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Author Topic: What is the water yield from natural gas combustion?  (Read 9400 times)

Offline CZARCAR

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1 gallon natural gas burned in a ventless heater will produce 2 gallons of water?
« Last Edit: 31/01/2010 12:35:08 by chris »


 

Offline lightarrow

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What is the water yield from natural gas combustion?
« Reply #1 on: 31/01/2010 13:43:20 »
1 gallon natural gas burned in a ventless heater will produce 2 gallons of water?
1. The term "natural gas" means a complex mix of hydrocarbons, the main component is methane.
2. If you want to know about methane, the computation is simple, but you have to specify the pressure at which the gas is. Do you mean standard pressure (= 1 atm)? Then:

1 gallon of methane gas at 1 atm --> 0.00161 gallons of liquid water.

I have used as density of methane at standard conditions = 0.717 kg/m3 as written here:
http://en.wikipedia.org/wiki/Methane

If instead you intended methane in the liquid state (but it's a very unusual condition!) then from 1 gallon of methane you have 0.932 gallons of liquid water.
« Last Edit: 31/01/2010 14:04:01 by lightarrow »
 

Offline CZARCAR

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What is the water yield from natural gas combustion?
« Reply #2 on: 31/01/2010 14:30:33 »
1 gallon natural gas burned in a ventless heater will produce 2 gallons of water?
1. The term "natural gas" means a complex mix of hydrocarbons, the main component is methane.
2. If you want to know about methane, the computation is simple, but you have to specify the pressure at which the gas is. Do you mean standard pressure (= 1 atm)? Then:

1 gallon of methane gas at 1 atm --> 0.00161 gallons of liquid water.

I have used as density of methane at standard conditions = 0.717 kg/m3 as written here:
http://en.wikipedia.org/wiki/Methane

If instead you intended methane in the liquid state (but it's a very unusual condition!) then from 1 gallon of methane you have 0.932 gallons of liquid water.
thanx. i was analogyzing ng to propane. using i therm [100,000 btu] of NG as a gallon equivalent.
cH4 +2o2= co2 + 2H2o? molar weight of ch4 & h2o are similar enough i think.
 

Offline lightarrow

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What is the water yield from natural gas combustion?
« Reply #3 on: 31/01/2010 16:51:35 »
thanx. i was analogyzing ng to propane. using i therm [100,000 btu] of NG as a gallon equivalent.
cH4 +2o2= co2 + 2H2o? molar weight of ch4 & h2o are similar enough i think.
Molar mass(CH4) = 16
Molar mass(H2O) = 18
The reaction you wrote is correct.
 

Offline CZARCAR

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What is the water yield from natural gas combustion?
« Reply #4 on: 31/01/2010 17:44:40 »
thanx. i was analogyzing ng to propane. using i therm [100,000 btu] of NG as a gallon equivalent.
cH4 +2o2= co2 + 2H2o? molar weight of ch4 & h2o are similar enough i think.
Molar mass(CH4) = 16
Molar mass(H2O) = 18
The reaction you wrote is correct.
oops i was adding atomic #s & not weight, been a while! so does it seem that 1 gal. ch4 [approximated as 100,000btu] will combust into 2 gal. h2o---approximately?
 

Offline lightarrow

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What is the water yield from natural gas combustion?
« Reply #5 on: 31/01/2010 19:50:45 »
thanx. i was analogyzing ng to propane. using i therm [100,000 btu] of NG as a gallon equivalent.
cH4 +2o2= co2 + 2H2o? molar weight of ch4 & h2o are similar enough i think.
Molar mass(CH4) = 16
Molar mass(H2O) = 18
The reaction you wrote is correct.
oops i was adding atomic #s & not weight, been a while! so does it seem that 1 gal. ch4 [approximated as 100,000btu] will combust into 2 gal. h2o---approximately?
If water were a gas at P = 1 atm and T = 25C...
 

Offline CZARCAR

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What is the water yield from natural gas combustion?
« Reply #6 on: 31/01/2010 20:06:59 »
thanx. i was analogyzing ng to propane. using i therm [100,000 btu] of NG as a gallon equivalent.
cH4 +2o2= co2 + 2H2o? molar weight of ch4 & h2o are similar enough i think.
Molar mass(CH4) = 16
Molar mass(H2O) = 18
The reaction you wrote is correct.
oops i was adding atomic #s & not weight, been a while! so does it seem that 1 gal. ch4 [approximated as 100,000btu] will combust into 2 gal. h2o---approximately?
If water were a gas at P = 1 atm and T = 25C...
thanx again but me no rocket scientist! my house has a 100,000 btu ventless gas heater with adequate air for combustion & i'm guessing that when i burn 100,000 btu of methane i will humidify the air with 2 gal. of water? the room is heated to 70*f
 

Offline lightarrow

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What is the water yield from natural gas combustion?
« Reply #7 on: 31/01/2010 20:14:56 »
Approximately yes.
 

Offline CZARCAR

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What is the water yield from natural gas combustion?
« Reply #8 on: 31/01/2010 20:54:28 »
thanx, now how about propane?
1gal. propane combusts into ? gal. h2o
 

Offline CZARCAR

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What is the water yield from natural gas combustion?
« Reply #9 on: 01/02/2010 14:09:10 »
from different sites i come to the following conclusion
1 gal propane= .8 gal. h2o
100,000 btu methane= .9 gal. h2o
approximately?
 

Offline lightarrow

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What is the water yield from natural gas combustion?
« Reply #10 on: 01/02/2010 15:02:53 »
Propane: CH3-CH2-CH3

CH3-CH2-CH3 + 5O2 --> 3CO2 + 4H2O

so: 1 mole propane --> 4 moles water.
 

Offline CZARCAR

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What is the water yield from natural gas combustion?
« Reply #11 on: 02/02/2010 15:08:32 »
another forum sez :
[1therm,4.2lb] ch4 yields 1.1 gal h2o
[1 gal, 4.1lb.] c3h8 yieds .8 gal. h2o
 

Offline peppercorn

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What is the water yield from natural gas combustion?
« Reply #12 on: 02/02/2010 17:22:35 »
How much liquid water is released for every BTU of methane burnt?
 

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What is the water yield from natural gas combustion?
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