Department of Energy Process Engineering and Chemical Engineering

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1 Department of Energy Process Engineering and Chemical Engineering Poly-generation Evaluation of technologies and concepts for demand driven co-production of electricity and liquids from coal Robert Pardemann (IEC), Kristin Boblenz (IEC), Lars-Erik Gärtner (IEC), Manfred Wirsum (ALSTOM), Bernd Meyer (IEC) International Freiberg Conference on IGCC & XtL Technologies 3rd 5th May 2010 Dresden, Germany TU Bergakademie Freiberg I Department of Energy Process Engineering and Chemical Engineering Reiche Zeche I Freiberg I Germany I Phone +49(0)3731/ I Fax +49(0)3731/ evt@iec.tu-freiberg.de I Web

2 Outline 1. Concept assessment applying QFD 1. Motivation for poly-generation 2. Classification of poly-generation concepts 3. Methodology of QFD 4. Evaluation of results from QFD 2. Evaluation of poly-generation concepts including demand driven power generation and production of methanol 2

3 Motivation for Poly-generation 1. Efficiency and environment related aspects: Increase of process efficiency in comparison to mono-generation Reduction of CO 2 emissions by increase of efficiency and by coupling of processes with inherent CO 2 capture to processes without CO 2 capture Promotion of CO 2 emission reduction Maximisation of fuel utilisation in the most efficient way 2. Economic aspects: Maximisation of gas island operation time (only for syngas based concepts) Increase of robustness towards economic fluctuations addressing different markets Improvement of IGCC-economics by sharing gas island costs with synthesis block Improvement of IGCC-economics due to potential on-site production of backup-fuel Decoupling of energy demand and energy consumption by storing energy in a chemical/fuel 3. Other aspects Poly-generation as gateway to an economic and ecological non-electricity utilisation of coal: Intelligent combination of various processes to provide products requested by the market In general coal based technologies with higher costs than today's common technologies FUEL ALTERNATIVE to oil and gas Poly-generation as approach to change from maximal to optimal fuel utilisation 3

4 Classification of poly-generation concepts Poly-generation producing multiple liquids from coal Poly-generation producing electricity and liquids from coal Staged utilisation of coal dependent on coal quality Syngas based production of multiple chemicals/ fuels Conventional steam generation with steam turbine linked with chemicals/ liquids production Combined Cycle linked with chemicals/liquids production Unproven Staged coal utilisation State of the art Syngas based Parallel synthesis + constant electricty generation Load flexible generation of electricity + synthesis Unproven Load flexible gas island Load flexible synthesis 4

5 Quality Function Deployment approach for process evaluation Approach to quantify qualitative process knowledge Method to derive the basis for decision making instead of a disordered compilation of facts Information from literature Objective General definition of motivation for poly-generation Information from experts and personal knowledge Subjective Criterion catalogue Definition of criteria and assignment of criteria to superior blocks Weighing of importance of criteria + weighing of importance of blocks Criterion matrix with importance factors Assessment of every concept for each criterion assignation of grades Reward=Importance Grade Table including detailed status description for each concept and each criterion + reward values Value suitable for concept assessment Standardisation of average reward values for all concepts Determination of average reward value for all concepts 5

6 Aspects/criteria to assess poly-generation concepts CO 2 emission reductions and resource utilisation Process complexity Process integration Efforts for gas and product purification Number of process units to produce a chemical Complexity of the power block Low CO 2 emissions Capability for further CO 2 emissions reduction High efficiency of single units High overall efficiency Highest level of fuel utilisation Poly-generation concept Product flexibilty Option for power generation Capability for demand driven power generation Lowest effort for demand driven power generation Capability to use multiple fuels (synthesis product as backup fuel) 6

7 QFD poly-generation concept assessment Results Concept evaluation was done for 9 concepts from utility and chemical companies perspective according to the above mentioned criteria and method Concept evaluation results with a reward value scale between 5 (promising) and 0 (not promising) Average reward value from chemical Average reward company point of value from utility Rank Concept view point of view 1 Syngas based synthesis + flexible electricity generation (CC) + (varying 5,0 5,0 synthesis load, fresh syngas = fuel) 2 Syngas based coal utilisation (multiple products) 4,7-3 Syngas based synthesis + conventional boiler 3,6 3,5 4 Syngas based synthesis + simultaneous electricity generation (CC) + incomplete 3,3 3,2 syngas conversion (unconverted syngas = fuel) 5 Syngas based synthesis + simultaneous electricity generation (CC) + maximal 3,2 3,1 syngas conversion (fresh syngas = fuel) 6 Syngas based synthesis + flexible electricity generation (CC) + (constant syngas 3,1 3,1 conversion, variable gas island load, fresh syngas = fuel) 7 Syngas based synthesis + simultaneous electricity generation (CC) + maximal 2,7 2,4 conversion (product = fuel) 8 Coal utilisation dependent on coal quality + conventional boiler 2,4 2,1 9 Coal utilisation dependent on coal quality 1,0 - Conclusions All results with subjective influence High reward values indicate high potential or high level of development of the concept Low scores indicate high demand for research or process enhancement Average reward values not helpful for comprehensive process evaluation 7

8 QFD poly-generation concept assessment A gateway to deeper understanding of concepts Example for detailed QFD results analysis Pre-modelling overall concept evaluation from chem. comp. point of view Results on superior criterion block level Process complexity 1200,0 800,0 400,0 Economically advantageous 0,0-400,0-800,0 Product flexibility Pre-modelling concept evaluation from chemical company point of view Process integration Level of demonstrated process integration Market availabilty 300,0 200,0 Efforts for gas and product purification Number of process units to get the chemical Maximisation of gas island operation time 100,0 0,0 Complexity of the power block CO2 emission reduction and resource utilisation Maturity of equipment in the required scale Improvement of IGCC economics -100,0-200,0-300,0 Option for power generation Capability for demand driven power generation Minimum plant capacity Highest level of fuel utilisation 1.1) Coal utilisation dependent on coal quality 1.2) Syngas based coal utilisation (multiple products) High overall efficiency High single unit efficiency 2.1.1) Coal utilisation dependent on coal quality + conv. boiler 2.1.2) Syngas based synthesis + conv. boiler a) Syngas based synthesis + simultan. electr. generation (GT) + maximal conv. (prod. = fuel) b) Syngas based synthesis + simultan. electr. generation (GT) + maximal syngas conv. (fresh syngas = fuel) Lowest effort for demand driven power generation Capability to use the liquid product as backup fuel Low CO2 emissions Capability for further CO2 emission reduction ) Syngas based synthesis + simultan. electr. generation (GT) + incomplete syngas conv. (unconverted syngas = fuel) ) Syngas based synthesis + flexible electr. generation (GT) + (varying synthesis conv., fresh syngas = fuel) ) Syngas based synthesis + flexible electr. generation (GT) + (constant syngas conv., fresh syngas = fuel) Results on single criterion level The more criteria are defined (diversity ): Requirement for information Reliability and significance of results 8

9 Outline 1. Concept assessment applying QFD 2. Evaluation of poly-generation concepts including demand driven power generation and production of methanol 1. Introduction / modelling approach / boundary conditions 2. Comparison of stand alone operation of different types of MeOH syntheses 3. Derivation of operational concepts dependent on synthesis type 4. Energy balancing of different concepts for coupled production of electricity and MeOH 5. Evaluation of concept modelling results for peak load electricity generation 9

10 Background Poly-generation including peak load electricity generation Development of poly-generation concepts based on lignite and hard coal Emphasis on cost optimised process plant and operation concepts - Investigation of poly-generation concepts including various syntheses - Detailed thermodynamic modelling concept evaluation based on energy and material balances - Investigation of load flexibility (steady state modelling of part load conditions) - Identification of bottle necks and technological constraints for load flexible operation by including OEM-knowledge selection of advantageous concepts - Economic and technological analysis definition of optimised plant and operational concepts Operational concepts for peak load electricity generation in poly-generation plants: P th Gasifier Synthesis Peak Load Electricity Production Power Block Gas phase synthesis (MegaMethanol-type) Liquid phase synthesis (LPMeOH-type) 10

11 Modelling approach Claus process Sulphur Coal Gasification Water scrubbing CO-Shift CO 2 / H 2S Removal Syngas MeOH-synthesis Upgrading Distillation (3 columns) Methanol Oxygen Carbon Dioxide CO 2 compression (spare pumps) Electricity Air Air separation Nitrogen Power Block Air E-class gas turbine (auxiliary power + peak load) HRSG Steam turbine Electricity Gas Turbine Map - Methane EES/Excel INPUT fueltype GT load T fuel LHV mix ASU rat H2/CO 1 1, ,00 0,50 - C kj/kg - - RUN OUTPUT P gross eta gross TIT TAT m in m fuel m exh PI T p exh 166,8 0, ,0 523,0 523,5 9,4 532,8 14,0 1,045 MW - C C kg/s kg/s kg/s - bar ASPEN Legend I. Fueltype III. Note the Calculation Boundaries GT load Gas Turbine Load 1 Methane (LHV = 50 MJ/kg) GT load 0..1 * Tfuel Fuel Temperature (mixed) 2 Methanol (LHV = 19.9 MJ/kg) Tfuel 15, 50, 150, 300 ** LHV mix Low Heating Value (mixed) * 3 Oil No.2 * (LHV = 23.7 MJ/kg) LHV mix ASU ASU Integration Level (m_asu / m_in) 4 Syngas ASU 0, 0.08, 0.15 rat H2/CO Ratio H 2/CO (volumetric basis) 5 Hydrogen rat H2/CO P gross Gross Power Output * Omega = 0.8 (Water/Fuel ratio) * for reasons of combustion safety etagross Gross Efficiency ** min Load = 0.5 for Syngas and Hydrogen TIT Turbine Inlet Temperature (ISO mixed) II. Specify for ** Tfuel = 50 C for Methane, Methanol, Oil TAT Turbine Outlet Temperature Methane GT load, T fuel min Compressor Inlet Massflow Methanol GTload, Tfuel m fuel Fuel Massflow * Oil No.2 GT load, T fuel mexh Turbine Outlet Massflow Syngas GTload, Tfuel, Hu,mix, ASU, rath2/co PI T Turbine Pressure Ratio (blading) Hydrogen GT load, T fuel, H u,mix, ASU p exh Turbine Outlet Pressure * includes diluent (N2) or NOx-water in case of syngas/oil ** definition excludes sensible heat of fuel Ebsilon Overall model linking through Excel 11

12 Major modelling boundary conditions (I) Coal composition Coal Kuzbass Pittsburgh #8 Wyodak (PRB) Coal rank Ultimate analysis Proximate analysis LHV Ash C H N Cl S O Moisture Fixed carbon Volatile matter Ash Wt. % Wt. % MJ/kg Semi 5,55 85,76 3,59 2,17 0,00 0,28 2,64 5,00 84,08 10,37 5,55 23,11 Antracite H Vol A 7,80 76,56 5,26 1,44 0,05 3,01 5,88 5,00 53,07 39,13 7,80 30,06 Bitum SUBC 10,60 66,54 3,66 0,87 0,03 0,92 17,39 5,00 39,62 49,79 10,60 31,29 Gasification process: - Entrained flow gasification: Water quench type/gas quench with syngas cooler - Gasification agent: O 2 /steam - Temperature: Wyodak: C Pittsburgh: 1.350/1.500/1.650 C Kuzbass: 1.500/1.650 C - Pressure: 40 bar(a) - Carbon conversion: 99.8 % Rectisol: - Aux. power demand: MegaM. type syngas: 0,06 kwh/kg CO2 LPMeOH type syngas: 0,1 kwh/kg CO2 - CO 2 pressure: 2.3 bar(a) 12

13 Major modelling boundary conditions (II) MegaMethanol type synthesis process: - Modul (H 2 -CO 2 )/(CO+CO 2 ): 2,03 2,1 - Syngas LHV: approx. 20 MJ/kg - Molar recycle ratio (recycle gas/feed gas): 4 - Operation pressure: 60 bar(a) - MeOH capacity: 10 6 t/yr - Heat recovery from synthesis: IP steam (acc. to CC pressure) - 3-column distillation (MeOH purity): 99,92 mol-% (grade AA) LPMeOH type synthesis process: - Modul H 2 /CO: 0,6 - Syngas LHV: approx. 13 MJ/kg - Molar recycle ratio (recycle gas/feed gas): 6 - Operation pressure: 80 bar(a) - MeOH capacity: 10 6 t/yr - Heat recovery from synthesis: IP steam for CC Steam for internal CO shift - 3-column distillation (MeOH purity): 99,92 mol-% (grade AA) Power block Combined cycle (E-class gas turbine): - Fuel gas LHV: 10,000 kj/kg - ISO standard conditions: 15 C, 1,01325 bar, rel. humidity: 60 % - Gas turbine load: 0, pressure single reheat bottoming cycle: 120/484 45/487 5/225 - Integrated oxygen pre-heat: 200 C - Steam side integration with gas island and synthesis 13

14 Modelling results Synthesis scaling Thermal capacity requirement for the production of 1 Mio. t MeOH /year: MegaMethanol type synthesis comparison process conditions Coal Wyodak Pittsburgh#8 Kuzbass Gasifier type GQ WQ GQ WQ GQ WQ T gasification C Specific methanol kg MeOH /kg coal yield 0,704 0,718 0,914 0,933 0,961 0,977 Coal demand for 1Mt MeoH/year t coal /yr Thermal throughput (LHV) MW kg syngas /s 40,49 39,33 39,67 38,38 39,99 38,53 LPMeOH type synthesis comparison process conditions Coal Wyodak Pittsburgh#8 Kuzbass Gasifier type GQ WQ GQ WQ GQ WQ T gasification C Specific methanol kg MeOH /kg coal yield 0,631 0,645 0,820 0,838 0,840 0,859 Coal demand for 1Mt MeoH/year t coal /yr Thermal throughput (LHV) MW kg syngas /s 71,23 69,07 69,97 67,90 71,91 69,51 Thermal capacity (just for synthesis) Specific MeOH yield : Wyodak Pittsburgh#8 Kuzbass WQ GQ 14

15 Modelling results Summary operational concepts for coupling of CC to MeOH synthesis Operational concept evaluation: MegaMethanol-type synthesis with gas quench entrained flow gasification Gas island load 84,8% Gas island load 100,0% LPMeOH-type synthesis with gas quench entrained flow gasification Gas island load 100,0% Gas island load 100,0% 100,0% 100,0% 81,0% 100,0% 50,0% Synthesis load GT load 100,0% 50,0% Synthesis load GT load 100,0% Base load operation Peak load operation MegaMethanol load inflexibility results in significant gasifier capacity Gas island requires 15 % load flexibility for peak load electricity production Base load operation Peak load operation Approx. 20 % load flexibility required from the synthesis Gas island capacity reduced by 6,8 9,5 % vs. MegaMethanol Conclusion: LPMeOH advantageous towards MegaMethanol with respect to operational behaviour LPMeOH advantageous towards MegaMethanol regarding the thermal throughput to the poly-generation plant 15

16 Modelling results Concept comparison dep. on synthesis type Maximum power output and efficiency for coupling with gas quench type gasification Coal Wyodak Pittsburgh#8 Kuzbass Synthesis type MegaMeth LPMeOH MegaMeth LPMeOH MegaMeth LPMeOH Maximum power production GT power output (gross) MW 188,82 180,57 188,66 180,48 188,79 180,54 37,8% 37,0% 37,8% 36,9% 37,8% 37,0% BC power output (gross) MW 151,61 154,43 160,75 162,29 168,49 163,21 48,80 50,50 51,70 52,70 54,20 53,00 CC gross efficiency % (LHV) 47,56% 47,28% 48,12% 47,73% 48,64% 47,80% Peak load electr. to the grid MW 236,05 259,36 254,85 273,98 253,62 268,76 O ll Efficiency of electricity generation in case of maximum electricity generation Auxilliary power consumption lower for LPMeOH vs. MegaMethanol due to reduced synthesis load at peak load electricity conditions Higher net power output to the electric grid for LPMeOH Efficiency of power production slightly lower for LPMeOH concepts Concepts with water quench gasification expected to show lower power output to the grid but to follow the same trend Concepts with gas quench type gasification to be expected to show less part load capability due to stronger steam side integration with combined cycle MegaMethanol-type synthesis concepts expected to be less part load capable 16

17 Outlook Finalisation of evaluation for MeOH concepts Investigation of part load capabilities taking into account OEM knowledge Dito for Fischer Tropsch and MtG syntheses concepts Derivation of advantageous concepts and economic assessment Acknowledgement This project is funded by the German Ministry for Economics and Technology (BMWi) and jointly supported by ALSTOM (Schweiz) AG. The title of the project is Kohleverstromung durch Polygeneration and the BMWi project identification number is: A. 17

18 The End Thanks for your attention! Questions are welcome. 18