Nitrogen compound poisoning

Modeling Zeolite Catalyst Deactivation by Coking and Nitrogen Compound Poisoning... 

Based on the above results, it can be mentioned that the catalyst having both hydrogenation and acidic functions can successfully convert heavy oil derived from plastic wastes (relatively clean) into environmentally acceptable transport fuels. However, for the heavy oils containing impurities, the dual functional hydrocracking catalysts still need to be improved. In the hydrocracking process over the acidic catalyst, nitrogen content in feed is limited because basic nitrogen compounds poison the acidic sites of the catalyst. 

Nitrogen compounds poison catalysts used in secondary processing. Basic nitrogen is a major source of coke formation in catalytic cracking and neutralizes the acid sites in the catalyst. They are also a source of instability in fuels and a source of NO emission on burning of heavy fuels. The only industrial method for removing nitrogen from petroleum fractions is HDN. 

The adventitious discovery of the antitumor action of the nitrogen mustard poison war gases led to intensive investigation of the mode of action of these compounds. In brief, it has been fairly well established that these agents owe their effect to the presence of the highly reactive bis(2-chloroethyl)amine group. The cytotoxic activity of... 

From a practical viewpoint ideal hydrocracking offers an utmost degree of product flexibility. However, as a consequence of the catalysts required contents of poisons in the feed materials such as sulfur and nitrogen compounds are strongly limited. 

Essentially all the commercial catalysts for the polymerization of olefins from cracked gases contain phosphoric acid and therefore are poisoned by alkaline materials in the reactor feed. The most commonly encountered poisons of this type are ammonia and combined organic nitrogen compounds of a basic nature. 

Crude oils contain a certain amount of combined nitrogen which sometimes breaks down in thermal crackers to form these harmful nitrogen compounds. California, West Texas, and Venezuelan crudes seem to break down this way much more readily than other crudes. Catalytic-cracking units convert the nitrogen compounds in their feed to these polymerization catalyst poisons almost without exception. Other basic materials which have poisoned polymerization catalyst at times are sodium hydroxide and diethanolamine. Both of these materials are used extensively for the removal of hydrogen sulfide from the feed to polymerization units. Catalyst poisons of a basic nature can be removed from the... 

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