The invention relates to novel nitrogen compounds belonging to the family of tertiary diamines of general formula (I) below, wherein R is an alkanediyl radical (CH.sub.2)n with n=2, 3, 4, 5 or 6.

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The compound according to the invention is for example N,N,N,N-(tetramethyl)-1,6-diamino-2,5-hexanediol or N,N,N,N-(tetramethyl)-1,8-diamino-2,7-octanediol. The invention also relates to the method for preparing them and to their use for removing acid compounds contained in a gaseous effluent.

A solvent system for the removal of acid gases from mixed gas streams is provided. Also provided is a process for removing acid gases from mixed gas streams using the disclosed solvent systems. The solvent systems may be utilized within a gas processing system.

A method for removing amine contaminants from both liquid and gaseous hydrocarbon streams and methods thereof are described. An additive that reacts with said contaminant to form water-soluble compounds is injected into the hydrocarbon streams.

Copper sorbents which are resistant to the reduction by hydrogen are used as a guard bed for an acetylene conversion zone. The adsorbents include cuprous oxide, cupric oxide, copper metal, and a halide and are pre-reduced prior to be loaded into the guard bed. The sorbents can remove contaminants that would poison selective hydrogenation catalysts used for a selectively hydrogenating acetylenic compounds in an olefin stream. The sorbents may also selectively hydrogenate the acetylenic compounds.

An apparatus and process for thermally de-manufacturing tires and other materials. The apparatus is a retort chamber with various zones in which tires are combusted to provide energy for the thermal depolymerization reaction, depolymerization takes place, and products leave the retort chamber. In one embodiment, the process reacts water with iron present in steel-belted tires to produce hydrogen, which helps to break sulfur-sulfur bonds in vulcanized materials. The water also helps control the temperature of the reaction, which allows for control over the types and relative amounts of the various depolymerization products.

A process for recovering a steam cracking feed from FCC absorber off-gas comprising ethylene, ethane and heavier hydrocarbons and light gases involves removing hydrogen, nitrogen, sulfur species, carbon monoxide/dioxide, methane and other impurities from the off-gas. An absorption zone is upstream of an acetylene selective hydrotreating reactor to remove sufficient hydrogen sulfide that can poison the selective hydrotreating catalyst but leave sufficient sulfur in the feed stream to prevent temperature runaway.

Copper adsorbents which are resistant to the reduction by the components of the synthesis gas at normal operation conditions. The adsorbents are produced by admixing small amounts of an inorganic halide, such as NaCl, to the basic copper carbonate precursor followed by calcination at a temperature sufficient to decompose the carbonate. The introduction of the halide can be also achieved during the forming stage of adsorbent preparation. These reduction resistant copper oxides can be in the form of composites with alumina and are especially useful for purification of synthesis gas and the removal of mercury, arsine, phosphine, as well as hydrogen sulfide.

A desulfurization system removes sulfur ingredients included in synthetic gas generated from gasification of coal in a high temperature dry state. The system includes a desulfurization reactor, a desulfurization cyclone, and first and second regeneration reactors branched with the desulfurization cyclone. A first oxidizing agent is injected to a first oxidizing agent inlet of the first regeneration reactor, and a second oxidizing agent is injected to a second oxidizing agent inlet of the second regeneration reactor. A controller operates one of the first and second regeneration reactors in a regeneration mode, controlling the other to operate in a desulfurization mode.

A compound of the general formula (I)

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in which R.sub.1, R.sub.2 and R.sub.3 are independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.4 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.5 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is an integer from 0 to 10. A preferred compound of the formula (I) is 2-(2-tert-butylaminoethoxy)ethylamine. Absorbents comprising a compound of the formula (I) have rapid absorption of carbon dioxide from fluid streams and are also suitable for processes for the simultaneous removal of H.sub.2S and CO.sub.2, where given H.sub.2S limits have to be observed but complete removal of CO.sub.2 is not required.

We provide a method for removing contaminants from a gas, comprising: alternating input of the gas between two or more beds of adsorbent particles that comprise zeolite SSZ-36, zeolite SSZ-39, or zeolite SSZ-45; wherein the gas contacts one of the beds during an adsorption and a tail gas is simultaneously vented from another of the beds by desorption; wherein a contacting pressure is from about 345 kPa to about 6895 kPa and produces a product gas containing no greater than about 2 mol % carbon dioxide, at least about 10 wppm water, at least about 65 mol % of methane recovered from the feed gas, and at least about 25 mol % of ethane recovered from the feed gas; and wherein the tail gas is vented from the feed end of the beds. We also provide a method for removing a contaminant from a gas, wherein the gas contains hydrogen sulfide.