Analysis of Gas-Steam Combined Cycles With Natural Gas Reforming and CO2 Capture

2005 ◽  
Vol 127 (3) ◽  
pp. 545-552 ◽  
Author(s):  
Alessandro Corradetti ◽  
Umberto Desideri

In the last several years greenhouse gas emissions, and, in particular, carbon dioxide emissions, have become a major concern in the power generation industry and a large amount of research work has been dedicated to this subject. Among the possible technologies to reduce CO2 emissions from power plants, the pretreatment of fossil fuels to separate carbon from hydrogen before the combustion process is one of the least energy-consuming ways to facilitate CO2 capture and removal from the power plant. In this paper several power plant schemes with reduced CO2 emissions were simulated. All the configurations were based on the following characteristics: (i) syngas production via natural gas reforming; (ii) two reactors for CO-shift; (iii) “precombustion” decarbonization of the fuel by CO2 absorption with amine solutions; (iv) combustion of hydrogen-rich fuel in a commercially available gas turbine; and (v) combined cycle with three pressure levels, to achieve a net power output in the range of 400 MW. The base reactor employed for syngas generation is the ATR (auto thermal reformer). The attention was focused on the optimization of the main parameters of this reactor and its interaction with the power section. In particular the simulation evaluated the benefits deriving from the postcombustion of exhaust gas and from the introduction of a gas-gas heat exchanger. All the components of the plants were simulated using ASPEN PLUS software, and fixing a reduction of CO2 emissions of at least 90%. The best configuration showed a thermal efficiency of approximately 48% and CO2 specific emissions of 0.04 kg/kWh.

Author(s):  
Alessandro Corradetti ◽  
Umberto Desideri

In the last years greenhouse gas emissions, and in particular carbon dioxide emissions, have become a major concern in the power generation industry and a large amount of research work has been dedicated to this subject. Among the possible technologies to reduce CO2 emissions from power plants, the pre-treatment of the fossil fuels to separate carbon from hydrogen before the combustion process is one of the least energy consuming way to facilitate CO2 capture and removal from the power plant. In this paper several power plant schemes with reduced CO2 emissions were simulated. All the configurations were based on the following characteristics: (1) syngas production via natural gas reforming; (2) two reactors for CO-shift; (3) “pre-combustion” decarbonization of the fuel by CO2 absorption with amine solutions; (4) combustion of hydrogen rich fuel in a commercially available gas turbine; (5) combined cycle with three pressure levels, to achieve a net power output in the range of 400 MW. The base reactor employed for syngas generation is the ATR (Auto Thermal Reformer). The attention was focused on the optimization of the main parameters of this reactor and its interaction with the power section. In particular the simulation evaluated the benefits deriving from the post-combustion of exhaust gas and from the introduction of a gas-gas heat exchanger. All the components of the plants were simulated using Aspen Plus software, and fixing a reduction of CO2 emissions of at least 90%. The best configuration showed a thermal efficiency of approximately 48% and CO2 specific emissions of 0.04 kg/kWh.


2014 ◽  
Vol 63 ◽  
pp. 2394-2401
Author(s):  
Satoshi Saito ◽  
Norihide Egami ◽  
Toshihisa Kiyokuni ◽  
Mitsuru Udatsu ◽  
Hideo Kitamura ◽  
...  

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.


2017 ◽  
Vol 143 (5) ◽  
pp. 04017025
Author(s):  
Zhongyuan Huang ◽  
Jin Li ◽  
Chaowen Jing ◽  
Hongguang An ◽  
Yiying Tong ◽  
...  

Author(s):  
Stéphanie Hoffmann ◽  
Michael Bartlett ◽  
Matthias Finkenrath ◽  
Andrei Evulet ◽  
Tord Peter Ursin

This paper presents the results of an evaluation of advanced combined cycle gas turbine plants with precombustion capture of CO2 from natural gas. In particular, the designs are carried out with the objectives of high efficiency, low capital cost, and low emissions of carbon dioxide to the atmosphere. The novel cycles introduced in this paper are comprised of a high-pressure syngas generation island, in which an air-blown partial oxidation reformer is used to generate syngas from natural gas, and a power island, in which a CO2-lean syngas is burnt in a large frame machine. In order to reduce the efficiency penalty of natural gas reforming, a significant effort is spent evaluating and optimizing alternatives to recover the heat released during the process. CO2 is removed from the shifted syngas using either CO2 absorbing solvents or a CO2 membrane. CO2 separation membranes, in particular, have the potential for considerable cost or energy savings compared with conventional solvent-based separation and benefit from the high-pressure level of the syngas generation island. A feasibility analysis and a cycle performance evaluation are carried out for large frame gas turbines such as the 9FB. Both short-term and long-term solutions have been investigated. An analysis of the cost of CO2 avoided is presented, including an evaluation of the cost of modifying the combined cycle due to CO2 separation. The paper describes a power plant reaching the performance targets of 50% net cycle efficiency and 80% CO2 capture, as well as the cost target of 30$ per ton of CO2 avoided (2006 Q1 basis). This paper indicates a development path to this power plant that minimizes technical risks by incremental implementation of new technology.


2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Oghare Victor Ogidiama ◽  
Mohammad Abu Zahra ◽  
Tariq Shamim

High energy penalty and cost are major obstacles in the widespread use of CO2 capture techniques for reducing CO2 emissions. Chemical looping combustion (CLC) is an innovative means of achieving CO2 capture with less cost and low energy penalty. This paper conducts a detailed techno-economic analysis of a natural gas-fired CLC-based power plant. The power plant capacity is 1000 MWth gross power on a lower heating value basis. The analysis was done using Aspen Plus. The cost analysis was done by considering the plant location to be in the United Arab Emirates. The plant performance was analyzed by using the cost of equipment, cost of electricity, payback period, and the cost of capture. The performance of the CLC system was also compared with a conventional natural gas combined cycle plant of the same capacity integrated with post combustion CO2 capture technology. The analysis shows that the CLC system had a plant efficiency of 55.6%, electricity cost of 5.5 cents/kWh, payback time of 3.77 years, and the CO2 capture cost of $27.5/ton. In comparison, a similar natural gas combined cycle (NGCC) power plant with CO2 capture had an efficiency of 50.6%, cost of electricity of 6.1 cents/kWh, payback period of 4.57 years, and the capture cost of $42.9/ton. This analysis shows the economic advantage of the CLC integrated power plants.


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