Role and relationship of desulfurization catalyst in desulfurization process. Desulfurization catalyst is the core of the composition of desulfurization solution. It is very important to maintain stable catalyst concentration and alkalinity. As desulfurization with Na2CO3 as alkali source, when controlling pH8 ~ 8.5, the equivalent concentration of buffer solution should not be too low or too high. Too low is not conducive to absorption and desulfurization, and the re flotation is poor and the foam is not formed. If it is too low for a long time, it is easy to cause component imbalance, and it is very difficult to increase the alkalinity below 0.3. The generation of side reactions in desulfurization production process is inevitable. Desulfurization catalyst should be used to reduce the generation of side reactions. It is generally believed that the total amount of by-salt ≤ 200g / l can maintain normal production. If the side reaction is serious, the alkali consumption will increase sharply, and it is difficult to maintain the alkalinity with a large amount of alkali supplement. When the total amount of secondary salt in the solution is very high, the viscosity and specific gravity of the solution increase, the power consumption increases, and even the circulating pump does not pump liquid. Seriously affect absorption and reabsorption *. When Na2SO4 in the solution is ≥ 80g / L, the equipment corrosion intensifies, the sulfur recovery rate decreases, it is very easy to crystallize and block the pipeline or tower at low temperature, and the desulfurization working condition is disordered. The sulfur evolution speed and degree of HS - depend on the reasonable desulfurization liquid composition, catalyst * * and other factors. Our company has developed a special catalyst for biogas desulfurization in combination with the gas composition and working condition characteristics of biogas desulfurization.
Under the condition that biogas gas contains high carbon dioxide, hydrogen sulfide and carbon dioxide are acid gases. It is more difficult for alkaline solution to selectively absorb acid gases, and a large amount of sodium bicarbonate will be produced, reducing the absorption of sodium carbonate. Biogas is a high CO2 gas working condition. As a desulfurization solution prepared with Na2CO3 as alkali source, it not only completes the absorption process of Na2CO3 and H2S, but also completes the reaction process of Na2CO3 and CO2 to generate NaHCO3 in the desulfurization tower. As a buffer solution, although the desulfurization solution with high NaHCO3 can remove H2S, the desulfurization efficiency decreases significantly. The more serious situation is that the content of Na2CO3 in desulfurization solution is zero. NaHCO3 index of 50-60g / L is also common. At this time, active measures should be taken to adjust the ratio of NaHCO3 / Na2CO3, or NaOH can be added to the system temporarily to adjust NaHCO3 (relatively fast). The author believes that the adjustment of NaHCO3 and Na2CO3 can achieve their own balance through the management of production process. The requirements for desulfurization catalyst under biogas desulfurization conditions are higher. In recent years, according to the specific characteristics and working conditions of biogas desulfurization, our company has developed a special catalyst suitable for biogas desulfurization, which has the characteristics of high desulfurization efficiency, high sulfur capacity, less side reactions, simple solution components, easy operation and not easy to block the tower, lower consumption and higher catalytic efficiency to serve biogas desulfurization.