| 摘要 |
Organic sulfur is removed from coal by extraction with a water/methanol/carbon dioxide mixture under supercritical conditions of temperature and pressure, i.e., at a temperature and pressure of the critical temperature and pressure, respectively. The preferred solvent used for extraction has the following composition (expressed as a mole fraction); -Carbon Dioxide from 0 to 0.30 -Methanol from 0.20 to 0.70 -Water from 0.20 to 0.70 - Preferably, the mole fraction carbon dioxide is at least 0.05 and mole fraction of water is not greater than 0.65. Either fixed bed (semi-batch) or mixed reactor systems can be used. Operations may be carried out in a single stage using a solvent of constant composition, or it may be carried out in plural stages in which the critical temperature of the solvent used in each stage (except the first) is higher than that of the solvent used in the preceding stage. Overall molar quantities of solvent used in plural stage operations are in accordance with the mole fractions given above. A substantial amount of the total organic sulfur present is removed. |
