摘要:
A multistage method for making a homopolymer or copolymer of an alpha-olefin having increased stiffness and broadened molecular weight distribution.
摘要:
Methods are provided for producing a jet fuel composition from a feedstock comprising a natural oil. The methods comprise reacting the feedstock with a low-weight olefin in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product. The methods further comprise hydrogenating the metathesized product under conditions sufficient to form a jet fuel composition.
摘要:
The present disclosure relates to the use of aptamers in solid phase extraction, chromatography and chromatography-mass spectrometry systems. More specifically, the present disclosure relates to the use of aptamers in SPE and chromatography systems to selectively retain, extract and/or pre-concentrate target molecule(s) having a specific affinity for the particular aptamer(s). The target molecule(s) can be further analyzed by mass spectrometry with limited interferences and/or enhanced sensitivity.
摘要:
Methods are provided for refining natural oil feedstocks. The methods comprise reacting the feedstock with a low-molecular-weight olefin or mid-weight olefin in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters. In certain embodiments, the methods further comprise separating the olefins from the esters in the metathesized product. In certain embodiments, the methods further comprise transesterifying the esters in the presence of an alcohol to form a transesterified product.
摘要:
A catalyst includes a carrier body and a catalytic portion carried by the carrier body. The catalytic portion includes a plurality of distinct layers of catalytic material, which layers may be deposited through atomic layer deposition techniques. The catalyst may have a selectivity for the conversion of alkanes to alkenes of over 50%. The catalyst may be incorporated in a reactor such as a fluidized bed reactor or a single pass reactor.
摘要:
A solid, hydrocarbon-insoluble, olefin-polymerization catalyst component having substantially uniform particles useful in polymerizing olefins is formed by:reacting a magnesium-containing compound with carbon dioxide or sulfur dioxide;forming a two-phase mixture of the resulting magnesium-containing compound with a suitable liquid hydrocarbon-miscible phase and a suitable polar solvent phase;forming particles by adding the two-phase mixture after vigorous agitation to a liquid hydrocarbon; andcontacting the formed particles at least once with a transition metal halide in the presence of an electron donor.
摘要:
A class of novel heterocyclic aromatic carbamate compounds is described. A method of derivatizing amine-functional compounds with the novel carbamates is also disclosed. The derivatives can be detected using a fluorescence detector. The present composition and method allow femtomole quantities of amine compounds to be detected and measured.
摘要:
The method for separating from a mother liquor containing at least two liquids, one of the two liquids including the steps of:(a) forming a precipitatable complex from one of the liquids and a complexing agent;(b) precipitating the precipitatable complex from the method liquor; and(c) recovering the second liquid from the remaining mother liquor. Typically, the two liquid substances are tetrahydrofuran and toluene and the complexing agent is titanium tetrachloride. The precipitatable complex is TiCl.sub.4.2C.sub.4 H.sub.8 O or TiCl.sub.4.C.sub.4 H.sub.8 O. Preferably, a cooling step is included in the method to enhance the removal of the precipitatabe complex. Superfractionation of the remaining liquor in distillation columns enables one to recover toluene, hexane, titanium tetrachloride and tetrahydrofuran. An apparatus for carrying out the method of recovering solvents in also disclosed.
摘要:
This invention relates to heterometallic thiocubane compositions containing the M.sub.2.sup.1 M.sub.2.sup.2 S.sub.4 cluster core and methods of making them wherein M.sup.1 is Re, V, Mo or W and M.sup.2 is Co, Cr, Cu, Ni or Fe but preferably Co. More particularly, the invention relates to compositions of the formula M.sub.2.sup.2 M.sub.2.sup.2 S.sub.4 L.sub.2.sup.1 L.sub.2.sup.2 L.sub.2.sup.3 wherein M.sup.1 and M.sup.2 are as above, L.sup.1 is a bidentate sulfur or nitrogen bearing ligand (most preferably a dialkyldithiocarbamate), L.sup.2 is optional but may be an O, N, P or S-containing monodentate donor ligand, and L.sup.3 may be CO, a monodentate anion ligand such as a halide (preferably C1), mercaptide or alkoxide, or another O, N, P, or S containing monodentate donor ligand. The compositions are suitable for making active hydrotreating catalysts.
摘要:
Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.