Coal has an energy density of about (depending on type) 24 MJ/kg, which is a shade under 7 kWh per kg, so your final number is off by a factor of 7 or so [EDIT:

Coal has an energy density of about (depending on type) 24 MJ/kg, which is a shade under 7 kWh per kg, so your final number is off by a factor of 7 or so [EDIT: I think? Or you're saying that coal creates 1 kg CO2 per kWh? Ok... Yeah, I think that's right!]