费托合成水的冷冻浓缩处理及能耗估算

Treatment of F-T water with freeze concentration and energy consumption estimation

为提高费托合成水中有机物浓度,降低废水处理量,以冷冻浓缩处理费托合成水,主要采用2种不同进料方式考察冷冻浓缩后的结果。一是以费托合成水作为进料直接浓缩,考察不同浓缩倍率时浓缩液组分和产水水质;二是以NaOH中和费托合成水至pH=6—7,进行冷冻浓缩,考察浓缩倍率和产水水质。结果表明:冷冻浓缩可以对有机物和羧酸盐溶液进行浓缩,经浓缩分离后,产水中的含氧有机物和羧酸盐含量均大幅降低,产水品位较高,水质基本满足回用要求。通过对冷冻浓缩过程进行能耗估算,计算结果与文献值差别不大,浓缩倍率由3倍提高到6倍时,单位原料水的电功消耗增加,但由于获得更多产水,因而单位产水的能耗并未增加。

In order to increase the concentration of organic compounds in Fischer-Tropsch(F-T)synthetic water and reduce the capacity of wastewater treatment,two different feeding methods of F-T synthetic water were investigated by freeze concentration.One method is that F-T synthetic water was used as the feed directly.The concentrated components and the produced water were investigated at different concentration ratios.Another is that the F-T synthetic water was neutralized with NaOH to pH=6-7,then the concentration ratio and produced water quality were determined.The result shows that the organic matters and carboxylate in the solution can both been condensed by freeze concentration.The contents of oxygen-containing organic compounds and carboxylate in the produced water reduces greatly,the grade of produced water is high enough to fulfill the requirements of recycle water.By calculating energy consumption of freeze concentration process,the calculated results show little difference with the literature values.When the concentration ratio increases from 3 to 6 times,the energy consumption per unit of raw water increases.But the energy consumption of produced water doesn’t increase too much because of obtaining more produced water at high concentration ratio.