What is the difference between natural gas desulfurization and flue gas desulfurization?

Natural gas desulfurization is different from flue gas desulfurization; the former is aimed at obtaining clean natural gas, while the latter is done for environmental protection purposes.

The requirements for desulfurization purity vary; the former requires a higher MS value~~ and the form in which sulfur exists is also different, I guess

For the desulfurization of natural gas, different raw materials have varying requirements; generally, it is sufficient for them to meet the requirements of the installation. For flue gas desulfurization, which is directly related to environmental emissions and requires direct treatment, there is more available information; natural gas desulfurization can be handled using the same principles as those applied to flue gas.

The former removes hydrogen sulfide, while the latter removes sulfur dioxide

Yes, the former mainly removes hydrogen sulfide, while the latter mainly removes sulfur oxides.

The responses from those on the 5th and 6th floors were not entirely appropriate. Natural gas varies in composition depending on its source, and the amount of sulfur it contains also differs. The main forms of sulfur present in natural gas are carbon monoxide sulfide (COS), hydrogen sulfide, and thiols; their presence can affect the production of subsequent products. Therefore, it is necessary to remove various organic and inorganic sulfur compounds. The desulfurization process involves converting organic sulfur into inorganic sulfur using catalysts, followed by the use of adsorbents to remove both organic and inorganic sulfur from the natural gas. For example, the natural gas used at the Sichuan Dazhou Fertilizer Plant operated by the Qilu Branch (Puguang natural gas, with COS being the main form of sulfur present and a total sulfur content of around 200 mg/m3) is first subjected to pre-desulfurization using iron oxide as a catalyst along with a COS hydrolysis catalyst (with Al2O3 as the carrier), thereby reducing the total sulfur content to 20 mg/m3. Subsequently, final desulfurization is carried out using a cobalt-molybdenum hydrogenation catalyst and zinc oxide as a desulfurizing agent, resulting in a total sulfur content of 0.5 ppm, which meets the requirements of subsequent processing steps. The fertilizer projects I have been involved with do not face the issue of flue gas desulfurization, as the sulfur content in natural gas is already within acceptable levels before it enters the main processing stages. The fuel gas used is also desulfurized natural gas, so there is no need for desulfurization of the flue gas. Last edited by poatmc on 2008-1-8 19:28.]

The main purpose of natural gas desulfurization is to remove impurity sulfur from the gas intended for transmission, so that it meets the requirements for transmission or those set by users; generally, a level of less than 20 ppm is required. The main methods for natural gas desulfurization are dry and wet processes. The dry method uses solid adsorbents such as molecular sieves ； The wet method uses a liquid solvent for adsorption. The key to both lies in the desulfurization agent, which is usually a patent.

For natural gas desulfurization, the natural gas used in our plant is primarily served as a raw material for ammonia synthesis and methanol production processes. Compounds such as carbon monoxide sulfide (COS), hydrogen sulfide, thiols, and thiophenes present in natural gas, if not removed, can poison the catalysts used in these processes, preventing normal operation. A two-stage desulfurization method is typically employed: in the first stage, MEA desulfurization is used to reduce the H2S concentration to 25 mg/M3; in the second stage, cobalt-molybdenum hydrogenation is utilized to convert organic sulfur compounds into inorganic ones, and finally, zinc oxide is used to remove the inorganic sulfur. As a result, the sulfur content in the methanol synthesis gas is reduced to less than 0.1 mg/M3, while that in the ammonia synthesis gas is kept below 0.5 mg/M3； For flue gas desulfurization, the goal is to ensure that the flue gas emitted by the boilers meets the **specified emission standards. This plant has four circulating fluidized bed boilers, and desulfurization is achieved by adding limestone into the furnace; the results are satisfactory, with sulfur content below 200 Mg/M3, which fully meets the **standards. These are all specific examples; I hope they will be helpful to you.

Natural gas desulfurization is carried out to meet the requirements of downstream production processes, while flue gas desulfurization is done to meet environmental protection requirements. The general approach to desulfurization is the same, but the specific processes vary greatly. Natural gas desulfurization generally uses specialized desulfurizing agents such as MDEA, which are commonly referred to as amine solutions. It’s an entirely closed-loop system with quite a number of devices. Flue gas desulfurization generally involves the use of lime, and it is usually carried out in an open system, which is relatively simple.