Recherche Dans Les Collections De Brevets Nationales ... - Patentscope

Apparatus for removing carbon dioxide from a stream of air or other gas, which includes a vertical gas absorption reactor containing loosely packed mixing units submerged in a carbon dioxide absorbent liquid; gas to be treated is admitted at or near this base of the rector, is broken into small bubbles by the mixing units, and passes through the absorbent liquid to remove a high percentage of carbon dioxide; treated gas leaves from the top of the reactor, a regenerator associated with the reactor continually or intermittently regenerates the absorbent liquid and is arranged to receive absorbent liquid to be treated through an outlet from the reactor which is located higher up the wall of the reactor than the inlet for returning treated liquid to the reactor.

This disclosure relates to a process for removing acid gases from a gas stream enriched in acid gases, wherein: (a) the gas stream enriched in acid gases is contacted in an absorption zone with an absorption medium, wherein the absorption medium is an aqueous medium comprising an amine, to form a gas stream depleted in acid gases which comprises an entrained amine and an absorption medium enriched in acid gases; and (b) treating the gas stream depleted in acid gases which comprises an entrained amine in a first scrubbing zone with a first scrubbing medium, wherein the first scrubbing medium is an aqueous medium comprising an amine, the amount of amine comprised by the scrubbing medium being about 0.1 to about 50.0 wt. %, wherein the aqueous medium is saturated with carbon dioxide such that at least 75 wt. % of the amine, based on the total amount of amine comprised by the aqueous medium, is in its carbamate or carbonate form, to form a gas stream depleted in acid gases and in amine and a first scrubbing medium enriched in amine.

A method and composition are disclosed for sweetening, i.e., selectively reducing the levels of H.sub.2 S and organic sulfides, in gaseous hydrocarbons streams, particularly natural gas streams. A natural gas in a pipe line, at the well head, or at a common collection point from a number of wells, is contacted with a sweetening agent comprising the reaction product of ethylene diamine with 50% uninhibited aqueous formaldehyde. The reaction product is prepared by reacting one part 99% ethylene diamine with two parts 50% aqueous uninhibited formalin at a temperature of about 55-60.degree. C. (higher temperatures may be used if the reaction is carried out under pressure) and is characterized by having a higher flash point, lower toxicity, and a lower freezing point, and better reaction rates, than other sweetening agents currently in use. The sweetening solution is water soluble, free from methanol or other alcohols, does not foam uncontrollably in use, and is free from water insoluble solids which would interfere with the injectability of the solution into a stream of flowing natural gas. The sweetening reaction takes place in-line without the need for a holding tank or reaction vessel. However, the treatment with the sweetening agent may also be carried out in a conventional gas treating tower. The reaction is complete and effective to completely sweeten a sour gas system.

A system and method for treating process gas streams containing isopropyl alcohol (IPA) to reduce the concentration of IPA therein. The invented system includes a scrubber unit that receives a process stream containing a concentration of IPA and reduces the concentration of IPA therein to below a determined threshold. The scrubber includes a reverse osmosis assembly that significantly reduces water consumption for the scrubbing process as compared to conventional once-through systems. The system may be operated at an elevated pH to prevent biofouling from inhibiting the operation of the reverse osmosis assembly. The system may contain a softening step on the make up water system to prevent scaling in the reverse osmosis system and a softening step on a sidestream of the scrubber water recirculation loop to reduce scrubber tower salting/scaling and to control the pH of the scrubbing liquid.