A biofilter irrigation system comprises a cylindrical vessel having a central axis, a media bed positioned within the vessel, a spray head system positioned above the media bed, the spray head system comprising a central hub positioned at the central axis of the vessel, at least one arm extending distally from the central hub toward a wall of the vessel and configured to rotate about the central axis, and a plurality of nozzles connected to the at least one arm. The biofilter irrigation system further comprises a fluid outlet positioned below the media bed.

A method for removing hydrogen sulfide (H.sub.2S) from an acid gas comprises feeding the gas to a membrane separation unit, collecting the product gas from the membrane unit, heating the permeate stream to the necessary inlet temperature for catalytic oxidation of H.sub.2S and feeding the heated permeate stream to a catalytic oxidation unit, where H.sub.2S is oxidized to SO.sub.2. The heating of the permeate stream is accomplished by using a fraction of the feed gas to heat the permeate stream in a separate heater or by using a steam-fired heater. The method is especially suited for use on an off-shore facility.

A process for altering the composition of a feed gas containing H.sub.2S equivalents is disclosed. The process comprises (a) contacting the feed gas with a solid adsorbent at a temperature of 250-500° C., to obtain a loaded adsorbent, (b) purging the loaded adsorbent with a purge gas comprising steam, thus producing a product stream which typically contains substantially equal levels of CO.sub.2 and H.sub.2S. The process further comprises a step (c) of regenerating the purged adsorbent by removal of water. The adsorbent comprises alumina and one or more alkali metals, such as potassium oxides, hydroxide or the like.

A catalyst for selectively oxidizing hydrogen sulfide to element sulfur, catalyst for burning tail-gas, and process for deeply catalytically oxidizing hydrogen sulfide to sulfur are disclosed. The catalyst for selectively oxidizing hydrogen sulfide to element sulfur is prepared by: 10-34% of iron trioxide and 60-84% of anatase titanium dioxide, and the balance being are auxiliary agents. Also a catalyst for burning tail-gas is prepared by: 48-78% of iron trioxide and 18-48% of anatase titanium dioxide, and the balance being auxiliary agents. The catalyst of the present invention has high selectivity and high sulfur recovery rate. An isothermal reactor and an adiabatic reactor of the present invention are connected in series and are filled with the above two catalysts for reactions, thus reducing total sulfur in the vented gas while having a high sulfur yield and conversion rate.

Acid gas compounds are removed from a process gas such as, for example, syngas or natural gas, by flowing a feed gas into a desulfurization unit to remove a substantial fraction of sulfur compounds from the feed gas and flowing the resulting desulfurized gas into a CO.sub.2 removal unit to remove a substantial fraction of CO.sub.2 from the desulfurized gas.

Systems and methods for removing hydrogen sulfide from an ammonia stream in the NH3 purification and liquefaction stage of a conventional two-column sour water stripping system using an adsorbent bed.

Systems and methods for controlling an amine contactor are provided. An exemplary method includes determining a pickup ratio for a solvent in the contactor, measuring a temperature of a lower tray of the contactor, adjusting the pickup ratio based, at least in part, on the temperature, and adjusting a flow rate for an injection of lean solvent into the contactor based, at least in part, on the pickup ratio.

A catalyst system comprising a combination of: 1) an activator; 2) one or more metallocene catalyst compounds; 3) a support comprising an organosilica material, which is a mesoporous organosilica material. The organosilica material is a polymer of at least one monomer of Formula [Z.sup.1OZ.sup.2 SiCh.sub.2].sub.3(i), where Z.sup.1 represents a hydrogen atom, a C1-C4 alkyl group, or a bond to a silic-on atom of another monomer and Z.sup.2 represents a hydroxyl group, a C.sub.1-C.sub.4alkoxy group, a C.sub.1-C.sub.6 salkyl group, or an oxygen atom bonded to a silicon atom of another monomer. This invention further relates to processes to polymerize olefins comprising contacting one or more olefins with the above catalyst system.

The present invention relates to a gas-filtering system (1000, 3000, 4000, 5000, 6000) comprising: an input (1100) for the gas, a reactor (1301, 1302, 1303) for filtering the gas at the input (1100) and thus obtaining a filtered gas, an output (1200) for the filtered gas, a vacuum generator (1401, 1402) for generating a vacuum inside the reactor (1301, 1302, 1303), where the vacuum generator (1401, 1402) is configured so as to apply a first predetermined vacuum value (VI) in a first vacuum phase (T2) and so as to apply a second predetermined vacuum value (V2) in a second vacuum phase (T3); the filtering system (1000, 3000, 4000) further comprising a flow controller (1501, 1502, 1503) connected at the output to the reactor (1301, 1302, 1303), where the flow controller (1501, 1502, 1503) is configured so as to block the introduction of the filtered gas into the reactor (1301, 1302, 1303) during the first vacuum phase (T2), and where the flow controller (1501, 1502, 1503) is configured so as to allow the introduction of the filtered gas and/or a second gas into the reactor (1301, 1302, 1303), starting from the output (1200) during the second vacuum phase (T3).

The invention provides a process to purify a gas stream by using an adsorbent bed and a secondary device to remove heavy hydrocarbons with a recycle stream then sent first to a vessel containing an amine solvent to remove acid gases including carbon dioxide and hydrogen sulfide and then in most embodiments of the invention sending the treated gas stream to a dehydration unit such as an adsorbent bed or to a triethylene glycol absorbent to remove water. The invention further provides improved integration of the process streams to allow for smaller amine solvent and dehydration units as compared to the prior art.