What is the impact of quench water pH on the system?

Being too high or too low can cause severe corrosion in both the quench tower and pipelines; therefore, alkali must be added to adjust the pH of the quench water to neutral.

The function of the quench water is to cool the exhaust gases from the hydrogenation reactor; it also serves to remove ash, wash away impurities, and absorb gases such as H2S and CO2. As a result, after absorbing these acidic gases, the quench water becomes slightly acidic, and ammonia must be added regularly to adjust its pH value. Too low; distinctly acidic, corroding equipment and pipelines and reducing their service life ； It is too high and alkaline; on one hand, the alkalinity causes corrosion, and more importantly, it leads to the formation of ammonium salt crystals, which block the acid water pumps and the tower fillers, resulting in system blockages and severe shutdowns.

Either a low or high pH level of the quench water can cause corrosion in the system； Will a high (or low) value not lead to an increase in the solvothermally stable salt?

I compare the pH value of the quench water to the body temperature. The normal body temperature should fall within a certain range; similarly, this is true for the pH value in the quench tower. A low pH value indicates that sulfur dioxide has entered the quench tower, which inevitably leads to corrosion. However, our focus should not be on the measures to take after the pH value drops, but rather on why it drops in the first place. I believe that when the pH value decreases, the load on the hydrogenation reactor becomes severely insufficient – in other words, what is commonly referred to as \"sulfur dioxide penetration\" occurs. At this point, blockages and corrosion in the quench tower system become quite severe

A pH level that is too low or acidic indicates that SO2 has penetrated the exhaust gas hydrogenation reactor; upon entering the quench tower, it forms sulfurous acid, which causes the pH level of the quench water to drop rapidly and make it acidic. This leads to severe corrosion of the equipment, especially carbon steel, and may even cause perforations, thereby affecting the safe operation of the facility； SO2 penetrates into the hydrogenation reactor, and the hydrogen sulfide generated as a result of reduction undergoes further Claus reaction in the subsequent process to produce sulfur, which leads to blockages in the quench tower; in severe cases, the system cannot be fed with material, forcing the plant to shut down for maintenance of the quench tower ； When the pH value of the quench water becomes acidic, the FeS2 protective layer formed on the surface of the pipes and the impurities on the surface of the packing are corroded away. After being impacted by the quench water, these substances accumulate at the bottom of the packing, resulting in an increase in the pressure drop in the quench tower and darkening of the water quality; in severe cases, this affects production. The high pH value of the quench water is mainly caused by excessive ammonia injection; an increase in the alkalinity of the quench water can also lead to corrosion of the equipment, although the degree of corrosion is much less severe than that caused by acidity ； If the pH value is too high, some of the ammonia that enters the absorption tower can cause the solvent to age, resulting in a decrease in the concentration of the absorption solvent and thereby affecting the efficiency of exhaust gas absorption.