if coke doesn't has hydrogen so it meas it does not has hydrocarbon then how does it burn?
A hydrocarbon is class of compound containing C and H. If we remove H from it then it will no more remain hydrocarbon but it will become some thing else. We can not expect a non-hydrocarbon compound to show the property of hydrocarbon.
Similarly coke without H will not be coke, then it will or will not burn depends on property of the compound.