New ideas for energy savings – Creative approaches to the “Energy-efficient and efficient renovation of acid waste dehydration tanks”
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Energy-saving and efficiency-improving renovation of the waste acid dehydrogenation tank: currently, a large amount of gas is vented through flares, resulting in significant waste of liquefied petroleum gas. Analysis shows that the main source of air released is the hydrocarbons contained in the waste acid, which enter the venting system via the waste acid dehydrocarbonation tank, the acid discharge tank, and the alkaline scrubbing tower. After acid hydrocarbon separation in the acid precipitation tank, only a very small amount of hydrocarbons remain dissolved in the acid. Currently, waste acid dehydrogenation tanks, due to their high pressure and small volume, are not conducive to the removal and recovery of hydrocarbons; as a result, these hydrocarbons end up being wasted in the subsequent venting system. If these hydrocarbons could be fully recovered and utilized, significant benefits could be achieved over time. During operation, it was found that in the slightly positive-pressure acid removal tank, hydrocarbons can be easily removed and enter the alkali scrubber as well as the subsequent venting system. When the acid discharge pump is started, the venting pressure drops, causing the first-stage flare vent to fail to burn. The calculated amount of air released over 24 hours is approximately 500 kilograms. With the current device layout and piping arrangement, the acid waste dehydrogenation tank needs to have a pressure of around 0.2 MPa in order to push the acid waste into the acid discharge tank; however, this pressure is not conducive to the removal of hydrocarbons. The following technical modifications will be carried out: the waste acid dehydrogenation tank will be moved to the second floor of the facility, and the liquid level difference will be utilized to allow the waste acid to flow into the acid discharge tank. This will reduce the pressure in the waste acid dehydrogenation tank, thereby facilitating the removal of hydrocarbons. The valve that sends the hydrocarbons back to the flash tank is opened, so that the pressure in the waste acid dehydrocarbonation tank remains at a slight positive pressure, equal to that in the flash tank. Enlarging the waste acid dehydrogenation tank by increasing its cross-sectional area facilitates the precipitation of hydrocarbons; existing idle horizontal pressure vessels can be modified for this purpose. Currently, the acid separation tank is unable to separate the oil; as a further solution, fillers can be added to the dehydrogenation tank to help separate the oil from the waste acid. A small space on the oil side is sufficient; the majority of the space is used for acid-oil separation.
It is estimated that implementing this renovation plan will generate annual benefits of 1 million.
Energy conservation means creating benefits, resulting in cost savings.
Is the recovery rate higher for vacuum flash distillation? Feasibility to be determined.
There are a few questions I’d like to ask: Engineer Guo, 1. Have you calculated the residence time in the acid dehydration tank and the acid discharge tank of your alkylation unit? 2. For the hydrocarbon removal flash tank in the spent acid dehydrogenation tank, haven’t you considered the issue of acidic gases? 3. Do you know how great the danger of doing this is?
I suggest that you make adjustments to your approach. With the method you use of placing the acid removal tank at a higher position, this was also the approach adopted by DuPont back in 2013. It’s not true that simply increasing the volume of something is always the best solution; strengthening the foundation and understanding the principles behind design are the proper approaches. If you proceed with these changes, the company will suffer even greater losses.
Think boldly, verify carefully, prioritize safety, and seek breakthroughs.
In the future, I’ll just keep watching on Haichuan; I can’t express my opinions, as that might offend people. I’ll just watch quietly, wait quietly, watch the jokes unfold quietly, and wait patiently for something good to appear.
The results of my experiments here are good; could it be that you didn’t choose the right filler for the modification at that time?