The purification and separation of durene from the mixture containing durene isomers were studied.Since the boiling points of tetramethyl benzene isomers are very close but their melting points are of great difference...The purification and separation of durene from the mixture containing durene isomers were studied.Since the boiling points of tetramethyl benzene isomers are very close but their melting points are of great differences,static melt crystallization was applied to separate and purify durene from its isomers.Crystallization experiments were carried out under various operating conditions.The effects of cooling rate,crystallization temperature,sweating temperature and sweating time on the yield and purity of crystal were investigated.Orthogonal experimental design method was adopted to analyze the factors that may affect the yield of durene.Under the optimal crystallization conditions,the purity of durene could reach as high as 99.06%with the yield of 75.3%through one crystallization process.By fitting purification data based on sweating time in isothermal operations,the purification rate coefficient was obtained.展开更多
Mineral salts are of great importance on the regulation of different metabolic activities of living organisms. The well-functioning of the body depends on mineral salts. These salts, existing naturally in small quanti...Mineral salts are of great importance on the regulation of different metabolic activities of living organisms. The well-functioning of the body depends on mineral salts. These salts, existing naturally in small quantity in our diverse diets （grains, legumes, fruit, tea, egg, etc.）, are concentrated in seawater. In this paper, the indirect fi＇eezing is used as a concentration process to recover the most of salt minerals naturally present in seawater. Freezing is known as a purification process, but this paper recovers the brine instead of the formed ice. A 3.5% salinity solution with an appropriate setup is used to recover the maximum of salt in the brine. The work aims to develop a process for freezing salt concentration on cold walls. The influence of operating parameters has highlighted the important role of the cooling ramp and stay time on the salt concentration produced.展开更多
基金Supported by the National Natural Science Foundation of China(21176172)Top Talents Program of Yunnan Province,China(2011HA010)
文摘The purification and separation of durene from the mixture containing durene isomers were studied.Since the boiling points of tetramethyl benzene isomers are very close but their melting points are of great differences,static melt crystallization was applied to separate and purify durene from its isomers.Crystallization experiments were carried out under various operating conditions.The effects of cooling rate,crystallization temperature,sweating temperature and sweating time on the yield and purity of crystal were investigated.Orthogonal experimental design method was adopted to analyze the factors that may affect the yield of durene.Under the optimal crystallization conditions,the purity of durene could reach as high as 99.06%with the yield of 75.3%through one crystallization process.By fitting purification data based on sweating time in isothermal operations,the purification rate coefficient was obtained.
文摘Mineral salts are of great importance on the regulation of different metabolic activities of living organisms. The well-functioning of the body depends on mineral salts. These salts, existing naturally in small quantity in our diverse diets （grains, legumes, fruit, tea, egg, etc.）, are concentrated in seawater. In this paper, the indirect fi＇eezing is used as a concentration process to recover the most of salt minerals naturally present in seawater. Freezing is known as a purification process, but this paper recovers the brine instead of the formed ice. A 3.5% salinity solution with an appropriate setup is used to recover the maximum of salt in the brine. The work aims to develop a process for freezing salt concentration on cold walls. The influence of operating parameters has highlighted the important role of the cooling ramp and stay time on the salt concentration produced.
