The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Gary T. Rochelle - One of the best experts on this subject based on the ideXlab platform.
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approaching a reversible stripping process for co2 capture
Chemical Engineering Journal, 2016Co-Authors: Yu-jeng Lin, Gary T. RochelleAbstract:Amine scrubbing is the most mature CO2 capture technology for coal-fired power plants. However, the energy consumption for regeneration incurs a 20–25% penalty on electricity output. This loss can be reduced by alternative stripper design. This work uses exergy analysis to quantify the inefficiencies and demonstrate the effectiveness of a new configuration, the advanced flash stripper, without having to consider numerous alternatives. The lost work from the Overhead Condenser and the cross exchanger makes the simple stripper inefficient. The advanced flash stripper successfully eliminates the lost work of the Condenser and improves the reversibility of the cross exchanger. It reduces the reboiler duty by 16% and the overall work requirement by 11% compared to the simple stripper. The new design when used with piperazine showed a remarkable 74% thermodynamic efficiency. Further improvement of energy efficiency is expected to be marginal. This work not only provides a better design that reduces the energy consumption, but also indicates that the state-of-the-art is approaching the theoretical work limit.
Yu-jeng Lin - One of the best experts on this subject based on the ideXlab platform.
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approaching a reversible stripping process for co2 capture
Chemical Engineering Journal, 2016Co-Authors: Yu-jeng Lin, Gary T. RochelleAbstract:Amine scrubbing is the most mature CO2 capture technology for coal-fired power plants. However, the energy consumption for regeneration incurs a 20–25% penalty on electricity output. This loss can be reduced by alternative stripper design. This work uses exergy analysis to quantify the inefficiencies and demonstrate the effectiveness of a new configuration, the advanced flash stripper, without having to consider numerous alternatives. The lost work from the Overhead Condenser and the cross exchanger makes the simple stripper inefficient. The advanced flash stripper successfully eliminates the lost work of the Condenser and improves the reversibility of the cross exchanger. It reduces the reboiler duty by 16% and the overall work requirement by 11% compared to the simple stripper. The new design when used with piperazine showed a remarkable 74% thermodynamic efficiency. Further improvement of energy efficiency is expected to be marginal. This work not only provides a better design that reduces the energy consumption, but also indicates that the state-of-the-art is approaching the theoretical work limit.
Rajesh K Pandey - One of the best experts on this subject based on the ideXlab platform.
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failure analysis of refinery tubes of Overhead Condenser
Engineering Failure Analysis, 2006Co-Authors: Rajesh K PandeyAbstract:Abstract Failure analysis of cupronickel Condenser tubes of a crude distillation unit of a petrochemical refinery has been conducted. Condenser tubes carrying sea water were found to undergo premature failure which was preceded by extensive overall thinning, formation of shallow channels, pits, etc., and greyish-black internal deposits in one of the units. In the other unit, the failure of tubes was noticed without any significant overall thinning and in the presence of adherent, hard and black-brown deposits. The studies indicated that the increased velocity of sea water as well as the deficiency of iron in the alloy had resulted in failure in one case whereas relatively low velocity of water associated with deposition of sludge and bio-fouling were the causes of failure in the other case. The failure of tubes could be controlled by maintaining the water velocity within a specified range, flushing the tubes with clean water, use of anti fouling paints, selecting a more appropriate composition of the cupronickel alloy, through control of sea water sulphur level, etc.
Alfons Kather - One of the best experts on this subject based on the ideXlab platform.
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optimised integration of post combustion co2 capture process in greenfield power plants
Energy, 2010Co-Authors: I Pfaff, Jochen Oexmann, Alfons KatherAbstract:Abstract Newly built (greenfield) power plant offer the advantage of optimised integration measures to reduce the efficiency penalty associated with the application of a post-combustion CO2 capture process by wet chemical absorption. Especially, the integration of waste heat from the desorber Overhead Condenser of the CO2 capture unit (CCU) and from the CO2 compressor into the water-steam-cycle of the power plant offers optimisation potential. In this work, the adaptation of pressure levels in the water-steam-cycle regarding the steam requirements of the CCU is evaluated. Particular focus is put on waste heat integration by condensate pre-heating and combustion air pre-heating for minimisation of the overall net efficiency loss. The efficiency potential of the available options as well as the limits of integration, especially with respect to a power plant in commercial operation, are discussed. EBSILON® Professional is used to develop a model of the overall process including power plant, CO2 compressor and CCU. The power plant represents a state-of-the-art hard-coal-fired power plant with 600 MW power output (gross). The CCU is modelled as a black box, where the interface quantities of the black box are determined by a detailed model of the capture process in ASPEN Plus® using monoethanolamine (MEA) as solvent.
Ystad, Paul Andreas Marchioro - One of the best experts on this subject based on the ideXlab platform.
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Power Plant with CO2 Capture based on Absorption : Integration Study
Institutt for energi- og prosessteknikk, 2010Co-Authors: Ystad, Paul Andreas MarchioroAbstract:This thesis gives a detailed evaluation of the integration of power plants and post-combustion CO2 capture based on absorption. The study looks at natural gas combined cycles and pulverized coal power plants. Also the absorption process has been evaluated separately, aiming at reducing energy requirements in the capture process. In the first part of the thesis a theoretical part was given on fundamentals of CO2 capture by absorption, power generation, and process integration. Based on this theory, several case studies were defined for each of the three main processes. Simulation models were built accordingly and investigated. Simulation results from the capture process showed that there was a reboiler energy saving potential of 29% and 27% for NGCC and PC plant, respectively, when including vapor compression and absorption intercooling in the capture process. Another interesting observation made was reduced cooling duty in the Overhead Condenser of the stripper when applying vapor compression.Analysis of steam extraction from the NGCC plant showed it was possible to cover 1 MJ/kg CO2 directly from the HRSG. This steam can be provided directly from the LPB. For duties above 1 MJ/kg CO2 a secondary extraction point was required. In this study the IP/LP crossover was considered the most appropriate point to extract the remaining steam. The efficiency penalty when integrated with the different CO2 capture cases ranged from 7-8%, giving a net plant efficiency of 49.6-50.5%. At part load it was shown that the LPT should be throttled in order to secure constant pressure at the extraction point.For the PC plant the feedwater heat system showed potential in terms heat recovery in the return stream from the capture process. By integrating the return stream with FWH2, energy savings of 11.9% compared to the base case plant were found. Also it was found that the IP/LP crossover pressure should be set to 4.5 bar, since the IPT has the highest efficiency and therefore power production in this unit should be maximized. The final results for the PC plant efficiency range from 30-31.7% and the percentual efficiency penalty was 10-11.7% for the four capture case studies. As was the case for the NGCC plant, the LPT should be throttled when operating at part load
