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Published by Water Network Research, Official research team of The Water Network
answer from open ai chat gpt:
This process appears to be related to the sweetening of C4/C5 hydrocarbons —likely in a refinery or petrochemical plant where the hydrocarbons are treated to remove impurities (such as nitriles and acetone) using a washing tower . The ultra-pure water (UPW) used to wash these hydrocarbons has a rising pH, which could indicate the removal of certain acidic or polar impurities, leading to an increase in pH.
Process Description:
Washing Tower in Hydrocarbon Sweetening :
The washing tower is used to treat the C4/C5 hydrocarbons by washing them with UPW to remove polar impurities like nitriles and acetone . These impurities may react with water, causing the pH of the water to rise as the wash liquid interacts with acidic impurities.pH Rise in UPW :
The ultra-pure water (UPW) has an initial pH of 6-7, but after being used to wash the C4/C5 hydrocarbons, the pH rises to 9-10 . This suggests that some acidic impurities are being removed, which could lead to the formation of alkaline compounds in the UPW, raising the pH.pH of 9.6 :
After washing, the UPW pH is 9.6 , but the analysis does not show any alkali substances (such as hydroxides or carbonates). The lack of alkali matter in the UPW suggests that the alkali is likely in the form of less easily detectable species or may be bound to other compounds.
Possible Missing Substances to Test:
Given the pH rise and absence of typical alkali substances, here are a few potential substances to consider testing :
Amines : Some impurities may involve amine compounds that could raise the pH but may not show up as typical alkali materials. Amine-based compounds are commonly found in hydrocarbon sweetening processes.
Organic Acids or Anions : The hydrocarbon impurities could also include organic acids (such as acetic acid or formic acid), which could neutralize and form salts or other species that contribute to the pH change.
Aldehydes/Ketones : Acetone and other ketones could potentially react with the UPW and may influence the pH but may not necessarily appear as simple alkali substances.
Ammonium Compounds : The presence of nitriles may lead to the formation of ammonium salts or similar nitrogen-containing compounds, which could contribute to the pH increase.
Buffering Agents : If any buffering agents are used in the sweetening process, they may also raise the pH without showing typical alkali compounds.
Testing Recommendations:
Amines (such as methylamine, diethylamine) should be tested, as they can influence pH.
Acidic compounds , especially organic acids , might also be a source of the pH rise.
Ammonium ions (NH₄⁺) could also be tested as a byproduct of nitrile washing.
Consider looking for complexing agents (e.g., chelating agents) that may bind alkali ions in a less detectable form.
By testing for these potential impurities, you can better determine the source of the pH change and confirm whether alkali matter is indeed present in a different form.
This process is likely part of a hydrocarbon purification or sweetening process in the petrochemical or refining industry , where removing impurities from the C4/C5 fraction is crucial to ensure the quality of the final product.