Does producing one ton of ammonia require around 3,300 cubic meters of semi-water gas?
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I’m doing calculations related to the consumption of ammonia in synthesis. I often come across information that states directly that \"about 3,300 cubic meters of semi-water gas are required per ton of ammonia consumed.\" No matter how I calculate it, I can’t arrive at this figure – where does this number come from? Please feel free to share your insights!
This indicator is related to the contents of various components in the semi-water gas as well as the conditions of process control. For example, if we use briquetted coal for gas production, the CO content in the semi-water gas is only around 23%, and in that case we won’t be able to achieve the target value of 3300. There are also issues with leaks in the system; if too much gas is lost, it will not be possible to meet this target
Reply to 2# chen-jun-1024: Leaks are not taken into account; we also produce gas from briquettes, with the gas composition being 26.5% CO, 37% H2, 10.0% CO2, 2.5% CH4, 0.5% O2, and 23.5% N2. The key issue at present is that we cannot obtain results close to 3300. Could you share your calculation process? dinongge@163.com would work as well.
It’s quite simple: one molecule of carbon monoxide is equivalent to one molecule of hydrogen. Based on the chemical equation for the synthesis of ammonia from nitrogen and hydrogen, it is calculated that 1 ton of ammonia requires approximately 2,900 cubic meters of nitrogen and hydrogen. Given that the composition of the gases includes 87% nitrogen, carbon monoxide, and hydrogen, dividing 2,900 by 87% yields 3,333 cubic meters. If the gas composition is good, that is, when the carbon dioxide content is low, the gas consumption is low, at around 3,300 cubic meters.
Depending on the composition of the gas used for gas production and the purification processes employed, there are also instances of leaks and venting. Generally, 3,000–3,300 cubic meters of semi-water gas is consumed per ton of ammonia, or 2,800–3,000 cubic meters of refined gas (these figures refer to traditional production methods). With the use of methanol washing and nitrogen washing nowadays, the quality of the gas improves, and venting occurs less frequently; the amount of refined gas required per ton of ammonia can be reduced to below 2,800 cubic meters. Theoretically, 2,635 cubic meters of nitrogen-hydrogen gas is sufficient per ton of ammonia
Calculation: The effective gas composition is 26.5% CO2 and 37% H2, for a total of 63.5%. (2635*3/4)/0.635 = 3112 cubic meters; leaks and venting are not taken into account