Direct Fired Oxy-Fuel Combustor for sCO2 Power Cycles: 1MW Scale Design and Preliminary Bench Top Testing

Author(s):  
Jacob Delimont ◽  
Aaron McClung ◽  
Marc Portnoff

Direct fired oxy-fuel combustion as a heat source for supercritical carbon dioxide (sCO2) power cycles is a promising method for providing the needed thermal energy input. The method of combustion has the potential to provide efficient power generation with integrated carbon capture at up to 99% of generated CO2. One of the highest efficiency power cycles being considered for sCO2 cycles in the recompression cycle. In the recompression sCO2 power cycle, the amount of energy recovered from the recuperation is roughly five times the energy added via the combustor. Because of this high degree of recuperation in sCO2 power cycles, the inlet temperature of the combustor is much higher than a more traditional combustor design. This elevated combustor temperature leads to some unique design challenges and approaches which are quite different from a traditional combustion system. A combustor designed for these conditions has never been built, and thus the design of the combustor discussed in this paper started from a clean slate. This necessitates a large degree of fundamental research which might not be necessary for a more well understood traditional combustor design process. Building on previous thermodynamic and chemical kinetics studies, a reduced order reaction kinetics model was used with ANSYS CFX software to explore various auto-ignition type combustor geometries. A discussion of some geometries and the modelling techniques used is presented. Various injector configurations were examined and metrics were used to compare the various configurations. By utilizing the CFD flow field results, a preliminary design for a 1MW-class oxy-fuel combustor was developed. In the past, little experimental research has been conducted on combustion within carbon dioxide at pressures above 200 bar. In order to confirm the validity of the auto-ignition style combustor a small bench top test rig was constructed to test the oxy-fuel combustion at the full pressure and temperature. This system was designed to validate some of the fundamental properties of the combustion. This includes a gas sampling system and a measurement of auto-ignition delay. Preliminary, data from a bench top scale, sCO2 oxy-fuel combustor experiment will be presented. The results from this work will enable future development of sCO2 power cycles which enable 99% carbon capture, while maintaining overall cycle efficiency which is competitive with natural gas combined cycle power plants.

Author(s):  
Anand Pavithran ◽  
Meeta Sharma ◽  
Anoop Kumar Shukla

The energy generation from the fossil fuels results to emit a tremendous amount of carbon dioxide into the atmosphere. The rise in the atmospheric carbon dioxide level is the primary reason for global warming and other climate change problems for which energy generation from renewable sources is an alternative solution to overcome this problem. However, the renewables sources are not as reliable for the higher amount of energy production and cannot fulfil the world’s energy demand; fossil fuels will continue to be consumed heavily for the energy generation requirements in the immediate future. The only possible solution to overcome the greenhouse gas emission from the power plant is by capturing and storing the carbon dioxide within the power plants instead of emitting it into the atmosphere. The oxy-fuel combustion power cycle with a carbon capture and storage system is an effective way to minimize emissions from the energy sectors. The oxy-fuel power cycle can reduce 90–99% of carbon dioxide emissions from the atmosphere. Moreover, the oxy-fuel power cycles have several advantages over the conventional power plants, these include high efficiency, lesser plant footprint, much easier carbon-capturing processes, etc. Because of these advantages, the oxy-fuel combustion power cycles capture more attention. In the last decades, the number of studies has risen exponentially, leading to many experimental and demonstrational projects under development today. This paper reviews the works related to oxy-fuel combustion power generation technologies with carbon capture and storage system. The cycle concepts and the advancements in this technology have been briefly discussed in this paper.


2021 ◽  
Vol 2053 (1) ◽  
pp. 012005
Author(s):  
I I Komarov ◽  
O V Zlyvko ◽  
A N Vegera ◽  
B A Makhmutov ◽  
I A Shcherbatov

Abstract Coal-fired steam turbine thermal power plants produce a large part of electricity. These power plants usually have low efficiency and high carbon dioxide emission. An application of combined cycle power plants with coal gasification equipped with carbon capture and storage systems may increase the efficiency and decrease the harmful emission. This paper describes investigation of the oxidizer type in the integrated gasification combined cycle combustion chamber and its influence upon the energy and environmental performance. The integrated gasification combined cycle and oxy-fuel combustion technology allow the carbon dioxide capture and storage losses 58% smaller than the traditional air combustion one. The IGCC with air combustion without and with carbon dioxide capture and storage has 53.54 and 46.61% and with oxy-fuel combustion has 34.94 and 32.67% net efficiency. Together with this the CO2 emission drops down from 89.9 to 10.6 gm/kWh. The integrated coal gasification combined cycle with air oxidizer has the best net efficiency.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2927
Author(s):  
Andrey Rogalev ◽  
Nikolay Rogalev ◽  
Vladimir Kindra ◽  
Ivan Komarov ◽  
Olga Zlyvko

The transition to oxy-fuel combustion power cycles is a prospective way to decrease carbon dioxide emissions into the atmosphere from the energy sector. To identify which technology has the highest efficiency and the lowest emission level, a thermodynamic analysis of the semiclosed oxy-fuel combustion combined cycle (SCOC-CC), the E-MATIANT cycle, and the Allam cycle was carried out. The modeling methodology has been described in detail, including the approaches to defining the working fluid properties, the mathematical models of the air separation unit, and the cooled gas turbine cycles’ calculation algorithms. The gas turbine inlet parameters were optimized using the developed modeling methodology for the three oxy-fuel combustion power cycles with CO2 recirculation in the inlet temperature at a range of 1000 to 1700 °C. The effect of the coolant flow precooling was evaluated. It was found that a decrease in the coolant temperature could lead to an increase of the net efficiency up to 3.2% for the SCOC-CC cycle and up to 0.8% for the E-MATIANT cycle. The final comparison showed that the Allam cycle’s net efficiency is 5.6% higher compared to the SCOC-CC cycle, and 11.5% higher compared with the E-MATIANT cycle.


Author(s):  
Jacob Delimont ◽  
Nathan Andrews ◽  
Lalit Chordia

Direct fired oxy-fuel combustion provides a promising method for heat addition into a supercritical carbon dioxide (sCO2) power cycle. Using this method of thermal energy input into the cycle allows for potentially higher fuel to bus bar cycle efficiency. In addition, the nature of the sCO2 power cycle lends itself to easy and efficient capture of 99% of the CO2 generated in the combustion process. sCO2 power cycles typically operate at pressures above 200 bar, and due to the high degree of recuperation found in these cycles, have a very high combustor inlet temperature. Past works have explored combustor inlet temperatures high enough to be in the autoignition regime. The inlet temperatures which will be explored in this work will be limited to 700°C, which will allows for very different combustor geometry than that which has been studied in the past. While this combustor inlet temperature is lower than that previously studied, when combined with the extremely high pressure, this poses several unique and difficult design challenges. In order to explore these unique design conditions a reliable and robust CFD solution method was developed. This reliable CFD solution methodology enables rapid iteration on various geometries. This paper will explore the CFD modeling setup and the assumptions which were made in the absence of well experimental data in this combustor regime. Exploration of methodology to account for possible variations in chemical kinetics due to the lack of validated kinetic models in the current literature will also be discussed. The results from the CFD runs will be discussed and the combustor design, and next steps to complete a detailed combustor design will also be discussed. This work will enable future work in the development of oxy-fuel combustors for direct fired sCO2 power. This promising technology enables the use of fossil fuels with up to 99% carbon capture, while maintaining an overall cycle efficiency competitive with natural gas combined cycle power plants.


Author(s):  
J. Jeffrey Moore ◽  
Marybeth G. Nored

In order to reduce the amount of carbon dioxide (CO2) greenhouse gases released into the atmosphere, significant consideration has been given to the sequestration of CO2 from power plants and other major producers of greenhouse gas emissions. Integrated Gasification Combined Cycle (IGCC) power plants offer an alternative to pulverized coal plants because the carbon dioxide may be separated from the process gas stream prior to combustion. The compression of the captured carbon dioxide stream requires a sizeable amount of power, which impacts plant availability, capital expenditures and operational cost. Preliminary analysis has estimated that the CO2 compression process reduces the plant efficiency by 8% to 12% for a typical IGCC plant. The detailed thermodynamic analysis presented here examines methods to minimize the power penalty to the producer through integrated, low-power compression concepts. The goal of the present research is to reduce this penalty through novel compression concepts and integration with existing IGCC processes. The research supports the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) objectives of reducing the energy requirements for carbon capture and sequestration in electrical power production. The primary objective of this study is to boost the pressure of CO2 to pipeline pressures with the minimal amount of energy required. Fundamental thermodynamic analysis methods related to the compression of CO2 are used in the following paper to explore pressure and enthalpy rise in both liquid and gaseous states.


Author(s):  
Jongsup Hong ◽  
Ahmed F. Ghoniem ◽  
Randall Field ◽  
Marco Gazzino

Oxy-fuel combustion coal-fired power plants can achieve significant reduction in carbon dioxide emissions, but at the cost of lowering their efficiency. Research and development are conducted to reduce the efficiency penalty and to improve their reliability. High-pressure oxy-fuel combustion has been shown to improve the overall performance by recuperating more of the fuel enthalpy into the power cycle. In our previous papers, we demonstrated how pressurized oxy-fuel combustion indeed achieves higher net efficiency than that of conventional atmospheric oxy-fuel power cycles. The system utilizes a cryogenic air separation unit, a carbon dioxide purification/compression unit, and flue gas recirculation system, adding to its cost. In this study, we perform a techno-economic feasibility study of pressurized oxy-fuel combustion power systems. A number of reports and papers have been used to develop reliable models which can predict the costs of power plant components, its operation, and carbon dioxide capture specific systems, etc. We evaluate different metrics including capital investments, cost of electricity, and CO2 avoidance costs. Based on our cost analysis, we show that the pressurized oxy-fuel power system is an effective solution in comparison to other carbon dioxide capture technologies. The higher heat recovery displaces some of the regeneration components of the feedwater system. Moreover, pressurized operating conditions lead to reduction in the size of several other critical components. Sensitivity analysis with respect to important parameters such as coal price and plant capacity is performed. The analysis suggests a guideline to operate pressurized oxy-fuel combustion power plants in a more cost-effective way.


Author(s):  
Walter W. Shelton ◽  
Robin W. Ames ◽  
Richard A. Dennis ◽  
Charles W. White ◽  
John E. Plunkett ◽  
...  

The U.S. Department of Energy’s (DOE) provides a worldwide leadership role in the development of advanced fossil fuel-based energy conversion technologies, with a focus on electric power generation with carbon capture and storage (CCS). As part of DOE’s Office of Fossil Energy, the National Energy Technology Laboratory (NETL) implements research, development, and demonstration (RD&D) programs that address the challenges of reducing greenhouse gas emissions. To meet these challenges, NETL evaluates advanced power cycles that will maximize system efficiency and performance, while minimizing CO2 emissions and the costs of CCS. NETL’s Hydrogen Turbine Program has sponsored numerous R&D projects in support of Advanced Hydrogen Turbines (AHT). Turbine systems and components targeted for development include combustor technology, materials research, enhanced cooling technology, coatings development, and more. The R&D builds on existing gas turbine technologies and is intended to develop and test the component technologies and subsystems needed to validate the ability to meet the Turbine Program goals. These technologies are key components of AHTs, which enable overall plant efficiency and cost of electricity (COE) improvements relative to an F-frame turbine-based Integrated Gasification Combined Cycle (IGCC) reference plant equipped with carbon capture (today’s state-of-the-art). This work has also provided the basis for estimating future IGCC plant performance based on a Transformational Hydrogen Turbine (THT) with a higher turbine inlet temperature, enhanced material capabilities, reduced air cooling and leakage, and higher pressure ratios than the AHT. IGCC cases from using system-level AHT and THT gas turbine models were developed for comparisons with an F-frame turbine-based IGCC reference case and for an IGCC pathway study. The IGCC pathway is presented in which the reference case (i.e. includes F-frame turbine) is sequentially-modified through the incorporation of advanced technologies. Advanced technologies are considered to be either 2nd Generation or Transformational, if they are anticipated to be ready for demonstration by 2025 and 2030, respectively. The current results included the THT, additional potential transformational technologies related to IGCC plant sections (e.g. air separation, gasification, gas cleanup, carbon capture, NOx reduction) are being considered by NETL and are topics for inclusion in future reports.


Author(s):  
R. Chacartegui ◽  
D. Sa´nchez ◽  
F. Jime´nez-Espadafor ◽  
A. Mun˜oz ◽  
T. Sa´nchez

The development of high efficiency solar power plants based on gas turbine technology presents two problems, both of them directly associated with the solar power plant receiver design and the power plant size: lower turbine intake temperature and higher pressure drops in heat exchangers than in a conventional gas turbine. To partially solve these problems, different configurations of combined cycles composed of a closed cycle carbon dioxide gas turbine as topping cycle have been analyzed. The main advantage of the Brayton carbon dioxide cycle is its high net shaft work to expansion work ratio, in the range of 0.7–0.85 at supercritical compressor intake pressures, which is very close to that of the Rankine cycle. This feature will reduce the negative effects of pressure drops and will be also very interesting for cycles with moderate turbine inlet temperature (800–1000 K). Intercooling and reheat options are also considered. Furthermore, different working fluids have been analyzed for the bottoming cycle, seeking the best performance of the combined cycle in the ranges of temperatures considered.


2021 ◽  
Vol 2119 (1) ◽  
pp. 012101
Author(s):  
I G Donskoy

Abstract One of the main problems in the use of solid fuels is inevitable formation of significant amounts of carbon dioxide. The prospects for reducing CO2 emissions (carbon capture and storage, CCS) are opening up with the use of new coal technologies, such as thermal power plants with integrated gasification (IGCC) and transition to oxygen-enriched combustion (oxyfuel). In order to study the efficiency of solid fuel conversion processes using carbon dioxide, thermodynamic modeling was carried out. Results show that difference between efficiency of fuel conversion in O2/N2 and O2/CO2 mixtures increases with an increase in the volatile content and a decrease in the carbon content. The effect of using CO2 as a gasification agent depends on the oxygen concentration: at low oxygen concentrations, the process temperature turns out to be low due to dilution; at high oxygen concentrations, the CO2 concentration is not high enough for efficient carbon conversion.


Sign in / Sign up

Export Citation Format

Share Document