a future sustainable energy economy.

The Thermodynamic Performance of Two Combined Cycle Power Plants Integrated With Two Coal Gasification Systems

1981 ◽  
Vol 103 (3) ◽  
pp. 572-581 ◽  
Author(s):  
F. L. Stasa ◽  
F. Osterle
Keyword(s):  
Power Plants ◽  
Coal Gasification ◽  
Waste Heat ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Gasification Process ◽  
Heat System ◽  
Thermodynamic Performance ◽  
Gas Recirculation

Thermodynamic models of both an adiabatic and an endothermic coal gasifier integrated with either a waste heat combined cycle or a supercharged boiler combined cycle are developed. The adiabatic gasification process requires air and steam, while the endothermic gasification process requires only steam. The combined cycle is composed of an open Brayton cycle and a superheated regenerative Rankine cycle without reheat. Certain components are added to each configuration in an effort to improve thermodynamic performance. From the results, it appears that with consideration of the pollution criteria, the station efficiencies for each configuration are within 1 percentage point of each other when flue gas recirculation is used as a means to control the nitric oxide. With a gas turbine inlet temperature of 2000°F, and with consideration of the pollution criteria, the configuration employing an adiabatic gasifier and a waste heat system is marginally the best with a station efficiency of only 37 percent.

scholarly journals Ruhrchemie/Ruhrkohle’s Technical Version of the Texaco Coal Gasifier as Part of a Combined Cycle Plant

1982 ◽  
Author(s):  
B. Cornils ◽  
J. Hibbel ◽  
P. Ruprecht ◽  
R. Dürrfeld ◽  
J. Langhoff
Keyword(s):  
High Pressure ◽  
Power Plants ◽  
Coal Gasification ◽  
Operating Time ◽  
Combined Cycle ◽  
Gas Generation ◽  
Load Following ◽  
Gasification Process ◽  
Steady State Operation ◽  
Combined Cycle Plant

The Ruhrchemie/Ruhrkohle variant of the Texaco Coal Gasification Process (TCGP) has been on stream since 1978. As the first demonstration plant of the “second generation” it has confirmed the advantages of the simultaneous gasification of coal: at higher temperatures; under elevated pressures; using finely divided coal; feeding the coal as a slurry in water. The operating time so far totals 9000 hrs. More than 50,000 tons of coal have been converted to syn gas with a typical composition of 55 percent CO, 33 percent H2, 11 percent CO2 and 0.01 percent of methane. The advantages of the process — low environmental impact, additional high pressure steam production, gas generation at high pressure levels, steady state operation, relatively low investment costs, rapid and reliable turn-down and load-following characteristics — make such entrained-bed coal gasification processes highly suitable for power generation, especially as the first step of combined cycle power plants.

Development of the Shell-Koppers coal gasification process

1981 ◽  
Vol 300 (1453) ◽  
pp. 111-120 ◽  
Keyword(s):  
Coal Gasification ◽  
Combined Cycle ◽  
Hard Coal ◽  
Steam Turbines ◽  
Power Station ◽  
Gasification Process ◽  
Coal Gasifier ◽  
Large Size ◽  
Wide Range ◽  
By Products

The Shell-Koppers process for the gasification of coal under pressure, based on the principles of entrained-bed technology, is characterized by: practically complete gasification of virtually all solid fuels; production of a clean gas without by-products; high throughput; high thermal efficiency and efficient heat recovery; environmental acceptability. There are numerous possible future applications for this process. The gas produced (93-98 vol. % hydrogen and carbon monoxide) is suitable for the manufacture of hydrogen or reducing gas and, with further processing, substitute natural gas (s.n.g.). Moreover, the gas can be used for the synthesis of ammonia, methanol and liquid hydrocarbons. Another possible application of this process is as an integral part of a combined-cycle power station featuring both gas and steam turbines. The integration of a Shell-Koppers coal gasifier with a combined-cycle power station will allow of electricity generation at 42-45 % efficiency for a wide range of feed coals. The development programme includes the operation of a 150 t/day gasifier at Deutsche Shell’s Harburg refinery since November 1978 and of a 6 t/day pilot plant a Royal Dutch Shell’s Amsterdam laboratories from December 1976 onwards. Both facilities run very successfully. With hard coal a conversion of 99% is reached while producing a gas with only 1 vol. % CO 2 . The next step will be the construction and operation of one or two 1000 t/day prototype plants which are scheduled for commissioning in 1983-4. Towards the end of the 1980s large commercial units with a capacity of 2500 t/day are contemplated. The economy, especially of these large size units, is very competitive.

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