M.S.

The production of levulose from sucrose was originally outlined to determine the optimum conditions for producing levulose using the Dubrunfout method for separating the levulose from the mother liquor by precipitating it as calcium levulate. This investigation was to include the study of the effect of invert sugar concentrations, the effect of mol ratio of Ca(OH)₂ to levulose and temperature, on the workability of the calcium levulate precipitate obtained and the yield of levulose resulting. A study to determine the possibility of using ion exchange material for the purification of the levulose solution was also planned. In all tests, the sucrose was inverted by acidifying the syrup with sufficient H₂SO₄ to obtain a pH of 1.0-1.5 and heating to 70°C for 90 minutes. An inversion of 92-97 percent resulted. The mol ratio of Ca(OH)₂ to levulose for precipitation was varied from 1:1 to 3:1 and it was found that the 3:1 ratio resulted in the best yield, a 59.6 percent yield being obtained. It was found that a 55-58 percent invert sugar solution resulted in an unworkable mass when the levulose was precipitated as calcium levulate, but a 28-29 percent solution could be centrifuged satisfactorily. Using a 28-29 percent invert sugar solution and a 3:1 mol ratio of Ca(OH)₂ to levulose for precipitation, the effect of the precipitating temperature on the yield of levulose was determined. It was found that the precipitating temperature varied inversely with yield, with the best yield of 59.6 percent resulting at 0°C and no yield being obtained at 30°C. Attempts to purify the levulose solution resulted in a nine-fold loss in capacity of the exchange material in one use and regeneration, when H₂SO₄ was used as the regenerant. When HC1 was used as regenerant for the material a recovery of some of the capacity resulted. The recovery of capacity was four times the capacity exhibited in the last where H₂SO₄ was used, but only 13 percent of its original capacity. The assumptions made in conducting this investigation were held to a minimum, but it was necessary to make several assumptions when making analytical tests. / M.S.

M.S.

A study of the production of levulose from sorghum syrup with the application of ion exchange was made to determine the optimum conditions for the production of a levulose-rich syrup by means of the Dubrunfaut method and to determine the applicability of ion exchange methods to the purification of a levulose solution obtained through the carbonation of a suspension of calcium levulate. A sorghum juice that had an analysis comparable to that of a typical defecated Louisiana sugar cane juice was prepare from a commercial sorghum syrup by the addition of four liters of distilled water to 750 grams of the syrup. In all tests, the sucrose present in the prepared juice was inverted by acidifying the juice with sufficient 38.7-per-cent hydrochloric acid to obtain a pH of 1.0 to 1.2 and heating to 90°C for one hour; an inversion of 95 to 99 percent of theoretical resulted. A molar ratio of calcium hydroxide to levulose 3:1, based on the theoretical yield, was used to precipitate the levulose as calcium levulate. The calcium levulate was suspended in two liters of distilled water and carbonated to free the levulose and precipitate the calcium as calcium carbonate. The carbonation consisted of bubbling carbon dioxide through the calcium levulate suspension at a rate of approximately 0.5 cubic foot per hour for 48 hours. It was found that the addition of ten milliliters of 38.7-percent hydrochloric acid to the suspension of calcium levulate effected a two-fold increase in the yield. Purification of the levulose solution was accomplished by means of an experimental ion-exchange apparatus. Passage of the levulose solution through columns containing 300 grams of zeo-karb H and de-acidite, resulted in a levulose solution of 98 to 99 percent purity. It was determined that the capacity of the cation-exchange material, zeo-karb H, could be maintained for three cycles of treatment with 0.3013 to 0.3521 N sodium hydroxide for 24 hours at 20° to 25° and regeneration with 0.2197 and 0.3925 N hydrochloric acid for 24 hours at temperatures ranging from 20° to 25°C. The maximum capacity of zeo-karb H for sodium ions was found to be 0.088 gram per gram of adsorbent when treated with 0.3013 N sodium hydroxide for 12 hours at temperatures ranging from 20° to 25°C/ The maximum capacity of de-acidite for chlorine ions was found to be 0.113 gram pepr gram of adsorbent when treated with 0.3437 N hydrochloric acid for 12 hours at temperatures ranging from 20° to 25°C. / M.S.