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Last day to register!. https://www.regonline.com/builder/site/Default.aspx?EventID=1356389. ENVS3070/PHYS3070 Homework #2, (oil and gas) due in class Monday February 3. 2014
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Last day to register! https://www.regonline.com/builder/site/Default.aspx?EventID=1356389
ENVS3070/PHYS3070 Homework #2, (oil and gas) due in class Monday February 3. 2014 1.(10 points) Imagine that we can get all of the oil out of the oil shale deposits of the Green River Formation (Table 2.8). The US currently consumes 19 million bbl of oil per day. How many years would the shale oil last if we used only this source? 2. (R and K problem 2.7, altered) On a cold day, a home furnace consumes one million BTU of heat energy from natural gas. A) (5 points) How many hundred cubic feet of gas (CCF) is that? B) (6 points) Some of the heat energy is lost through the chimney stack, with only 80% useful to heat the house. How many BTU is that? How many Joules? c)(10 points) I recently paid $27.02 for 78 hundred cubic feet (CCF) of gas, not including taxes and fees. How much will I pay for gas heat in a very cold week at that same rate of consumption? 3.(10 points) (R and K 11, modified) How many Joules of energy are required to lift one barrel of crude oil from a depth of 25,000 feet? The density of ‘light’ crude oil is 0.828 kg/liter. What fraction of the energy content of the oil is this? This is a very local contribution to ‘emergy’. NOTE—not all HW sets have the same number of points!
Today Natural gas—where is it and how do we get it, Today, by conventional means as in the text. All power point images are only for the exclusive use of Phys3070/Envs3070 Spring term 2014
What is natural gas? A gas at ‘STP’ Can be liquified LNG, and shipped as that cold pressurized liquid. Mostly methane CH4. May contain CO2, H2S, water, mists…
US www.eia.gov
How much do we pay for gas? Xcel energy bill Dec. 27, 2013 Measured usage= 78 (ccf=hundred cubic feet) Therm. Multiplier=0.893127 (One therm = 100,000 Btu) Therms used – 70 • Usage charge 70 x $0.108429 =$7.59 ---? • Interstate pipeline 70x 0.084740 =$5.93 ---- pipeline • Natural gas 70 x 0.386060 =$27.02 ------gas itself • Service & facility =$14.31 ---meters, billing etc. • Franchise fee =$1.90---City of Boulder, access • Occupation/Sales tax =$4.13 • Total =$58.98 • Gas itself was 46% of the bill.
Distribution of proved natural gas reserves Distribution of proved reserves in 1988, 1998 and 2008 Percentage Global
Natural gas production by area Production by region Billion cubic metres Siberia!
Natural gas reserves-to-production (R/P in years) From BP 2008 by region Reserves-to-production (R/P) ratios Years 200 60 2008
Major gas trade movements Major trade movements Trade flows worldwide (billion cubic metres)
USA www.iea.gov
Burning gas C + O2CO2 +29,300 Btu/kg of C CH4+2O2 CO2 + 2H2O +53,000 Btu/kg of CH4 To make one million Btu needs 34 kg of coal or 19 kg of methane. “Cleaner fuel” Q? How do these compare in kg of CO2?
Masses in chemical reactions( this is NOT in the text) • We have balanced atoms and molecules, but they do not all have the same mass. • Relative weights • H = 1 H2 =2 • C=12 • O=16 O2=32 • So CO2= 12 +2x16 =44
C + O2CO2 • One atom of C one molecule of CO2 • 12 grams of C give 44 grams of CO2 • 12 tons of C give 44 tons of CO2 • ….etc • 1 ton of C gives 44/12 tons of CO2 KNOW THIS!!
Products of burning When a ‘hydrocarbon’ is burned completely the only products are CO2 and H2O.
CH4+x O2y CO2 + z H2O • One carbonone carbon, so y=1 • 4 Hz H2 = 2z H, so z=2 • Check the oxygen • Left side x O2 = 2x O • Right side (2y + z) O = 4 O=2O2 So x=2 CH4 +2 O2 CO2 + 2 H2O Carbon 1, Oxygen 4, Hydrogen 4, on each side
Masses • The one molecule of CH4 has a relative weight of 12 + 4*1 = 16 • The one Molecule of CO2 has a relative weight of (12 + 2*16) = 44 • If you burn 16 grams of methane, you make 44 grams of CO2. • If you burn 16 metric tonnes of methane, you make 44 metric tonnes of CO2. • If you burn 17.4 kg of methane you make (17.4*44 / 16) =47.85 kg of CO2. (if you burn 17.4 kg of carbon you get 17.4*44/12=63.8 kg of CO2, and less heat)
Check with heptane C7H16 + 11 O27 CO2 + 8 H2O One molecule of heptane has a relative weight of 7*12 + 16*1 = 100 Seven molecules of CO2 have a relative weight of 7*(12 + 2*16) = 308 If you burn 100 tons of heptane you make 308 tons of CO2. If you burn 10 pounds of heptane you make 30.8 pounds of CO2. Etc.!!!!
This winter • January 24, 2014 Boulder Daily Camera • futures gas =$5.18/ thousand cubic feet, highest in 3.5 years. • 50% above one year ago • 29% above two weeks ago • ‘fracking’ often in cold states • Spot price=$120/thousand cubic feet on the East Coast ( the energy equivalent of $700 per barrel of oil)
Read ahead for Feb. 7 How do we turn coal into gas or liquid? www.liquidcoal.com “Coal in your gas tank” www.coaltoliquid.net wikipedia
ENVS3070/PHYS3070 Homework #2, (oil and gas) due in class Monday February 3. 2014 1.(10 points) Imagine that we can get all of the oil out of the oil shale deposits of the Green River Formation (Table 2.8). The US currently consumes 19 million bbl of oil per day. How many years would the shale oil last if we used only this source? 2. (R and K problem 2.7, altered) On a cold day, a home furnace consumes one million BTU of heat energy from natural gas. A) (5 points) How many hundred cubic feet of gas (CCF) is that? B) (5 points) Some of the heat energy is lost through the chimney stack, with only 80% useful to heat the house. How many BTU is that? How many Joules? c)(10 points) I recently paid $27.02 for 78 hundred cubic feet (CCF) of gas, not including taxes and fees. How much will I pay for gas heat in a very cold week at that same rate of consumption? 3.(10 points) (R and K 11, modified) How many Joules of energy are required to lift one barrel of crude oil from a depth of 25,000 feet? The density of ‘light’ crude oil is 0.828 kg/liter. What fraction of the energy content of the oil is this? This is a very local contribution to ‘emergy’. Note! Not all HW has the same number of points!
Next week • Monday- coal--- R and K 2.12-2.13 Homework set #2 is due • Wednesday-Nonconventional fossil fuels, ‘fracking’ R and K 2.14-2.15, and more • Friday- how to make gasoline, how to turn coal into gas ---extra reading-