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.

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.

Comparative Analysis of Advanced H2/Air Cycle Power Plants Based on Different Hydrogen Production Systems From Fossil Fuels

2004 ◽  
Author(s):  
M. Gambini ◽  
M. Vellini
Keyword(s):  
Hydrogen Production ◽  
Power Plants ◽  
Fossil Fuels ◽  
Coal Gasification ◽  
Fossil Fuel ◽  
H2 Production ◽  
Combined Cycle ◽  
Methane Reforming ◽  
Steam Methane Reforming ◽  
Steam Methane

In this paper two options for H2 production by means of fossil fuels are presented, evaluating their performance when integrated with advanced H2/air cycles. The investigation has been developed with reference to two different schemes, representative both of consolidated technology (combined cycle power plants) and of innovative technology (a new advance mixed cycle, named AMC). The two methods, here considered, to produce H2 are: • coal gasification: it permits transformation of a solid fuel into a gaseous one, by means of partial combustion reactions; • steam-methane reforming: it is the simplest and potentially the most economic method for producing hydrogen in the foreseeable future. These hydrogen production plants require material and energy integrations with the power section, and the best connections must be investigated in order to obtain good overall performance. The main results of the performed investigation are quite variable among the different H2 production options here considered: for example the efficiency value is over 34% for power plants coupled with coal decarbonization system, while it is in a range of 45–48% for power plants coupled with natural gas decarbonization. These differences are similar to those attainable by advanced combined cycle power plants fuelled by natural gas (traditional CC) and coal (IGCC). In other words, the decarbonization of different fossil fuels involves the same efficiency penalty related to the use of different fossil fuel in advanced cycle power plants (from CC to IGCC for example). The CO2 specific emissions depend on the fossil fuel type and the overall efficiency: adopting a removal efficiency of 90% in the CO2 absorption systems, the CO2 emission reduction is 87% and 82% in the coal gasification and in the steam-methane reforming respectively.

scholarly journals Combined Closed Cycle (C3) Systems for Underwater Power Generation

1992 ◽  
Author(s):  
Aristide Massardd ◽  
Gian Marid Arnulfi
Keyword(s):  
Power Generation ◽  
Power Plants ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Primary Energy ◽  
Combined Cycle ◽  
Working Fluid ◽  
Mass Reduction ◽  
Efficiency Increase

In this paper three Closed Combined Cycle (C3) systems for underwater power generation are analyzed. In the first, the waste heat rejected by a Closed Brayton Cycle (CBC) is utilized to heat the working fluid of a bottoming Rankine Cycle; in the second, the heat of a primary energy loop fluid is used to heat both CBC and Rankine cycle working fluids; the third solution involves a Metal Rankine Cycle (MRC) combined with an Organic Rankine Cycle (ORC). The significant benefits of the Closed Combined Cycle concepts, compared to the simple CBC system, such as efficiency increase and specific mass reduction, are presented and discussed. A comparison between the three C3 power plants is presented taking into account the technological maturity of all the plant components.

Combined-Cycle Power Plants From Gas Turbines and Geothermal Source Integration

1993 ◽  
Author(s):  
R. Bettocchi ◽  
G. Cantore ◽  
G. Negri di Montenegro ◽  
A. Peretto ◽  
E. Gadda
Keyword(s):  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Combined Cycle ◽  
Point Of View ◽  
Total Power ◽  
Geothermal Fluid ◽  
Exhaust Gases ◽  
Plant Power

Geothermal power plants have difficulties due to the low conversion efficiencies achievable. Geothermal integrated combined cycle proposed and analyzed in this paper is a way to achieve high efficiency. In the proposed cycle the geothermal fluid energy is added, through suitable heat ecxhangers, to that of exhaust gases for generating a steam cycle. The proposed cycle maintains the geothermal fluid segregated from ambient and this can be positive on the environmental point of view. Many systems configurations, based on this possibility, can be taken into account to get the best thermodynamic result. The perfomed analysis examines different possible sharings between the heat coming from geothermal and exhaust gases, and gives the resulting system efficiencies. Various pressures of the geothermal steam and water dominated sources are also taken into account. As a result the analysis shows that the integrated plant power output is largely greater than the total power obtained by summing the gas turbine and the traditional geothermal plant power output, considered separately.

Thermoeconomic Model Considering the Environment Impacts on Thermoelectric Power Plants: Natural Gas Versus Diesel

2006 ◽  
Author(s):  
Irai´des Aparecida de Castro Villela ◽  
Jose´ Luz Silveira
Keyword(s):  
Natural Gas ◽  
Environmental Impact ◽  
Thermoelectric Power ◽  
Power Plants ◽  
Combined Cycle ◽  
Point Of View ◽  
Manufacturing Cost ◽  
Ecological Efficiency ◽  
General Terms ◽  
Thermoelectric Power Plants

In this paper a comparative analysis of the environmental impact caused by the use of natural gas and diesel in thermoelectric power plants utilizing combined cycle is performed. The objective is to apply a thermoeconomical analysis in order to compare the two proposed fuels. In this analysis, a new methodology that incorporates the economical engineering concept to the ecological efficiency once Cardu and Baica [1, 2], which evaluates, in general terms, the environmental impacts caused by CO2, SO2, NOx and Particulate Matter (PM), adopting as reference the air quality standards in vigour is employed. The thermoeconomic model herein proposed utilizes functional diagrams that allow the minimization the Exergetic Manufacturing Cost, which represents the cost of production of electricity incorporating the environmental impact effects to study the performance of the thermoelectric power plant [3,4]. It follows that it is possible to determine the environmental impact caused by thermoelectric power plants and, under the ecological standpoint, the use of natural gas as a fuel is the best option compared to the use of the diesel, presenting ecological efficiency values of 0.944 and 0.914 respectively. From the Exergoeconomic point of view of, it was found out that the EMC (Exergetic Manufacturing Cost) is better when natural gas is used as fuel compared to the diesel fuel.

Is Nuclear Power Also the Key to Economically Clean Coal Gasification?

2006 ◽  
Author(s):  
Jay F. Kunze ◽  
Gary M. Sandquist ◽  
David Martinez Pardo
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cells ◽  
Carbon Dioxide Emissions ◽  
Nuclear Power ◽  
Power Plants ◽  
Coal Gasification ◽  
Energy System ◽  
Primary Energy ◽  
Combined Cycle ◽  
Pure Oxygen

Reducing the amount of carbon dioxide emitted to the atmosphere is a major goal and an imperative need for most of the world’s nations, even for those nations such as the USA who are not Kyoto Treaty signatories. A response by the current USA administration is to develop a national transportation economy for automobiles based upon efficient, environmentally sound fuel cells. However, hydrogen is a secondary fuel requiring a primary energy source for production. Nuclear power (or renewables such as hydroelectric, wind or solar) must be the source of the primary energy required to produce hydrogen from water, if the overall energy system is to be free of carbon dioxide emissions to the atmosphere. The dissociation of water leaves oxygen as a major byproduct. Currently, there are no existing commercial markets for the large quantities of oxygen that would result from a US transportation economy based upon hydrogen fuel cells. However, Integrated Coal Gasification Combined Cycle (IGCC) power plants operating on pure oxygen for both gasification and combustion produce no greenhouse gas releases. This highly desirable feature results from the combustion output being only water and carbon dioxide. Pure CO2 can be relatively easily captured and delivered to a sequestration site. Also, hazardous trace metal compounds (e.g., Hg, As, Pb, Sn, Sb, Se, U, Th, etc.) that would ordinarily be emitted to the atmosphere could be captured as solids, for environmentally acceptable disposal.

Addressing the Energy Trilemma With LPG-Fuelled, Water-Free Combined Cycle Power Plants

2020 ◽  
Author(s):  
Michael Welch
Keyword(s):  
Environmental Impact ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Gas Production ◽  
Combined Cycle ◽  
Liquefied Petroleum Gas ◽  
Distributed Power ◽  
The Impact

Abstract Many parts of the world are facing the triple challenge of providing secure energy to fuel economic growth at an affordable cost while minimizing the impact of energy production on the environment. Island nations especially struggle to address this trilemma, as renewable resources are usually limited and fossil fuels imported. Traditionally such distributed power plants have relied on liquid fuels and multiple open cycle reciprocating engines to provide both redundancy and the ability to load follow across a broad load range to maximize efficiency. This approach has created high electricity prices and significant negative environmental impact, especially that attributed to CO2, NOx, and SOx. With increasing natural gas production, the availability of Liquefied Petroleum Gas (LPG) has grown, and costs have fallen, allowing the potential to switch from fuel oils to LPG to reduce environmental impacts. Energy costs and environmental impact can be further reduced by using high efficiency Gas Turbine Combined Cycle plants with dry low emissions combustion technology. However, a further hurdle facing many locations is lack of the fresh water required for combined cycle operations. LPG-fuelled Gas Turbine Combined Cycle using Organic Rankine Cycle (ORC) technology can address all aspects of this energy trilemma. This paper reviews the conceptual design of a proposed 100MW distributed power plant for an island location, based on multiple LPG-fuelled gas turbines to follow load demand, with an ORC bottoming cycle to maximize efficiency.

The History of Integrated Gasification Combined-Cycle Power Plants

2017 ◽  
Author(s):  
Jeffrey N. Phillips ◽  
George S. Booras ◽  
Jose Marasigan
Keyword(s):  
Electric Power ◽  
Power Plants ◽  
Coal Gasification ◽  
High Efficiency ◽  
Combined Cycle ◽  
Electric Power Research Institute ◽  
Liquid Hydrocarbons ◽  
Integrated Gasification Combined Cycle ◽  
History Of ◽  
Integrated Gasification

Integrated gasification combined-cycle (IGCC) power plants offer a way to use solid or heavy liquid hydrocarbons, such as asphalt, in high-efficiency combined-cycle power plants. This paper reviews the history of IGCC power plants from the first unit, which was built in Germany in the 1970s, to the current wave of IGCCs being deployed in the 2010s. It draws heavily from the Electric Power Research Institute (EPRI) archive of information about IGCCs, which chronicles 40 years of nurturing the development of a number of coal gasification technologies. Insights from the operating experiences of earlier IGCCs will be examined, a comprehensive table listing all IGCCs built to date is provided and photos from many of the plants are included. The paper concludes with some recommendations for research and development which could set the direction for future applications of IGCC technologies.

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.

Sign in / Sign up

Export Citation Format

Share Document