Pyrolysis of organosulphur compounds

The role of labile sulfur compounds in thermochemical sulfate reduction

“…However, it is possible to argue that LSC may simply serve as a source of inorganic S species, such as elemental S or H 2 S, which are known to be formed during pyrolysis of thiols (Martin, 1993;Katritzky et al, 2001). Inorganic reduced S has previously been suggested to have a catalytic effect on the TSR reaction (Goldstein and Aizenshtat, 1994); however, it is thought that relatively high concentrations of elemental S or high pressures of H 2 S are needed to effectively catalyze TSR.…”

“…Free radicals are very active and readily abstract H from other organic compounds, which initiate free radical chain reactions (Martin, 1993). Consequently, the thermal stability of the HC decreases and more radicals and double bonds are formed.…”

“…The amounts of 1-pentanethiol in octane were relatively low and ranged from 0.1 to 1 wt% HC that is equal to $0.03 to 0.3 wt% S (Table 3). Because the thermal degradation of 1-pentanethiol alone generates H 2 S (Martin, 1993;Katritzky et al, 2001), we ran several control experiments without CaSO 4 to determine the amount of H 2 S that was released by thermal degradation of 1-pentanethiol (Table 3). The results of these control experiments show that, after 14 h at 356°C, 1-pentanethiol is completely thermally degraded to yield predominantly H 2 S (Table 3).…”

“…Organic S species are known to produce free radicals according to the following equation (Martin, 1993;Katritzky et al, 2001):…”

“…There is also some evidence that organic labile sulfur compounds (LSC), such as thiols and sulfides that are commonly found in crude oils, may be important in enhancing the reaction . TSR-altered oils are enriched in organosulfur species which are formed in reservoir via reactions with H 2 S (Ho et al, 1974;Martin, 1993;Cai et al, 2003). Detailed examination of H 2 S generation rates during TSR experiments has indicated that it may proceed as a two-stage reaction.…”