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TOMORROW evening. Today Overview of fossil fuel energy. How much is there? Demand projections? How is it all working out? All power point images are only for the exclusive use of Phys3070/Envs3070 Spring term 2014. CAPA solutions.
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TodayOverview of fossil fuel energy How much is there? Demand projections? How is it all working out? All power point images are only for the exclusive use of Phys3070/Envs3070 Spring term 2014
CAPA solutions 1.To go to all coal, using Table 1.1 for 2003, when we used 98.3 QBtu/year: Now (+10%) we use 1.10 * 98.3 Quads = 108.13 *1015 Btu/year. Table 1.1, upper left corner, gives 1QBtu=47.8*106 tons Tons = 108.13 QBtu *47.8 * 106 tons/QBtu =5168.6*106 tons=5.168*109 tons =5.168E9 for CAPA OR—if you used from the front cover: Front cover, 1 ton (2000 pounds) of coal holds 2.668*107 Btu/ton Tons = Btu / (Btu/ton) 108.13 *1015 Btu / (2.66*107Btu/ton)=40.65 * 10 15-7 =40.65*108 tons = 4.065*109 tons 4.065E9 for CAPA Which is correctly done, but CAPA will mark it wrong. (compare to Fig. 2.7, with about 1050*106 tons/year; 1.050*109/4.065*109 = 26%, much as this problem) 2. Your share=( 5.168*109 tons *2000 pounds/ton) / (320*106 people) = 32.3*109-6 =32,300 pounds/person each year = 32,300/365 =88.4 pounds / day= 88.4 for CAPA
3. CH4 +2O2CO2 +2 H2O balances atoms Relative weights are (12+4*1) +2*(2*16) (12+2*16) + 2*(2*1+16) 16+64 44+36 (both sides match at 80=80) So 16 tons of CH4 makes 44 tons of CO2 And one ton of methane (CH4) makes 44/16 tons of CO2 = 2.75 tons = 2.75 for CAPA
4. A) if ‘recoverable’ = ‘proved’ from Fig 2.2 • Time = R/P =29*109 bbl / 2*109 bbl/year =14.5 years R • Or—if ‘recoverable’ = ‘proved’ + ‘undiscovered’ • Time = R/P = (29+105) *109 bbl / 2*109 bbl/year=67 years, also R • B) (oil shale/ton) / (coal/ton) (for ‘good quality > 25 gal/ton,) • =3.5*106Btu/ton (page 55) / 2.66 *10 7 Btu/ton (front cover) =0.13 = 13%, not near 1%, U • Qinfinity (US coal) = 250 *109 tons (table 2.7), not near 1.5E9 tons U • D) Figure 2.2 shows about 2*109 bbl/year • =2*109 ( bbl/year) * 42 gal/bbl *1/365 year/day = 0.23*109 gal/day, • not near 6E9U • E) 3E8 years old?R
5) C + O2CO2 + 95 kcal/mol and one mol has a mass of 12 for carbon (C) 1 ton of coal = 1 ton of carbon (not really) holds 2000 pounds/ton * 1 / (2.2046 pound/kg) *1000 gram/kg *1 mol/12 grams *95 kcal/mol = 7.18*106 kcal, but we need to answer in Btu = 7.18*106kcal * 1000 cal/kcal *3.97*10-3 Btu/ cal (front cover) = 28.5 *106+3-3 = 28.5 *106 Btu = 2.85*107 Btu = 2.85E7 for CAPA
January 13 POWER = RATE of Energy = energy / time BTU per year, Calories/hour…… One Watt = I Joule / sec Back to energy 1 kW-hr ( power x time) =103 J/sec x 3600 sec = 3.6 x 10 6 J English unit of power = the horse power = 550 ft pounds per sec Energy used by a 100 W bulb in one year 100 J/sec x 3.16x107sec = 3.16x109 J OR=0.10 kW * 8766 hr/year * 1 year=877 kW-hr.
January 15 Available heat energy is related to changes in temperature. ( this is NOT in the text) DQ = mass or weight * DT * C (specific heat) Specific heat depends upon the material. For water, C= 1 cal / gram deg C=4184 J/kg-deg C = 1 Btu/pound deg F (actually, these are the definitions of calorie and BTU) Aluminum = 900 J/kg-deg C Units check! cal =? grams * deg C *cal / gramdeg C
USA Jan. 17 Energy content of coal=7800 kW-hr/ton (text) Usage(electrical)=1,733,430 million kW-hr =1.73x1012 kW-hr (EIA.gov) Tons = (kW-hr) / (kW-hr/ton) =1.73x1012 (kW-hr)/7800 (kW-hr/ton) =0.0002218 x1012 tons =2.218 x10-4x1012 =2.218 x108 tons =221.8 million tons of coal (text Fig. 2.7 shows 1060 million tons in 2005) Something is wrong or missing!
January 27 C + O2CO2 CH4+ 2O22 H2O + CO2 C8H18 + 12.5 O29 H20+8 CO2 2 C8H18+25 O218 H2O+16 C O2 New one--Ethanol C2H6O + X O2Y CO2 + Z H2O
Complete Combustion of hydrocarbons C3H8 + XO2YCO2 + Z H2O Atoms are forever, must balance. On the left, 3 carbons 3 on the right Y=3 On the left, 8 hydrogens8 on the right Z=4 On the left, 2X oxygens= 2*Y + 1*Z=6+4=10 X=5 C3H8+5 O23 CO2+4 H2O (+heat)
Incomplete combustion,starve the oxygen C3H8 + 4 O2X CO2 + Y H2O + Z CO 3 C (X + Z) 8 H(2Y) HY=4 8 O2X +Y + Z=2X+4+Z X+Z=3 2X+4+Z=8 X=1, Z=2 C3H8 + 4O2CO2 + 4H2O + 2 CO
How much carbon in Valmont plant coal? Feb. 3 • 535,00 tons of coal, containing X % of carbon • 1,300,00 tons of CO2. reaction C + O2CO2 Relative weights C-12, O2-32, CO2-44 So 1,300,000 tons of CO2 came from burning 12/44 * 1,300,000 = 354,545 tons of carbon So the coal was 354,545/535,000 =66% carbon
Feb. 7 Water gas C + H2O+heatH2 + CO Fischer-Tropsch (2n+1)H2 + nCO + heat CnH2n+2 + nH2O Net formula to make C8H18 Which is gasoline, octane
How much does it cost for the same amount of energy, 109 Joules? • Your daily share of US energy(Fig. 1.8) is 100 Quads=100 Quadrillion Btu=100* 1015Btu /9.49*10-4Btu/Joule= 10.54*1015+4 J =10.54*1019 J • Divided by 300*106 people and 365 days/year • 10.54 *1019/(300*106 *365)= 9.62 *108 Joules/person each day • Call this 109 Joules
Oil 1 bbl holds 6.12*109 J (text) 109 Joules needs 109J/6.12 *109J/bbl= 0.1634 bbl Oil at $80/ bbl Your 109 Joules costs = $80 /bbl * 0.1634 bbl = $13.07
Gas 1000 cubic feet of gas holds 1.09*109 J (text) 109 Joules needs 109J/1.09*109J/thousand cubic feet =0.917 thousand cubic feet =0.917*103 cubic feet of gas RJP December bill for gas alone was $27.02 for 78 hundred cubic feet (ccf). 109 Joules cost=$27.02/ 78 ccf * 9.17 *102 cubic feet =$27.02/78 ccf* 9.17 ccf = $3.18
Coal 1 ton holds 2.81*1010 Joules (text)=28.1*109 J 109 Joules needs 109J/28.1*109J/ton = 0.056 ton Appalachian coal costs $50/ton your energy 109 J costs $50/ton * 0.056 ton = $1.78
What source of energy do you want? • Coal $1.78 • Gas $3.18 • Oil $13.07 Externalities?
Trends, impact, geopolitics of fossil fuels • Fossil fuels gave us the Industrial Revolution. • We continue to need such fuels, especially in advanced economies • Not all nations are self-sufficient in fossil fuels • Therefore, there is a strong reliance on imports, and a reliance on the funds from exports.
RussiaEconomist Feb. 1, 2014, page 7,18 • The Russian government relies heavily on fees, taxes, etc from oil and gas exports, which are 75% of all exports • Russia can balance its budget if oil costs $103/bbl. Ten years ago, this was possible at $20/bbl. • Today, ‘Urals blend’ oil brings $108. • Russian GDP growth is projected to fall to 2% in 2014. • 45% of all Russian purchases are imported!
China • Coal R / P <40 years
Next HW #3 • 1. The Fischer-Tropsch process turns coal (carbon=C) into gasoline=octane (=C8H18) by a series of chemical reactions. The first reaction combines carbon with water (steam) and heat to make water gas or coal gas, a mixture of hydrogen and carbon monoxide. C+H2OH2 + CO. More hydrogen is added to run the F-T reaction. The final reaction is • 17 H2 + 8 CO C8H18 + 8 H2O. • A)(5) How many molecules of carbon do you need to react to make enough CO to make one molecule of octane? • B) (5) How many tons of carbon do you need to react to make one ton of CO?C)(10) How many tons of octane can you make from that one ton of CO (and the other ingredients)?
2. (10) There is a temperature difference between very deep ocean water (4 deg C) and surface waters (25 deg C). This difference allows you to construct a heat engine. What is the best possible (Carnot) efficiency for such a hypothetical engine? Why don’t remote tropical islands use this for power? 3. (5) Instead, image a heat engine that burns waste on that island and exhausts its waste heat into that 25 deg C water. How hot must the fire be (in deg C) to attain 30% efficiency?
4.(10) A power plant converts the heat energy in coal to electricity with 35% efficiency. Transmission losses are 10%. A factory then uses that electricity to make a new exotic and special rocket fuel, with 60% efficiency. What is the total efficiency of converting coal energy into the final energy product? 5.a) (5) If Congress taxes CO2 at $40 per ton (of CO2), what is the tax on one ton (2000 pounds) of burned coal which is 60% carbon? b)(5) How much heat energy can you get from burning that coal? Take the book value per ton of coal to represent this 60% variety. c)(5) What is the tax on one ton of burned methane (CH4)? First, write the reaction for complete combustion in air. d) (5) Methane gas has a density of 0.0443 pounds per cubic foot. How many cubic feet are in that (2000 pound) ton? e) (5) How much heat energy can be gained from that ton of methane? Use the book number for natural gas. f)(10) Make a brief summary of what you would write Rep. Polis (D-2d District of CO) about these four energy and tax numbers.
Rest of the week • Wednesday: Chapter 3, Heat Engines • Friday: Efficiency. What is the best possible?