Abstract:
This invention relates to methods for spraying liquid compositions containing volatile solvent by using compressed fluids, such as carbon dioxide or ethane, to form solid particulates, coating powders, and catalyst materials, which can be produced with narrow particle size distributions and can be sprayed at higher solids levels, in ambient air or with heated air applied to just the spray instead of a spray chamber. Novel catalyst supports can be produced having a beneficial morphology such as for olefin catalysis. Drier water-borne coatings can be applied to substrates by using compressed fluids to spray water-borne coating compositions having conventional water levels, thereby reducing runs and sags and shortening dry times.
Abstract:
This invention relates to methods for spraying liquid compositions containing volatile solvent by using compressed fluids, such as carbon dioxide or ethane, to form solid particulates, coating powders, and catalyst materials, which can be produced with narrow particle size distributions and can be sprayed at higher solids levels, in ambient air or with heated air applied to just the spray instead of a spray chamber. Novel catalyst supports can be produced having a beneficial morphology such as for olefin catalysis. Drier water-born coatings can be applied to substrates by using compressed fluids to spray water-born coating compositions having conventional water levels, thereby reducing runs and sags and shortening dry times.
Abstract:
The invention is directed to a method and apparatus for coating substrates by a liquid spray so as to avoid entrapment of gaseous bubbles, particularly air bubbles, in the coating and desirably to thereby obtain bubble-free coatings. More particularly, the invention involves spray applying the coating to a substrate in an atmosphere consisting of gases having appreciable solubility in the applied coating, such as carbon dioxide, such that gas bubbles that may become entrapped in the coating are removed after application by the gases dissolving into the coating and diffusing to the surface.
Abstract:
The present invention provides a catalyst for the oxidative dehydrogenation of a lower hydrocarbon to form at least one higher hydrocarbon and/or lower olefin. In one embodiment, the catalyst includes a nonstoichiometric rare earth oxycarbonate of the formula MXCYOZ having a disordered and/or defect structure, wherein M is at least one rare earth element selected from the group consisting of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Tm; X=2; Z=3+AY; A is less than about 1.8, and Y is the number of carbon atoms in the oxycarbonate. When used for the oxidative dehydrogenation of a lower hydrocarbon at a pressure above about 100 psig, the catalyst has a selectivity of at least about 40% to at least one higher hydrocarbon and/or lower olefin. Methods for preparing catalysts taught by the invention and processes for using the catalysts for the oxidative dehydrogenation of lower hydrocarbons are also provided.
Abstract:
This invention relates to methods for spraying liquid compositions containing volatile solvent by using compressed fluids, such as carbon dioxide or ethane, to form solid particulates, coating powders, and catalyst materials, which can be produced with narrow particle size distributions and can be sprayed at higher solids levels, in ambient air or with heated air applied to just the spray instead of a spray chamber. Novel catalyst supports can be produced having a beneficial morphology such as for olefin catalysis. Drier water-borne coatings can be applied to substrates by using compressed fluids to spray water-borne coating compositions having conventional water levels, thereby reducing runs and sags and shortening dry times.
Abstract:
Processes are disclosed for the use of subcritical compressed fluids, such as carbon dioxide or ethane, to reduce viscosity and to enhance atomization when spray applying coating compositions containing low molecular weight polymers to substrates, by using spray conditions that produce choked flow in the liquid mixture being sprayed, wherein the subcritical compressed fluid is a gas at standard conditions of 0° C. temperature and one atmosphere pressure and is miscible with the coating composition.
Abstract:
The present invention provides methods for manufacturing olefins such as ethylene and propylene from lower alkanes, that is, methane, ethane and/or propane, by oxidative dehydrogenation at elevated pressure. The olefins are selectively recovered from unconverted lower alkane feed and reaction byproducts by using a complexation separation, such as an absorption separation that uses aqueous silver nitrate as the complexation agent. Catalysts are used that give high selectivity for oxidative dehydrogenation of lower alkanes to olefins at elevated pressure, such as a nonstoichiometric rare earth oxycarbonate catalyst.
Abstract:
The present invention provides a catalyst for the oxidative dehydrogenation of a lower hydrocarbon to form at least one higher hydrocarbon and/or lower olefin. In one embodiment, the catalyst includes a nonstoichiometric rare earth oxycarbonate of the formula MXCYOZ having a disordered and/or defect structure, wherein M is at least one rare earth element selected from the group consisting of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Tm; X=2; Z=3+AY; A is less than about 1.8, and Y is the number of carbon atoms in the oxycarbonate. When used for the oxidative dehydrogenation of a lower hydrocarbon at a pressure above about 100 psig, the catalyst has a selectivity of at least about 40% to at least one higher hydrocarbon and/or lower olefin. Methods for preparing catalysts taught by the invention and processes for using the catalysts for the oxidative dehydrogenation of lower hydrocarbons are also provided.