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研究了先超滤脱盐后浓缩 (A模式 )、先浓缩再超滤脱盐 (B模式 )、间歇超滤脱盐 (C模式 ) 3种操作模式下木聚糖抽提液脱盐过程。结果表明 :木聚糖溶液中的无机盐及其小分子物质能引起溶剂透过率降低 ;木聚糖抽提液超滤脱盐时 ,最经济的置换体积数为 4。此时 ,A ,B ,C 3种操作模式的钠离子总脱除率分别为 93% ,92 % ,96% ,B操作模式耗水量仅为其它两操作模式的一半 ,而且 ,总操作时间比A ,C模式的低 30 %左右 ,同时保持了 97%的总还原糖回收率 ,所以B模式为最经济的操作模式。但是 ,如果要求较高的脱盐率 ,则C操作模式较为适宜 ,在置换体积数为 4时 ,钠离子总脱除率为 96% ,总还原糖回收率为 97%。
The desalting process of xylan extracts was studied under the three operation modes: first ultrafiltration and desalination (A mode), first concentration and then ultrafiltration desalination (B mode), intermittent ultrafiltration desalination (C mode). The results showed that the inorganic salts and their small molecules in the xylan solution can cause the decrease of the solvent permeability. When the xylan extract was desalted by ultrafiltration, the most economical replacement volume was 4. At this moment, the total sodium ion removal rates of A, B and C were 93%, 92% and 96% respectively. The water consumption of B mode was only half that of the other two modes, and the total operation time ratio A, C mode is about 30% lower, while maintaining a 97% recovery of total reducing sugar, so B mode is the most economical mode of operation. However, if a higher desalination rate is required, the C mode of operation is more suitable. When the volume of substitution is 4, the total removal rate of sodium ions is 96% and the total recovery rate of reducing sugars is 97%.