摘要:
A process for producing sugar from cane includes the step of filtering a sucrose-containing feed juice, which has been obtained from macerated sugar cane, through a first ultrafiltration membrane that has a first molecular weight cutoff. This ultrafiltration step produces a first ultrafiltration permeate and a first ultrafiltration retentate. The first ultrafiltration permeate is filtered through a second ultrafiltration membrane that has a second molecular weight cutoff that is lower than the first molecular weight cutoff. This second ultrafiltration step produces a second ultrafiltration permeate and a second ultrafiltration retentate. The second ultrafiltration permeate is nanofiltered through a nanofiltration membrane, thereby producing a nanofiltration permeate and a nanofiltration retentate. The nanofiltration retentate has a higher concentration of sucrose on a dry solids basis than the feed juice in step (a), and can be used in evaporation and crystallization operations to produce crystals of white sugar. The process can optionally include ion exchange and/or electrodialysis purification steps, prior to or after the nanofiltration step. Recycle syrups can be treated with a chromatographic separator to remove excess invert, ash and color.
摘要:
A process for producing sugar from beets includes the step of filtering a sucrose-containing feed juice, which has been obtained by diffusion from sliced sugar beets, through a first ultrafiltration membrane that has a first molecular weight cutoff. This ultrafiltration step produces a first ultrafiltration permeate and a first ultrafiltration retentate. The first ultrafiltration permeate is filtered through a second ultrafiltration membrane that has a second molecular weight cutoff that is lower than the first molecular weight cutoff. This second ultrafiltration step produces a second ultrafiltration permeate and a second ultrafiltration retentate. The second ultrafiltration permeate is nanofiltered through a nanofiltration membrane, thereby producing a nanofiltration permeate and a nanofiltration retentate. The nanofiltration retentate has a higher concentration of sucrose on a dry solids basis than the feed juice in step (a), and can be used in evaporation and crystallization operations to produce crystals of white sugar. The process can optionally include ion exchange and/or electrodialysis purification steps, prior to or after the nanofiltration step. Recycle syrups can be treated with enzyme or a chromatographic separator to remove raffinose.
摘要:
A nanofiltration process for obtaining sucrose uses a feed syrup, such as molasses, that comprises sucrose and no less than about 2% by weight invert sugars (on a dry solids basis). The nanofiltration produces a permeate and retentate. The nanofiltration permeate will comprise invert sugars that have passed from the feed through the nanofiltration membrane, and preferably will also comprise ash from the feed. The nanofiltration retentate has a higher concentration of sucrose and a lower concentration of invert sugars than the feed syrup. Sucrose can then be crystallized from the nanofiltration retentate. The reduction of the invert content in the syrup facilitates crystallization and thus enhances sucrose recovery.
摘要:
An efficient method for manufacturing a purified juice product from sugar beets. Untreated beet juice is initially prelimed using lime and CaCO.sub.3 to produce a prelimed juice product. Instead of subjecting the prelimed product to main liming and dual carbonation stages, the product is delivered to a porous filtration membrane which allows sugar molecules to pass therethrough which preventing the passage of solid matter and dissolved impurities. Optimum results are achieved if the prelimed product flows across the membrane from end to end. The membrane permeate is thereafter combined with CO.sub.2(g) in a single carbonation stage to remove dissolved lime. This step generates a purified juice product which can be processed to manufacture pure crystalline sugar. The membrane retentate can be combined with water and refiltered to collect residual sugar materials. The foregoing process uses less energy and raw materials (e.g. lime) compared with conventional methods.
摘要:
A process for producing sugar from beets includes the step of filtering a sucrose-containing feed juice, which has been obtained from macerated sugar beets, through a first ultrafiltration membrane that has a first molecular weight cutoff. This ultrafiltration step produces a first ultrafiltration permeate and a first ultrafiltration retentate. The first ultrafiltration permeate is filtered through a second ultrafiltration membrane that has a second molecular weight cutoff that is lower than the first molecular weight cutoff. This second ultrafiltration step produces a second ultrafiltration permeate and a second ultrafiltration retentate. The second ultrafiltration permeate is nanofiltered through a nanofiltration membrane, thereby producing a nanofiltration permeate and a nanofiltration retentate. The nanofiltration retentate has a higher concentration of sucrose on a dry solids basis than the feed juice in step (a), and can be used in evaporation and crystallization operations to produce crystals of white sugar. The process can optionally include ion exchange and/or electrodialysis purification steps, prior to or after the nanofiltration step. Recycle syrups can be treated with enzyme or a chromatographic separator to remove raffinose.
摘要:
A nanofiltration process for obtaining sucrose uses a feed syrup, such as molasses, that comprises sucrose and no less than about 3% by weight invert sugars (on a dry solids basis). The nanofiltration produces a permeate and retentate. The nanofiltration permeate will comprise invert sugars that have passed from the feed through the nanofiltration membrane, and preferably will also comprise ash from the feed. The nanofiltration retentate has a higher concentration of sucrose and a lower concentration of invert sugars than the feed syrup. Sucrose can then be crystallized from the nanofiltration retentate. The reduction of the invert content in the syrup facilitates crystallization and thus enhances sucrose recovery.
摘要:
Installation for treating a biological liquid, including a circulation pump (5), a filter element (9), a container for collecting treated liquid, a first circuit section connecting a source of said biological liquid to an inlet orifice of said filter element (9), including a circuit element adapted to cooperate with said circulation pump (5); a second circuit section, connecting an outlet orifice of said filter element (9) to said treated liquid collecting container; characterized in that said treated liquid collecting container, said first circuit section and said second circuit section are disposable and said installation further includes a first cart (1) carrying said pump (5) and a second cart (2) including a housing (14) for said collecting container, separable from the first cart (1) and adapted to be at least partly nested in said first cart (1).
摘要:
Installation for treating a biological liquid, including a circulation pump (5), a filter element (9), a container for collecting treated liquid, a first circuit section connecting a source of said biological liquid to an inlet orifice of said filter element (9), including a circuit element adapted to cooperate with said circulation pump (5); a second circuit section, connecting an outlet orifice of said filter element (9) to said treated liquid collecting container; characterized in that said treated liquid collecting container, said first circuit section and said second circuit section are disposable and said installation further includes a first cart (1) carrying said pump (5) and a second cart (2) including a housing (14) for said collecting container, separable from the first cart (1) and adapted to be at least partly nested in said first cart (1).
摘要:
A method of and an apparatus for tangential filtration with filter cleaning in which a fluid to be filtered forms a liquid loop and circulates tangentially to one surface of a membrane at a pressure Ph in which a filtrate flows from the other surface of the membrane through a pipe, provided with a flow meter and a first valve, to a tank at atmospheric pressure Pa, filtration taking place by virtue of a positive transmembranal pressure Ph - Pa. In the filtration phase, the hydrodynamic pressure Ph is adjusted by means of a second regulable valve. During the filter cleaning phase the first valve is closed and at the same time the second valve is slightly opened, the second valve is suddenly opened, the first valve is opened and the second valve is progressively closed. The method and apparatus in particularly suited to the filtration of corrosive liquids.
摘要:
Installation for treating a biological liquid, including a circulation pump (5), a filter element (9), a container for collecting treated liquid, a first circuit section connecting a source of said biological liquid to an inlet orifice of said filter element (9), including a circuit element adapted to cooperate with said circulation pump (5); a second circuit section, connecting an outlet orifice of said filter element (9) to said treated liquid collecting container; characterized in that said treated liquid collecting container, said first circuit section and said second circuit section are disposable and said installation further includes a first cart (1) carrying said pump (5) and a second cart (2) including a housing (14) for said collecting container, separable from the first cart (1) and adapted to be at least partly nested in said first cart (1).