Seeking advice on the modified delustering technique using tannin method
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First of all, I would like to wish all marine friends a happy National Day and joy for your entire families! Now, getting to the point: I’ll share the tannin extraction analysis data from our facility. I hope the experts here can help us identify any issues with our process. As follows: The flow rate of the gas entering the system is 12,000 NM3/H; the temperatures at the system’s inlet and outlet are 40/28.1°C respectively, while the pressures are 0.802/0.773 MPa. The flow rate of the tannin solution is 650 M3/h. The temperature of the gas phase exiting the treatment tower is 37.9°C. The pressure and temperature in the regeneration tank are 0.398 MPa/40°C respectively, while the pressure in the flash tank is 0.509 MPa. The H2S levels at the inlet and outlet are 71.4/0.59. Analysis of the composition of the tannin solution shows the following values: NAVO3 – 0.09%, tannin – 1.27%, NA2CO3 – 2.65%, NAHCO3 – 20.6%; pH level – 8.94; H2S level – 0.0215%. Our method of preparing this mixture involves adding soft water to the tank, heating it with steam to 40°C, then adding alkali to raise the temperature to 80°C. After that, V2O5 is added, followed by the addition of processed tannin. Air is introduced for half an hour, after which the mixture is cooled before being fed into the system. Add it in 3 portions per day, 300 kilograms of soda ash, 10 kilograms of tannin, and 2 kilograms of vanadium per portion; occasionally add 888 or PDS as well. The other components for September are as follows: September 1st, 8th, 15th, 23rd, 30th – suspended sulfur: 0.0237, 0.0204, 0.0217, 0.0271, 0.0114; sodium thiosulfate: 3.043, 1.623, 2.411, 3.943, 4.78; sodium bicarbonate: 2.68, 3.42, 4.98, 4.67, 1.79. The level of sodium carbonate, which is used in the liquid removal process, has been decreasing slightly recently. The level of sodium bicarbonate has risen from 8 to over 20 over the course of a week, and the pH value remains relatively stable, generally ranging between 8.6 and 8.9, with one instance where it reached 9.02. I would like to ask if there are any issues with the materials we use in the preparation process How can the content of sodium carbonate be increased? What are the negative effects of an increase in sodium bicarbonate content on the process? I’d appreciate it if fellow sailors could help diagnose this; thanks in advance.
If you need device data, please let me know. Thank you
Have you calculated the ratio of tannin to vanadium? It’s the ratio of tannin to vanadium; according to experienced practitioners, this ratio should be between 1.1 and 1.3. The problems you’re facing are similar to those we encounter here, except that the pressure levels are different!
As a supplement, it would be best to list all the ingredients of the solution for this month; fill them in in WORD or Excel first, then copy and paste them here.
Okay, I’ll go to the office tomorrow to do the statistics
Also, how is the vanadium-to-adhesive ratio you mentioned calculated? Could you elaborate? It would be better if there were examples with data. Thank you
For example: if your tannin content is 1.27 g/L and vanadium content is 0.09 g/L, then the ratio of tannins to vanadium is 1.27/0.09 = 14.1. This value differs significantly from what senior experts have stated. Also, since the analysts in each factory are different, the analysis methods and results will surely vary as well. But it can’t be that much different, right? ! !
Apart from the low vanadium level, the circulation rate is on the high side. First raise the vanadium level to at least 0.6, and then consider controlling the circulation rate at 300–500 based on the H2S output (this is based on the gas volume; if the tower diameter is large, no adjustment may be necessary)
In the past 2 days, new problems have arisen with the tannin solution: the pH level has risen above 9, and the sodium carbonate level has also increased, while the sodium bicarbonate level has decreased slightly. The desulfurization efficiency has dropped from 98 to 90 – that’s serious
Although the suspended sulfur level is acceptable, given the values of 0.09 for NAVO3, 2.65 for Na2CO3, and 20.6 for NAHCO3, there is a high likelihood of oxygen deficiency during regeneration; it’s advisable to check the injector to see how it performs
Reply to 9# guan_870321, OP – the data provided is too limited. How are your injectors performing? How is the current dosage of chemicals determined? What is the total alkali content? How is the foam layer? How is the suspended sulfur at the moment? Will the price of by-products increase? Please explain in detail your regeneration situation. It’s best for you to go to the site in person before confirming. It’s better than here!