Evaluation of a Micro Gas Turbine With Post-Combustion CO2 Capture for Exhaust Gas Recirculation Potential With Two Experimentally Validated Models

2017 ◽  
Author(s):  
Homam Nikpey Somehsaraei ◽  
Usman Ali ◽  
Carolina Font-Palma ◽  
Mohammad Mansouri Majoumerd ◽  
Muhammad Akram ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Exhaust Gas Recirculation ◽  
Software Tools ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Capture Process ◽  
Micro Gas Turbine ◽  
Gas Recirculation

The growing global energy demand is facing concerns raised by increasing greenhouse gas emissions, predominantly CO2. Despite substantial progress in the field of renewable energy in recent years, quick balancing responses and back-up services are still necessary to maintain the grid load and stability, due to increased penetration of intermittent renewable energy sources, such as solar and wind. In a scenario of natural gas availability, gas turbine power may be a substitute for back-up/balancing load. Rapid start-up and shut down, high ramp rate, and low emissions and maintenance have been achieved in commercial gas turbine cycles. This industry still needs innovative cycle configurations, e.g. exhaust gas recirculation (EGR), to achieve higher system performance and lower emissions in the current competitive power generation market. Together with reduced NOx emissions, EGR cycle provides an exhaust gas with higher CO2 concentration compared to the simple gas turbine/combined cycle, favorable for post-combustion carbon capture. This paper presents an evaluation of EGR potential for improved gas turbine cycle performance and integration with a post-combustion CO2 capture process. It also highlights features of two software tools with different capabilities for performance analysis of gas turbine cycles, integrated with post-combustion capture. The study is based on a combined heat and power micro gas turbine (MGT), Turbec T100, of 100kWe output. Detailed models for the baseline MGT and amine capture plant were developed in two software tools, IPSEpro and Aspen Hysys. These models were validated against experimental work conducted at the UK PACT National Core Facilities. Characteristics maps for the compressor and the turbine were used for the MGT modeling. The performance indicators of systems with and without EGR, and when varying the EGR ratio and ambient temperature, were calculated and are presented in this paper.

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.

Performance Improvement of a Micro Gas Turbine Adopting Exhaust Gas Recirculation for CO2 Capture by Integration With Liquid Air Energy Storage

2018 ◽  
Author(s):  
Min Jae Kim ◽  
Dong Hyeok Won ◽  
Tong Seop Kim
Keyword(s):  
Energy Storage ◽  
Co2 Capture ◽  
Carbon Capture ◽  
Capture Rate ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Capture Process ◽  
Micro Gas Turbine ◽  
Compressor Inlet ◽  
Gas Recirculation

Exhaust gas recirculation (EGR) can be applied to a micro gas turbine (MGT) for the efficient removal of CO2 using post-combustion capture. The EGR increases the CO2 concentration of the exhaust gas for the capture process, which augments the capture rate. However, the performance penalty of the MGTs caused by the rise in the compressor inlet temperature due to the EGR is a drawback. In this research, we investigated the integration of an MGT, adopting EGR with liquid air energy storage (LAES), an emerging energy storage technology. LAES stores electric energy from renewables or the power grid in the form of cryogenic liquid air. The liquefied air is pressurized and regasified to generate electricity during peak demand hours. In our proposed system, a portion of the cryogenic air is injected into the MGT’s compressor inlet. The purpose of the injection is twofold. Firstly, it decreases the compressor inlet air temperature, which enhances the MGT performance, especially the power output. Secondly, it increases the carbon dioxide composition of the exhaust gas, which enhances the carbon capture performance. An MGT system, equipped with a post-combustion capture and integrated with the cryogenic air injection, was analyzed. The analysis shows that the system power, system efficiency, and CO2 capture rate were improved, with the heat duty of the carbon capture process reduced in accordance with the increase in cryogenic flow rate, as expected. Moreover, the heat duty of the carbon capture process decreased significantly due to the increase in temperature and O2 concentration in the cryogenic air.

Study of an exhaust gas recirculation equipped micro gas turbine supplied with bio-fuels

2013 ◽  
Vol 59 (1-2) ◽  
pp. 162-173 ◽  
Author(s):  
Maria Cristina Cameretti ◽  
Raffaele Tuccillo ◽  
Renzo Piazzesi
Keyword(s):  
Gas Turbine ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Micro Gas Turbine ◽  
Gas Recirculation

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.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document