Woodrow Wilson School 585b cross-listed: MAE 580 Living in a Greenhouse: Technology and Policy Robert Socolow Phil Hannam, AI Week 4: Monday, October 7,

Woodrow Wilson School 585bcross-listed: MAE 580

Living in a Greenhouse: Technology and Policy

Robert SocolowPhil Hannam, AI

Week 4: Monday, October 7, 2013

Abundant hydrocarbonsThe energy conversion system: key concepts

Phil and I read your midcourse evaluations(Six received. Thank you.)

1. I will promote more discussion, on topics identified in advance.

2. I will go faster, provided that every one of you promises to tell me when I am going too fast – not after the class is over, but at that moment.

3. Phil will conduct an optional precept.

Next four classesL4 (October 7, today) Fossil energy below ground (begun in L3)Conversion of fossil fuel into electricity, vehicle fuel, and heat

L5 (October 9, this Wednesday)AR5 WG1 SPM

drawing on your First Papers, submitted Tuesday at midnight Group discussion.Personal energy use : a) One billion high emitters; b) Poverty.

L6 (October 16, a week from Wednesday)Personal energy use: c) Your own. Group discussion drawing from your Second Problem Sets (If you can, please submit electronically by Tuesday, October 15, at midnight, to help me prepare L6 Wed morning). National and regional energy strategiesGuest at 3 pm: Jim Hansen – Group discussion

L7 (October 21, the following Monday)Phil Hannam: International climate governance. Group discussion topic to be identified.

BREAK WEEK (L8 is November 6, 16 days later)

Outline for L4

Abundant hydrocarbons

Conversion and distribution systems for coal, oil, and natural gas (and biomass)

Electricity

Committed emissions

Abundant hydrocarbons

Know your hydrocarbons!

Memorize four words, in order: 1. Methane C CH4

2. Ethane C-C C2H6

3. Propane C-C-C C3H8

4. Butane C-C-C-C C4H10

After that, pentane, hexane, heptane, octane,…

Each carbon has four bonds: l – C –

I

Melting and Boiling Points of the Hydrocarbonsat One Atmosphere of Pressure

0 5 10 15 200

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Boiling Point Melting Point

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(ºC

)Gas

Solid

LiquidWater boils

Ice freezes

Shortest straight-chain liquid at 1 atm.C5 C8 C13 C18

Commercial fuels are blends

Source of graph: Arthur H. Lefebvre, Gas Turbine Combustion

Coal > oil > gas for C/E

Rubin, p. 519

C/E

Note: C/E = 0 (nominally) for hydro, wind, biofuels, nuclear.

Carbon Intensity of Primary Energy, by country

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Units: Mt(C)/1015 Btu.

Check for U.S.: 100*1015 Btu/yr, 6000*(3/11)*MtC/yr 16, surprisingly close.

Shame on me: I recorded neither where this slide came from nor the year shown.

COAL SUPPLIES BY RANK

About half of “recoverable” coal reserves are low-rank coals (sub-bituminous and lignite). These have higher moisture and/or ash content and lower heat of combustion.

Slide from R. H. Williams, 2007

U.S. has Abundant Coal

U.S. Coal DepositsWorld Coal Reserves

U.S.25%

Russia16%

China12%

India9%

Australia8%

Germany7%

S. Africa5%

Rest ofWorld18%

U.S. unconventional oil bonanza

Source: International Energy Agency, World Energy Outlook 2012

International Oil & Gas: Focus on Shale

14

Source of slide (with permission): David McCabe (Clean Air Task Force), Princeton lecture, 1 October 2012.

Source of Figure: IEA, 2011. “Are We Entering a Golden Age of Gas?”

Why is there energy below ground?

We are reversing ancient photosynthesis:Simplest explanation: In ancient times:

Δ+ CO2 + H2O CH2O + O2

Now: Δ + CO2 + H2O CH2O + O2

Δ is energy.

More accurately…We mostly find hydrocarbons (molecules with H and C, but no O). So, over tens to hundreds of millions of years there have been further changes:

CH2O CxHy.

Coal does not migrate from where it was formed. But “conventional” oil and gas is recovered from “host rock” after it has migrated upward from “source rock.” The driving force is buoyancy, as fluids less dense than brine rise through porous brine formations. Fluids flowing upward reach the surface at “seeps,” unless they are trapped by impermeable “caprock” directly above the host rock.

“Unconventional” oil and gas is recovered from source rock. Paradigm shift.

A natural gas resource unexpectedly becomes a reserve

Natural gas and oil have been extracted almost exclusively from porous rock. Under pressure and sometimes aided by mixing with chemicals, the hydrocarbons flow out.

In the past ten years the technology has been developed to extract oil and gas from rock where flow via pressure and chemicals is not sufficient, but fracturing (“fracking”) the rock in place releases the hydrocarbons. In many places in the world, this can now be done at a competitive cost. A resource has become a reserve.

I find it hard to believe, but much of the oil and gas industry was caught by surprise, as a few maverick companies proved that it could be done.

The policy community was also caught by surprise.

The problem generalizes: There are other kinds of buried hydrocarbons, too: resources waiting to become reserves. Shale oil and methane clathrates are two examples.

Tight gas and shale gasBoth tight gas and shale gas are considered unconventional natural gas, and both require fracking.

Tight gas is more clearly on a continuum. The formations are much tighter (lower in permeability), but like conventional gas it has migrated from a source rock to a host rock. The host rock is typically silt or sandstone.

Shale gas is still in the rock where it was formed. The rock has negligible permeability.

Shale gas was initially commercialized by small companies.

Tight gas and shale gas

Source: MIT Future of Natural Gas, 2010 (via Dan Giammar, PEI Energy Group 2012)

Hydraulic fracturing (“fracking”)

Source: Al Granberg via www.propublica.org/special/hydraulic-fracturing-national

Horizontal drilling has been the key to shale gas development

Source (with permission): David McCabe (Clean Air Task Force), Princeton lecture, 1 October 2012.

How important is fracking for oil?Very. Natural gas and oil have become more competitive than expected.

First, oilFracking is being done where the trapped hydrocarbons are in wet-gas and dry-gas formations. At wet-gas formations, oil comes out with the gas. Often, the oil is the point, and unless there is a pipeline system, the gas is flared.

The dominance of the Middle East in the oil markets of the next few decades will be reduced.

North America, via efficient automobiles, oil sands, and oil from fracking, may become a net-zero importer of oil. This is unlikely to reduce the globalization of energy markets, though it will encourage the concept of Fortress America.

How many barrels per day could fracking contribute to an 80 million-barrels-per-day global oil market at various times in the future? I need to learn more. So might a few of you.

How important is fracking for natural gas?

Second, natural gas (which has gotten most of the attention)The natural gas reserve will expand – it is asserted, dramatically.

Incremental natural gas has many claimants, and they cannot all be served.

Incremental natural gas could:

compensate for depletion of conventional gas, so existing grids, like those that serve Princeton University and my own home, are viable

invade electricity marketsgas instead of coalgas instead of nuclear powergas instead of renewables

invade oil markets in the transport sectorCNG – compressed natural gasLNG – liquefied natural gasGTL – gas-to-liquids (synthetic fuels)

be exported by Country A to Country B for the same purposes.

Methane leakage

Source: http://stateimpact.npr.org/pennsylvania(slide layout from Dan Giammar, PEI Energy Group 2013)

(Osborn et al., PNAS 2011. See counterpoint by Davies, PNAS 2011)

Potential emission points: shale gas

25

Water storage off-gas

Well emissions- venting and flaring of flowback emissions at completion

Condensate tank emissions

Drilling and fracking equipment

Compressor Stations (offsite)

Emissions include methane, VOC, NOx, PM, CO2, BC and toxics

Trucks

Source (with permission): David McCabe (Clean Air Task Force), Princeton lecture, 1 October 2012.

Environmental damage from fracking: methane leakage

Methane escape. Assume methane is 25 times* more potent per ton as a greenhouse gas than CO2. Assume 4%** of the methane removed by fracking escapes to the atmosphere. Then each ton of CH4 produced by fracking emits a ton of CO2eq before the CH4 is sold and burned.

Each ton of CH4 also produces 44/16 = 2.75 tons of CO2 via burning. Thus, for this case, methane leakage increases the greenhouse impact of burning methane by a factor of 3.75/2.75 = 1.36, or an additional 36%.

*The factor of 25 is the 100-year global warming potential (GWP) for methane. The 20-year GWP is 72.

** Systematic measurements of leakage are underway. Leakage in urban distribution may be larger and harder to fix than “upstream” leakage.

Environmental damage from fracking:contaminated water

Hydrocarbons in water. Fracking can conceivably create channels all the way from the deep extraction formations to drinking-water formations and to the surface. But poor handling of contaminated water at the surface is a much larger problem.

Can fracking lose its stigma?

My personal guess is that the oil and gas industry will choose to pursue “best practices” and will eventually endorse regulations – including federal regulations. If so, fracking will gradually lose its stigma.

It is sobering that the oil and gas industry showed so little interest in doing things right the first time around.

As a direct result, European governments and civil society are impeding fracking in Europe based on the U.S. experience!

Brussels, last Tuesday 1 of 2

“Gas: Too much of a good thing?” Academic Policy Symposium, Brussels. Host: Science/Business. Participants: European Commission (DG Energy, DG Climate Action, DG Enterprise and Industry), European academics and business, two Americans.

Opposition to fracking: Community opposition, amplified by U.S. experience. (And they didn’t even bring up flaring until I did.) Unlike U.S., landowner has no mineral rights, so no royalties to landowners.

Pressures in favor of fracking: 1)Growing price gap for natural gas: EU up, US down. Impact on competitiveness of the chemical industry. 2)Climate targets: Europe is turning to coal.

European decision making is complicated!

Brussels, last Tuesday 2 of 2

My three key points:

1.Why has “fracking” become a discontinuity? Normally, the incorporation of new technology by extractive industries is treated as evolutionary. Answer: Industry exploited loose regulation and willing landowners to make quick returns and created this resistance. It didn’t have to.

2.Natural gas is both a half-full and a half-empty glass, from the perspective of climate change.

3.The emerging carbon budget concept makes this conversation particularly apt. Which carbon resources will be left below ground?

What would you have said? What would you have wanted to know?

Fracking has challenged the scarcity paradigm

The deepest impact of fracking may be on our way of thinking about energy. The conventional narrative about hydrocarbons has been one of scarcity (peak oil, in particular). In industry, a scarcity perspective was self-serving: the public accepts high prices for scarce goods. Among policymakers, it was misguided.

As it relates to climate change, a scarcity narrative makes the transition from fossil fuels to renewables (or nuclear power) less formidable. Several of the elaborate integrated assessment models currently informing policymakers (e.g., via Working Group 3 of the IPCC) show CO2 emissions falling in the second half of this century, even in the absence of a carbon price. This results because scarcity drives the cost of fossil fuels upward (including coal), while “learning by doing” drives the cost of renewables downward.

By implication, the fossil fuel industry won’t learn – a risky premise.

Conversion and distribution systems for coal, oil, and natural gas (and biomass)

From primary energy to end use by stages

Two closely related classifications:

1. Conversion to electricity or not. Then to four “sectors”: residential/commercial, industrial, transportation, and “non-fuel” (chemicals).

2. Conversion of “primary energy” to “energy carriers” (“secondary energy”) and then to “end uses.” Electricity (produced at power plants) and processed fuels (produced at refineries) are energy carriers.

The final conversion process results in motive power (for stationary or mobile applications), chemical transformation, or heat at some desired temperature.

Distribution systemsGrids (networks) carry primary and secondary energy

Oil and gas via ships, pipelines, and trucks

Electricity via “transmission” (high-voltage) and “distribution” (low-voltage) power lines

Heat via pipelines carrying steam (short distances)

Two other systems issues: The scale of individual production and conversion units

The reach of any grid: centralized conversion vs. “distributed” conversion (roof-top collection, “microgrids”)

U.S. LNG terminals are being “reversed” at this time, as expectations change from importing to exporting

Spaghetti diagram, U.S., 1976

Secondary source: R. H. Socolow, “Reflections on the 1974 APS Energy Study” Physics Today, January 1986.

“Lost” vs.“useful” energy! Yuk.

Unit here is the Quad: 1 Quad = 1015 Btu.

Spaghetti diagram for U.S., 2007Unit: PJ

70% of oil used in U.S. goes to vehicles (54% in 1976)

70% of electricity goes to buildings(60% in 1976)

Spaghetti diagram for China, 2007

Spaghetti diagram for Brazil, 2007

Spaghetti diagram for Qatar, 2007

Spaghetti diagram for Benin, 2007

[Jakob and Marschinski 2012]

Carbon embedded in international trade: Production vs. consumption accounting

Carbon embedded in international trade: Production vs. consumption accounting

[Davis and Caldeira 2010]

BREAK

Required reading for Week 5:Personal energy use (1 of 2)

Agarwal, A., & Narain, S. (1991). Global warming in an unequal world: A case of environmental colonialism.

Singer, P. (1972). Famine, affluence, and morality. Philosophy & Public Affairs,1(3), 229-243.

Cole, M. A., Rayner, A. J., & Bates, J. M. (1997). The environmental Kuznets curve: an empirical analysis. Environment and development economics, 2(04), 401-416.

Chakravarty, S., Chikkatur, A., de Coninck, H., Pacala, S., Socolow, R., & Tavoni, M. (2009). Sharing global CO2 emission reductions among one billion high emitters. Proceedings of the National Academy of Sciences, 106(29), 11884-11888.

[See also Baer, P., Athanasiou, T., Kartha, S., & Kemp-Benedict, E. (2009). Greenhouse development rights: A proposal for a fair global climate treaty. Ethics Place and Environment, 12(3), 267-281.]

Required reading for Week 5:Personal energy use (2 of 2)

Ehrlich, P. R., & Holdren, J. P. (1971). Impact of population growth. Science,171(3977), 1212-1217. (Also, Chertow, M. R. (2000). The IPAT equation and its variants. Journal of Industrial Ecology, 4(4), 13-29, to understand the evolution and debate surrounding IPAT).

UN Secretary General (2012). Sustainable Energy for All. [Executive Summary and Vision pp.iii-4.]

Bhattacharyya, S. C. and S. Ohiare (2012). "The Chinese electricity access model for rural electrification: Approach, experience and lessons for others." Energy Policy 49(0): 676-687.

Fromm, E. 1995. “Essentials of a Life between Having and Being,” In Fromm, E. and R. Funk, The Essential Fromm: Life between Having and Being. New York, Continuum. (pp. 68-104)

Required reading for Week 5:Personal energy use

Agarwal, A., & Narain, S. (1991). Global warming in an unequal world: A case of environmental colonialism.

Singer, P. (1972). Famine, affluence, and morality. Philosophy & Public Affairs,1(3), 229-243.

Cole, M. A., Rayner, A. J., & Bates, J. M. (1997). The environmental Kuznets curve: an empirical analysis. Environment and development economics, 2(04), 401-416.

Chakravarty, S., Chikkatur, A., de Coninck, H., Pacala, S., Socolow, R., & Tavoni, M. (2009). Sharing global CO2 emission reductions among one billion high emitters. Proceedings of the National Academy of Sciences, 106(29), 11884-11888.

[See also Baer, P., Athanasiou, T., Kartha, S., & Kemp-Benedict, E. (2009). Greenhouse development rights: A proposal for a fair global climate treaty. Ethics Place and Environment, 12(3), 267-281.]

Ehrlich, P. R., & Holdren, J. P. (1971). Impact of population growth. Science,171(3977), 1212-1217. (Also, Chertow, M. R. (2000). The IPAT equation and its variants. Journal of Industrial Ecology, 4(4), 13-29, to understand the evolution and debate surrounding IPAT).

UN Secretary General (2012). Sustainable Energy for All. [Executive Summary and Vision pp.iii-4.]

Bhattacharyya, S. C. and S. Ohiare (2012). "The Chinese electricity access model for rural electrification: Approach, experience and lessons for others." Energy Policy 49(0): 676-687.

Fromm, E. 1995. “Essentials of a Life between Having and Being,” In Fromm, E. and R. Funk, The Essential Fromm: Life between Having and Being. New York, Continuum. (pp. 68-104) Recommended: Sen, A. (1999) Development as freedom. Oxford University Press, Oxford.Goldemberg, J., Johansson, T. B., Reddy, A. K., & Williams, R. H. (1988). Energy for a sustainable world. Wiley.Compare Sachs, Easterly and Collier:

Sachs, J. (2006). The end of poverty: economic possibilities for our time. Penguin.

Easterly, W. (2006) “The White Man's Burden: Why the West's Efforts to Aid the Rest Have Done So Much Ill and So Little Good.” Penguin Press.

Collier, P. (2008). The bottom billion: Why the poorest countries are failing and what can be done about it. Oxford University Press. [particularly chapter 7]

Recommended reading for Week 5:

Personal energy useSen, A. (1999) Development as freedom. Oxford University Press, Oxford.

Goldemberg, J., Johansson, T. B., Reddy, A. K., & Williams, R. H. (1988). Energy for a sustainable world. Wiley.

Compare Sachs, Easterly and Collier:Sachs, J. (2006). The end of poverty: economic possibilities for our time.

Penguin.Easterly, W. (2006) “The White Man's Burden: Why the West's Efforts to Aid

the Rest Have Done So Much Ill and So Little Good.” Penguin Press.Collier, P. (2008). The bottom billion: Why the poorest countries are failing and

what can be done about it. Oxford University Press. [particularly chapter 7]

Electricity

U.S. Fossil-fuel CO2 emissionsU.S. CO2 Emissions 2007

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U.S. total emissions: 6.0 billion tons CO2

Source: J. Sweeney, 2009

At the power plant, CO2 heads for the sky, most electrons head for buildings!

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U.S. CO2 emissions, 2007, electricity allocated. Source: J. Sweeney, 2009.

Legacy: U.S. Power Plants

Source: Benchmarking Air Emissions, April 2006. The report was co-sponsored by CERES, NRDC and PSEG.

U.S. power plant capacity, by vintage (year by year)

Source: http://www.eia.gov/energy_in_brief/age_of_elec_gen.cfm

Issues: Grandfathering, retirement, relicensing, retrofit, repowering

U.S. power plant capacity, by vintage (by decade)

Source: http://www.eia.gov/energy_in_brief/age_of_elec_gen.cfm

Coal Power

Gibson, in southern Indiana, with 3440 MW capacity, is the largest coal power plant in the U.S. It consumes about 10 millions tons of coal a year.

Source: Marty Irwin, Purdue, Sept 27, 2010

Coal power issuesThe coal itself: Quantity, accessibility (surface vs. deep), rank, ash and moisture, sulfur

Coal extraction: Worker safety, land and water impact

Coal use: Produce power, produce fluid fuels, use carbon for chemical reduction (metallurgy), distribute for space heating and cooking

Coal power: steam turbine vs. gas turbine; efficiency and capital costs

Coal and air pollution: Criteria pollutants, rules for existing plants

Competition with natural gas

CO2 capture

Solid fuels to electricity: Gasify or raise steam?

Steam turbine Gas turbine

Natural gas Aging sunbelt plants

Most new plants

Coal, other solid fuel

Most of stock The future??

Graphics courtesy of DOE Office of Fossil Energy

The 1990s Wabash DemoThe 1990s Wabash Demo

Wabash is the longest continuously operating coal gasification plant in the U.S.

Fay & Golomb, p.50

Steam turbines are huge!

Fay & Golomb, p. 55

Gas turbines are compact

Gas power vs. coal power from a climate perspective

60

Gas is cleaner than coal in most respects. It is better for climate in almost all respects. But the methane leaks erode the advantages of gas a lot.

Source (with permission): David McCabe (Clean Air Task Force), Princeton lecture, 1 October 2012.

Work vs. heat

Work and heat are both forms of energy. This was not understood until the early 19th century. Previously, heat was thought to involve the flow of a special substance, “caloric.”

We now understand work to be organized energy and heat to be disorganized energy. Work is better (see below).

Heat is further described by an ordering parameter, temperature, and more specifically by absolute temperature. 300K = 27oC = 81oF. Add 1C and one adds 1K. High temperature heat is high quality heat.

Forms of Work: Organized flow of electrons (electricity); organized motion (wind, falling water).

Forms of heat at power plants: Steam, hot gas, other hot fluids.

Steam: typically produced in a boiler by transfer across a heat exchanger of heat produced when a chemical fuel burns or a nucleus fissions

Hot gas: Same heat sources, but gas impinges on gas turbine directly

Conversions of work and heatEnergy conversion can be of five kinds:

1. Work to work: Possible in principle at 100% efficiency. Examples: falling water to electricity, a rotating shaft to electricity.

2. Work to heat: Usually means energy is being wasted, especially if heat is not at a high temperature. An electric water heater and a gas home furnace are examples of inefficient systems.

3. Heat to work: The most interesting case. The car engine, the steam engine, the gas turbine. Heat in. Work and heat out. There is always rejected heat:

Wmax = Qhigh-T*[(Tmax – Tmin)/Tmax]

Opportunity for cogeneration.

4. Heat to heat “uphill”: Heat pumps (thermodynamic levers).

Wmin = Qhigh-T*[(Tmax – Tmin)/Tmax]

5. Heat to heat “downhill”: Temperature cascades. Thermal management in a plant seeks small steps, to minimize the “pinch.”

W is work;Q is heat;T is absolute temperature.

Absolute temperature scale

1500K ≈1200oC

1200K ≈ 900oC

900K ≈ 600oC

600K ≈ 300oC

300K ≈ 0oC

0.0K = -273oC

“Ambient”

Absolute zero

Nuclear-power steam

Coal-power steam

Space heating and coolingWater heating

Engine: Best possible efficiency in converting heat to work:

Wmax = Qhigh-T*[(Tmax – Tmin)/Tmax]

Heat pump: Minimum work required to raise the temperature of heat

Wmin = Qhigh-T*[(Tmax – Tmin)/Tmax]

5600K: sunlight

Gas-turbine inlet

Second-Law InsightsRaising the temperature of heat by a small fraction of its absolute temperature can be achieved with very little work. The electric water heater that converts 90% of its electricity into 50oC heat, while starting from 10oC heat, is not an impressive device. The minimum electricity required (“ideal” device) would be 40/323 = 12% of the heat delivered at 50oC.

Second-Law considerations point to the value of co-locating

demands for work and demands for heat (e.g., cogeneration of heat and power)

demands for high- and low-temperature heat (e.g., heat cascades, as in steam integration).

Committed emissions

Committed CO2 emissions from global power plants

Assume 40-year life for power plants. Update for retirements and plant-life extensions. Figure shows 2009 view: remaining emissions are 318 GtCO2.

Committed emissions, 2009, by fuel and region

Committed emissions, 1950-2009, by fuel

No sign of saturation. Rather, an acceleration in commitments to future emissions.

Committed emissions, 1950-2009, by region

Note: The U.S. reduces its remaining commitments (negative values in panel B) when, as a “post-industrial” country, it runs on already-built plants. Note also: U.S. “rush to gas,” 2000-2005.

Global Fossil Carbon ResourcesResource Base, TtC Additional,TtC

Conventional oil (85 wt. % C) 0.25

Unconventional oil (low?) 0.44 1.55

Conventional nat. gas (75% C) 0.24

Unconventional nat. gas (low?) 0.25 0.22

Clathrates 10.60

Coal (70% C)

3.40 2.90

Total 4.60 15.30

Source Rogner, Ann. Rev. Energy and Env. 22, p. 249. Also used: 1 toe = 41.9 GJ; 20.3 kg(C)/GJ(oil); 13.5 kg(C)/GJ (gas); 24.1 kg(C)/GJ(coal).

AR5 WG1 SPM: Budget for 2oC cap with 66% probability: 1 TtC ever. Note: ≈ 0.5 TtC already emitted. All serious budgets: Leave resources in the ground!

Decisions generated by an emissions budget

When?Which fuel? (The best quality? The cheapest?)Whose?Used where?For what?

How will and should past allocations influence future allocations?Sunk costs, e.g., in natural gas infrastructure.Historical concerns related to equity and “fairness.”

We have set the stage for the rest of this course

• A collision: the emissions from abundant and seductive fossil fuels induce unwanted climate change.

• We have not yet bent the curve of emissions, not even the curve of capital commitments

• Innovative policies and technologies – perhaps behavioral change as well – are needed.

EXTRA SLIDES

Methane venting occurs at many stages

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Centrifugal compressor venting & leaks

Adapted from picture courtesy of American Gas Association

Venting of casinghead gas

Oil Production

Flash emissions from crude oil storage tanks Reciprocating, centrifugal

compressor leaks & venting

Venting from dehydrators and pumps

Gas-driven pneumatic devicesGas well completions,

workovers and blowdowns

Natural Gas Production & Processing

Compressor station venting & leaks

Pipeline leaks & blowdowns

Gas Transmission

Platform cold vents

Offshore Production

Fugitive leaks

Processing plant blowdowns & leaks

Reciprocating, centrifugal compressor leaks & venting

Gas-driven pneumatic devices

Leaks from unprotected steel mains and service lines

Leaks at metering and regulating stations

Gas Distribution

Pipeline blowdowns

Source (with permission): David McCabe (Clean Air Task Force), Princeton lecture, 1 October 2012.

Main fix: “Reduced Emission Completion”

When a shale gas well is “fracked” millions of liters of water are pushed into the well at high pressure. REC uses simple tanks to capture natural gas that comes out of the well when the water flows back to the surface.

75

Well

This equipment can be mounted on trucks and easily moved from well to well

Diagram and Photo from US EPA, “Lessons Learned: Reduced Emissions Completion”

Source (with permission): David McCabe (Clean Air Task Force), Princeton lecture, 1 October 2012.

Effort needed by 2063 for one wedge:

Replace the output of 1400 GW of coal-fired electric plants with natural-gas-fired plants.

A wedge requires an amount of natural gas equal to that used for all purposes today.

A wedge requires 50 LNG tanker deliveries every day, or the equivalent of 50 Alaska pipelines

Fuel Switching: Coal to gasFuel Switching: Coal to gas

Photo by J.C. Willett (U.S. Geological Survey).

Capacity, total by source

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U.S. power plant capacity, by vintage

Issues: Grandfathering, retirement, relicensing, retrofit, repowering

Source: EIA. [email protected]

Edwardsport, Gibson, RockportEdwardsport when completed will be the newest, the cleanest and the most technologically advanced coal fired power plant in the world. It will also be the most expensive and it will not even rate in the top ten in size of coal fired power plants in Indiana.

Wabash, Edwardsport, and FutureGen (the zero emission, now 96% emission free) are all within the Wabash Valley.

Two photos of the Gibson Power plant show the vast size of the power plants. Gibson, at 3340 MW, is the largest coal-fired power plant in the US. It is in southern Indiana. Indiana is the base load power producer for the entire Midwest, not just Indiana.

The largest single source of CO2 is the Rockport power plant (2,600 MW) in southern Indiana. Rockport emits more CO2 than Gibson, because it burns western coal which emits more CO2 per ton than Illinois basin coal.

A schematic of how much space a CO2 control system will require.

Indiana:140 MtCO2/yr (2% of U.S.) from 20 GW of centralized coal-base CO2 sources in 2007. [Check: 20 GW* 7 Mt/GW-yr= 140 Mt/yr.]

Coal-electricity Wedges

700 aspirational* (50% efficient) 1-GW coal plants, with a 90% capacity factor and with CO2 vented, will emit a total of 1 GtC each year. Electricity-supply wedges result from not building these plants.

*By “aspirational,” we mean, “likely to be available by 2050.” Their carbon intensity is:

0.18 kgC/kWh, or 0.66 kgCO2/kWh.

This is about two-thirds of the carbon intensity of today’s coal power.

Emission Commitments from Capital Investments

Historic emissions, all uses

2003-2030 power-plant lifetime CO2 commitments WEO-2004 Reference Scenario.Lifetime in years: coal 60, gas 40, oil 20.

Policy priority: Deter investments in new long-lived high-carbon stock:not only new power plants, but also new buildings.

Needed: “Commitment accounting.” Credit for comparison: David Hawkins, NRDC

Gasification: a common route to power and synfuels

Pulverized-coal steam cycles

Coal gasification Direct liquefaction by H2 addition

POWER SYNFUEL

Historic path, buthigher-cost CO2 capture

Lower quality fuel

But, in both cases, it has competition:

Am I holding up the future of energy or the past?

Governor Schweitzer (Montana), at a conference of coal-dependent industries in Phoenix, held up a lump of coal and warned:

"You are the people who represent the companies who will decide whether I'm holding up the future of energy or the past. Take a look at all the other people sitting at your table. You know who you see? You see the last remaining people on the planet who don't believe CO2 is a problem. ... The only way you will make this the energy of the future is to recognize CO2 as a problem and that you have to be part of the solution."

And by the way, he added:

“There is a lot of money in it for you guys. You can sell this technology all over the world."

Source Thomas Friedman, Op Ed., New York Times, Jan 10, 2007

“No CTL without CCS”1. Climate-change concerns will dominate the future of coal.

2. Key question is whether coal-to-liquids (CTL) option is competitive in a carbon-constrained world.

3. Incremental costs of CO2 capture and storage (CCS), relative to costs with CO2 venting, are likely to be lower at CTL plants than at coal power p[lants.

4. Competitiveness of CTL with CCS, vs. many other options, is uncertain:

a. CCS costs will come down with experience, but

b. CCS costs could rise if public distrust inhibits CO2 storage.

5. Policy conclusion: CTL, starting with the first pilots, should proceed only with CCS.

U.S. Electricity Generating Capacity (1999)Update this slide or remove it. Also, use kWh, not kW.

Waste Heat0.6%

Pumped Storage Hydro2.7%

Wind0.006%

Solar0.001%

Multi-Fuel0.031%

Gas19.1%

Other0.155%

Coal43.8%

Conventional Hydro10.6%

Petroleum8.0%

Nuclear15.1%

Wood and Wood Waste0.039%

Nonwood Waste0.039%

Geothermal0.038%

Total: 680 GW

Brazil’s Electricity Generation Capacity (1998)Update this slide or remove it. Also, use kWh, not kW.

Other Thermal1.6%

Hydroelectric87.2%

Coal1.7%

Petroleum and Natural Gas

5.0%

Geothermal/Solar/Wind

2%Nuclear

1.0%

Biomass1.3%

Total: 63 GW

Thermal cyclesMany thermal cycles involve four steps, where work

and/or heat is added to or removed from a system reversibly.

1) A Rankine cycle: The system undergoes a phase change (evaporation, condensation). Well approximates a steam engine.

2) A Brayton cycle: The system remains a gas. Well approximates a gas-turbine engine.

Steam turbine and gas turbines are competing fiercely at this time.

The Steam Turbine ( Rankine Cycle)

The Gas Turbine (Brayton cycle)

The Ideal Brayton Cycle

The Brayton cycle (s,P,s,P). A gas: 1. passes through an isentropic compressor (s); 2. is heated at constant pressure (P);3. passes through an isentropic turbine (s):4. is cooled at constant pressure, returning to the

initial state (P).

State-space diagramsP-v picture h-s picture

P

v

h

s

Combustor

Compressor

Turbine Turbine

Compressor

CombustorP2

P1P1

P2

Pressure ratio, pr = P2/P1.Typical values of pr: 10-30.

1

2

41

3

24

3

If cP is constant, h is linear in T. since dh = cPdT. Then the T-s and the h-s pictures look exactly the same.

Turbines for Thrust vs. Power

h or T

s

High-Pturbine

Compressor

Combustor

Powerturbine or nozzle 4

P1

P2

1

2

3

5

Ideal Brayton cycle.

Define State 5 by: h3 – h5 = h2 – h1.

The turbine output has paid for the compressor input by the time the system has reached State 5. The rest of the work is available as either shaft work or thrust.

If thrust, the gas at State 5 enters a nozzle.

If power, the gas at State 5 enters a power turbine.

What made jet aircraft hard to develop?

Real Brayton Cycle*

s

Combustor

Entropy increases during flow through both turbine and compressor. It is a struggle to get positive net work out.

Turbine: Work out(h3 – h4)

Compressor: Work in(h2 – h1)

Ideal Brayton Cycle

T or h

s

P1

P2

1

4

3

2

T or h

*Neglected here: pressure drops.