Desulfurization removes sulfur to prevent contamination and reduce emissions. Natural gas is desulfurized through adsorption, while flue gas is treated with scrubbers. Coal desulfurization is achieved through separation by density, flotation, or magnetic susceptibility. Oil desulfurization uses activated carbon filters or microbial desulfurization.
Desulfurization is the process of removing sulfur from something to prevent contamination. Also known as hydrodesulfurization or HDS, this chemical process reduces sulfur dioxide emissions and converts them into sulfuric acid. The sulfuric acid is then used in car batteries and fertilizers. The most commonly requested desulfurization process is in natural gas. Further desulphurisation is required for flue gas, coal and oil.
Desulfurization of natural gas is typically accomplished by adsorption. A bed of activated carbon is used as a filter for gas pipelines. As the natural gas flows through the pipeline, it passes through the activated carbon at set intervals. The sulfur is left behind and adsorbed into the activated carbon. Tests are performed regularly to ensure sulfur levels remain within the acceptable range.
Flue gas is the by-product of power plants and refers to the exhaust from burning fossil fuels. Flue gas desulphurization is necessary to reduce the amount of sulfur dioxide entering the air. It is an important factor in the formation of acid rain.
A device called a scrubber is used to remove sulfur from the fumes. It works by combining sulfur with lime or limestone to create a compound or slurry. The slurry is then removed by absorbing the slurry and converting it into plaster, which is used to make wallboard or concrete.
Coal desulfurization is achieved in three ways. The most common method is separation by density. Swing tables or jigs sift the material and separate it into smaller particles. The impurities are then removed. Commercial practices for large quantities of coal employ a coal spiral or cyclone that uses centrifugal force to separate the coal from the sulfur.
Another method is by flotation or flocculation. In this method, charcoal is immersed in a liquid. The mineral matter is lighter than coal, so it floats upwards, allowing pollutants to be removed. A final method is magnetic susceptibility. This method passes an electric current through the coal, which attracts the pyrite sulfur, and works only with fine-particle coal.
Oil desulphurization works in two main ways. The first is similar to natural gas desulfurization in that it also uses activated carbon filters. This method is typically only used if the oil has a relatively low sulfur level, less than 50ppm, to begin with. The other method, microbial desulfurization, uses the Rhodococcus organism to remove sulfur compounds, which reduces air pollution during the refining process.
Protect your devices with Threat Protection by NordVPN
