Polymer degradation into the bore of the pipe, and fuel leakage and fire may follow. The problem of ozone cracking can be prevented by adding anti-ozonants to the rubber before vulcanization. Ozone cracks were commonly seen in automobile tire sidewalls, but are now seen rarely thanks to these additives. On the other hand, the problem does recur in unprotected products such as rubber tubing and seals. The polymers are susceptible to attack by atmospheric oxygen, especially at elevated temperatures encountered during processing to shape. Many process methods such as extrusion and injection moulding involve pumping molten polymer into tools, and the high
Chemical looping reforming and gasification SMR reaction heat, two CLC-SMR schemes can be configured. In Scheme 1 (Fig 2a), the reaction heat is provided by the reducer (fuel reactor). In Scheme 2 (Fig 2b), the reaction heat is provided by the combustor (air reactor). In either scheme, the combustion of metal oxide by air in the chemical looping system provides the heat source that sustains the endothermic SMR reactions. In the chemical looping system, natural gas and the recycled off-gas from the pressure swing adsorption (PSA) of the SMR process system are used as the feedstock for the CLC fuel reactor operation with CO and