Precombustion capture. Professor Dianne Wiley School of Chemical Engineering, UNSW Australia

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1 Precombustion capture Professor Dianne Wiley School of Chemical Engineering, UNSW Australia IEAGHG Summer School 2015 University of Western Australia Perth AUSTRALIA 6-12 December 2015

2 Combustion Burning of fuel and oxidant to produce heat and/or work fuel can be solid, liquid or gas fuel can be fossil fuel or biomass (alone or co-fired) fuel + oxygen/air (O 2 ) carbon dioxide (CO 2 ) + water (H 2 O) + other gases (N 2, SO x, NO x, CO) + ash + HEAT/ENERGY 2

3 Gasification Partial oxidation, oxidation and reforming of fuel and oxidant to produce syngas and heat fuel can be solid, liquid or gas fuel can be fossil fuel or biomass (alone or co-fired) Syngas can be burnt or reacted further fuel + oxygen/air (O 2 ) + steam (H 2 O) carbon monoxide (CO) + hydrogen (H 2 ) + methane (CH 4 ) + carbon dioxide (CO 2 ) + water (H 2 O) + other gases (H 2 S, COS, NH 3, HCN) + ash + slag + HEAT 3

4 Gasification reactions Source: 4

5 Gasification for chemicals production Source: 5

6 Pre-combustion capture Capture CO 2 for storage or reuse Use water-gas shift reactor to maximise H 2 production CO + H 2 O CO 2 + H 2 Use H 2 combust in a combined cycle gas turbine plant to produce electricity sell for distributed energy production provide to fuel cell Similar processes apply to H 2 production using SMR (steam methane reforming) ATR (autothermal reforming) 6

7 Pre-combustion capture 7

8 Example IGCC power plant with capture Source: Vatenfall 8

9 Solvent absorption capture >> Animation of absorption process 9

10 Solvents for pre-combustion capture Physical solvents Rectisol (methanol) o Lurgi and Linde, Germany o Lotepro, USA Purisol (N-methyl-2-pyrolidone: NMP) o Lurgi, Germany Selexol (dimethyl ethers of polyethyleneglycol: DMPEG) o Union Carbide, USA Chemical solvents MDEA (Methyl diethanolamine (N-methyl-diethanolamine)) o Union Carbide, USA 10

11 Coal gasification: Beulah, North Dakota, USA Dakota Gasification Company s Great Plains synfuels plant Gasification of lignite coal: 55 tonnes/h in14 Lurgi Mark IV gasifiers operating at 1200 C produces syngas and a range of chemical products o synthetic natural gas o ammonium sulphate o fertilisers o phenol o cresylic acid o liquid nitrogen o methanol o naptha, o krypton o xenon Source: Dakota Gasification Company 11

Dakota gasification plant: CO 2 removal CO 2 separated using solvent absorption Rectisol process (methanol) pressure change regeneration 3 Mtpa CO 2

12 Dakota gasification plant: CO 2 removal CO 2 separated using solvent absorption Rectisol process (methanol) pressure change regeneration 3 Mtpa CO 2 96% pure, dry, oxygen and nitrogen free transported 205 miles by pipeline to Saskatchewan, Canada used for EOR Source: Dakota Gasification Company 12

13 IGCC: Kemper County, Mississippi, USA New 582 MW net IGCC using TRIG technology air blown gasification Selexol for H 2 S and CO 2 removal Mississippi lignite coal Capture 3.5 Mtpa CO 2 65% capture rate used for on-shore EOR operational 2016 Source: Mississippi Power 13

14 Advantages of pre-combustion solvent capture High CO 2 concentration (for oxygen blown gasification) large driving force for separation easy separation requirements High flow-rate large economies of scale Gasification is an established industrial process 14

15 Challenges for pre-combustion solvent capture High temperature (unless pre-cooled) increases materials degradation High H 2 concentration causes materials embrittlement High flow-rate increases equipment size High capital cost of gasification plant Limited commercial-scale energy ~ 250 MW (more recently 437 MW) expensive compared to conventional supercritical plants Difficult to retrofit to existing plant 15

16 2 nd & 3 rd generation pre-combustion capture technologies Some technologies under investigation VSA or PSA (Vacuum or Pressure Swing Adsorption) SEWGS (Sorbent Enhanced Water Gas Shift) Gas separation membranes Low temperature separation IGFC (Integrated Coal Gasification Fuel Cell) Major focus on combined CO shift and CO 2 capture Reduce capital cost Reduce energy penalty Reduce complexity 16

17 Port Arthur: VSA and PSA following SMR CO 2 separation with VSA followed by PSA concentrate CO 2 from 10-20% to >97% 90% recovery 1 Mtpa CO 2 used for EOR in Texas first stage operational in 2012 Source: netl.doe.gov/file%20library/factsheets/project/fe pdf 17

18 Reforming & Carbonation Regeneration / Calcination Sorbent Enhanced Water Gas Shift Process Hydrogen Sorbent Purge Sorbent Makeup Regeneration Gas + CO 2 CO 2 -loaded Sorbent Regeneration Energy Regenerated Sorbent Natural Gas & Steam Regeneration Gas 18

19 Advantages of SEWGS Process intensification simultaneous production of H 2 and capture of CO 2 with a combined sorbent catalyst eliminate shift reactor Lower operating temperature reduce energy requirements replace high temperature, high alloy steels in reformer reduction or elimination of carbon deposition in reformer Potential cost reduction 19

20 Challenges for SEWGS Issues with sorbent catalyst decay in activity sintering attrition and fragmentation control of competing reactions Ash fouling in the calciner 1 st carbonation 1 st carbonation 1 cycle 30 cycles a a C N [%] b Cycle no. [-] 30 th carbonation 30 th carbonation Havelock, 10% steam Longcliffe, 10% steam Cadomin, 10% steam Purbeck, 10% steam Source: Donat et al. (2012) Influence of high-temperature steam on the reactivity of CaO Sorbent for CO 2 capture, Environ Sci Technol, 46: b g-co 2 / g-sorbent [%] 2 mm 2 mm 2 mm 2 mm Source: Abanades & Alvarez (2003) Conversion limits in the reaction of CO 2 with lime, Energy Fuels, 17:

Pre-combustion membranes Process options membrane: H 2 selective (metallic, porous inorganic, carbon, molecular sieve) or CO 2 selective (polymeric) placement: before/between/within shift, during CO

21 Pre-combustion membranes Process options membrane: H 2 selective (metallic, porous inorganic, carbon, molecular sieve) or CO 2 selective (polymeric) placement: before/between/within shift, during CO 2 compression Advantages compact and modular with no moving parts low maintenance and highly reliable Challenges high recovery of H 2 delivery of product at high pressure membrane lifetime scale-up Source: Integration of H 2 separation membranes with CO 2 capture and compression (2009) DOE/NETL-401/

22 Low temperature separation Process conditions: -60 C Advantages produces liquid CO 2 potentially low energy and cost cooling can be provided by expanding feed gas low temperature separation is a well established technology Source: Berstad et al (2013) Energy Procedia 37: Challenges high recovery needs high pressure or hybrid process (e.g. with solvent capture) no pilot or demonstration yet 22

23 Integrated Coal Gasification Fuel Cell Advantages some fuel cells have high efficiency and use H 2 inherent CO 2 capture if anode and cathode gases are separate Challenges SOFC stack degradation raise conversion efficiency o reduce cell over-potential o higher methane content syngas full integration of SOFC stack to IGCC with capture not tested Source: Keairns & Newby (2010) Integrated gasification fuel cell (IGFC) systems, 11 th Annual SECA Workshop, Pittsburgh 23

24 Technology status Technology TRL Potential to reduce LCOE of capture IGCC with selexol % to 130% of baseline H 2 separation membrane with warm gas clean-up 5-25% SEWGS 5-30% Low temperature separation 2-30% Low temperature separation with CO 2 recycle 2-50% IGFC % to 95% Adapted from: IEAGHG (2014) Assessment of emerging CO 2 capture technologies and their potential to reduce costs Report 2014/TR4 24

25 Useful resources 25

26 Government, Industry and Research Partners

Pre-combustion with Physical Absorption E.R. van Selow R.W. van den Brink

Pre-combustion with Physical Absorption E.R. van Selow R.W. van den Brink Presented at the 2 nd ICEPE, 18 November 2011, Frankfurt, Germany ECN-L--11-126 November 2011 Pre-combustion with Physical Absorption