Gas KG/hr to Nm3/hr

[chris102030]

Hi All,

I have been stumped on how to convert this mixture of gases from kg/hr to nm3/h assuming 1 atmosphere and 0^oC the gas mixture is as follows Hydrogen 35%, Carbon Dioxide 20.8%, Carbon Monoxide 11.68%, Methane 16.28%, ethane 1.34%, Ethene 3.11% Nitrogen 10.2%. The total weight of the gas being produced is 300kg/hr by my calculations this will equate to 1459 nm3/h is anyone able to assit me with this? I only have a basic background in chemistry

[gubment_cheez]

Hello Chris, what calculations did you use to come up with your 1459 nm3/h value?

[JohnS]

You need to determine the average molar mass of the mixture. Your constituents only add to 98.41% of the mixture, so something is missing or there is a typo. For each gas determine its molar mass (I cheated and used integer atomic mass units.)Compute the weighted average. For what is identified i get 20.2 g/mol (or kg/kmol). A mole of ideal gas at "normal" conditions occupies 22.414 L/mol (or m³/kmol).

300 kg x 1 kmol/20.2 kg x 22.4 m³ = 333 m³

My numbers are all rounded and approximate, because some constituents are missing, and I used rounded atomic masses.

[gubment_cheez]

I reached a value of 325.7491405
I pulled the density value in g/L from Wikipedia's Physical Property panel of each gas at 0°C. For values that were not available on wikipedia I searched bing for gas density at 0c and took the first value available. If this was not in g/L I converted it to g/L using the conversion tools provided by onlineconversion.com. All conversions were 1:1 (i.e. kg/m³ to g/L).
Since all conversions were 1:1 I was able to convert 1:1 g/L into kg/m³ and am using these conversions for my table math.

Additionally I was also able to observe the error in the percentage of the mixture, and I believe it is either a typo, or some particulate matter in the gas production. I extrapolated about 4.9714 kg/m³ other material based on the unidentified percentage and volume percentage remaining after the other gasses were accounted for.

	kg/m³	%	kg/m³ × %	Total mass per hour
Hydrogen	0.179	35	0.0627	20.408
Co2	1.977	20.80	0.4112	133.953
Co	1.25	11.68	0.1460	47.559
Methane	0.717	16.28	0.1167	38.024
Ethane	1.3562	1.34	0.0182	5.920
Ethylene (Ethene)	1.242	3.11	0.0386	12.582
Nitrogen	1.2506	10.20	0.1276	41.553
			Subtotal	300 kg
Total		98.41	0.921%	325.75 m³
Other/Unlisted		1.59	0.079%

[rubelahamed]

Hi All,

I have been stumped on how to convert this mixture of gases from kg/hr to nm3/h assuming 1 atmosphere and 0^oC the gas mixture is as follows Hydrogen 35%, Carbon Dioxide 20.8%, Carbon Monoxide 11.68%, Methane 16.28%, ethane 1.34%, Ethene 3.11% Nitrogen 10.2%.Since all conversions were 1:1 I was able to convert 1:1 g/L into kg/m³ and am using these conversions for my table math.