2 results about "Fractionation" patented technology

Process for producing low-molecular olefins by pyrolysis of hydrocarbons comprising mixing of feedstock with steam-diluent, preheating the resulting mixture, rapid heating the said mixture up to pyrolysis temperature and maintaining this temperature inside reactor during residence time, quenching product stream and subsequent fractionation of products. The reactor has an annular work cavity where stationary blades and rotatable work blades are located. A ring vortex flow is created and maintained in the work cavity when the work blades are rotated. A heat needed for pyrolysis is generated due to hydrodynamic drag of rotated work blades. Heating the mixture up to pyrolysis temperature is performed by mixing with hot process stream recirculated in the work cavity for a negligible time in comparison with the residence time. The process enables increase of the low-molecular olefins yield.

A method for preparing clean diesel oil form inferior diesel oil comprises the following steps: carrying out an aromatic hydrocarbon extracting treatment on inferior diesel oil so as to obtain raffinate oil rich in saturated hydrocarbon and extract oil rich in polycyclic aromatic hydrocarbon, carrying out a hydrogenation refining treatment on the raffinate oil, subjecting the hydrogenation refining reaction product to a fractionation treatment, taking the fraction below 180 DEG C as the gasoline blending component and the fraction above 180 DEG C as the clean diesel, carrying out a hydrogenation modification treatment on the extract oil rich in polycyclic aromatic hydrocarbon, mixing the hydrogenation modification reaction product with inferior diesel oil, and then carrying out an aromatic hydrocarbon extracting treatment on the mixture for another time. The method adopts a combined technology to process inferior diesel oil, and can produce diesel oil, which meets the diesel oil standards and has a low sulfur content and a high cetane value.