High Level Heat Recovery in Coal and Coke Gasification Combined Cycle Systems

1995 ◽  
Author(s):  
Uday Mahagaokar ◽  
Egon L. Doering
Keyword(s):  
Petroleum Coke ◽  
Heat Recovery ◽  
High Efficiency ◽  
Economic Benefits ◽  
Combined Cycle ◽  
Level Energy ◽  
Water Quench ◽  
Cycle Systems ◽  
High Level ◽  
The Cost

Integrated coal gasification combined cycle systems offer a very efficient and environmentally superior method for converting coal or petroleum coke to electric power. The high efficiency is derived from effective utilization of high level energy in all parts of the IGCC system. Entrained flow gasification represents one of the cleanest and most efficient technologies for converting coal or coke to syngas, and also produces significant quantities of high level sensible heat in the raw syngas exiting the gasifier. This heat can be recovered as high pressure steam through the use of syngas coolers. Alternatively, the syngas cooler capital may be saved by using a water quench at the expense of heat recovery. This paper examines the economic benefits of heat recovery in a syngas cooler relative to water quench by determining the value of the recovered energy versus the cost of recovery. The results show that for power generation in a gasification combined cycle configuration, the cost of syngas cooling is justified by the value of the energy recovered — this applies not only to coal feeds but also to low-priced feeds like petroleum coke.

Design Criteria and Optimization of Heat Recovery Steam Cycles for High-Efficiency, Coal-Fired, Fischer-Tropsch Plants

2012 ◽  
Author(s):  
Emanuele Martelli ◽  
Thomas G. Kreutz ◽  
Manuele Gatti ◽  
Paolo Chiesa ◽  
Stefano Consonni
Keyword(s):  
Heat Recovery ◽  
High Efficiency ◽  
Thermal Power ◽  
Combined Cycle ◽  
Synthesis Process ◽  
Integrated Gasification Combined Cycle ◽  
Fischer Tropsch ◽  
Ft Synthesis ◽  
Optimization Methodology ◽  
Integrated Gasification

In this work, the “HRSC Optimizer”, a recently developed optimization methodology for the design of Heat Recovery Steam Cycles (HRSCs), Steam Generators (HRSGs) and boilers, is applied to the design of steam cycles for three interesting coal fired, gasification based, plants with CO2 capture: a Fischer-Tropsch (FT) synthesis process with high recycle fraction of the unconverted FT gases (CTL-RC-CCS), a FT synthesis process with once-through reactor (CTL-OT-CCS), and an Integrated Gasification Combined Cycle (IGCC-CCS) based on the same technologies. The analysis reveals that designing efficient HRSCs for the IGCC and the once-through FT plant is relatively straightforward, while designing the HRSC for plant CTL-RC-CCS is very challenging because the recoverable thermal power is concentrated at low temperatures (i.e., below 260 °C) and only a small fraction can be used to superheat steam. As a consequence of the improved heat integration, the electric efficiency of the three plants is increased by about 2 percentage points with respect to the solutions previously published.

scholarly journals Membrane separation of carbon dioxide in the integrated gasification combined cycle systems

2010 ◽  
Vol 31 (3) ◽  
pp. 145-164 ◽  
Author(s):  
Janusz Kotowicz ◽  
Anna Skorek-osikowska ◽  
Katarzyna Janusz-szymańska
Keyword(s):  
Carbon Dioxide ◽  
High Efficiency ◽  
Membrane Separation ◽  
Combined Cycle ◽  
Electricity Production ◽  
Energetic Cost ◽  
Recovery Ratio ◽  
Integrated Gasification Combined Cycle ◽  
Cycle Systems ◽  
Integrated Gasification

Membrane separation of carbon dioxide in the integrated gasification combined cycle systemsIntegrated gasification combined cycle systems (IGCC) are becoming more popular because of the characteristics, by which they are characterized, including low pollutants emissions, relatively high efficiency of electricity production and the ability to integrate the installation of carbon capture and storage (CCS). Currently, the most frequently used CO2capture technology in IGCC systems is based on the absorption process. This method causes a significant increase of the internal load and decreases the efficiency of the entire system. It is therefore necessary to look for new methods of carbon dioxide capture. The authors of the present paper propose the use of membrane separation. The paper reviews available membranes for use in IGCC systems, indicates, inter alia, possible places of their implementation in the system and the required operation parameters. Attention is drawn to the most important parameters of membranes (among other selectivity and permeability) influencing the cost and performance of the whole installation. Numerical model of a membrane was used, among others, to analyze the influence of the basic parameters of the selected membranes on the purity and recovery ratio of the obtained permeate, as well as to determine the energetic cost of the use of membranes for the CO2separation in IGCC systems. The calculations were made within the environment of the commercial package Aspen Plus. For the calculations both, membranes selective for carbon dioxide and membranes selective for hydrogen were used. Properly selected pressure before and after membrane module allowed for minimization of energy input on CCS installation assuring high purity and recovery ratio of separated gas.

scholarly journals The Optimization of Combined Cycle HRSGs as a Function of the Plant Load Duty

1996 ◽  
Author(s):  
P. J. Dechamps
Keyword(s):  
Power Generation ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Combined Cycle ◽  
Load Factor ◽  
Heat Recovery Steam Generator ◽  
Economic Optimization ◽  
Cost Of Electricity ◽  
The Cost

Natural gas fired combined cycle power plants now take a substantial share of the power generation market, mainly because they can be delivering power with a remarkable efficiency shortly after the decision to install is taken, and because they are a relatively low capital cost option. The power generation markets becoming more and more competitive in terms of the cost of electricity, the trend is to go for high performance equipments, notably as far as the gas turbine and the heat recovery steam generator are concerned. The heat recovery steam generator is the essential link in the combined cycle plant, and should be optimized with respect to the cost of electricity. This asks for a techno-economic optimization with an objective function which comprises both the plant efficiency and the initial investment. This paper applies on an example the incremental cost method, which allows to optimize parameters like the pinch points and the superheat temperatures. The influence of the plant load duty on this optimization is emphasized. This is essential, because the load factor will not usually remain constant during the plant life-time. The example which is presented shows the influence of the load factor, which is important, as the plant goes down in merit order with time, following the introduction of more modern, more efficient power plants on the same grid.

Performance and Cost Analysis of Advanced Gas Turbine Cycles With Precombustion CO2 Capture

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Stéphanie Hoffmann ◽  
Michael Bartlett ◽  
Matthias Finkenrath ◽  
Andrei Evulet ◽  
Tord Peter Ursin
Keyword(s):  
High Pressure ◽  
Power Plant ◽  
Natural Gas ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Co2 Separation ◽  
The Cost

This paper presents the results of an evaluation of advanced combined cycle gas turbine plants with precombustion capture of CO2 from natural gas. In particular, the designs are carried out with the objectives of high efficiency, low capital cost, and low emissions of carbon dioxide to the atmosphere. The novel cycles introduced in this paper are comprised of a high-pressure syngas generation island, in which an air-blown partial oxidation reformer is used to generate syngas from natural gas, and a power island, in which a CO2-lean syngas is burnt in a large frame machine. In order to reduce the efficiency penalty of natural gas reforming, a significant effort is spent evaluating and optimizing alternatives to recover the heat released during the process. CO2 is removed from the shifted syngas using either CO2 absorbing solvents or a CO2 membrane. CO2 separation membranes, in particular, have the potential for considerable cost or energy savings compared with conventional solvent-based separation and benefit from the high-pressure level of the syngas generation island. A feasibility analysis and a cycle performance evaluation are carried out for large frame gas turbines such as the 9FB. Both short-term and long-term solutions have been investigated. An analysis of the cost of CO2 avoided is presented, including an evaluation of the cost of modifying the combined cycle due to CO2 separation. The paper describes a power plant reaching the performance targets of 50% net cycle efficiency and 80% CO2 capture, as well as the cost target of 30$ per ton of CO2 avoided (2006 Q1 basis). This paper indicates a development path to this power plant that minimizes technical risks by incremental implementation of new technology.

Exergoeconomic Analysis of a Combined Cycle of Three Levels of Pressure

2016 ◽  
Author(s):  
Edgar Vicente Torres González ◽  
Raúl Lugo-Leyte ◽  
Martín Salazar-Pereyra ◽  
Miguel Toledo Velázquez ◽  
Helen Denise Lugo-Méndez ◽  
...  
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Systematic Approach ◽  
Combined Cycle ◽  
Exergetic Efficiency ◽  
Steam Generators ◽  
Combined Cycle Power Plant ◽  
Exergoeconomic Analysis ◽  
The Cost

This paper presents an exergoeconomic analysis of the combined cycle power plant Tuxpan II located in Mexico. The plant is composed of two identical modules conformed by two gas turbines generating the required work and releasing the hot exhaust gases in two heat recovery steam generators. These components generate steam at three different pressure levels, used to produce additional work in one steam turbine. The productive structure of the considered system is used to visualize the cost formation process as well as the productive interaction between their components. The exergoeconomic analysis is pursued by 1) carrying out a systematic approach, based on the Fuel-Product methodology, in each component of the system; and 2) generating a set of equations, which allows compute the exergetic and exergoeconomic costs of each flow. The thermal and exergetic efficiency of the two gas turbines delivering 278.4 MW are 35.16% and 41.90% respectively. The computed thermal efficiency of the steam cycle providing 80.96 MW is 43.79%. The combined cycle power plant generates 359.36 MW with a thermal and exergetic efficiency of 47.27% and 54.10% respectively.

scholarly journals Large Combined Cycle HRSG Units Impact of Operating Considerations

1993 ◽  
Author(s):  
James S. Davis ◽  
Mark Steffen ◽  
Anthony T. Thompson
Keyword(s):  
Heat Recovery ◽  
High Efficiency ◽  
Combined Cycle ◽  
High Availability ◽  
Life Cycle Costs ◽  
Heat Recovery Steam Generator ◽  
Reliable Operation ◽  
Start Up ◽  
Reasonable Cost ◽  
Environmental Considerations

Combustion turbine combined cycle plants continue to increase their role in worldwide power generation. Advanced combined cycle plants provide: • high efficiency, often in excess of 50% • short project schedules • reasonable cost with minimum environmental considerations For reliable operation of these facilities, it is essential the Heat Recovery Steam Generator (HRSG) design adequately address issues to include: • required load rangeability • transient operation, particularly start-up and shutdown • low life cycle costs through high availability This paper will address the more detailed aspects of the design configuration of large HRSG units.

scholarly journals Economic aspects in the design process of heat recovery installations - case study

2019 ◽  
Vol 20 (1-2) ◽  
pp. 340-343
Author(s):  
Zbigniew Stempnakowski ◽  
Piotr Nikończuk
Keyword(s):  
Energy Efficiency ◽  
Heat Recovery ◽  
Geographical Location ◽  
Economic Benefits ◽  
Economic Aspects ◽  
Recovery Unit ◽  
Proposed Model ◽  
Spray Booth ◽  
The Cost

The paper presents a proposal of economic aspects application in the process of optimizing the construction of heat recovery unit. The proposed model includes the cost of heat exchanger installation and the predicted economic benefits during the operation of the device. The predicted benefits include an increase of energy efficiency resulting from the number of modules of heat recovery unit, decrease unit efficiency during operation, the cost of heat production, average temperatures in the geographical location and working time. A case study was carried out on the example of a spray booth.

Decay of Excitation Load From Heat Recovery Steam Generators (HRSG) to Attached Piping System As a Function of Pipe Supports Locations

2019 ◽  
Author(s):  
Emmanuel Appiah ◽  
Kshitij Gawande
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
High Efficiency ◽  
Acoustic Resonance ◽  
Combined Cycle ◽  
High Mass ◽  
Piping System ◽  
Steam Generation ◽  
System Integrity ◽  
Compact Size

Abstract Construction of combined cycle gas turbine (CCGT) plants, which are combination of a simple cycle gas turbine (Brayton cycle) and a steam power cycle (Rankine cycle), have increased in recent years due to their high efficiency, low emissions, relative compact size, and minimal delivery time, among other advantages. One key component of CCGT is a heat recovery steam generator (HRSG). The HRSG is basically a heat exchanger composed of a series of preheaters (economizers), evaporator, reheaters, and superheaters. Combustion gas from gas turbine is used as an energy source for steam generation in the HRSG. Due to high mass flowrate of combustion turbine exhausts gas and injection of water to reduce NOx contents, high vibration and severe noise are created. The noise induces acoustic resonance in the HRSG duct cavities. The high vibration together with the acoustic resonance creates large forces. These forces have been attributed to excitation mechanisms including fluid elastic instability, random turbulence excitation, and periodic wake shedding. Some of the forces are transmitted to the attached pipes. Integrity of the piping system to withstand the forces depends on rigid and variable pipe supports. It is therefore paramount to determine the load induced into the supports to design them adequately. The purpose of this paper is to provide relative magnitude of loads experienced at various pipe supports as a function of distance from the HRSG (load decay). This knowledge is expected to help support designers to optimize material allocation to ensure pipe system integrity at optimum cost.

Pyrolysis in Waste to Energy Conversion (WEC)

2006 ◽  
Author(s):  
Alex E. S. Green ◽  
Sean M. Bell
Keyword(s):  
Natural Gas ◽  
Energy Conversion ◽  
Solid Waste ◽  
Cost Estimation ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Waste To Energy ◽  
Specific Product ◽  
The Cost

Solid waste (SW), mostly now wasted biomass, could fuel approximately ten times more of USA’s increasing energy needs than it currently does. At the same time it would create good non-exportable jobs, and local industries. Twenty four examples of wasted or under-utilized solids that contain appreciable organic matter are listed. Estimates of their sustainable tonnage lead to a total SW exceeding 2 billion dry tons. Now usually disposal problems, most of these SW’s, can be pyrolyzed into substitutes for or supplements to expensive natural gas. The large proportion of biomass (carbon dioxide neutral plant matter) in the list reduces Greenhouse problems. Pyrolysis converts such solid waste into a medium heating value gaseous fuel usually with a small energy expenditure. With advanced gas cleaning technologies the pyrogas can be used in high efficiency gas turbines or fuel cells systems. This approach has important environmental and efficiency advantages with respect to direct combustion in boilers and even air blown or oxygen blown partial combustion gasifiers. Since pyrolysis is still not a predictive science the CCTL has used an analytical semi-empirical model (ASEM) to organize experimental measurements of the yields of various product {CaHbOc} yields vs temperature (T) for r dry ash, nitrogen and sulfur free (DANSF) feedstock having various weight % of oxygen [O] and hydrogen [H]. With this ASEM each product is assigned 5 parameters (W, T0, D, p, q) in a robust analytical Y(T) expression to represent yields vs. temperature of any specific product from any specified feedstock. Patterns in the dependence of these parameters upon [O], [H], a, b, and c suggest that there is some order in pyrolysis yields that might be useful in optimize the throughput of particular pyrolysis systems used for waste to energy conversion (WEC). An analytical cost estimation (ACE) model is used to calculate the cost of electricity (COE) vs the cost of fuel (COF) for a SW pyrogas fired combined cycle (CC) system for comparison with the COE vs COF for a natural gas fired CC system. It shows that high natural gas prices solid waste can be changed from a disposal cost item to a valuable asset. Comparing COEs when using other SW capable technologies are also facilitated by the ACE method. Implications of this work for programs that combine conservation with waste to energy conversion in efforts to reach Zero Waste are discussed.

Off-Design Performance of Multipressure Heat Recovery Boilers

1995 ◽  
Author(s):  
Nicola Bettagli ◽  
Bruno Facchini
Keyword(s):  
Heat Recovery ◽  
Power Plants ◽  
High Efficiency ◽  
Combined Cycle ◽  
Thermodynamic Efficiency ◽  
Heat Recovery Steam Generator ◽  
Gas Temperature ◽  
Recovery Boilers ◽  
Very High ◽  
Plant Behaviour

Combined cycle power plants are systems with very high thermodynamic efficiency. Off-design plant behaviour prediction is very important to allow for high efficiency regulation of systems. The aim of this paper is to study heat recovery steam generator (HRSG) performance, varying inlet gas temperature and mass flow rate. One, two and three pressure level heat recovery boilers are considered. A HRSG simulation program based on heat transfer and thermodynamic fundamental laws is carried out.

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