The function of the standby external circulation pipe
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Which expert knows the function of the raw material external circulation pipe (the circulation pipe from the settler to the second reactor) in the MIP process? What are the advantages and disadvantages of this design compared to other processes? This post was last edited by longff on 2009-3-28 12:39.]
As the raw material external circulation pipe enters the bottom of the second reaction zone from the settler, one element allows for controlling the density of the bed layer in that zone, while the other enables easy temperature adjustment~~~~~~~~~~~~~
MIP technology is used to produce a variety of heteroalkanes and aromatics. It has two reaction zones; the first reaction zone is primarily for cracking, featuring high temperatures, highly active catalysts, and high flow rates, while the second reaction zone is for hydrogen transfer and isomerization, with lower temperatures and less active catalysts. The function of the raw material external circulation pipe is to transport the catalyst from the stripping section to the second reaction zone, thereby facilitating hydrogen transfer and isomerization.
The so-called MIP is a riser process for producing various heteroalkanes and aromatics. A typical MIP process consists of a riser and two reaction zones. The feed oil enters the riser and first goes to the first reaction zone where reactions take place; this zone is primarily used for cracking reactions, under conditions of high temperature, a highly active catalyst, and a short residence time ； The second reaction zone is primarily involved in hydrogen transfer and isomerization reactions, which require lower temperatures, lower catalyst activity, and longer residence times. Meeting these conditions is achieved first by enlarging the diameter of the second reaction zone in the lift column; second, by using a raw catalyst external circulation line to transport the catalyst from the stripping section to the second reaction zone, thereby reducing the temperature in that zone and the equilibrium activity of the catalyst there, and thus lowering the space-time velocity in the second reaction zone. Thirdly, it is accomplished by injecting a terminator (though this method is not used in some plants).