Aspen Chromatography

The basic principle of one-column process is identical to four-zone SMB. The performance of the process for the amino acids separation was compared with four-zone SMB by computer simulation using Aspen Chromatography. The system and operating parameters are listed in Table 1. It was set that T2, T3 and T4 are initially filled with desorbent and T1 is empty in the simulation. Liquid in each tank is ideally mixed. Liquid of the average solute concentration in a tank is introduced into the column. The simulated concentration profile of two amino acids in the one-column process is presented in Figure 3. 

Aspen Chromatography (Aspen Technology, Inc., USA) http / /www.aspentech.com... 

Since process simulators are used extensively in commercial practice, I have continued to include process simulation examples and homework problems throughout the text. I now teach the required three-credit, junior-level separations course at Purdue as two lectures and a two-hour conputer lab every week. The computer lab includes a lab test to assess the ability of the students to use the simulator. Although 1 use Aspen Plus as the simulator, any process simulator can be used. Chapters 2. 6, 8,10,12, 13. and 16 include appendices that present instructions for operation of Aspen Plus. The appendices to Chapters 2. 4, 5,15, and 17 have Excel spreadsheets, some of which use Visual Basic programs. I chose to use spreadsheets instead of a higher-level mathematical program because spreadsheets are universally available. The appendix to Chapter 18 includes brief instructions for operation of the commercial Aspen Chromatography simulator—more detailed instruction sheets are available from the author wankat purdue.edu. 

Chapter 18 Appendix. Introduction to the Aspen Chromatography Simulator... 

The Aspen Chromatography V7.2 simulator is fairly conplicated. This appendix contains material from two of the nine labs that were developed for an elective course fWankat. 20061. The conplete set of labs is available from the author by sending a request to wankat ecn.purdue.edu. The numerical method used by Aspen Chromatography is the method of lines, (e.g., see Schiesser. 19911. 

Lab 1. The goal of this lab is to get you started in Aspen Chromatography V7.2. It consists of a cookbook on running Aspen Chromatography, some helpful hints, and the simulation of a real separation. The assistance of Dr. Nadia Abunasser in developing the original version of this lab was critically helpful. 

Log in to the computer. Use your local operating system method of getting into Aspen Chromatography. Most likely, Aspen Tech Aspen Process Development Aspen Chromatography. 

Figure 5. Composite MWD diagram showing the calculated distributions of four of the five master fractions obtained from preparative chromatography of organosolv aspen lignin (fraction number 4 to 1 from left to right). The Mw values for the master fractions from left to right are 1,110, 1,310, 2,420, and 8,050, respectively. The insert shows the elution profile of organosolv aspen lignin from the YMC preparative /z-Styragel column (5 x 200 cm). The 30 fractions collected were pooled into the five master fractions shown.

The results from conventional gel permeation chromatography (GPC) of four acetylated aspen lignin derivatives are shown in Table 1. These data were collected with a sensitive ultraviolet HPLC detector, permitting 0.2 mg column loadings. The values for, and (35) proved to be similar to those... 

In a later extension of the thioacidolysis reaction, a second step, a Raney nickel reduction, was introduced, thereby also permitting the analysis of dimeric and trimeric degradation products by gas chromatography [20,76]. By this method, more than 20 different dimeric and 16 trimeric structures, representing aU the various inter-unit linkages depicted in Fig. 9.5, except the 3-0-4 and dibenzodioxocin structures, have been qualitatively identified from spruce wood. Similar data from birch and aspen wood are also available [23]. 

Himmel, M.E. Tatsumoto, K. Grohmann, K. Johnson, D.K. Chum, H.L. Molecular weight distribution of aspen hgnins from conventional gel permeation chromatography, universal cahhration and sedimentation equilibrium. J. Chromatogr. 1990, 498, 93-104. 

Rounds, M.A., J.F. Gregory, High performance hquid chromatography, in Food Analysis, 2nd Ed., S.S. Nielsen, Ed., Aspen Publ., Gaithersburg, 1998, p. 509. 

Fernandez, M.P., Watson, P.A., and Breuil, C., Gas chromatography-mass spectrometry method for the simultaneous determination of wood extractive compounds in quaking aspen, J. Chromatogr. A, 922, 225, 2001. 

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