Purging shutdown procedure

Many start-up/shutdown procedures have aimed to reduce the corrosion current through practices such as anode purging and shunting. Others have attempted to nse more stable carbon materials such as graphitized carbon and carbon nanotnbes (CNTs). - To delay the onset of the COR during fuel starvation, WOR catalysts have been incorporated into the anode electrodes. Increasing anode ionomer content has also been recommended for a fnel starvation-resistant anode because it increases the amount of water available for the WOR. - In general, the materials approaches are applicable to all kinds of carbon corrosion. 

Yu, P.T. et al., The effect of air purge on the degradation of PEM fuel cells during startup and shutdown procedures, in Proceedings of the AIChE 2004 Spring National Meeting, 37C, New Orleans, April 25-29, 2004. 

Yu PT, Kocha SS, Paine L, Gu W, Wagner FT (2004) The effects of air purge on the degradation of PEMFCS during startup an shutdown procedures. Proc AIChE 2004 Annual Meeting, New Orleans, LA, April 25-29 (2004)... 

Losses associated with startup and shutdown of equipment and aitire units are common (e.g., a notable industry incident occurred in 1989 with the Piper Alpha North Sea platform loss). As with any operating procedure development, employees should be involved for their insight and concurrence. Particular care should always be given when developing equipment startup and shutdown procedures. This includes commissioning new faciUties (e.g., purging and leak testing). 

The semiregenerative procedure for catalyst regeneration varies slightly between catalyst vendors however, it typically follows these general steps plant shutdown, carbon bum, oxidation and chlorination, nitrogen purge, reduction, and plant start-up. During the plant shutdown, Hquid hydrocarbons... 

The shutdown is usually very simple. Procedures for shutdown without cleanout starts by stop feeding plastic into the plasticator and reduce all heat settings to the melt heat. Reduce the screw speed to 2 to 5 rpm, purging the plastic if requires into a water bucket or drum prior to reducing the melt heat. The screw rotation continues until no more plastic exits the die. Rotations of the screw stops resulting in the so-called pumping the screw dry of plastics. 

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