The total alkalinity of the desulfurization liquid is low
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We have been using the liquid-phase catalytic desulfurization method with ammonia. Some time ago we tried switching to the alkali (Na2CO3) method, but no matter how much alkali was added, the total alkalinity wouldn’t increase. After trying it for nearly 10 days with no success, we reverted to using ammonia. I’m not sure why the total alkalinity isn’t increasing; please help analyze it. The catalyst is 888.
If the total alkalinity cannot be increased, it is recommended to analyze the issue from the following two aspects: high CO2 content in the gas； High gas temperature and high solution temperature lead to the formation of by-products and salts
Pay special attention to the formation of by-products; enhance solution replacement, and be willing to add chemicals
When using it for the first time, be willing to add enough alkali; otherwise, the amount used might not be sufficient. :) This post was last edited by wulashan on 2009-2-16 07:59 ]
If alkali is added and the total alkalinity does not increase, it may be due to side reactions.
It might be due to gas desulfurization; there is a high amount of carbon dioxide in the gas, and after desulfurization, the desulfurization liquid stays in the rich liquid tank for too short a time, which hinders the removal of carbon dioxide. A suitable amount of sodium hydroxide can be added. However, efforts are still needed to reduce the occurrence of side effects, decrease the amount of air used for regeneration, and lower the temperature of the desulfurization liquid – measures that should address the root causes of the problem.
First, determine whether the amount of alkali added is sufficient; additionally, check the secondary salts in the solution to see if their level is continuously increasing. If it’s a problem with the by-products, then this balance needs to be disrupted.
The inability to increase the alkalinity of semi-water gas may be due to a high temperature of the gas, high levels of carbon dioxide in the gas, or an overly small liquid-rich tank that results in insufficient residence time and thus excessive formation of by-products. Was there often liquid discharge when ammonia water was used? If it’s not discharged, the alkalinity won’t increase either.
It’s likely due to poor regeneration; consider replacing the catalyst
The main issue is that your regeneration process isn’t effective enough; perhaps adding some vanadium could help with composite desulfurization. You shouldn’t expect 888 to have a very significant desulfurization effect. I feel that tannin and vanadium also have good desulfurization effects. Does your solution turn into a white, turbid liquid when heated?