STUDY OF THE EVAPORATION PROCESS OF MOTHER LIQUORS IN THE PRODUCTION OF POTASSIUM NITRATE

"The aim was to study the influence of the main technological parameters on the process of evaporation off the primary mother liquors of the filtration process of a potassium nitrate suspension formed as a result of crystallization of the conversion solution at a temperature of 0 °C. A theoretical analysis of the system diagram and experimental data established the sequence of the formation of components during the evaporation of mother liquors. At the same time, in the studied intervals of variation of the parameters, potassium chloride is formed first, and then, the joint crystallization of potassium and ammonium chlorides occurs with the continuation of the evaporation process, and when the evaporation degree is more than 30-35%, the joint crystallization of potassium, ammonium and potassium nitrate chlorides occurs. The process analytical parameters influence of the ratio of the primary mother liquor and ammonium nitrate, as well as, the degree of evaporation have been studied. A nomogram has been developed showing the dependence of the input and output parameters on the value of the residual pressure, and it makes possible to determine the values ​​of the evaporation degree at given conditions. "

PREPARATION OF FEED-GRADE MONOCALCIUM PHOSPHATE BY CRYSTALLIZATION IN AQUEOUS MEDIUM: CALCULATION AND EXPERIMENTS

In this paper, we present the results of calculation, and experiments for the preparation of feed-grade monocalcium phosphate by crystallization method in phosphoric acid solution. Some parameters influence to the production such as the reaction and crystallization temperature, the ratio of recycle mother liquor to reactant mixture have been investigated. The results show that the crystallization method in the preparation of monocalcium phosphate will give product with higher quality, less impurities that will be suitable for animal feed additives.

Stepwise metabolic engineering of Candida tropicalis for efficient xylitol production from xylose mother liquor

Background Commercial xylose purification produces xylose mother liquor (XML) as a major byproduct, which has become an inexpensive and abundant carbon source. A portion of this XML has been used to produce low-value-added products such as caramel but the remainder often ends up as an organic pollutant. This has become an issue of industrial concern. In this study, a uracil-deficient Candida tropicalis strain was engineered to efficiently convert XML to the commercially useful product xylitol. Results The xylitol dehydrogenase gene was deleted to block the conversion of xylitol to xylulose. Then, an NADPH regeneration system was added through heterologous expression of the Yarrowia lipolytica genes encoding 6-phosphate-gluconic acid dehydrogenase and 6-phosphate-glucose dehydrogenase. After process optimization, the engineered strain, C. tropicalis XZX-B4ZG, produced 97.10 g L− 1 xylitol in 120 h from 300 g L− 1 XML in a 5-L fermenter. The xylitol production rate was 0.82 g L− 1 h− 1 and the conversion rate was 92.40 %. Conclusions In conclusion, this study performed a combination of metabolic engineering and process optimizing in C. tropicalis to enhance xylitol production from XML. The use of C. tropicalis XZX-B4ZG, therefore, provided a convenient method to transform the industrial by-product XML into the useful material xylitol.

The Effect of Molasses Addition on Physical and Chemical Quality of Corn Plant Silage Given Fermented Mother Liquor

Background: Making silage added with additives can improve the quality of silage nutrition and speed up the fermentation process. Molasses are widely used by farmers as additives for making silage. The use of molasses can be replaced with Fermented Mother Liquor (FML) in making silage. Purpose: to determine the effect of molasses addition on physical and chemical quality of corn plant silage given Fermented Mother Liquor (FML). Method: Observative data collection by making direct observations on making silage with two treatments consist of P0 (Corn Plant + 2% Fermented Mother Liquor (FML)) and P1 (Corn Plant + 2% Fermented Mother Liquor (FML) + 2% Molasses). The silage storage time was one week and on the seventh day observations were made on the physical and chemical quality of silage in each treatment. Result: The corn plant silage given fermented mother liquor (FML) without the addition of molasses produced better physical and chemical quality compared to corn plant silage given Fermented Mother Liquor (FML) with the addition of molasses. Conclusion: the corn plant silage given Fermented Mother Liquor (FML) only had better physical and chemical quality