Please take a look at these two options and give some suggestions. . .
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The methane, carbon dioxide, carbon monoxide, dimethyl ether, methanol, hydrogen, and nitrogen at medium pressure that emerge from the fluidized bed at 243 degrees – in order to separate dimethyl ether and methanol and make use of the heat and pressure contained in this gas mixture – I have two proposals. The first is to pass the gas directly through a heat exchanger, then drive a turbine, and after that through a condenser to obtain liquid methanol and dimethyl ether; the remaining impure gases are then vented. The second proposal is to first use the high-temperature medium-pressure steam to drive a turbine, then pass it through a heat exchanger, and finally through a condenser to obtain liquid methanol and dimethyl ether ； Which one is more reasonable, or do you have any good suggestions? . .
Personally, I think the second option is better; the temperature of the mixed gas after passing through the turbine remains high. If direct condensation is used, it requires significant capacity from the condensation equipment. On the other hand, the heating medium after heat exchange can be used for other purposes, making it more cost-effective.
The advantage of the first approach is that heat exchange allows for the recovery of waste heat at high temperatures; however, the steam generated after this heat exchange is needed to drive the turbine, which results in a higher consumption of steam compared to the second approach. Moreover, the temperature during condensation is higher, which may lead to more waste of the condensing medium used； The second option is more reliable: less steam is required to drive the turbine, which makes it more economical. Although the amount of waste heat recovered through heat exchange is less than in the first option, the temperature at the inlet of the condenser is easier to control. So personally, I think the second option is safer and more reasonable.
Reply to 2# zhufeiwu: The heating medium after heat exchange can be used for other purposes as well; I thought of that back then. Do you have any good suggestions regarding its uses?
I don’t quite understand. Your medium-pressure gas is a Class A gas; be careful. I thought of using the residual heat, the by-product steam, or to preheat the raw materials or something like that.
This post was last edited by Albertlu on 2010-7-10 at 11:01. It is recommended to consider two scenarios: the two processes in which the permeator and the heat exchanger are arranged one after the other, to determine which one allows for smoother automatic control. Calculate to see which of the two options offers the greatest economic benefit in terms of heat recovery. The above analysis requires specific information regarding the performance of the equipment, as well as the process conditions and parameters.
The last edit to this post was made by pengshujie on 2010-7-10 at 19:03. The second option is better, as heat utilization can be easily adjusted; however, for the turbine, it is necessary to ensure stable gas flow