摘要:
The present invention relates to a method of producing xylose by chromatographic separation of the xylose from a sulphite cooking liquor containing for example xylose and xylonic acid. The xylose yield of the separation is affected by the xylonic acid and xylose content in the cooking liquor used in the separation and the amount of base cation used in the sulphite cooking.
摘要:
The device comprises at least one column 1 that is filled with a number of beds A.sub.n having an adsorbent that are separated by a fluid distributor plate P.sub.1. Each plate is divided into a number of sectors P.sub.10 and P.sub.11, and each sector comprises at least one fluid distribution chamber 13 that is pierced with openings and a circulation space 8 in the vicinity of the openings. The chambers of the plate are connected to a line 10 for transfer to the outside. With respect to the chambers on a plate, transfer line 10 P, is connected to another transfer line 20 relative to chambers 23 on another plate (P.sub.i+1 or P.sub.i+2) that is arranged downstream by a bypass line L.sub.1,2. The latter comprises means 14, 15, 16 for monitoring and adjustment of the flow of fluid that circulates there, such that the distribution chambers are flushed by a fluid which has approximately the same composition as that of the fluid that circulates through circulation space 8 at each of the chambers.
摘要:
The invention is a column for separating a substance from a liquid having a plurality of separable compounds. The column has at least a first and a second bed of granular solids separated by at least one device, the device has at least a collection device which collects the substance to be separated, the collection device being in fluid connection to at least one mixing chamber, at least a first circuit for injection and/or removal of a first secondary fluid B.sub.1 and at least a second injection and/or removal circuit of a second secondary fluid B.sub.2. The injection and/or removal circuits are in communication with the mixing chamber with at least one opening allowing passage of the secondary fluids B.sub.1, B.sub.2 into the mixing chamber. The mixing chamber has at least one inlet orifice and at least one outlet orifice, and a device which redistributes the fluid coming from the mixing chamber, wherein the injection and/or removal circuits are separated and disposed in a vicinity of the mixing chamber along at least one wall of the chamber that has a direction substantially parallel to the device axis.
摘要:
The chiral isomers of 3-hydroxytetrahyrofuran are separated by means of liquid chromatography using a stationary phase comprising a substituted polysaccharide carbamate. The separation may be performed using a simulated moving bed adsorbent system. Suitable mobile phase materials comprise a mixture of a light paraffin and a low molecular weight aliphatic alcohol such as a mixture of n-hexane and ethanol. Amylose is the preferred polysaccharide.
摘要:
Resolution of a mixture of organic materials by simulated moving bed chromatography using a weakly interacting adsorbent as a stationary phase can be routinely effected with a liquid mobile phase characterized by atypically low values of k' with recoveries of at least 95% and a purity of at least 95%. In particular, values in the range 0.1
摘要:
Various chemicals such as pharmaceuticals and petrochemicals are chromatographically separated in small quantities using an apparatus comprising a number of serially connected adsorbent-containing chambers. The chambers are linked together with valving necessary to simulate the continuous countercurrent flow of the adsorbent and liquid phases. The apparatus employs three three-port valves per chamber to direct liquid flow. Pressure pairing of the valves and the four major process streams protects product purity.
摘要:
Various chemicals such as pharmaceuticals and petrochemicals are chromatographically separated in pilot plant quantities using an apparatus comprising a number of chambers containing an adsorbent linked together with valving necessary to simulate the continuous countercurrent flow of the adsorbent and liquid phases. The apparatus preferably comprises five multiport rotary valves, each having at least one port for each column. The fifth rotary valve provides a serial interconnection between the columns and also ensures the desired unidirectional flow of fluid in the apparatus.
摘要:
A process for the liquid phase adsorptive separation of arabinose from an aqueous feed mixture of monosaccharides containing arabinose along with other aldopentoses and aldohexoses. The feed is contacted with a calcium-Y or clacium-X type zeolite. Arabinose is selectively adsorbed to the substantial exclusion of other aldoses and thereafter is recovered in high purity by desorption with water or ethanol. The process can be carried out on a commercial scale by means of a simulated moving bed flow scheme.
摘要:
A method is disclosed for controlling a simulated moving bed system of a type including at least four series-arranged beds each packed with a solid adsorbent, with the downstream end of each bed and the upstream end of the next succeeding bed being connected by conduits to form an endless loop, and in which a fluid is caused to circulate through the beds in one direction, a feed stock and a desorbent are introduced into the system while a raffinate and a sorbate are withdrawn from the system, and the positions of introduction and withdrawal of the four kinds of fluid are periodically shifted in the direction of the circulating fluid flow. In accordance with the invention, two or more circulating pumps, provided with variable speed controllers and pressure detectors for detecting the suction pressure of each of the circulating pumps, are disposed between two beds. The flow rates of three of the four fluids introduced into or withdrawn from the system are adjusted to predetermined values, and the flow rate of the other fluid is controlled in such a manner that the suction pressure of one of the circulating pumps or the average of the suction pressures of two or more of the circulating pumps is held constant, and a rotational speed of each of the circulating pumps is controlled independently so as to control the flow rate of the circulating fluid and to maintain the suction pressure of each circulating pump at a low level.