243results about "Refining by dialysis" patented technology

An onboard fuel separation apparatus separates a material fuel (gasoline) into a high-octane fuel having a higher octane value than the material fuel and a low-octane fuel having a lower octane value than the material fuel using a separation membrane which selectively allows high-octane value components (such as aromatic components) permeate through the membrane. The apparatus increases the ratio of the amount of the high-octane value components permeating through the membrane to the amount of the high-octane value components contained in the material fuel by, (A) Controlling the temperature of the material fuel supplied to the membrane (B) Increasing partial pressure of the low-octane value components on the high-octane fuel side of the membrane and removing volatiles from the permeate, and (C) Bypassing volatiles in the material feed around the membrane.

The present invention pertains to a process for the separation of aromatics from a feed stream, including aromatics and non-aromatics by selectively permeating the aromatics through a membrane comprising feeding a mixed phase vapor-liquid feed to a membrane wherein said liquid phase preferentially wets the surface of the membrane.

A sieving membrane comprises a thin, microporous barrier to provide a high flux. The membrane structure can tolerate defects yet still obtain commercially-attractive separations.

The present invention is for high performance UV-cross-linked membranes from polymers of intrinsic microporosity (PIMs) and the use of such membranes for separations. More specifically, the invention involves the methods of making UV-cross-linked membranes from PIMs. These membranes were prepared by cross-linking the UV-cross-linkable membranes from PIMs by exposure to UV-radiation. Pure gas permeation test results demonstrate that the UV-cross-linked membranes from PIMs exhibit CO₂/CH₄ performance well above the Robeson's polymer upper bound trade-off curve for CO₂/CH₄ separation. They have more than doubled selectivity for CO₂/CH₄ and extremely high permeability of CO₂ compared to the original UV-cross-linkable membranes from PIMs. These membranes also show excellent separation performance for CO₂/N₂, H₂/CH₄, O₂/N₂, and propylene/propane separations. These high performance UV-cross-linked membranes are very useful for gas and liquid separations such as CO₂/CH₄, CO₂/N₂, H₂/CH₄, O₂/N₂, olefin/paraffin, deep desulfurization of gasoline and diesel fuels, and ethanol/water separations.

A petroleum feedstock upgrading method is provided. The method includes supplying a mixed stream that includes hydrocarbon feedstock and water to a hydrothermal reactor where the mixed stream is maintained at a temperature and pressure greater than the critical temperatures and pressure of water in the absence of catalyst for a residence time sufficient to convert the mixed stream into a modified stream having an increased concentration of lighter hydrocarbons and/or concentration of sulfur containing compounds. The modified stream is then supplied to an adsorptive reaction stage charged with a solid adsorbent operable to remove at least a portion of the sulfur present to produce a trimmed. The trimmed stream is then separated into a gas and a liquid streams, and the liquid stream is separated into a water stream and an upgraded hydrocarbon product stream.

A process for the recovery of natural gas liquids (NGL) (ethane, ethylene, propane, propylene and heavier hydrocarbons) from liquefied natural gas (LNG) is disclosed. The LNG feed stream is split with at least one portion used as an external reflux, without prior treatment, to improve the separation and recovery of the natural gas liquids (NGL).

A process for the recovery of gaseous products from the product mixture obtained by contacting a hydrocarbon feed with a catalyst in a fluid catalytic cracking process, wherein the liquid, obtained by separating the top product of main fractionators into gaseous and liquid fraction, when supplied to the absorber has a temperature of between about 8–25 DEG C. This liquid may be pre-saturated with gaseous top product from absorber; or also a high boiling fraction (cat cracker naphtha/light cycle oil) may be first separated from this liquid by distillation.

A divided wall column can allow for fractionation of multiple streams while maintaining separate product qualities. Effluents from multiple stages of a reaction system can be processed in a single divided wall column. The divided wall column can produce multiple cuts from each separated area, as well as at least one output from a common area. At least one reaction stage can advantageously have a continuous liquid phase environment.

The process of the present invention is directed to the desulfurization of a sulfur-containing hydrocarbon stream with a membrane contactor, where sulfur compounds are concentrated in a sulfur-rich stream on a permeate side of the membrane using an extractive liquid, and a sulfur-lean stream is recovered as a retentate. The sulfur-rich stream, which has a small volume relative to the original hydrocarbon stream, is conveyed to a recovery zone to recover extractive liquid, and the remaining hydrocarbon stream having an increased concentration of sulfur compounds is passed to a downstream desulfurization apparatus or system, such as a hydrotreating system, to recover the hydrocarbons associated with the organosulfur compounds.

A membrane process for the removal of sulfur species from a naphtha feed, in particular, a FCC light cat naphtha, without a substantial loss of olefin yield is disclosed. The process involves contacting a naphtha feed stream with a membrane having sufficient flux and selectivity to separate a sulfur deficient retentate fraction from a sulfur enriched permeate fraction, preferably, under pervaporation conditions. Sulfur deficient retentate fractions are useful directly into the gasoline pool. Sulfur-enriched permeate fractions are rich in sulfur containing aromatic and nonaromatic hydrocarbons and are further treated with conventional sulfur removal technologies, e.g. hydrotreating, to reduce sulfur content. The process of the invention provides high quality naphtha products having a reduced sulfur content and a high content of olefin compounds.

The invention relates to an improved membrane pervaporation and vapor permeation system in which the vacuum is produced by a fluid passing through a Venturi-type nozzle. The fluid is chosen from solvents that have little or no affinity for the permeate molecules. It is applicable over process feed rates, and can be used for the separation of aromatic species from hydrocarbon.

In an internal combustion engine fuel system having a membrane separator for separating a primary fuel into a high octane fuel and a low octane fuel, and wherein the primary fuel is heated for separation in the membrane separator, the improvement comprising a heat pipe having an evaporator section positioned to be in the heat exchange relationship with exhaust gas from the internal combustion engine under conditions of use; and a heat output area in heat exchange relationship with a primary fuel as it is fed into the separator whereby the primary fuel is heated. In one embodiment the heat pipe is a variable conductance heat pipe having a top operating temperature not greater than about 160° C.

An oil gas separation membrane combines a gas permeable yet oil and temperature resistant bulk polymer membrane such as poly(tetrafluoroethylene) and poly(tetrafluoroethylene-co-hexafluoropropylene); a porous metal support such as sintered metal frit disk made with stainless steel, bronze or nickel; and an highly gas permeable adhesive that bonds firmly the bulk polymer membrane and the metal frit surface together. The adhesive is either a homogenous polymer that has desirable gas permeability, or a coalescent porous polymer particulates network. A gas sensor employing the oil gas separation membrane for detecting and monitoring fault gases of oil filled electrical equipment requires no mechanical wearing or moving part such as pump and valve and the gas sensor is operated normally under various temperature and pressure conditions.

Synthesis and use of a new class of polymeric materials with favorable separation characteristics for the dehydration of ethanol and other organic solvents is described herein. The thermally rearranged (TR) polybenzoxazole (PBO), polybenzimidazole (PBI) and polybenzothiazole (PBT) membranes of the present invention can be used for the dehydration of ethanol during processing to fuel grade biodiesel by either pervaporation or vapor permeation. The unique microstructure of the membranes provides excellent separation characteristics, and this, coupled with their inherent thermal and chemical stability, enables their usage in other separations, such as the dehydration of other organic solvents.

A fuel system for an energy conversion device includes a multiple of fuel plates, oxygen permeable membranes, porous substrate plates, and vacuum frame plates which define a wave pattern configuration. The wave configuration enhances deoxygenation by increasing the efficiency and integrality due to higher surface volume ration, increase of flow turbulence, and minimal sharp edges which may otherwise damage the oxygen permeable membranes compared to other configurations.

Methods for upgrading a hydrocarbon feed are disclosed. The methods include a hydrocarbon feed having an insolubility number, I_feed, with at least a first fluid to form a fluid-feed mixture; and inducing a centrifugal force to the fluid-feed mixture sufficient to form at least a higher density portion and a lower density portion, said lower density portion having an insolubility number, I_LD, wherein I_LD/I_feed≦0.95. Methods and apparatus for hydroprocessing the treated feed and blending with a fuel oil blend-stock are also described.

A membrane composition comprising an inorganic substrate which has a coating of an associating polymer. The membrane composition includes an inorganic substrate selected from the group consisting of a porous silica hollow tube, an alumina hollow tube and a ceramic monolith.

This invention relates to a process for separating a heavy hydrocarbon stream to produce at least one permeate product stream and at least one retentate product stream. The process utilizes an ultrafiltration process to designed to maximize the quality of the permeate and retenate product streams as well as process embodiments which improve permeate production quantities as well as improve the quality of the product streams obtained by the separations process. In preferred embodiments, the process includes configuration and operational parameters to maximize permeate yield and selectivity.

A fuel system for an energy conversion device includes a deoxygenator system with an oxygen permeable membrane having a textured surface. A sweep gas and/or vacuum maintains an oxygen concentration differential across the membrane to deoxygenate the fuel. The textured surface increases the surface area of the oxygen permeable membrane. The textured surface of the oxygen permeable membrane is fabricated by pressing the textured surface into the oxygen permeable membrane with a microreplication-based tooling system. Another fabrication method presses the textured surface into a sacrificial film and the oxygen permeable membrane is then formed upon the sacrificial film to transfer the textured surface to the oxygen permeable membrane and the sacrificial film is then subsequently removed. Another fabrication method applies additional material to the oxygen permeable membrane through a porous sacrificial film.