Exhaust Gas Recirculation Performance in Dry Low Emissions Combustors

2011 ◽  
Author(s):  
A. M. Elkady ◽  
A. R. Brand ◽  
C. L. Vandervort ◽  
A. T. Evulet
Keyword(s):  
Gas Turbine ◽  
Co2 Capture ◽  
Carbon Capture ◽  
Power Plants ◽  
Nox Reduction ◽  
Co2 Concentration ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Low Oxygen ◽  
Gas Recirculation

In a carbon constrained world there is a need for capturing and sequestering CO2. Post-combustion carbon capture via Exhaust Gas Recirculation (EGR) is considered a feasible means of reducing emission of CO2 from power plants. Exhaust Gas Recirculation is an enabling technology for increasing the CO2 concentration within the gas turbine cycle and allow the decrease of the size of the separation plant, which in turn will enable a significant reduction in CO2 capture cost. This paper describes the experimental work performed to better understand the risks of utilizing EGR in combustors employing dry low emissions (DLE) technologies. A rig was built for exploring the capability of premixers to operate in low O2 environment, and a series of experiments in a visually accessible test rig was performed at representative aeroderivative gas turbine pressures and temperatures. Experimental results include the effect of applying EGR on operability, efficiency and emissions performance under conditions of up to 40% EGR. Findings confirm the viability of EGR for enhanced CO2 capture; In addition, we confirm benefits of NOx reduction while complying with CO emissions in DLE combustors under low oxygen content oxidizer.

Exhaust Gas Recirculation in DLN F-Class Gas Turbines for Post-Combustion CO2 Capture

2008 ◽  
Author(s):  
Ahmed M. ElKady ◽  
Andrei Evulet ◽  
Anthony Brand ◽  
Tord Peter Ursin ◽  
Arne Lynghjem
Keyword(s):  
Co2 Capture ◽  
Experimental Work ◽  
Gas Turbines ◽  
Co2 Concentration ◽  
Exhaust Gas Recirculation ◽  
Inert Gases ◽  
Exhaust Gas ◽  
Enabling Technology ◽  
Series Of Experiments ◽  
Gas Recirculation

This paper describes experimental work performed at General Electric, Global Research Center to evaluate the performance and understand the risks of using Dry Low NOx (DLN) technologies in Exhaust Gas Recirculation (EGR) conditions. Exhaust Gas Recirculation is viewed as an enabling technology for increasing the CO2 concentration of the flue gas while decreasing the volume of the post-combustion separation plant and therefore allowing a significant reduction in CO2 capture cost. A research combustor was developed for exploring the performance of nozzles operating in low O2 environment at representative pressures and temperatures. A series of experiments in a visually accessible test rig have been performed at gas turbine pressures and temperatures, in which inert gases such as N2/CO2 were used to vitiate the fresh air to the levels determined by cycle models. Moreover, the paper will discuss experimental work performed using a DLN nozzle used in GE’s F-class heavy-duty gas turbines. Experimental results using a research combustor operating in partially premixed mode, incorporate the effect of applying EGR on operability, efficiency and emissions performance under conditions of up to 40% EGR. Experiments performed in fully premixed mode using DLN single nozzle combustor revealed that further reductions in NOx could be achieved and at the same time still complying with CO emissions. While most existing studies concentrate on limitations related to the Minimum Oxygen Concentration (MOC) at the combustor exit, we report the importance of CO2 levels in the oxidizer. This limitation is as important as the MOC and it varies with the pressure and firing temperatures.

Study of Using Exhaust Gas Recirculation on a Gas Turbine for Carbon Capture

2020 ◽  
Author(s):  
Dan Burnes ◽  
Priyank Saxena ◽  
Paul Dunn
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Carbon Capture ◽  
Hydrocarbon Fuel ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Hybrid Solutions ◽  
Industrial Gas Turbines ◽  
Industrial Gas Turbine ◽  
Gas Recirculation

Abstract The growing call of minimizing carbon dioxide and other greenhouse gases emitting from energy and transportation products will spur innovation to meet new stringent requirements while striving to preserve significant investments in the current infrastructure. This paper presents quantitative analysis of exhaust gas recirculation (EGR) on industrial gas turbines to enable carbon sequestration venturing towards emission free operation. This study will show the effect of using EGR on gas turbine performance and operation, combustion characteristics, and demonstrate potential hybrid solutions with detailed constituent accounting. Both single shaft and two shaft gas turbines for power generation and mechanically driven equipment are considered for application of this technology. One key element is assessing the combustion system operating at reduced O2 levels within the industrial gas turbine. With the gas turbine behavior operating with EGR defined at a reasonable operating state, a parametric study shows rates of CO2 sequestration along with quantifying supplemental O2 required at the inlet, if needed, to sustain combustion. With rates of capture known, a further exploration is examined reviewing potential utilities, monetizing these sequestered constituents. Ultimately, the objective is to preview a potential future of operating industrial gas turbines in a non-emissive and in some cases carbon negative manner while still using hydrocarbon fuel.

Investigation of a Generic Gas Turbine Combustor With Exhaust Gas Recirculation

2013 ◽  
Author(s):  
Sebastian Ulmer ◽  
Franz Joos
Keyword(s):  
Heat Release ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Release Rate ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Nitric Oxides ◽  
Gas Turbine Combustor ◽  
A Minor ◽  
Gas Recirculation

On the topic of CO2 capture from gas turbines, exhaust gas recirculation (EGR) is a commonly discussed method to increase CO2 concentration at a gas turbine outlet to make the CO2 capture process more efficient. This paper presents the influence of the recirculation on heat release rate and emissions. The investigation is made using the commercial RANS solver ANSYS CFX coupled with an in-house code for a hybrid transported PDF/RANS simulation using detailed chemistry of GRI 3.0. Initially an investigation on reactivity was made using numerical calculation of laminar flame speed. It is found that exhaust gas recirculation has only a minor effect on reactivity in lean premixed combustion. Therefore, the operation point of the combustor can be kept constant with and without EGR. Simulations of the combustor with exhaust gas recirculation using the hybrid PDF/RANS with GRI 3.0 show a minor influence of NO and NO2 doping of the vitiated air on the flame speed and the doping delays heat release slightly. CO doping has no effect on heat release rate. CO emissions at combustor exit remain unaffected by NO, CO or NO2 doping. Seeding the vitiated air with 50ppm nitric oxides reveal that any NO2 present in the vitiated air is reduced to NO in the flame. NO2 emissions increase with NO2 doping but are still 2 magnitudes lower than NO emissions. It is found that NO is reduced by 3% due to of NO reburn. Based on literature data it is concluded that there is a deficit of the GRI 3.0 reaction mechanism. Experimental data taken from literature reveal of NO reburn by approximately 20%. Therefore emission data of nitric oxides of flames that should show a considerable reburn effect should be used with caution, while heat release and CO emissions are predicted more accurately. It is shown, that with the model created for the generic gas turbine combustor it is possible to study the effects of exhaust gas recirculation on the combustion process in detail and resolve detailed kinetic effects.

Process Analysis of Selective Exhaust Gas Recirculation for CO2 Capture in Natural Gas Combined Cycle Power Plants Using Amines

2017 ◽  
Author(s):  
Maria Elena Diego ◽  
Jean-Michel Bellas ◽  
Mohamed Pourkashanian
Keyword(s):  
Natural Gas ◽  
Co2 Capture ◽  
Flue Gas ◽  
Power Plants ◽  
Exhaust Gas Recirculation ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Natural Gas Combined Cycle ◽  
The Cost ◽  
Gas Recirculation

Post-combustion CO2 capture from natural gas combined cycle (NGCC) power plants is challenging due to the large flow of flue gas with low CO2 content (∼3–4%vol.) that needs to be processed in the capture stage. A number of alternatives have been proposed to solve this issue and reduce the costs of the associated CO2 capture plant. This work focuses on the selective exhaust gas recirculation (S-EGR) configuration, which uses a membrane to selectively recirculate CO2 back to the inlet of the compressor of the turbine, thereby greatly increasing the CO2 content of the flue gas sent to the capture system. For this purpose, a parallel S-EGR NGCC system (53% S-EGR ratio) coupled to an amine capture plant using MEA 30%wt. was simulated using gCCS (gPROMS). It was benchmarked against an unabated NGCC system, a conventional NGCC coupled with an amine capture plant (NGCC+CCS), and an EGR NGCC power plant (39% EGR ratio) using amine scrubbing as the downstream capture technology. The results obtained indicate that the net power efficiency of the parallel S-EGR system can be up to 49.3% depending on the specific consumption of the auxiliary S-EGR systems, compared to the 49.0% and 49.8% values obtained for the NGCC+CCS and EGR systems, respectively. A preliminary economic study was also carried out to quantify the potential of the parallel S-EGR configuration. This high-level analysis shows that the cost of electricity for the parallel S-EGR system varies from 82.1–90.0 $/MWhe for the scenarios considered, with the cost of CO2 avoided being in the range of 79.7–105.1 $/tonne CO2. The results obtained indicate that there are potential advantages of the parallel S-EGR system in comparison to the NGCC+CCS configuration in some scenarios. However, further benefits with respect to the EGR configuration will depend on future advancements and cost reductions achieved on membrane-based systems.

scholarly journals Thermodynamic, Environmental and Economic Assessment of Exhaust Gas Recirculation for NOx Reduction in Gas Turbine Based Compressor Station

1999 ◽  
Author(s):  
K. K. Botros ◽  
G. R. Price ◽  
G. Kibrya
Keyword(s):  
Gas Turbine ◽  
Mechanical Energy ◽  
Nox Reduction ◽  
Economic Assessment ◽  
Exhaust Gas Recirculation ◽  
Simulation Software ◽  
Environmental Cost ◽  
Exhaust Gas ◽  
Compressor Station ◽  
Gas Recirculation

A thermodynamic, environmental and economic assessment of an exhaust gas recirculation (EGR) system for NOx reduction has been carried out on an RB211 gas turbine based compressor station. The configured system was evaluated using a commercial process simulation software ASPEN PLUS® for the EGR process, along with a one dimensional model for the prediction of NOx. The assessment was focused on a realistic system of 20% gas recirculation cooled 300 °C with an aerial cooler. Detailed economic analysis based on present value cost per unit mechanical energy (kWh), showed that there is no economic advantage in implementing an EGR system in an existing gas turbine based station. Although the environmental cost was lower with the EGR system, it was offset by the cost of the EGR system itself combined with the additional incremental cost of fuel due to the decrease in the thermal efficiency.

Operational Scenarios of a Gas Turbine Using Exhaust Gas Recirculation for Carbon Capture

2021 ◽  
Author(s):  
Daniel Burnes ◽  
Priyank Saxena
Keyword(s):  
Gas Turbine ◽  
Carbon Capture ◽  
Exhaust Gas Recirculation ◽  
Energy System ◽  
Appropriate Technology ◽  
Exhaust Gas ◽  
Term Survival ◽  
Exhaust Heat ◽  
Industrial Gas Turbine ◽  
Gas Recirculation

Abstract Finding viable economic solutions to significantly reduce or eliminate greenhouse gas emissions from energy and transportation products in the near future is paramount for the long-term survival of fossil fuel burning systems. One of which, the industrial gas turbine, has proven for decades to be a versatile energy system providing high efficiencies in combined heat and power applications melding well within existing infrastructure. Applying appropriate technology, the industrial gas turbine could be augmented to both sequester carbon and improve efficiency leveraging the full heating value of the fuel. The paper considers a more detailed operational assessment of a gas turbine using exhaust gas recirculation (EGR) to enable cost effective post combustion carbon sequestration and utilization. In this study, the effect of using EGR will be assessed at part load and throughout the operational envelope quantifying component and overall performance, detailed combustion characteristics, and maximizing the utilization of exhaust heat and sequestered carbon in various applications. This study will also attempt to quantify true carbon footprint of gas turbine installations and endeavor to understand the relative change of replacing the gas turbine with an all-electric alternative. Fundamentally, we are looking to see if there is a future to sustain and adapt this significant natural gas (NG) energy infrastructure to a net-zero carbon emissive future by 2050.

Performance Assessment of a Micro Gas Turbine Cycle With Exhaust Gas Recirculation Fueled by Biogas for Post-Combustion Carbon Capture Application

2018 ◽  
Author(s):  
Homam Nikpey Somehsaraei ◽  
Mohammad Mansouri Majoumerd ◽  
Mohsen Assadi
Keyword(s):  
Renewable Energy ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Carbon Capture ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Micro Gas Turbine ◽  
Wide Range ◽  
Gas Recirculation ◽  
Gas Turbine Cycle

As a renewable energy source, biogas produced from anaerobic digestion seems to play an important role in the energy market. Unlike wind and solar, which are intermittent, gas turbines fueled by biogas provide dispatchable renewable energy that can be ramped up and down to match the demand. If post-combustion carbon capture systems are implemented, they can also result in negative CO2 emissions. However, one of the major challenges here is the energy needed for CO2 chemical absorption in post-combustion capture, which is closely related to the concentration of CO2 in the exhaust gas upstream of the capture unit. This paper presents an evaluation of the effects of biogas and exhaust gas recirculation use on the performance of the gas turbine cycle for post-combustion CO2 capture application. The study is based on a combined heat and power micro gas turbine, Turbec T100, delivering 100kWe. The thermodynamic model of the gas turbine has been validated against experimental data obtained from test facilities in Norway and the United Kingdom. Based on the validated model, performance calculations for the baseline micro gas turbine (fueled by natural gas), biogas-fired cases and the cycle with exhaust gas recirculation have been carried out at various operational conditions and compared together. A wide range of biogas composition with varying methane content was assumed for this study. Necessary minor modifications to fuel valves and compressor were assumed to allow the engine operation with different biogas composition. The methodology and results are fully discussed in this paper.

Combustion Simulation of an Exhaust Gas Recirculation Operated Micro-gas Turbine

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Maria Cristina Cameretti ◽  
Renzo Piazzesi ◽  
Fabrizio Reale ◽  
Raffaele Tuccillo
Keyword(s):  
Gas Turbine ◽  
Nox Reduction ◽  
Exhaust Gas Recirculation ◽  
Point Of View ◽  
Exhaust Gas ◽  
Micro Gas Turbine ◽  
Computational Fluid Dynamics Analysis ◽  
Combustion Simulation ◽  
Chemically Reacting ◽  
Gas Recirculation

Following their recent experiences in the search of methods for reducing the nitric oxide emissions from a micro-gas turbine, the authors discuss in this paper the results of the combustion simulation under different conditions induced by the activation of an exhaust recirculation system. The theoretical approach starts with a matching analysis of the exhaust gas recirculation equipped microturbine, and then proceeds with the computational fluid dynamics analysis of the combustor. Different combustion models are compared in order to validate the method for NOx reduction by the point of view of a correct development of the chemically reacting process.

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