[khamush]

hello,

have a small question about the products of coke gas combustion.
it is said that the gas contains 60% hydrogen, 25% methane, 5% carbon monoxide, 3% carbon dioxide,3% ethene,3% nitrogen and 1% oxygen.
for the neutralization of its combustion products NaOH is used.
so my question is: what are the products to be neutralized? only CO2? what about combustion of nitrogen then?

[AWK]

For combustion of N2 in oxygen you need an electric arc (over 3000 C)
Only traces of NO are formed in car engine (temperature  ~ 1000 C)
and
significant amount of CO is formed over 1200 C. You can obtain temperature over 1000 C only using pure oxygen, usually air is used.
Hence balance reaction with CO2 and H2O as products, and neutralize CO2 with NaOH

[Mr Peanut]

Also, trace SO2 removed with NaOH.

[Donaldson Tan]

Your description fits the gasification of coke using high pressure superheated steam, not combustion of coke. Given you have 3% of CO2, it is advisable that you should use a reactive mean to remove CO2. NaOH would be too corrosive for industrial usage. You might be better off with MEA or DEA.