Steffen process

Steffen process Steffen sequence Steinhart-Hart equation Stelazine Stellar Stellite... 

The Steffen process, which uses calcium oxide for precipitation of sucrose from molasses, has been applied to the recovery of lactose from cheese whey (Cerbulis 1973). By proper control of the reaction, over 90% of the lactose can be recovered as an insoluble calcium-lactose complex. The addition of ferric chloride in combination with calcium oxide improves lactose yields. Addition of equal volumes of acetone or methanol gives almost complete precipitation of lactose and protein from whey. 

Cerbulis, J. 1973. Application of Steffen process and its modifications to recovery of lactose and proteins from whey. J. Agri. Food Chem. 21, 255-257. 

Sucrose can be partly recovered from molasses by means of lime, strontia, or byryta processes. These processes are all based on the formation of insoluble saccharates. The process using dry lime as the precipitant is known as the Steffen process. About 95 percent of the sucrose is recovered from beet molasses. The diluted molasses is cooled to about 6°C and dry lime is added. The precipitated calcium saccharate is carbonated to reduce the lime content, filtered, and concentrated. About 90 percent of the sucrose can be recovered by the Steffen process. The calcium carbonate precipitated can be roasted and reconverted to quick lime. 

Steffen process. A process used in beet sugar manufacture to separate residual sugar from molasses. Based on the formation of insoluble tricalcium saccharate and its subsequent decomposition to sugar in the presence of a weak acid such as carbonic. 

Additional quantities of sucrose may be obtained from the molasses by diluting it to a concentration of about 7 % sugar, cooling to 12 , and adding lime (Steffen process). A difficultly soluble compound of sucrose with three moles of lime, tricalcium saccharate, crystallizes. The tricalcium saccharate, after separation from the final molasses, serves in the place of lime for the purification of the warm diffusion juice. Some beet sugar factories recover additional sugar from the molasses by a treatment with barium hydroxide, which forms the difficultly soluble barium saccharate. This saccharate is decomposed with carbon dioxide, and the insoluble barium carbonate is separated from the sucrose. The barium carbonate is reclaimed and reconverted to barium hydroxide. The final molasses is usually sold for cattle food or for industrial fermentations particularly when mixed with blackstrap molasses. 

P. K. Ladwig, T. R. Steffens, S. L. Laley, D. P. Leta, and R. D. Patel, "Resid Processing in Fluid Catalytic Crackers," Foster Wheeler Heavy Oils Conference, Orlando, Fla., June 7, 1993. 

Chemical Micro Process Engineering Fundamentals, Modelling and Reaaions Volker Hessel, Steffen Hardt, Holger Lowe... 

Oeters, F., Zhang, L., and Steffen, R., Considerations on Process Technologies of Smelting Reduction Including Scrap Melting, Turkdogan Symp. Proc., p. 23 (1994)... 

Steffens A process for separating sugar from beet sugar molasses by adding calcium hydroxide to precipitate calcium saccharate. Treatment of the liquor with carbon dioxide precipitates calcium carbonate and regenerates the sucrose. Invented in Vienna in 1883 by C. Steffens. See also Boivan-Louiseau, Scheibler. 

Three processes have been worked out and extensively used. In order of their success as chemical processes they are (1) the osmose process in which the crystalliz-able materials in the molasses are separated from the non-cryscallizable by osmosis in cells with permeable diaphragms (2) the Steffens or lime process, in which the sugar is precipitated as calcium trisaccharate (3) the barium process, in which the sugar is precipitated as barium trisaccharate. 

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