DEVELOPMENT AND ANALYSIS OF AN INTEGRATED MILD/PARTIAL GASIFICATION COMBINED (IMPGC) CYCLE

2021 ◽  
pp. 1-34
Author(s):  
Ting Wang ◽  
Henry Long
Keyword(s):  
Power Plants ◽  
Energy Content ◽  
Energy Resource ◽  
Rankine Cycle ◽  
High Energy ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Efficient Manner ◽  
Volumetric Heating ◽  
Partial Gasification

Abstract Around 50% of the world's electrical power supply comes from the Rankine cycle, and the majority of existing Rankine cycle plants are driven by coal. Given how unattractive coal is as an energy resource in spite of its high energy content, it becomes necessary to find a way to utilize coal in a cleaner and more efficient manner. Designed as a potential retrofit option for existing Rankine cycle plants, the Integrated Mild/Partial Gasification Combined (IMPGC) Cycle is an attractive concept in cycle design that can greatly increase the efficiency of coal-based power plants, particularly for retrofitting an old Rankine cycle plant. Compared to the Integrated Gasification Combined Cycle (IGCC), IMPGC uses mild gasification to purposefully leave most of the volatile matters within the feedstock intact (hence, yielding more chemical energy) compared to full gasification and uses partial gasification to leave some of the remaining char un-gasified compared to complete gasification. The larger hydrocarbons left over from the mild gasification process grant the resulting syngas a higher volumetric heating value, leading to a more efficient overall cycle performance. This is made possible due to the invention of a warm gas cleanup process invented by Research Triangle Institute (RTI), called the High Temperature Desulfurization Process (HTDP), which was recently commercialized. The leftover char can then be burned in a conventional boiler to boost the steam output of the bottom cycle, further increasing the efficiency of the plant, capable of achieving a thermal efficiency of 47.9% (LHV). This paper will first analyze the individual concepts used to create the baseline IMPGC model, including the mild and partial gasification processes themselves, the warm gas cleanup system, and the integration of the boiler with the heat recovery steam generator (HRSG). This baseline will then be compared with four other common types of power plants, including subcritical and ultra-supercritical (USC) Rankine cycles, IGCC, and natural gas. The results show that IMPGC consistently outperforms all other forms of coal-based power. IMPGC is more efficient than the standard subcritical Rankine cycle by nine percentage points, more than a USC Rankine cycle by nearly four points, and more than IGCC by seven points.

Development and Analysis of an Integrated Mild/Partial Gasification Combined (IMPGC) Cycle: Part 1 — Development of a Baseline IMPGC System

2019 ◽  
Author(s):  
Ting Wang ◽  
Henry A. Long
Keyword(s):  
Power Plants ◽  
Energy Content ◽  
Energy Resource ◽  
Rankine Cycle ◽  
High Energy ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Efficient Manner ◽  
Volumetric Heating ◽  
Partial Gasification

Abstract Around 50% of the world’s electrical power supply comes from the Rankine cycle, and the majority of existing Rankine cycle plants are driven by coal. Given how politically unattractive coal is as an energy resource in spite of its high energy content, it becomes necessary to find a way to utilize coal in a cleaner and more efficient manner. Designed as a potential retrofit option for existing Rankine cycle plants, the Integrated Mild/Partial Gasification Combined (IMPGC) Cycle is an attractive concept in cycle design that can greatly increase the efficiency of coal-based power plants, particularly for retrofitting an old Rankine cycle plant. Compared to the Integrated Gasification Combined Cycle (IGCC), IMPGC uses mild gasification to purposefully leave most of the volatile matters within the feedstock intact (hence, yielding more chemical energy) compared to full gasification and uses partial gasification to leave some of the remaining char un-gasified compared to complete gasification. The larger hydrocarbons left over from the mild gasification process grant the resulting syngas a higher volumetric heating value, leading to a more efficient overall cycle performance. This is made possible due to the invention of a warm gas cleanup process invented by Research Triangle Institute (RTI), called the High Temperature Desulfurization Process (HTDP), which was recently commercialized. The leftover char can then be burned in a conventional boiler to boost the steam output of the bottom cycle, further increasing the efficiency of the plant, capable of achieving a thermal efficiency of 47.9% (LHV). The first part of this paper will analyze the individual concepts used to create the baseline IMPGC model, including the mild and partial gasification processes themselves, the warm gas cleanup system, and the integration of the boiler with the heat recovery steam generator (HRSG). Part 2 will then compare this baseline case with four other common types of power plants, including subcritical and ultra-supercritical Rankine cycles, IGCC, and natural gas.

Performance of an Integrated Mild/Partial Gasification Combined (IMPGC) Cycle With Carbon Capture in Comparison With Other Power Systems

2019 ◽  
Author(s):  
Henry A. Long ◽  
Ting Wang
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Co2 Emissions ◽  
Carbon Capture ◽  
Rankine Cycle ◽  
High Energy ◽  
Combined Cycle ◽  
Percentage Points ◽  
Partial Gasification ◽  
Better Than

Abstract With rising concerns about potential CO2 emissions and the effects of which on climate change and ocean acidification, it becomes necessary to consider developing newer and cleaner power plant technologies, including carbon capture. A conceptual clean coal technology called the Integrated Mild/Partial Gasification Combined (IMPGC) cycle implemented with a post-combustion carbon capture process is introduced in this paper. The IMPGC cycle employs mild gasification to preserve the high energy volatile matters within the coal and partial gasification to supplement the steam bottom cycle with a purely char-fired PC plant boiler. The performance of this newly conceptualized model is compared to those of other types of power plants, including natural gas combined cycle (NGCC), integrated gasification combined cycle (IGCC), and pulverized coal (PC) Rankine cycle plants under the condition that all plants utilize carbon capture in some form so as to achieve the same overall CO2 emissions as a high-performing NGCC plant. The results show that, while natural gas is still the top-performing power plant, IMPGC with carbon capture has the highest performance of all coal plants studied (∼39.7%), able to achieve the same CO2 emissions as natural gas, but with the same efficiency as a top-of-the-line subcritical Rankine cycle plant without carbon capture. This is about 2.5 percentage points better than an IGCC plant with carbon capture, ∼8 percentage points better than an ultra-supercritical Rankine cycle plant with carbon capture, and over 9 points better than a subcritical plant with carbon capture. This high performance is achieved through the use of a warm gas cleanup process based on the technology developed by RTI with the support of the U.S. Department of Energy.

The Use of Integrated Mild/Partial Gasification Combined (IMPGC) Cycle Technology As a Potential Retrofit Option for Pulverized Coal Plants

2020 ◽  
Author(s):  
Henry A. Long ◽  
Ting Wang
Keyword(s):  
Power Output ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Electrical Power ◽  
Rankine Cycle ◽  
Steam Pressure ◽  
Combined Cycle ◽  
Plant Performance ◽  
Performance And Emissions ◽  
Partial Gasification

Abstract Around 50% of the world’s electrical power supply comes from the Rankine cycle, and the majority of existing Rankine cycle plants are driven by coal. The problem is that coal power plants are environmentally unfriendly; particularly, older plants have low thermal efficiency and poor emissions. In addition, the conventional and common practices for retrofitting those older plants can only provide incremental improvements for plant performance and emissions. This paper introduces the concept of the Integrated Mild/Partial Gasification Combined (IMPGC) Cycle as one promising new technology that has the potential to significantly increase the thermal efficiency of these older plants as well as reduce their emissions. In contrast to the conventional Integrated Gasification Combined Cycle (IGCC), IMPGC makes use of warm gas cleanup as well as mild and partial gasification to conveniently and seamlessly convert a simple Rankine cycle to a combined cycle, greatly improving the efficiency of the plant without altering the base plant’s design. Three different scenarios in total were simulated in addition to a simple subcritical Rankine cycle plant as a baseline for comparison: (1) a case using the same fuel input as the original baseline, (2) a case with the same total maximum power output as the baseline, and (3) a case where the turbine with the highest steam pressure (HPST) has the same mass flow rate through it as the equivalent turbine from the baseline case. The results show that IMPGC can improve the efficiency of Rankine cycles by up to nine (9) points (or ∼23%) and has the potential to augment total net power output by up to 2.5 times. This paper will analyze the specific challenges associated with retrofitting these plants and examine how the retrofit affects the plant performance and emissions.

scholarly journals Thermodynamic Analysis of Different Configurations of Combined Cycle Power Plants

2015 ◽  
Vol 5 (2) ◽  
pp. 89
Author(s):  
Munzer S. Y. Ebaid ◽  
Qusai Z. Al-hamdan
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Maximum Efficiency ◽  
Specific Work ◽  
Slight Effect ◽  
Turbine Engine ◽  
Gas Turbine Cycle ◽  
Cycle Efficiency

<p class="1Body">Several modifications have been made to the simple gas turbine cycle in order to increase its thermal efficiency but within the thermal and mechanical stress constrain, the efficiency still ranges between 38 and 42%. The concept of using combined cycle power or CPP plant would be more attractive in hot countries than the combined heat and power or CHP plant. The current work deals with the performance of different configurations of the gas turbine engine operating as a part of the combined cycle power plant. The results showed that the maximum CPP cycle efficiency would be at a point for which the gas turbine cycle would have neither its maximum efficiency nor its maximum specific work output. It has been shown that supplementary heating or gas turbine reheating would decrease the CPP cycle efficiency; hence, it could only be justified at low gas turbine inlet temperatures. Also it has been shown that although gas turbine intercooling would enhance the performance of the gas turbine cycle, it would have only a slight effect on the CPP cycle performance.</p>

A Case Study of Optimizing Combined Cycle Performance at Kalaeloa

2009 ◽  
Author(s):  
Helmer Andersen
Keyword(s):  
Power Plants ◽  
Performance Monitoring ◽  
Combined Cycle ◽  
Plant Performance ◽  
Operational Performance ◽  
Cycle Performance ◽  
Monitoring Tools ◽  
Online Performance Monitoring ◽  
On Line

Fuel is by far the largest expenditure for energy production for most power plants. New tools for on-line performance monitoring have been developed for reducing fuel consumption while at the same time optimizing operational performance. This paper highlights a case study where an online performance-monitoring tool was employed to continually evaluate plant performance at the Kalaeloa Combined Cycle Power Plant. Justification for investment in performance monitoring tools is presented. Additionally the influence of various loss parameters on the cycle performance is analyzed with examples. Thus, demonstrating the potential savings achieved by identifying and correcting the losses typically occurring from deficiencies in high impact component performance.

Development of a Novel Combined Absorption Cycle for Power Generation and Refrigeration

2006 ◽  
Vol 129 (3) ◽  
pp. 254-265 ◽  
Author(s):  
Na Zhang ◽  
Noam Lior
Keyword(s):  
Water System ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Cycle Performance ◽  
Base Case ◽  
Ammonia Water ◽  
Energy And Exergy ◽  
The Impact

Cogeneration can improve energy utilization efficiency significantly. In this paper, a new ammonia-water system is proposed for the cogeneration of refrigeration and power. The plant operates in a parallel combined cycle mode with an ammonia-water Rankine cycle and an ammonia refrigeration cycle, interconnected by absorption, separation, and heat transfer processes. The performance was evaluated by both energy and exergy efficiencies, with the latter providing good guidance for system improvement. The influences of the key parameters, which include the basic working solution concentration, the cooling water temperature, and the Rankine cycle turbine inlet parameters on the cycle performance, have been investigated. It is found that the cycle has a good thermal performance, with energy and exergy efficiencies of 27.7% and 55.7%, respectively, for the base-case studied (having a maximum cycle temperature of 450°C). Comparison with the conventional separate generation of power and refrigeration having the same outputs shows that the energy consumption of the cogeneration cycle is markedly lower. A brief review of desirable properties of fluid pairs for such cogeneration cycles was made, and detailed studies for finding new fluid pairs and the impact of their properties on cogeneration system performance are absent and are very recommended.

Effect of Deaerator Parameters on Simple and Reheat Gas/Steam Combined Cycle With Different Cooling Medium

2019 ◽  
Author(s):  
Mayank Maheshwari ◽  
Onkar Singh
Keyword(s):  
Gas Turbine ◽  
Mass Fraction ◽  
Power Plants ◽  
Performance Enhancement ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Inlet Temperature ◽  
Operating Pressure ◽  
Cooling Medium

Abstract Performance of gas/steam combined cycle power plants relies upon the performance exhibited by both gas based topping cycle and steam based bottoming cycle. Therefore, the measures for improving the performance of the gas turbine cycle and steam bottoming cycle eventually result in overall combined cycle performance enhancement. Gas turbine cooling medium affects the cooling efficacy. Amongst different parameters in the steam bottoming cycle, the deaerator parameter also plays its role in cycle performance. The present study analyzes the effect of deaerator’s operating pressure being varied from 1.6 bar to 2.2 bar in different configurations of simple and reheat gas/steam combined cycle with different cooling medium for fixed cycle pressure ratio of 40, turbine inlet temperature of 2000 K and ambient temperature of 303 K with varying ammonia mass fraction from 0.6 to 0.9. Analysis of the results obtained for different combined cycle configuration shows that for the simple gas turbine and reheat gas turbine-based configurations, the maximum work output of 643.78 kJ/kg of air and 730.87 kJ/kg of air respectively for ammonia mass fraction of 0.6, cycle efficiency of 54.55% and 53.14% respectively at ammonia mass fraction of 0.7 and second law efficiency of 59.71% and 57.95% respectively at ammonia mass fraction of 0.7 is obtained for the configuration having triple pressure HRVG with ammonia-water turbine at high pressure and intermediate pressure and steam turbine operating at deaerator pressure of 1.6 bar.

Evaluation of Using Supercritical Rankine Cycles in Integrated Coal Gasification Combined Cycles (IGCC)

2017 ◽  
Author(s):  
Henry A. Long ◽  
Ting Wang ◽  
Arian Thomas
Keyword(s):  
Coal Gasification ◽  
Energy Resource ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Modern World ◽  
Integrated Gasification Combined Cycle ◽  
Combined Cycles ◽  
Reduce Emissions ◽  
Integrated Gasification ◽  
Cycle Efficiency

Coal is a prominent energy resource in the modern world, particularly in countries with emerging economies. In order to reduce emissions, it is necessary to find a way to utilize coal in a cleaner manner, such as through supercritical and ultra-supercritical Rankine cycles and the Integrated Gasification Combined Cycle (IGCC). Two approaches — raising the boiler pressure and using a reheat scheme — have been proven to notably increase the Rankine cycle efficiency. Thus, this study aims to investigate the effects of implementing reheat and supercritical or ultra-supercritical pressure in the bottom Rankine cycle on the IGCC cycle efficiency. First, reference cases of a standalone Rankine cycle were studied with single and double reheat, including boiler pressure levels from subcritical to ultra-supercritical conditions, followed by similar combined cycle cases, and finally IGCC systems. The results indicate that the notable efficiency enhancement in the standalone subcritical Rankine cycle do not prevail in the studied IGCC systems. Thus, it is not economically worthwhile to implement supercritical or ultra-supercritical bottom Rankine cycles in IGCC applications.

Solar Hybrid Combined Cycle Performance Prediction: Influence of GT Model and Spool Arrangement

2012 ◽  
Author(s):  
G. Barigozzi ◽  
G. Bonetti ◽  
G. Franchini ◽  
A. Perdichizzi ◽  
S. Ravelli
Keyword(s):  
Gas Turbine ◽  
Performance Prediction ◽  
Gas Turbines ◽  
Control Strategies ◽  
Rankine Cycle ◽  
Simulation Method ◽  
Power Input ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Solar Field

A modeling procedure was developed to simulate design and off-design operation of Hybrid Solar Gas Turbines in a combined cycle (CC) configuration. The system includes an heliostat field, a receiver and a commercial gas turbine interfaced with a conventional steam Rankine cycle. Solar power input is integrated in the GT combustor by natural gas. Advanced commercial software tools were combined together to get design and off-design performance prediction: TRNSYS® was used to model the solar field and the receiver while the gas turbine and steam cycle simulations were performed by means of Thermoflex®. Three GT models were considered, in the 35–45 MWe range: a single shaft engine (Siemens SGT800) and two two-shaft engines (the heavy-duty GT Siemens SGT750 and the aero derivative GE LM6000 PF). This in order to assess the influence of different GT spool arrangements and control strategies on GT solarization. The simulation method provided an accurate modeling of the daily solar hybrid CC behavior to be compared against the standard CC. The effects of solarization were estimated in terms of electric power and efficiency reduction, fossil fuel saving and solar energy to electricity conversion efficiency.

Some Unconventional Aero Gas Turbines Using Hydrogen Fuel

2002 ◽  
Author(s):  
Stefano Boggia ◽  
Anthony Jackson
Keyword(s):  
Gas Turbines ◽  
Energy Content ◽  
Renewable Energy Sources ◽  
High Energy ◽  
Aviation Fuel ◽  
Cycle Performance ◽  
Turbine Engines ◽  
Pure Hydrogen ◽  
Hydrogen Fuel ◽  
Reduction Of Co2

The use of hydrogen as an aviation fuel can be beneficial for the reduction of CO2 emissions, if renewable energy sources are used for hydrogen production. Pure hydrogen fuel produces no CO2 in flight. NOx emissions can be significantly lower for hydrogen fuelled combustors than for current kerosene fuelled combustors. Other advantages derive from the high energy content, which reduces the necessary fuel mass, and from the availability of a valuable heat sink, useful to improve cycle performance. The present paper (based on the EU Cryoplane Project) focuses on the use of hydrogen in aero gas turbine engines. It studies the differences in performance produced by of its cryogenic properties in unconventional cycles. Three novel concepts are applied to a turbofan aero engine; for each cycle the improvement in performance at take-off and cruise is presented. An estimation of the weight and size of the engine is then made.

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