A critical step in the process of purifying natural gas, the desulphurisation of natural gas reaction removes sulphur compounds, especially hydrogen sulfide (H2S). Hydrogen sulfide not only causes corrosion and is toxic to humans (when burned), but it can also damage the environment in ways that contribute effects on a global span. High-tech features of this process typically involve such things as absorption towers, chemical solvents, and special catalysts which can help convert H2S into sulfur. Then the sulfur is pure enough for refining and sale. Thermal desulfurization is widely used in a variety of fields, including natural gas, petroleum, and biogas refining. While it has made such products more environmentally friendly in accordance with regulations that safeguard human lives as well as wildlife s' habitats, Thermal desulfurization has also been employed to refine metals, including copper ore from which all useful sulfur impurities are removed using the same process.