Integration of a CO 2 separation process in a coal fired power plant

Transkript

1 Integration of a CO 2 separation process in a coal fired power plant, Hans Fahlenkamp, Bernhard Epp Technische Universität Dortmund *AiF N: CO 2 Druckgaswäsche mit Membrankontaktoren Forschungsstellen: TU-Dortmund & IUTA e.v., Duisburg Analyse zur Nachrüstung von Kohlekraftwerken mit einer CO 2 -Rückhaltung Forschungsstellen: LUAT Uni Duisburg-Essen, LS UT TU-Dortmund & IUTA e.v., Duisburg 1

2 Motivation/ Contents 40% CO 2 -emission reduction by % of the emissions are caused by fossile firings Planning of new coal-fired power plants (25 GW) CO 2 -absorption with MEA: State of the art in gas purification processes Cross sensitivity of the CO 2 -capture process CO 2 -scrubbing process Integration of the CO 2 -capture plant in the power plant 2

3 Cross sensitivity of the CO 2 -capture process O 2 : degradation, formation of organic acids, NH 3 Corrosion inhibitors and further additives Minimization of leakages in the flue gas path SO x : >98% SO 2 : acid-formation with water, corrosion, formation of heat stable salts Increase of L/G-ratio Stratifications have to be reduced (prediction by CFD-Simulations) Further flue gas purification step, e.g. with NaOH or organic acids time and oxygen NO x : >95% NO, 5% NO 2 NO 2 : acid-formation with water, formation of heat stable salts, NO: uncertainty of side reactions, few literature available MEA-loss due to formation of heat stable salts with NO: 2 g MEA/t CO 2 (bench scale conditions) Dust: plugging of packings Condensation-wet-ESP removes dust, SO 3 and on neutral conditions SO 2! 3

4 Water balance of the CO 2 -capture process German edict TA-Luft : prescriptive limits for MEA-emissions: 0.1 kg/h, or 20 mg/m 3 4

5 Modeling of the CO 2 -capture process in Aspen Custom Modeler T vap/ C 70 Liquid feed Equation based simulation tool by AspenTech Mass transfer: Two-film theory Discretization of the liquid-film Properties from Aspen Properties Hydrodynamic parameters from correlations from literature c MEA,vap / mg/m³ ,2 0,4 0,6 0,8 1 Height /- Rocha, J.A., Bravo, J.L., Fair, J.: Distillation Columns Containing Structured Packings: A Comprehensive Model for Their Performance. 1. Hydraulic Model, Ind. Eng. Chem. Res., (1993) 32, Rocha, J.A., Bravo, J.L., Fair, J.: Distillation Columns Containing Structured Packings: A Comprehensive Model for Their Performance. 2. Mass-Transfer Model, Ind. Eng. Chem. Res., (1996) 35, ,2 0,4 0,6 0,8 1 Height / - Absorber 5 Water wash

6 Specific energy demand of the stripper towards the lean loading of the solvent Q Reb /MJ/kg CO ,18 0,23 0,28 0,33 0,38 lean-loading 6

7 Heat integration: Reference power plant NRW Gross output: 600 MW Modeling in Ebsilon Professional 7

8 Heat integration: 90% CO 2 -capture Integration of the heat sources and sinks identified in the Aspen Custom Modeler model and of the CO 2 - compression into the Ebsilon Professional - model 8

9 Heat integration: Improvement of the efficiency by a NH 3 -cycle Net efficiency ~36 % RPP NRW RPP NRW+ CO 2 - capture RPP+CO 2 - capture+nh 3 - cycle η net 45.9 % ~33-34 % ~ 36% Δη net %- points 10 %-points 9

10 Conclusion and further steps CO 2 -capure with amines: state of the art in natural gas purification Application to flue gases from power plants needs modifications in the flue gas path Modeling of the CO 2 -capture process in Aspen Custom Modeler Analysis of the heat sources and sinks Modeling of the reference power plant North Rhine-Westphalia in Ebsilon Professional Integration of the heat sources and sinks in the power plant model Improvement of efficiency through an additional ammonia-cycle to use waste heat Optimization of the CO 2 -absorption and desorption process Usage of a heat pump as alternative to use waste heat 10

11 Thank you for your kind attention! Technische Universität Dortmund Emil-Figge-Straße Dortmund *AiF N: CO 2 Druckgaswäsche mit Membrankontaktoren Forschungsstellen: TU-Dortmund & IUTA e.v., Duisburg Analyse zur Nachrüstung von Kohlekraftwerken mit einer CO 2 -Rückhaltung 11 Forschungsstellen: LUAT Uni Duisburg-Essen, LS UT TU-Dortmund & IUTA e.v., Duisburg