What impact does the amount of circulating hydrogen have on production operations?
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This is our exam question. I feel like I didn’t answer it well. Please give me a comprehensive answer.
The size of circulating hydrogen controls the pressure of the reactor, which also affects the conversion rate of the hydrogenation reaction itself. At the same time, sometimes the reaction temperature can be adjusted by circulating hydrogen so that the reaction proceeds under the operating conditions to be controlled. That's all I know, please give me some advice.
Excessive hydrogen concentration in the cycle means that the production capacity will decrease and the output will decrease, because too much hydrogen is equivalent to an inert gas. Of course, the current of the cycle machine will decrease and the power consumption will be reduced.
A large amount of circulating hydrogen means a large hydrogen-to-oil ratio. A large hydrogen-to-oil ratio means a high hydrogen partial pressure, which is beneficial to the hydrogenation reaction, delays catalyst coking, and extends the catalyst life. In addition, a large amount of "excess" hydrogen can quickly take the reaction products away from the reaction system and prevent excessive cracking from producing a large number of low-value products. A large hydrogen-to-oil ratio is beneficial to the control of the reaction temperature. Of course, a large amount of circulating hydrogen comes at the expense of power consumption. Excessive amount of circulating hydrogen is not only unnecessary but also increases power consumption and energy consumption of the device. The recommended volume ratio of hydrogen to oil in the hydrogenation unit is: Hydrocracking is not less than 700 ； Residual oil hydrogenation shall not be less than 600.
This post was finally edited by wwwh332 on 2009-8-2 19:44. The 4th floor gave a good answer and added a few points.: 1. The circulating hydrogen flow is too large, and the investment in equipment, especially the compressor, is very large. 2. Some dehydrogenation devices also have circulating hydrogen, which is different from the hydrogenation device. 3. The circulating hydrogen is large, and the hydrogen takes away a lot of heat, which is not conducive to the energy saving of the device. 4. The circulating hydrogen is too large, the material has less contact with the catalyst, and the unit time is short, which is not conducive to the improvement of the conversion rate.
The premise is to see whether hydrogen is a reactant or acts as a catalyst. A large hydrogen flow rate can increase the processing capacity, while also accelerating the flow speed and heat transfer.