A method and apparatus for isolating a first substance from a mixture by chromatography, the mixture including at least a second substance which in the chromatography is subject to a greater retention than the first substance, and having a third substance which in the chromatography is subject to a lower retention than the first substance. The mixture is supplied to a chromatography apparatus having multiple interconnected chromatography columns. The apparatus is supplied with the mixture and an eluent, and the second substance is withdrawn as an extract and the first substance as a raffinate. The third substance is withdrawn as an extract. Usefully the third substance and the second substance are withdrawn jointly as an extract.

A method for purifying a Fomes officinalis polysaccharide by sequential simulated moving chromatography is provided by the present application, relating to the technical field of biological extraction. The method includes the following steps: step 1, leaching Fomes officinalis to obtain a polysaccharide extractive solution; step 2, purifying the polysaccharide extractive solution by sequential simulated moving chromatography to obtain a purified solution; and step 3, subjecting the purified solution to a treatment of refining and removing impurities, followed by concentrating and drying to obtain the Fomes officinalis polysaccharide. The Fomes officinalis polysaccharide prepared the method is applied in preparing products for promoting NO production by macrophages.

Disclosed herein are processes for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce a paraxylene-rich extract stream that also contains a significant amount of the ethylbenzene and a paraxylene-depleted raffinate stream. Because a significant amount of the ethylbenzene is removed in the paraxylene-rich extract stream (at least enough to limit buildup in the isomerization loop), the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy- and capital-intensive hydrogen recycle loop.

An adsorptive separation process and system are used for separation of multi-component fluid mixtures. The separation process and system may include establishing, in a fluid flow within the system, a concentration distribution of the fluid mixture components based upon the components' relative affinities to the adsorbent. The concentration distribution could be establishing using a simulated moving bed system, wherein it is possible to maintain separately-identifiable portions of the fluid flow, respectively rich in strongly-adsorbing, intermediately-adsorbing, and weakly-adsorbing compounds of the fluid mixture. An intermediate raffinate of high purity in the intermediately-adsorbing compound is directly withdrawn from the portion of the fluid flow rich in intermediately-adsorbing compound(s), providing a single-stage adsorptive separation of a compound having intermediate affinity to the adsorbent. The portion of the fluid flow rich in intermediately-adsorbing compound(s) may be established directly upstream from the point of fluid mixture feed injection into the fluid flow.

A method for measuring the concentrations of species present at at least one point of a separation unit operating in simulated moving bed (SMB) mode, or a hybrid separation unit employing a step for simulated moving bed (SMB) separation and a step for crystallization, by calibration by inline acquisition of Raman spectra for different mixtures; analysis by inline signal processing of the Raman spectrum.

The present invention describes a process for the simulated moving bed separation of xylenes which can be used for the treatment of paraxylene-rich feeds (more than 25% by weight of paraxylene), in which the operating conditions are optimized by means of a specific relationship between the cycle time and the desorbant flow rate.

A system for separating components of a fluid containing at least a first component and a second component includes a device having an inlet for introducing the fluid into the device, a first outlet for directing the first component of the fluid from the device, and a second outlet for directing the second component of the fluid from the device. A material that has a gradient in properties is located in the device between the inlet and the first and second outlets. The material has a first portion with an affinity for the first fluid component and a second portion with an affinity for the second fluid component. The first portion is positioned with relation to the first outlet such that the first component is directed from said device through the first outlet. The second portion is positioned with relation to the second outlet such that the second component is directed from the device through the second outlet.

A process is described for separating paraxylene from a multicomponent fluid mixture of C8 aromatics. A mixture of C8 aromatics is fed to a simulated moving-bed adsorptive apparatus. The location of the feed to the apparatus is moved at set intervals. The rate of flow of feed to the apparatus is varied during each interval to enhance the separation of paraxylene from the multicomponent mixture.

The present invention relates to a method for fractionating a feedstock into two or more fractions enriched with different components, and more particularly to a method for fractionating a feedstock into two or more fractions by a chromatographic sequential simulated moving bed (SMB) system, wherein the SMB system comprises a separation loop comprising at least 2 compartments; and wherein the method comprises a separation cycle comprising at least one feeding step, at least one circulating step and at least one eluting step; wherein the dissolved substances in the feedstock form a separation profile as they progress through the separation loop; and the separation profile is progressed more than once or less than once through the separation loop in each separation cycle; and wherein at least two flow paths are present in the separation loop during each feeding step of the separation cycle; and at least one of said flow paths is an active flow path and at least one of said flow paths is an inactive flow path.

The present invention describes a process for the simulated moving bed separation of xylenes, in which the operating conditions are optimized by means of a specific relationship between the cycle time and the flow rate of the desorbant.