초록 ▼

In the process for reducing the total sulfur content of a high CO2-content feed gas stream, the feed gas is first passed to an absorption column. The unabsorbed, high CO2-content gas is then routed to a reduction step where it is combined with Claus off-gases and the sulfur compounds are reduced to

In the process for reducing the total sulfur content of a high CO2-content feed gas stream, the feed gas is first passed to an absorption column. The unabsorbed, high CO2-content gas is then routed to a reduction step where it is combined with Claus off-gases and the sulfur compounds are reduced to H2S. The treated gas is then passed to a second absorption column and the unabsorbed gas is vented to the atmosphere. The fat solvent from both absorption columns is stripped in a common stripper and the stripped gas is passed to a Claus unit for conversion to elemental sulfur.

대표청구항 ▼

A process for reducing the total sulfur content of a high CO2-content feed gas to environmentally acceptable levels comprising: (a) passing a feed gas stream comprising 40 to 95% volume CO2, 0.03 to 20% volume H2S, and 0.02 to 2% volume COS to a first absorption step where said feed gas stream is co

A process for reducing the total sulfur content of a high CO2-content feed gas to environmentally acceptable levels comprising: (a) passing a feed gas stream comprising 40 to 95% volume CO2, 0.03 to 20% volume H2S, and 0.02 to 2% volume COS to a first absorption step where said feed gas stream is contacted with a liquid and regenerable polyalkanolamine absorbent selective for hydrogen sulfide, therein producing an unabsorbed portion and a hydrogen sulfide-enriched polyalkanolamine absorbent; (b) passing said unabsorbed portion of the feed gas stream from step (a) together with a hydrogen- and/or carbon monoxide-containing gas, the off gases from the associated Claus process step (e), and a certain amount of steam over a sulfided Group VI and/or Group VIII metal catalyst supported on an inorganic oxidic carrier in a reduction step wherein the aount of steam is adjusted to reduce the COS concentration in the resulting treated gas to a level below about 0.05% volume; (c) passing the gas stream thus treated in said reduction step (b) to a second absorption step in which said treated gas stream is contacted with a liquid and regenerable polyalkanolamine absorbent under such conditions that the unabsorbed portion of said treated gas stream has below about 0.05% volume total sulfur compounds, discharging the unabsorbed portion of said treated gas stream, optionally after incineration, into the atmosphere, and producing a hydrogen sulfide-enriched polyalkanolamine absorbent; (d) regenerating the hydrogen sulfide-enriched absorbents from absorption steps (a) and (c) by heating and/or stripping and using them again for further absorption of hydrogen sulfide; (e) passing the hydrogen sulfide liberated in the regeneration step (d) to a Claus process step; and (f) passing the off-gases produced in said Claus process step (e) to said reduction step (b).