Gasoline desulfurization alcohol
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In the gasoline desulfurization process, fixed-bed reactors can have feed at the top and outlet at the bottom, or feed at the bottom and outlet at the top. Which configuration is appropriate? What are the advantages and disadvantages of each? Why is there such a difference in design? This post was last edited by chengkang on 2009-3-30 21:42]
I’ve never seen it happen where something comes out from below; if that does happen, then both the gasoline and the residue will come out together. Look at the reaction equations – gasoline desulfurization produces water. I wonder what to do with that water in such a situation. Do we need to use a separate container to collect it? This post was last edited by chengkang on 2009-3-30 21:43]
Both types of fixed-bed reactors are available, and this is also considered a difference between first-generation and second-generation technologies.
For general alkaline desulfurization, the flow is usually from bottom to top; whereas for hydrodesulfurization, it is from top to bottom!
Compared to the solvent, when the material is the heavier phase, it flows in from above and out from below; when it is the lighter phase, it flows in from below and out from above. Last edited by tanmx on 2009-3-30 22:10.]
The first generation of fixed-bed reactors use feed from below and discharge from above, while the second generation uses feed from above and discharge from below; this has nothing to do with what was mentioned above. The main consideration is that an activator is added to the gasoline; since both the gasoline and the activator are in liquid form, under a top-in-bottom-out flow regime the activator can move downward together with the gasoline due to gravity, thereby enabling effective activation of the entire bed. The outlet point does not refer to gasoline being drawn out from the bottom, but rather from the side of the lower part of the bed; it is the residues that are drawn out from the bottom. In the downward-in and upward-out process, due to the gravitational effect of the activator, the upper part of the bed layer often cannot be reached, resulting in insufficient activation of the bed layer.
Correct, a dedicated container is indeed needed for draining liquid.