CO2 Emissions Reduction From Coal-Fired Power Generation: A Techno-Economic Comparison

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Vittorio Tola ◽  
Giorgio Cau ◽  
Francesca Ferrara ◽  
Alberto Pettinau

Carbon capture and storage (CCS) represents a key solution to control the global warming reducing carbon dioxide emissions from coal-fired power plants. This study reports a comparative performance assessment of different power generation technologies, including ultrasupercritical (USC) pulverized coal combustion plant with postcombustion CO2 capture, integrated gasification combined cycle (IGCC) with precombustion CO2 capture, and oxy-coal combustion (OCC) unit. These three power plants have been studied considering traditional configuration, without CCS, and a more complex configuration with CO2 capture. These technologies (with and without CCS systems) have been compared from both the technical and economic points of view, considering a reference thermal input of 1000 MW. As for CO2 storage, the sequestration in saline aquifers has been considered. Whereas a conventional (without CCS) coal-fired USC power plant results to be more suitable than IGCC for power generation, IGCC becomes more competitive for CO2-free plants, being the precombustion CO2 capture system less expensive (from the energetic point of view) than the postcombustion one. In this scenario, oxy-coal combustion plant is currently not competitive with USC and IGCC, due to the low industrial experience, which means higher capital and operating costs and a lower plant operating reliability. But in a short-term future, a progressive diffusion of commercial-scale OCC plants will allow a reduction of capital costs and an improvement of the technology, with higher efficiency and reliability. This means that OCC promises to become competitive with USC and also with IGCC.

Author(s):  
Andrea Ciani ◽  
John P. Wood ◽  
Anders Wickström ◽  
Geir J. Rørtveit ◽  
Rosetta Steeneveldt ◽  
...  

Abstract Today gas turbines and combined cycle power plants play an important role in power generation and in the light of increasing energy demand, their role is expected to grow alongside renewables. In addition, the volatility of renewables in generating and dispatching power entails a new focus on electricity security. This reinforces the importance of gas turbines in guaranteeing grid reliability by compensating for the intermittency of renewables. In order to achieve the Paris Agreement’s goals, power generation must be decarbonized. This is where hydrogen produced from renewables or with CCS (Carbon Capture and Storage) comes into play, allowing totally CO2-free combustion. Hydrogen features the unique capability to store energy for medium to long storage cycles and hence could be used to alleviate seasonal variations of renewable power generation. The importance of hydrogen for future power generation is expected to increase due to several factors: the push for CO2-free energy production is calling for various options, all resulting in the necessity of a broader fuel flexibility, in particular accommodating hydrogen as a future fuel feeding gas turbines and combined cycle power plants. Hydrogen from methane reforming is pursued, with particular interest within energy scenarios linked with carbon capture and storage, while the increased share of renewables requires the storage of energy for which hydrogen is the best candidate. Compared to natural gas the main challenge of hydrogen combustion is its increased reactivity resulting in a decrease of engine performance for conventional premix combustion systems. The sequential combustion technology used within Ansaldo Energia’s GT36 and GT26 gas turbines provides for extra freedom in optimizing the operation concept. This sequential combustion technology enables low emission combustion at high temperatures with particularly high fuel flexibility thanks to the complementarity between its first stage, stabilized by flame propagation and its second (sequential) stage, stabilized by auto-ignition. With this concept, gas turbines are envisaged to be able to provide reliable, dispatchable, CO2-free electric power. In this paper, an overview of hydrogen production (grey, blue, and green hydrogen), transport and storage are presented targeting a CO2-free energy system based on gas turbines. A detailed description of the test infrastructure, handling of highly reactive fuels is given with specific aspects of the large amounts of hydrogen used for the full engine pressure tests. Based on the results discussed at last year’s Turbo Expo (Bothien et al. GT2019-90798), further high pressure test results are reported, demonstrating how sequential combustion with novel operational concepts is able to achieve the lowest emissions, highest fuel and operational flexibility, for very high combustor exit temperatures (H-class) with unprecedented hydrogen contents.


Author(s):  
Mohammad Mansouri Majoumerd ◽  
Mohsen Assadi ◽  
Peter Breuhaus ◽  
Øystein Arild

The overall goal of the European co-financed H2-IGCC project was to provide and demonstrate technical solutions for highly efficient and reliable gas turbine technology in the next generation of integrated gasification combined cycle (IGCC) power plants with CO2 capture suitable for combusting undiluted H2-rich syngas. This paper aims at providing an overview of the main activities performed in the system analysis working group of the H2-IGCC project. These activities included the modeling and integration of different plant components to establish a baseline IGCC configuration, adjustments and modifications of the baseline configuration to reach the selected IGCC configuration, performance analysis of the selected plant, performing techno-economic assessments and finally benchmarking with competing fossil-based power technologies. In this regard, an extensive literature survey was performed, validated models (components and sub-systems) were used, and inputs from industrial partners were incorporated into the models. Accordingly, different plant components have been integrated considering the practical operation of the plant. Moreover, realistic assumptions have been made to reach realistic techno-economic evaluations. The presented results show that the efficiency of the IGCC plant with CO2 capture is 35.7% (lower heating value basis). The results also confirm that the efficiency is reduced by 11.3 percentage points due to the deployment of CO2 capture in the IGCC plant. The specific capital costs for the IGCC plant with capture are estimated to be 2,901 €/(kW net) and the cost of electricity for such a plant is 90 €/MWh. It is also shown that the natural gas combined cycle without CO2 capture requires the lowest capital investment, while the lowest cost of electricity is related to IGCC plant without CO2 capture.


Author(s):  
Anup Singh

In the 1970s, power generation from gas turbines was minimal. Gas turbines in those days were run on fuel oil, since there was a so-called “natural gas shortage”. The U.S. Fuel Use Act of 1978 essentially disallowed the use of natural gas for power generation. Hence there was no incentive on the part of gas turbine manufacturers to invest in the development of gas turbine technology. There were many regulatory developments in the 1980s and 1990s, which led to the rapid growth in power generation from gas turbines. These developments included Public Utility Regulatory Policy Act of 1978 (encouraging cogeneration), FERC Order 636 (deregulating natural gas industry), Energy Policy Act of 1992 (creating EWGs and IPPs) and FERC Order 888 (open access to electrical transmission system). There was also a backlash from excessive electric rates due to high capital recovery of nuclear and coal-fired plant costs caused by tremendous cost increase resulting from tightening NRC requirements for nuclear plants and significant SO2/NOx/other emissions controls required for coal-fired plants. During this period, rapid technology developments took place in the metallurgy, design, efficiency, and reliability of gas turbines. In addition, U.S. DOE contributed to these developments by encouraging research and development efforts in high temperature and high efficiency gas turbines. Today we are seeing a tremendous explosion of power generating facilities by electric utilities and Independent Power Producers (IPPs). A few years ago, Merchant Power (generation without power purchase agreements) was unheard of. Today it is growing at a very fast pace. Can this rapid growth be sustained? The paper will explore the factors that will play a significant role in the future growth of gas turbine-based power generation in the U.S. The paper will also discuss the methods and developments that could decrease the capital costs of gas turbine power plants resulting in the lowest cost generation compared to other power generation technologies.


Author(s):  
Keiichi Ishida

Coal is a valuable primary energy source that has excellent supply stability and economic efficiency. Japan has extremely low energy self-sufficiency and coal-fired power generation is positioned as an important base load power supply. One urgent issue we face is to find realistic countermeasures that greatly reduce CO2 emissions from coal-fired power plants which produce a large volume of CO2 emissions. Therefore, we have launched the Osaki CoolGen Project since April 2012 as an “Integrated Coal Gasification Fuel Cell Combined Cycle (IGFC) Demonstration Project” subsidized by the Ministry of Economy, Trade and Industry (until 2015 FY) and New Energy and Industrial Technology Development Organization (from 2016 FY). This project aims to realize innovative low-carbon coal-fired power generation that combines an IGFC, an extremely efficient coal-fired power generation technology with high-performance CO2 capture technology for the purpose of dramatically reducing CO2 emissions from coal-fired power generation. This project consists of three steps. The first step will implement demonstration tests of the oxygen-blown Integrated coal Gasification Combined Cycle (IGCC) which is the base technology for IGFC. Toward the start of demonstration testing in March 2017, construction was started in March 2013 and commissioning was started in April 2016. In the second step, we plan to carry out demonstration tests of the oxygen-blown IGCC with CO2 capture equipment. In the third step, we plan to demonstrate an IGFC system combining the demonstration plant of the second step with a fuel cell.


2021 ◽  
Vol 11 (11) ◽  
pp. 4974
Author(s):  
Tran X. Phuoc ◽  
Mehrdad Massoudi

To our knowledge, the potential use of CO2 as a heat-transmitting fluid for cooling applications in power plants has not been explored very extensively. In this paper, we conduct a theoretical analysis to explore the use of CO2 as the heat transmission fluid. We evaluate and compare the thermophysical properties of both dry air and CO2 and perform a simple analysis on a steam-condensing device where steam flows through one of the flow paths and the cooling fluid (CO2 or air) is expanded from a high-pressure container and flows through the other. Sample calculations are carried out for a saturated-vapor steam at 0.008 MPa and 41.5 °C with the mass flow rate of 0.01 kg/s. The pressure of the storage container ranges from 1 to 5 MPa, and its temperature is kept at 35 °C. The pressure of the cooling fluid (CO2 or dry air) is set at 0.1 MPa. With air as the heat-removing fluid, the steam exits the condensing device as a vapor-liquid steam of 53% to 10% vapor for the container pressure of 1 to 5 MPa. With CO2 as the heat-removing fluid, the steam exits the device still containing 44% and 7% vapor for the container pressure of 1 MPa and 2 MPa, respectively. For the container pressure of 3 MPa and higher, the steam exits the device as a single-phase saturated liquid. Thus, due to its excellent Joule–Thomson cooling effect and heat capacity, CO2 is a better fluid for power plant cooling applications. The condensing surface area is also estimated, and the results show that when CO2 is used, the condensing surface is 50% to 60% less than that when dry air is used. This leads to significant reductions in the condenser size and the capital costs. A rough estimate of the amount of CO2 that can be stored and utilized is also carried out for a steam power plant which operates with steam with a temperature of 540 °C (813 K) and a pressure of 10 MPa at the turbine inlet and saturated-vapor steam at 0.008 MPa at the turbine outlet. The results indicate that if CO2 is used as a cooling fluid, CO2 emitted from a 1000 MW power plant during a period of 250 days could be stored and utilized.


2011 ◽  
Vol 382 ◽  
pp. 56-59
Author(s):  
Yong Hua Li ◽  
Jun Wang ◽  
Wei Ping Yan

In China, coal combustion to generate electric power is the primary method, the energy-saving and emission reduction is the urgent task. At present, the energy-saving dispatching trial method in some area evaluates energy-saving and emission reduction of coal combustion power generation according to power supply coal consumption rate only. But the power supply coal consumption rate can’t reflect the energy-saving and emission reduction effect of coal combustion power plant overall. For example, the same coal combustion unit, the coal consumption rate is difference when desulfuration system is operating or not; the coal consumption rate of the unit with SCR will be increased; the coal consumption rate of the air-cooled unit is higher than water-cooled unit; etc.. This paper considers synthetically coal consumption rate, pollution emission, water resource wastage, etc., establishes a integrated evaluation system, adopts factor analysis method, gets the integrated evaluation system and index of energy-saving and emission reduction of coal combustion power generation, evaluates energy-saving and emission reduction effect of 5 power plants reasonable. The results show that the index can reflect the energy-saving and emission reduction level of coal combustion power generation.


2020 ◽  
Vol 181 ◽  
pp. 03005 ◽  
Author(s):  
Alberto Boretti ◽  
Stefania Castelletto ◽  
Wael Al-Kouz ◽  
Jamal Nayfeh

In a recent publication, North European experts argue that “Saudi Arabia can achieve a 100% renewable energy power system by 2040 with a power sector dominated by PV single-axis tracking and battery storage”. They also say “Battery storage contributed up to 30% of the total electricity demand in 2040 and the contribution increases to 48% by 2050”. Based on considerations specific to the geography, climate conditions, and resources of Saudi Arabia, it is explained as batteries and photovoltaic solar panels are not the best choice for the country's energy sector. To cover all the total primary energy supply of Saudi Arabia by solar photovoltaic, plus battery storage to compensate for the sun's energy intermittency, unpredictability, and seasonal variability, is impracticable and inconvenient, for both the economy and the environment. Better environment and economy may be achieved by further valorizing the fossil fuel resources, through the construction of other high-efficiency plants such as the combined cycle gas turbine plants of Qurayyah, development of novel technologies for the production of clean fuels and clean electricity, including oxyfuel combustion and carbon capture and storage. Construction of nuclear power plants may also be more beneficial to the economy and the environment than photovoltaic and batteries. Regarding solar energy, enclosed trough solar thermal power systems developed along the coast have much better perspectives than solar photovoltaic, as embedded thermal energy storage is a better approach than battery storage. Further, a centralized power plant works better than distributed rooftop photovoltaic installations covered by dust and sand, rusted or cracked. Finally, pumped hydro energy storage along the coast may also have better perspectives than battery storage.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 543 ◽  
Author(s):  
Manuele Gatti ◽  
Emanuele Martelli ◽  
Daniele Di Bona ◽  
Marco Gabba ◽  
Roberto Scaccabarozzi ◽  
...  

The objective of this study is to assess the technical and economic potential of four alternative processes suitable for post-combustion CO2 capture from natural gas-fired power plants. These include: CO2 permeable membranes; molten carbonate fuel cells (MCFCs); pressurized CO2 absorption integrated with a multi-shaft gas turbine and heat recovery steam cycle; and supersonic flow-driven CO2 anti-sublimation and inertial separation. A common technical and economic framework is defined, and the performance and costs of the systems are evaluated based on process simulations and preliminary sizing. A state-of-the-art natural gas combined cycle (NGCC) without CO2 capture is taken as the reference case, whereas the same NGCC designed with CO2 capture (using chemical absorption with aqueous monoethanolamine solvent) is used as a base case. In an additional benchmarking case, the same NGCC is equipped with aqueous piperazine (PZ) CO2 absorption, to assess the techno-economic perspective of an advanced amine solvent. The comparison highlights that a combined cycle integrated with MCFCs looks the most attractive technology, both in terms of energy penalty and economics, i.e., CO2 avoided cost of 49 $/tCO2 avoided, and the specific primary energy consumption per unit of CO2 avoided (SPECCA) equal to 0.31 MJLHV/kgCO2 avoided. The second-best capture technology is PZ scrubbing (SPECCA = 2.73 MJLHV/kgCO2 avoided and cost of CO2 avoided = 68 $/tCO2 avoided), followed by the monoethanolamine (MEA) base case (SPECCA = 3.34 MJLHV/kgCO2 avoided and cost of CO2 avoided = 75 $/tCO2 avoided), and the supersonic flow driven CO2 anti-sublimation and inertial separation system and CO2 permeable membranes. The analysis shows that the integrated MCFC–NGCC systems allow the capture of CO2 with considerable reductions in energy penalty and costs.


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