The nature and effect of sulphur compounds on co₂ and air reactivity of petrol coke

Three different single-source coke types (SSA, SSB and SSC) were studied for their air and CO₂ reactivities using the Hydro method and the observed correlation with reactivity determinant parameter such as elemental composition was noted. The reaction temperatures were 525 °C and 960 °C for air and CO₂ reactivities, respectively. Coke sample SSA recorded the highest CO₂ reactivity value of 166 mg/g h while coke sample SSB recorded the lowest value of 25 mg/g h. The coke CO₂ reactivity showed a moderately strong correlation with the combined effect of Na, Fe and Ca concentrations. The inhibitory effect of sulphur as a catalytic poison on Na was observed with significant downward trend in CO₂ reactivity of the investigated cokes. Coke air reactivities showed the expected strong correlation with V. Air reactivity was highest in sample SSC (262 mg/g h) at V concentration of 378 ppm and lowest in sample SSB (39.6 mg/g h) at V concentration of 68 ppm. Sample SSA recorded reactivity value of 129.6 mg/g h at V concentration of 147 ppm. The compound 1-butanethiol was identified by 1-D ¹H NMR and ¹³C NMR, and by 2-D COSY, HSQC and HMBC NMR spectroscopic techniques. It is proposed that 1-butanethiol is one of the possible organosulphur compounds responsible for the reaction with Na forming a stable non-mobile complex partially inhibiting the catalytic effect of Na.