A novel cryogenic vapor-recompression air separation unit integrated to oxyfuel combined-cycle gas-to-wire plant with carbon dioxide enhanced oil recovery: Energy and economic assessments

2019 ◽  
Vol 189 ◽  
pp. 202-214 ◽  
Author(s):  
George Victor Brigagão ◽  
José Luiz de Medeiros ◽  
Ofélia de Queiroz F. Araújo
2004 ◽  
Vol 126 (1) ◽  
pp. 2-8 ◽  
Author(s):  
Joel Martinez-Frias ◽  
Salvador M. Aceves ◽  
J. Ray Smith ◽  
Harry Brandt

This paper presents a theoretical thermodynamic analysis of a zero-atmospheric emissions power plant. In this power plant, methane is combusted with oxygen in a gas generator to produce the working fluid for the turbines. The combustion produces a gas mixture composed of steam and carbon dioxide. These gases drive multiple turbines to produce electricity. The turbine discharge gases pass to a condenser where water is captured. A stream of pure carbon dioxide then results that can be used for enhanced oil recovery or for sequestration. The analysis considers a complete power plant layout, including an air separation unit, compressors and intercoolers for oxygen and methane compression, a gas generator, three steam turbines, a reheater, two preheaters, a condenser, and a pumping system to pump the carbon dioxide to the pressure required for sequestration. This analysis is based on a 400 MW electric power generating plant that uses turbines that are currently under development by a U.S. turbine manufacturer. The high-pressure turbine operates at a temperature of 1089 K (1500°F) with uncooled blades, the intermediate-pressure turbine operates at 1478 K (2200°F) with cooled blades and the low-pressure turbine operates at 998 K (1336°F). The power plant has a net thermal efficiency of 46.5%. This efficiency is based on the lower heating value of methane, and includes the energy necessary for air separation and for carbon dioxide separation and sequestration.


2014 ◽  
Vol 35 (3) ◽  
pp. 105-116 ◽  
Author(s):  
Janusz Kotowicz ◽  
Adrian Balicki ◽  
Sebastian Michalski

Abstract Among the technologies which allow to reduce greenhouse gas emissions, mainly of carbon dioxide, special attention deserves the idea of ‘zero-emission’ technology based on boilers working in oxy-combustion technology. In the paper a thermodynamic analysis of supercritical power plant fed by lignite was made. Power plant consists of: 600 MW steam power unit with live steam parameters of 650 °C/30 MPa and reheated steam parameters of 670 °C/6 MPa; circulating fluidized bed boiler working in oxy-combustion technology; air separation unit and installation of the carbon dioxide compression. Air separation unit is based on high temperature membrane working in three-end technology. Models of steam cycle, circulation fluidized bed boiler, air separation unit and carbon capture installation were made using commercial software. After integration of these models the net electricity generation efficiency as a function of the degree of oxygen recovery in high temperature membrane was analyzed.


Author(s):  
Majed Sammak ◽  
Marcus Thern ◽  
Magnus Genrup

The objective of this paper is to evaluate the performance of a semi-closed oxy-fuel combustion combined cycle (SCOC-CC) and its power penalties. The power penalties are associated with CO2 compression and high-pressure oxygen production in the air separation unit (ASU). The paper discusses three different methods for high pressure oxygen (O2) production. Method 1 is producing O2 directly at high pressure by compressing the air before the air separation takes place. Method 2 is producing O2 at low pressure and then compressing the separated O2 to the desired pressure with a compressor. Method 3 is alike the second method, except that the separated liquid O2 is pressurized with a liquid oxygen pump to the desired pressure. The studied SCOC-CC is a dual-pressure level steam cycle due to its comparable efficiency with three pressure level steam cycle and less complexity. The SCOC-CC, ASU and CO2 compression train are modeled with the commercial heat and mass balance software IPSEpro. The paper analyzed the SCOC-CC performance at different combustion outlet temperatures and pressure ratios. The combustion outlet temperature (COT) varied from 1200 °C to 1550 °C and the pressure ratio varied from 25 to 45. The study is concerned with mid-sized SCOC-CC with a net power output 100 MW. The calculations were performed at the selected design point which was at 1400°C and pressure ratio at 37. The calculated power consumption of the O2 separation at a purity of 95 % was 719 kJ/kgO2. The power consumption for pressurizing the separated O2 (method 2) was 345 kJ/kgO2 whereas it was 4.4 kJ/kgO2 for pumping liquid O2 to the required pressure (method 3). The calculated power consumption for pressurizing and pumping the CO2-enriched stream was 323 kJ/kgCO2. The SCOC-CC gross efficiency was 57.6 %. The SCOC-CC net efficiency at method 2 for air separation was 46.7 %. The gross efficiency was reduced by 9 % due to ASU and other 2 % due to CO2 compression. The SCOC-CC net efficiency at method 3 of the air separation was 49.6 %. The ASU reduced the gross efficiency by 6 % and additional 2 % by CO2 compression. Using method 3 for air separation gave a 3 % gain in cycle efficiency.


2000 ◽  
Author(s):  
Zelong Liu ◽  
Hongguang Jin ◽  
Rumou Lin

Abstract Integrated Gasification Combined Cycle (IGCC) is considered as one of the advanced clean coal power technologies. Here, we have investigated an IGCC with air separation unit (ASU) on the basis of exergy analysis, and clarified the distribution of exergy destruction in sub-systems including air separation unit, coal gasifier, coal gas clean-up unit, air compressor, combustor of gas turbine, gas turbine, heat recovery steam generation and steam turbine. Particularly, we have focused on the interaction between the ASU and the gas turbine (GT). The results obtained disclosed the significant role of the integration between air separation unit and air compressor in the GT, and the effect of nitrogen injection to the combustor on IGCC overall performance. The study also points out that larger exergy destruction take place in the processes of gasification, combustion in GT, and air separation, and so does the change of exergy destruction distribution with the air integration degree and the nitrogen injection ratio. We have demonstrated the potential for improving the IGCC system. This investigation will be valuable for the synthesis of next-generation IGCC.


2021 ◽  
Author(s):  
Shisir Acharya ◽  
Ting Wang

Abstract Coal is one of the major sources of energy currently as it provides up to 38.5% of the total electricity produced in the world. Burning coal produces pollutants and large amounts of CO2, which contribute to climate change, environmental pollution, and health hazards. Therefore, it is our obligation to utilize coal in a cleaner way. Cleaner coal energy can be produced by using an ultra-supercritical Pulverized Coal (PC) power plant, or by employing the Integrated Gasification Combined Cycle (IGCC). Since the 1970s, the IGCC technology has been developed and demonstrated, but it has still not been widely commercialized. One of the methods to improve IGCC performance is to save the compression power of the air separation unit (ASU) by extracting the compressed air from the exit of the gas turbine as a portion of or the entire air input to the ASU. This paper investigates the effect of various levels of air integration on the IGCC performance. The results show that a moderate air integration ranging from 15% to 20% provides the most effective air-integration. An analysis of implementing a sour-shift pre-combustion carbon capture results in a significant loss of about 5.5 points in efficiency. This study also provides the effect of air integration and carbon capture on emissions including NOx, SOx, CO2, and water consumption.


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