本期我們來對比干法、濕法和生物脫硫這三大工藝。隨著節(jié)能減排政策不斷深入人心，很多企業(yè)都打算利用污水站的沼氣部分代替天然氣，用于鍋爐燃燒或發(fā)電。那么，沼氣利用前的硫化氫脫除工藝，也就是脫硫，就成了工廠和站長們的選擇難點。當(dāng)前，比較常用的工藝主要有干法脫硫、濕法脫硫和生物脫硫這三種。

　　In this issue, we will compare the three major processes of dry, wet, and biological desulfurization. With the continuous deepening of energy-saving and emission reduction policies, many enterprises plan to use the biogas from sewage plants to replace natural gas for boiler combustion or power generation. So, the hydrogen sulfide removal process before biogas utilization, namely desulfurization, has become a difficult choice for factories and station managers. Currently, the commonly used processes include dry desulfurization, wet desulfurization, and biological desulfurization.

　　首先來說第一種，干法脫硫。干法脫硫的原理是利用固體吸附劑去除氣體中的硫化氫等酸性氣體，靠的是吸附劑表面的活性位點與硫化氫分子之間的物理或化學(xué)相互作用，把硫化氫分子吸附在吸附劑表面，從而達(dá)到脫除目的。

　　Firstly, let's talk about the first method, dry desulfurization. The principle of dry desulfurization is to use solid adsorbents to remove acidic gases such as hydrogen sulfide from the gas. It relies on the physical or chemical interactions between the active sites on the adsorbent surface and hydrogen sulfide molecules to adsorb hydrogen sulfide molecules on the adsorbent surface, thereby achieving the purpose of removal.

　　它的工藝流程很簡單，第一步是原料氣預(yù)處理，去除其中的雜質(zhì)和水分，避免影響吸附劑性能；第二步是吸附，預(yù)處理后的原料氣進(jìn)入吸附塔，與吸附劑接觸，硫化氫被吸附；第三步是解吸，當(dāng)吸附劑飽和后，通過加熱或降壓的方式釋放出硫化氫，恢復(fù)吸附劑的吸附能力；最后是產(chǎn)品氣干燥，得到的純凈硫化氫氣體可以作為化工原料或燃料使用。

　　Its process flow is very simple. The first step is the pre-treatment of the raw gas to remove impurities and moisture, avoiding affecting the performance of the adsorbent; The second step is adsorption. The pre treated feed gas enters the adsorption tower and comes into contact with the adsorbent, where hydrogen sulfide is adsorbed; The third step is desorption. When the adsorbent is saturated, hydrogen sulfide is released through heating or depressurization to restore the adsorption capacity of the adsorbent; Finally, the product gas is dried, and the pure hydrogen sulfide gas obtained can be used as a chemical raw material or fuel.

　　干法脫硫的優(yōu)點很突出，設(shè)備結(jié)構(gòu)簡單、占地面積小、投資成本低，操作也方便，不需要復(fù)雜的控制系統(tǒng)和儀表，維護(hù)保養(yǎng)費用低，適應(yīng)性還強，能滿足不同規(guī)模和性質(zhì)的氣體處理需求。但它也有缺點，脫硫效率相對較低，一般只能達(dá)到 70%~90% 左右，滿足不了太嚴(yán)格的排放標(biāo)準(zhǔn)；而且吸附劑壽命有限，需要定期更換，增加了運行成本；過程中還容易產(chǎn)生二次污染，比如吸附劑粉塵飛揚、廢氣排放等問題，得采取相應(yīng)措施治理。

　　The advantages of dry desulfurization are prominent, with simple equipment structure, small footprint, low investment cost, convenient operation, no need for complex control systems and instruments, low maintenance costs, strong adaptability, and can meet the gas treatment needs of different scales and properties. But it also has its drawbacks, with relatively low desulfurization efficiency, generally only reaching around 70% to 90%, which cannot meet too strict emission standards; Moreover, the lifespan of the adsorbent is limited and requires regular replacement, which increases operating costs; During the process, secondary pollution is also prone to occur, such as adsorbent dust flying and exhaust emissions, which require corresponding measures to be taken for treatment.

　　干法脫硫更適用于小規(guī)模氣體處理、高濃度硫化氫氣體處理以及間歇式氣體處理項目。舉個案例，某化工廠用干法脫硫技術(shù)處理含硫化氫廢氣，廢氣流量 1000m?/h，硫化氫濃度 1000mg/m?，采用活性炭作為吸附劑，設(shè)計了兩座直徑 2m、高度 10m 的吸附塔。它的工程參數(shù)大多是常溫常壓操作，吸附和解吸的流速一般在 0.5m/s~1.0m/s，時間在 30min~60min，解吸溫度會高一些，在 100℃~150℃。處理后，廢氣中硫化氫濃度能降低至 20mg/m? 以下，符合國家標(biāo)準(zhǔn)，該廠每年可減少硫化氫排放量約 100 噸，經(jīng)濟效益和環(huán)境效益都很顯著。

　　Dry desulfurization is more suitable for small-scale gas treatment, high concentration hydrogen sulfide gas treatment, and intermittent gas treatment projects. For example, a chemical plant uses dry desulfurization technology to treat waste gas containing hydrogen sulfide, with a flow rate of 1000m ?/h and a hydrogen sulfide concentration of 1000mg/m? Two adsorption towers with a diameter of 2m and a height of 10m were designed using activated carbon as the adsorbent. Its engineering parameters are mostly operated at normal temperature and pressure, with adsorption and desorption flow rates generally ranging from 0.5m/s to 1.0m/s and times between 30min and 60min. The desorption temperature may be higher, ranging from 100 ℃ to 150 ℃. After treatment, can the concentration of hydrogen sulfide in the exhaust gas be reduced to 20mg/m? According to national standards, the factory can reduce hydrogen sulfide emissions by about 100 tons per year, with significant economic and environmental benefits.

　　接下來是第二種，濕法脫硫。它的原理是利用液體吸收劑去除硫化氫等酸性氣體，通過吸收劑與硫化氫發(fā)生化學(xué)反應(yīng)，將其轉(zhuǎn)化為不溶于水的物質(zhì)，進(jìn)而實現(xiàn)脫除。

　　Next is the second method, wet desulfurization. Its principle is to use liquid absorbents to remove acidic gases such as hydrogen sulfide. Through a chemical reaction between the absorbents and hydrogen sulfide, it is converted into insoluble substances in water, thereby achieving removal.

　　工藝流程和干法類似，先對原料氣進(jìn)行預(yù)處理，去除雜質(zhì)和水分；然后進(jìn)入吸收塔，硫化氫被吸收劑吸收；吸收劑飽和后，通過加熱或減壓解吸，釋放出硫化氫，恢復(fù)吸收能力；最后對解吸后的產(chǎn)品氣進(jìn)行干燥，得到純凈的硫化氫氣體。

　　The process flow is similar to the dry method, where the raw gas is first pretreated to remove impurities and moisture; Then it enters the absorption tower, where hydrogen sulfide is absorbed by the absorbent; After saturation of the absorbent, hydrogen sulfide is released through heating or depressurization desorption to restore absorption capacity; Finally, dry the desorbed product gas to obtain pure hydrogen sulfide gas.

　　濕法脫硫的優(yōu)點是脫硫效率高，能達(dá)到 90% 以上，滿足嚴(yán)格的排放標(biāo)準(zhǔn)；吸收劑可以再生，降低了運行成本；而且不易產(chǎn)生二次污染，對環(huán)境友好。但它的缺點也很明顯，設(shè)備結(jié)構(gòu)復(fù)雜、占地面積大、投資成本高，操作難度大，需要復(fù)雜的控制系統(tǒng)和儀表，維護(hù)保養(yǎng)費用也高，適應(yīng)性還比較差，只能適應(yīng)一定規(guī)模和性質(zhì)的氣體處理需求。

　　The advantage of wet desulfurization is its high desulfurization efficiency, which can reach over 90% and meet strict emission standards; Absorbents can be regenerated, reducing operating costs; And it is not prone to secondary pollution and is environmentally friendly. But its disadvantages are also very obvious, such as complex equipment structure, large footprint, high investment cost, difficult operation, requiring complex control systems and instruments, high maintenance costs, and poor adaptability. It can only adapt to gas treatment needs of a certain scale and nature.

　　它更適用于大規(guī)模氣體處理、低濃度硫化氫氣體處理以及連續(xù)式氣體處理項目。比如某煉油廠，用濕法脫硫技術(shù)處理含硫化氫廢氣，廢氣流量 10000m?/h，硫化氫濃度 100mg/m?，采用碳酸鈉作為吸收劑，設(shè)計了三座直徑 4m、高度 20m 的吸收塔。工程參數(shù)方面，吸收溫度常溫 20℃~30℃，常壓操作，吸收和解吸的流速、時間與干法相近，解吸溫度同樣在 100℃~150℃。處理后，硫化氫濃度也能降至 20mg/m? 以下，該廠每年可減少硫化氫排放量約 1000 噸，效益顯著。

　　It is more suitable for large-scale gas treatment, low concentration hydrogen sulfide gas treatment, and continuous gas treatment projects. For example, a certain refinery uses wet desulfurization technology to treat hydrogen sulfide containing waste gas, with a flow rate of 10000m?/h and a hydrogen sulfide concentration of 100mg/m? Three absorption towers with a diameter of 4m and a height of 20m were designed using sodium carbonate as the absorbent. In terms of engineering parameters, the absorption temperature is at room temperature of 20 ℃~30 ℃, operating at atmospheric pressure. The flow rate and time of absorption and desorption are similar to those of dry process, and the desorption temperature is also between 100 ℃~150 ℃. After processing, can the concentration of hydrogen sulfide also be reduced to 20mg/m? Below, the factory can reduce hydrogen sulfide emissions by about 1000 tons per year, with significant benefits.

　　第三種是生物脫硫。它的原理是利用微生物的代謝活動去除硫化氫等酸性氣體，通過微生物體內(nèi)的酶系統(tǒng)將硫化氫轉(zhuǎn)化為無毒無害的物質(zhì)，從而實現(xiàn)脫除。

　　The third type is biological desulfurization. Its principle is to use the metabolic activity of microorganisms to remove acidic gases such as hydrogen sulfide, and convert hydrogen sulfide into non-toxic and harmless substances through the enzyme system in the microbial body, thereby achieving removal.

　　工藝流程主要包括原料氣預(yù)處理，去除雜質(zhì)和水分，避免影響微生物的生長和代謝；然后原料氣進(jìn)入生物反應(yīng)器，與微生物接觸，硫化氫被微生物代謝轉(zhuǎn)化；最后對反應(yīng)器內(nèi)的產(chǎn)物進(jìn)行分離、提純，得到的純凈產(chǎn)物可作為化工原料或燃料使用。

　　The process mainly includes pre-treatment of raw gas, removal of impurities and moisture, and avoidance of affecting the growth and metabolism of microorganisms; Then the feed gas enters the bioreactor and comes into contact with microorganisms, where hydrogen sulfide is metabolized and converted by the microorganisms; Finally, the products in the reactor are separated and purified, and the pure products obtained can be used as chemical raw materials or fuels.

　　生物脫硫的優(yōu)點是脫硫效率高，能達(dá)到 90% 以上，滿足嚴(yán)格排放標(biāo)準(zhǔn)；運行成本低，不需要消耗大量化學(xué)藥品和能源，只需提供適宜的溫度、濕度和營養(yǎng)物質(zhì)等條件；而且無二次污染，對環(huán)境友好。但它也存在設(shè)備復(fù)雜、占地面積大、投資成本高的問題，操作難度大，需要專業(yè)技術(shù)人員管理維護(hù)，否則容易出現(xiàn)故障，適應(yīng)性也比較差，只能適應(yīng)一定規(guī)模和性質(zhì)的氣體處理需求。

　　The advantage of biological desulfurization is its high desulfurization efficiency, which can reach over 90% and meet strict emission standards; Low operating costs, no need to consume large amounts of chemicals and energy, only providing suitable conditions such as temperature, humidity, and nutrients; And there is no secondary pollution, environmentally friendly. But it also has the problems of complex equipment, large footprint, high investment cost, high operational difficulty, and the need for professional technical personnel to manage and maintain it. Otherwise, it is prone to malfunctions and has poor adaptability, only able to adapt to gas processing needs of a certain scale and nature.

　　它適用于大規(guī)模氣體處理、低濃度硫化氫氣體處理以及連續(xù)式氣體處理項目。某化肥廠就用了生物脫硫技術(shù)，處理的廢氣流量 5000m?/h，硫化氫濃度 50mg/m?，采用固定床生物反應(yīng)器，設(shè)計了四座直徑 3m、高度 10m 的反應(yīng)器。工程參數(shù)上，反應(yīng)溫度在 30℃~35℃，最適溫度 32℃，常壓操作，反應(yīng)流速 0.5m/s~1.0m/s，反應(yīng)時間 30min~60min；營養(yǎng)液添加量為每立方米廢氣 0.5kg~1.0kg，pH 值控制在 6.0~8.0，最適 7.0，營養(yǎng)液溫度 25℃~30℃，最適 28℃。處理后，硫化氫濃度降至 20mg/m? 以下，該廠每年可減少硫化氫排放量約 250 噸，效益良好。

　　It is suitable for large-scale gas treatment, low concentration hydrogen sulfide gas treatment, and continuous gas treatment projects. A certain fertilizer plant has used biological desulfurization technology to treat waste gas with a flow rate of 5000m?/h and a hydrogen sulfide concentration of 50mg/m? Four reactors with a diameter of 3m and a height of 10m were designed using fixed bed bioreactors. In terms of engineering parameters, the reaction temperature is between 30 ℃ and 35 ℃, with an optimal temperature of 32 ℃, operating at atmospheric pressure. The reaction flow rate is between 0.5m/s and 1.0m/s, and the reaction time is between 30 minutes and 60 minutes; The amount of nutrient solution added is 0.5kg~1.0kg per cubic meter of exhaust gas, the pH value is controlled at 6.0~8.0, with an optimum of 7.0, and the temperature of the nutrient solution is 25 ℃~30 ℃, with an optimum of 28 ℃. After treatment, the concentration of hydrogen sulfide decreased to 20mg/m? Below, the factory can reduce hydrogen sulfide emissions by about 250 tons per year, with good benefits.

　　最后我們來總結(jié)對比一下這三種工藝。干法脫硫多用于硫化氫處理負(fù)荷小，或者對脫硫效果要求很高的工況，常作為濕法脫硫或生物脫硫之后的進(jìn)一步脫硫工藝。在制定脫硫效果時，建議根據(jù)后續(xù)設(shè)備（鍋爐或發(fā)電機）對硫化氫濃度的限制，以及沼氣與天然氣消耗量的比例，制定合理的脫硫標(biāo)準(zhǔn)，通常建議最終的硫化氫含量控制在 25 到 100ppm。

　　Finally, let's summarize and compare these three processes. Dry desulfurization is often used for conditions with low hydrogen sulfide treatment load or high requirements for desulfurization effect, and is often used as a further desulfurization process after wet desulfurization or biological desulfurization. When formulating the desulfurization effect, it is recommended to establish reasonable desulfurization standards based on the limitations of hydrogen sulfide concentration by subsequent equipment (boilers or generators), as well as the ratio of biogas and natural gas consumption. It is usually recommended to control the final hydrogen sulfide content at 25 to 100ppm.

　　以上，便是本期干法、濕法和生物脫硫三大工藝比較的介紹。今天就到這里啦，拜拜，點個關(guān)注唄。

　　Above is an introduction to the comparison of the three major processes of dry, wet, and biological desulfurization in this issue. That's all for today. Goodbye, just follow us.