Filter adjustment, calculation

THF Conversion. Tetrahydrofuran (THF) conversion was calculated from the difference between the initial and the final solubilities of the total coal-solvent slurry in THF. It was assumed that all of the solvent and none of the starting coal was soluble in THF. THF conversions were calculated on an MAF coal basis and adjusted for the coal not recovered from the autoclaves. The filter cake resulting from filtration of the product at 250 C was continuously extracted with THF for up to 3 days. 

The basic equation for water flow through saturated porous media was developed by Flenry Darcy in 1856 to calculate the flow of water through sand filters. This equation has been found to be valid for the flow of liquids through porous media when adjusted for the viscosity and density of the liquid. The original form of the equation, designed to calculate discharge is as follows ... 

The hydroxylamine reaction was used to estimate ketone and aldehyde groups. The method used was similar to one described by Kaverzneva and Salova (6). A 25-ml. solution of 5% aqueous hydroxylamine hydrochloride (previously adjusted to a pH 7.5-8 with sodium hydroxide) was added to 1.5 grams of sample and allowed to react for 18-24 hours at room temperature. The mixture was filtered, washed with water, and dried. The residue was analyzed for nitrogen, and the amount of aldehyde and ketone structure was calculated from the nitrogen increase. 

Place the uncovered beaker on a hot plate, and heat the contents vigorously until the center of the bottom of the beaker becomes clear. Remove the beaker, and cool to room temperature. Add 5 mL of hydrochloric acid, and heat again until white fumes evolve. After cooling, dilute the solution to approximately 100 mL with water, adjust to pH 6 0.2 with 10% sodium hydroxide, and heat the solution to boiling. Add 15 mL of 10% barium chloride solution, and leave the solution overnight in a fresh beaker in a steam bath at 90° to 95°. Filter through ashless filter paper (Whatman No. 42, or equivalent), and wash the precipitate with 200 mL of warm water. Transfer the paper and precipitate to a tared crucible. Heat the crucible slowly on a Bunsen burner to expel moisture. Place the crucible and contents in a muffle furnace at 850° for 1 h. Let the crucible cool in a desiccator, and then weigh the residue to the nearest 0.0001 g. Calculate the percent of sulfonate sulfur by the formula... 

Procedure Prepare a 50% (w/w) sample solution in water. Adjust the pH to 7.0 0.2 with 1% sodium hydroxide or 1% hydrochloric acid. Filter through a 0.45-pim pore-size membrane filter, using a vacuum and a diatomaceous earth filter aid (1% on solids) if necessary. Discard the first portion of the filtrate if it is cloudy. Determine the density and concentration of solids, in grams per milliliters, refractometrically. Rinse the measuring cell three times with the sample solution, and then fill the cell. Measure absorbancy (As) at 420 nm Calculate the color in ICUMSA units (IU) as follows ... 

Barium Hydroxide, 0.2 N [17.14 g Ba(OH)2 per 1000 mL] Dissolve about 36 g of barium hydroxide [Ba(0H)2-8H20] in 1 L of recently boiled and cooled water, and quickly filter the solution. Keep this solution in bottles with well-fitted rubber stoppers with a soda-lime tube attached to each bottle to protect the solution from carbon dioxide in the air. Standardize as follows Transfer quantitatively about 60 mL of 0.1 A hydrochloric acid, accurately measured, to a flask add 2 drops of Phenolphthalein TS and slowly titrate with the barium hydroxide solution, with constant stirring, until a permanent pink color is produced. Calculate the normality of the barium hydroxide solution and, if desired, adjust to exactly 0.2 A with freshly boiled and cooled water. 

In the recent years Simulated Moving Bed (SMB) technology has become more and more attractive for complex separation tasks. To ensure the compliance with product specifications, a robust control is required. In this work a new optimization bas adaptive control strategy for the SMB is proposed A linearized reduced order model, which accounts for the periodic nature of the SMB process is used for online optimization and control purposes. Concentration measurements at the raffinate and extract outlets are used as the feedback information together with a periodic Kalman filter to remove model errors and to handle disturbances. The state estimate from the periodic Kalman filter is then used for the prediction of the outlet concentrations over a pre-defined time horizon. Predicted outlet concentrations constitute the basis for the calculation of the optimal input adjustments, which maximize the productivity and minimize the desorbent consumption subject to constraints on product purities. 

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