Opportunities for Oxy-firing to Reduce Life-Cycle Greenhouse Gas Emissions from Transportation Fuels

Transcription

1 Opportunities for Oxy-firing to Reduce Life-Cycle Greenhouse Gas Emissions from Transportation Fuels K.E. Kelly, J. Wilkey, T. Ring, B. Castro, A.F. Sarofim, and D.W. Pershing

2 Outline GHGs and the transportation fuel cycle. Motivation for reducing GHG emissions. Use of oxy-firing for CO2 capture in refining of conventional fuel. Use of oxy-firing for extraction and upgrading of oil sands. GHG emissions from other scenarios Would oxy-firing provide enough GHG reduction to allow oil sands to meet a LCFS?

3 Transportation Fuel Cycle U.S. Average Fuel-Cycle GHG Emissions

4 Low-Carbon Fuel Standards California low- carbon fuel standard (2007) - effective Requires the mix of fuel sold in California to not exceed 86 g CO2 equiv./ MJ energy released by 2020 for gasoline (WTW). US EPA Renewable Fuel Standard (2010) - effective Requires renewable fuel use to increase from 13 billion gal (2010) to 36 billion gal. It includes mandatory life- cycle GHG thresholds for renewables. British Columbia low- carbon fuel standard (2008) - effective Requires transportation fuels contain 5% renewable fuel by 2010 and allows the development of life- cycle low- carbon fuel standards. European Union (2008) standard - effective Requires the reduction of WTP, life- cycle GHG emissions by up to 10% through the use of sustainability- certified biofuels, the reduction of flaring and venting, CCS technology, electric vehicles, and the purchase of GHG credits.

5 Stationary CO2 Sources Power 6% Cement 0% 1% 5% 3% Refineries iron & steel 7% Petrochemicals bioethanol Other 79% Largest stationary sources of CO2 globally (IPCC 2005).

6 Opportunities for Reducing the Carbon Footprint Fuel consumption - greatest opportunity Improving the average fuel efficiency of gasoline- powered passenger vehicles from 21.6 mpg to 28.6 mpg reduces the life- cycle WTW GHG emissions by 20% - equal to the average WTP GHG emissions (US DOE). Raw material extraction and processing - important for unconventional fuels and some conventional crude sources Refining - conventional sources, typically second most important life-cycle stage.

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8 Oxy-firing in a Refinery Grangemouth refinery, Scotland Production: 10 million tonnes/yr crude CO2 emissions: 4 million tonnes/yr Allam study (CCP) Conversion of 7 boilers, 1 reformer, and 13 process heaters to oxy-firing 5 300,000 lb/h steam and 2 500,000 lb/hr steam boilers firing a mix of 40% gas 60% oil MW box, cabin or vertical NG-fired process heaters. Build a cryogenic ASU and NGCC plant to power the ASU, increased cooling water needs, CO2 purification, compression and transport. Added GHG emissions from upstream (fuel recovery and transport).

9 Oxy-firing Evaluation Boiler NGCC ASU Coal, solar, wind, or hydropower includes upstream Heater Transport Fuel extraction CO2 purification, drying, compression & transport. Transport Fuel extraction

10 Oxy-firing Refinery Evaluation Three cases Case 1: A gas turbine and associated steam production provides power for the air separation unit and CO2 puri;ication, compression, and transport. Case 2: A gas turbine provides power to the air separation unit and other equipment, but steam from the turbine replaces a portion of the boiler steam. This results in a lower O2 requirement, a smaller ASU, and less cooling water. Case 3: The gas turbine is run in the precombustion decarbonisation mode with part of the oxygen being used for hydrogen production and CO2 removal using amine scrubbing. Plus Ef;iciency improvements to process heaters from 83-95% ef;iciency. Effect of improvements in air separation. Effect of electricity generation to power the ASU.

11 Oxy-firing Evaluation Process Heater: $6/tonne reduction savings %*())%+,%-'./%010%%2.3443,54% 15 year timeline, 12% rate of return Case 1: $38/tonne captured DOE, 2006 '&" Case 2: $36/tonne captured 5% Case 3: $34/tonne captured '%" 18% '$" 19%!"#$%&'()% '#" CO2 delivered: $48-52/tonne Allam et al. (2005) 34% ;0).*<104" '!" &" =+2"B"40).*<" %" C<*40+)D"E8#"2)<4F0+" $" #"!" ()*+,-.+" /012+**"3+)4" " 897"2)*+"'" 897"2)*+"#" 897"2)*+":"

12 Oxyfiring Evaluation: Improved Air Separation *())%+,%-'./%010%2.3443,54%&,6%074,)35(%% '&" '%" 18% '$" 19% 25%!"#$%&'()% '#" 26% Oxy case 1: 193 kw-hr/tonne O2 Advanced: 145 kw-hr/tonne O2 Advanced2: 132 kw-hr/tonne O2 34% 9:).*;<:=" '!" &" >+2"C"=:).*;" %" D;*=:+)E"F/#"2);=G:+" $" #"!" ()*+,-.+" /01"2)*+"'" /012)*+"'" 34567" /012)*+"'" /01"2)*+"#" /01"2)*+"8" 3)56#7"

13 Oxy-firing Evaluation: Electricity!"#$%&'()*+),-%.) Process Heater: 83-95% efficiency NGCC: 53% Efficiency )/%..)01)2-34)565)) :9) Coal: 33% '&" Efficiency 5% '%" 9% 18% '$" 21% 23% 24% '#" A+B.-.C"D"14E+0" &" A+B.-.C"D"197B0-.C" %" $" #"!" ()*+,-.+" /012+**" 897"2)*+"'" :1),"2)*+"'" ;1,)0"/<" 3+)4" " 37=01" >-.="

14 Oxy-firing Fuel-Cycle Results Baseline Oxycase 1 18/3% reduction 82.9g Oxycase 3 34%/6% reduction

15 Oxy-firing Costs Taxes $0.53 Distribution & marketing Refining $0.42 $2.36 Crude $0.21 Average price gasoline in the US: $3.52/gal Cost of capturing 40% of the CO2 in refineries: $0.01 $0.02/gal

16 Conclusions: Oxy-firing in Refining Feasible to capture approximately 40% of refinery CO2 emissions using oxy-firing. Improving process heater efficiency can reduce well-to-pump GHG emissions by up to 5%. In spite of the energy requirements of the ASU, cooling water, and CO2 purification/handling, and upstream life-cycle stages, oxy-firing can reduce WTP GHG emissions by 18 34%. Improved air separation technology likely to reduce energy penalty for oxy-firing for carbon capture. The electricity source for the ASU is important: coal power coal yields a 9% savings, but wind yields a 24% WTP GHG savings. Depending on California s GHG regulations for refineries, fuel producers may focus on oxy-firing, crude source, and/or efficiency improvements.

17 Oxy-firing for Oil Sands Extraction & Upgrading Two cases GREET for Canadian oil sands with Alberta Innovates study of oxy- ;iring for SAGD and upgrading (capture 60% of CO2 from extraction & upgrading). Process modeling of ex situ oil sands development in Utah s Uintah basin. Utah s Oil sands resources estimated at 32 billion barrels oil in place. Design: 20- year, 50,000 barrels/day from Asphalt Ridge Sand properties: 10.9% bitumen in a 30 ft thick, 6 mi long deposit that yields 0.64 bbl crude (not upgraded)/ton sand. Process: surface mining, hot- water/ citrus- based solvent extraction, solvent recovery by distillation, onsite hydrotreating, and H2 production. H2 produced by methane steam reforming. Promax process model exported to Excel for GHG emission estimates.

18 Utah Oil Sands Scenario Utah average upstream ASU electricity Mining & extraction Upgrading & hydrogen production CO2 compression ASU electricity Transport to refinery Refining Transport US averge CO2 compression Excluded: citrus solvent manufacture, plant construction; CO2 transport; CO2 emissions from mobile mining equipment; and credits for sold CO2

19 Well to Pump GHG Emissions: Oil Sands (!" '!"!"#$%&'()*+" &!" *" 9:;1.1<" %!" =>)" )8<3+2.1<" LCFS of 15 #!"!" )*+,"-./"0+120"+.3" )*+,"-./"0+120"-45" "-./"0+120" "-./"0+120" -45"

20 Oxyfiring with Oil Sands meeting a LCFS California LCFS of 86 g CO2eq./MJ 89):"-."/"),3" 89):"-./"012" 6193);<0*"="93)*>" 8?@3)+,*@" ()*)+,)*"-."/"),3"45667" A.8" 5BC*,*@" 73)*>?039" ()*)+,)*"-."/"012" 8>B" ()*)+,)*"-."/"012"012"!" #!" $!" %!"!"#$%&'()*+" &!" '!!" '#!"

21 Conclusions: Oxy-firing for Oil Sands Feasible to capture a large fraction of CO2 emissions from hydrogen production/upgrading/heating process for oil sands (approximately 30% reduction in WTP GHG emissions). Depending on process specifics, oxy-firing could help an unconventional fuel, such as oil sands, meet a low-carbon fuel standard. Likely need to employ oxy-firing in the extraction/upgrading and refining stage as well as efficiency measures.

22 Oil Sands and Oil Shale Scenarios '#!" '!!" &!"!"#$%&'(" 82/6*932," :1;6+6<" %!" $!" 82/6*932," , 55* (),2/AB36" #!" LCFS of 15!" ()"*+,-" ()"*+,-" 56"*+,-" 56"*+,-" ()"*+,-" ()"*+,-" 56"*+,-" 56"*+,-" *./01"/+2" *./01"3)4" *./01"/+2" *./01"3)4" */67*"/+2" */67*"3)4" */67*"/+2" */67*"/+2"

23 Future Work & Acknowledgments Refinements (add heavy oil) and joint publication with the assessment group Adapt approach to use with LANL s CLEAR model This material is based upon work supported by the Department of Energy under Award Number DEFE Thanks to Sho Kobayashi, Senior Fellow, Praxair, for advice on air separation and oxy-firing.