Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.

Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.

An absorbent for the selective removal of hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide, wherein the absorbent contains an aqueous solution, comprising: a) an amine or a mixture of amines of the general formula (I) wherein R.sup.1 is C.sub.1-C.sub.5-alkyl; R.sup.2 is C.sub.1-C.sub.5-alkyl; R.sup.3 is selected from hydrogen and C.sub.1-C.sub.5-alkyl; x is an integer from 2 to 10; and b) an ether or a mixture of ethers of the general formula (II): R.sup.4—[O—CH.sub.2—CH.sub.2].sub.y—OH; wherein R.sup.4 is C.sub.1-C.sub.5-alkyl; and y is an integer from 2 to 10; wherein R.sup.1 and R.sup.4 are identical; wherein the mass ratio of b) to a) is from 0.08 to 0.5. The absorbent is suitable for the selective removal of hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide. The absorbent has a reduced tendency for phase separation at temperatures falling within the usual range of regeneration temperatures for the aqueous amine mixtures and is easily obtainable. ##STR00001##

The invention relates to a method for the preparation of cyclic compounds in the metathesis of olefins from acyclic dienes comprising terminal and/or non-terminal C═C double bonds; the invention also relates to the use of homogeneous ruthenium complexes and homogeneous ruthenium complexes deposited on a solid support as catalysts and/or pre-catalysts for the preparation of cyclic olefins in olefin metathesis reactions.

The invention relates to a method for the preparation of cyclic compounds in the metathesis of olefins from acyclic dienes comprising terminal and/or non-terminal C═C double bonds; the invention also relates to the use of homogeneous ruthenium complexes and homogeneous ruthenium complexes deposited on a solid support as catalysts and/or pre-catalysts for the preparation of cyclic olefins in olefin metathesis reactions.

Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.

Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.

Systems and methods for the separation of classes of paraffins from a hydrocarbon sample can include a first column comprising a first zeolite adsorbent material for the isolation of one or more n-paraffins from the hydrocarbon sample and generation of a first eluate including one or more iso-paraffins and one or more one-ring or multi-ring naphthenes. The system can further include a second column, coupled to the first column, comprising a second zeolite adsorbent material for the isolation of one or more iso-paraffins or one-ring naphthenes from the first eluate and generation of a second eluate including one or more multi-ring naphthenes.

Systems and methods for the separation of classes of paraffins from a hydrocarbon sample can include a first column comprising a first zeolite adsorbent material for the isolation of one or more n-paraffins from the hydrocarbon sample and generation of a first eluate including one or more iso-paraffins and one or more one-ring or multi-ring naphthenes. The system can further include a second column, coupled to the first column, comprising a second zeolite adsorbent material for the isolation of one or more iso-paraffins or one-ring naphthenes from the first eluate and generation of a second eluate including one or more multi-ring naphthenes.

Systems and methods for the separation of classes of paraffins from a hydrocarbon sample can include a first column comprising a first zeolite adsorbent material for the isolation of one or more n-paraffins from the hydrocarbon sample and generation of a first eluate including one or more iso-paraffins and one or more one-ring or multi-ring naphthenes. The system can further include a second column, coupled to the first column, comprising a second zeolite adsorbent material for the isolation of one or more iso-paraffins or one-ring naphthenes from the first eluate and generation of a second eluate including one or more multi-ring naphthenes.