Reforming Flashcards
Semi Regenerative Reforming Process
The preheated feed is mixed with a recycle hydrogen stream and then heated in a furnace before entering the first reactor. In the first reactor the main reaction is the dehydrogenation of naphthenes to aromatics. The reaction is an endothermic reaction and hence there is a large temperature drop in the reactor. Due to this the mixture must under go heating before entering the second reactor.
As the mixture proceeds through the reactors, reaction rates increases and reaction diameters increase in order to have a high enough residence time to maintain a high level of conversion.
The product form the final reactor is then cooled to allow for formation of condensed liquid and then sent to a hydrogen separator. Hydrogen rich gas is separated and divided into a recycle stream and a by product stream.
the liquid product from the reactor is then sent to the fractionation for butanisation
Continous Catalyst Regeneration
CCR involves movement of catalyst between reactor and regenerator. The preheated feed and catalyst are introduced into the first reactor from the top of the reactor. The mixture then flow down the reactor allowing for a suitable residence time for the reforming process to occur. The product fro one reactor is taken out and heated before entering the successive reactor in order to maintain a high yield. After the final reactor the catalyst and product are separated with the catalyst going to the regenerator. The product stream is taken out and cooled down in a heat exchanger system before taken to a topping column for separation.
The spent catalyst is transported to the regenerator using a stream of Nitrogen gas. In the regenerator the catalyst moves downwards and is regenerated by burning of the coke deposits with a nitrogen gas stream containing a small amount of oxygen. It is then transported to the top of the reactor using a hydrogen gas stream.
The diameter of the reactor increase downwards because catalyst activity decreases downwards hence more intensive processing is required along with a higher residence time to achieve a high conversion.
