For the cracking of hydrocarbons, the selectivity of ethene and ethane following the carbonium ion mechanism is generally lower than that following the free radical mechanism.
Consequently, the selectivity of ethene is low, while that of propene is high.
The selectivity of ethene and ethane of catalytic pyrolysis is higher than that of thermal pyrolysis.
Several field studies of PCE/TCE-contaminated landfill sites and aquifers (61,66-70) have shown that, under specific conditions, PCE and TCE can be intrinsically biodegraded anaerobically to ethene by indigeneous methanogenic, acetogenic, and sulphate-reducing bacteria.
Occurrence, evaluation and analysis of vinyl chloride as a degradation product of chlorinated ethenes in contaminated areas [in German].
Although VC may be further degraded to less and nonchlorinated ethenes and possibly finally to carbon dioxide and ethane, this proceeds at a slow rate under highly reducing conditions (63-65); as a consequence, there can be a build-up of VC in landfills and surrounding areas.
ethene formation) at saturated PCE concentrations in batch systems with a dechlorinating consortium.
The discovery of numerous dechlorinating populations capable of converting PCE to cis-DCE and recognition of the importance of Dehalococcoides populations in the transformation of chloroethenes to ethene will likely improve future bioaugmentation strategies and further enhance posttreatment biopolishing.
Isolation of a bacterium that reductively dechlorinates tetrachloroethene to ethene.
limits) of reductive dechlorination of chlorinated ethenes are investigated.
The formation of benzene, ethene
, and acetylene was also frequently observed.