Catalytic converter test procedure

To counter the elevated emissions associated with enrichment, the EPA has adopted supplemental federal test procedures. The new laboratory test procedures contain higher speeds, higher acceleration and deceleration rates, rapid speed changes, and a test that requires the air conditioning to be in operation. These tests increase the probability that vehicles will go into enrichment under laboratory test conditions. Hence, manufacturers have an incentive to reduce the frequency of enrichment occurrence in the real world. Future catalytic converters and emissions control systems will be resistant to the high-temperature conditions associated with engine load, and will be less likely to require enrichment for protection. Thus, enrichment contributions to emissions will continue to decline. 

Selective oxidation of hydrogen. sulfide The catalytic properties of the different catalysts in the selective oxidation of HaS were tested in a continuous microflow apparatus. Care was taken to assure plug flow and isothermal conditions. The feed consisted of 1.0 vol% HaS, 5.0 vol% Oa, and 30 vol% HaO in He. The effluent was analysed with a gas chromatograph. In order to obtain a stable activity, the catalyst remained for 12 hours in the reactor under reaction conditions. This procedure converted the iron oxide into iron(II) sulfate. Subsequently the temperature of the microflow reactor was varied stepvnse from 453 K (180°C) to 593 K (320 C) and back to 453 K with a step size of 10 K. The thus obtained data provide information about the conversion and selectivity at various temperatures. The selectivity is defined by equation (2). 

---