脫硫催化劑在脫硫過程中的作用及關(guān)系。脫硫催化劑作為脫硫液組成的核心,維持穩(wěn)定的催化劑濃度和堿度是十分重要的事情,作為以Na2CO3為堿源的脫硫,控制PH8~8.5時(shí),作為緩沖溶液的當(dāng)量濃度控制不能過低也不能太高。過低不利于吸收脫硫效率低,再*浮選差且泡沫細(xì)不成型,長期過低,容易導(dǎo)致組分失調(diào),低于0.3時(shí)提堿度十分困難。脫硫生產(chǎn)過程副反應(yīng)的產(chǎn)生是不可避免的,應(yīng)采用脫硫催化劑以減少副反應(yīng)的生成。一般認(rèn)為副鹽總量≤200g/L是能夠維持正常生產(chǎn)。若副反應(yīng)嚴(yán)重時(shí),堿耗劇增,大量補(bǔ)堿也難以維持堿度。當(dāng)溶液中副鹽總量很高時(shí),溶液粘度、比重增加,動(dòng)力消耗增加,甚至出現(xiàn)循環(huán)泵不打液。嚴(yán)重影響吸收和再*。當(dāng)溶液中Na2SO4≥80g/L時(shí),設(shè)備腐蝕加劇,硫回收率降低,溫度低時(shí)非常容易結(jié)晶堵塞管道或堵塔,脫硫工況出現(xiàn)紊亂,HS-的析硫速度和程度決定于合理的脫硫液組分、催化劑的**等因素,我們公司結(jié)合沼氣脫硫的氣體成分和工況特點(diǎn)研發(fā)了沼氣脫硫?qū)S么呋瘎?
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.
針對沼氣氣體含有較高二氧化碳的工況,硫化氫和二氧化碳都是酸性氣體,堿性溶液選擇性吸收酸性氣體的困難增加,并且會有大量的碳酸氫鈉產(chǎn)生,降低碳酸鈉的吸收**。沼氣是高CO2氣體工況,作為以Na2CO3為堿源制備的脫硫液,在脫硫塔內(nèi)除了完成了Na2CO3和H2S的吸收過程,同時(shí)也完成了Na2CO3和CO2生成NaHCO3的反應(yīng)過程。作為緩沖溶液,高NaHCO3的脫硫液雖然能夠脫除H2S,但是脫硫效率明顯下降。更為嚴(yán)重的情況是脫硫液分析竟然Na2CO3含量為零。NaHCO3指標(biāo)50-60g/L也屢見不鮮。這時(shí)要采取積極措施調(diào)節(jié)NaHCO3/ Na2CO3之比也可暫時(shí)往系統(tǒng)補(bǔ)NaOH來調(diào)節(jié)NaHCO3(比較快速)。筆者認(rèn)為對于NaHCO3和Na2CO3的調(diào)節(jié)好通過生產(chǎn)過程的管理,來實(shí)現(xiàn)其自身平衡。沼氣脫硫工況對脫硫催化劑的要求更高了。這幾年,我們公司針對具體的沼氣脫硫的特點(diǎn)及工況,研發(fā)了適合沼氣脫硫的專用催化劑,具有脫硫效率高,硫容高,副反應(yīng)少,溶液組分簡單易操作,不易堵塔等特點(diǎn),更低消耗更高催化效率服務(wù)于沼氣脫硫等。
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.