| 摘要 |
<p>Two stage removal of hydrogen sulfide from a gas. In the first stage solutions of hydrogen sulfide and sulfur dioxide in a solvent react to produce sulfur and water. An excess of hydrogen sulfide is maintained in the first stage resulting in a solution containing sulfur, water and the excess hydrogen sulfide, or resulting in a gas containing the excess hydrogen sulfide. The excess hydrogen sulfide in the solution or in the gas is then treated in a second stage with a solution in the same solvent of sulfur dioxide in excess of or closely equal to that required to react with the hydrogen sulfide. Excess sulfur dioxide in the vapor phase from the second stage may be absorbed in neat solvent. The solvent is selected to have a high solvating power for sulfur dioxide, a lesser but substantial solvating power for hydrogen sulfide and to promote the reaction of hydrogen sulfide with sulfur dioxide. Such gases as natural gas, synthesis gas, and the tail gas of a claus plant may be so treated. By appropriate selection of solvents and/or conditions, accompanying minor components of the gas stream being treated may be removed and recovered if of value, e.g., propane from natural gas, carbon dioxide and water from synthesis gas, etc. The process avoids the need to maintain exact stoichiometric ratios of hydrogen sulfide and sulfur dioxide, it avoids the need to use high flow rates of solvent, a liquid phase capacitance for hydrogen sulfide is provided which dampens the effect of fluctuations in hydrogen sulfide content in the gas stream, etc.</p> |
