Enrichment of Semi-Volatile Organic Acids from Aqueous Solutions by Multiple-Effect Membrane Distillation  

作　　者：班睿 刘苗苗 秦英杰 王焕 崔东胜 

机构地区：[1]School of Chemical Engineering and Technology,Tianjin University [2]Chembrane Engineering and Technology,Inc.

出　　处：《Transactions of Tianjin University》2012年第5期320-329,共10页天津大学学报（英文版）

摘　　要：Multiple-effect membrane distillation （MEMD） process for enriching semi-volatile organic acids from their individual aqueous solutions was performed by using a hollow fiber-based air gap membrane distillation （AGMD） module with the function of internal heat recovery. Aqueous solutions of glyoxylic acid, glycolic acid, lactic acid, pyrnvic acid, malonic acid and glutaric acid were used as model feed. For a feed of 1% （mass fraction）, each acid could be enriched for 8--20 times, which depended on the surface tension of the concentrate. The operation performance of MEMD process was characterized by permeation flux J, performance ratio PR and acid rejection rate R. The effects of cold feed-in temperature, heated feed-in temperature, feed-in volumetric flow rate and feed-in concen- tration on MEMD performance were experimentally evaluated. Maximum values of J, PR and R were 4.8 L/（h-m2）, 9.84 and 99.93%, respectively. Moreover, MEMD process demonstrated a fairly good stability in a long-term experiment lasting for 30 d when aqueous solution of 4% （mass fraction） lactic acid was used as a feed.Multiple-effect membrane distillation(MEMD) process for enriching semi-volatile organic acids from their individual aqueous solutions was performed by using a hollow fiber-based air gap membrane distillation(AGMD)module with the function of internal heat recovery.Aqueous solutions of glyoxylic acid,glycolic acid,lactic acid,pyruvic acid,malonic acid and glutaric acid were used as model feed.For a feed of 1%(mass fraction),each acid could be enriched for 8-20 times,which depended on the surface tension of the concentrate.The operation performance of MEMD process was characterized by permeation flux J,performance ratio PR and acid rejection rate R.The effects of cold feed-in temperature,heated feed-in temperature,feed-in volumetric flow rate and feed-in concentration on MEMD performance were experimentally evaluated.Maximum values of J,PR and R were 4.8 L/(h·m 2),9.84 and 99.93%,respectively.Moreover,MEMD process demonstrated a fairly good stability in a long-term experiment lasting for 30 d when aqueous solution of 4%(mass fraction) lactic acid was used as a feed.

关 键 词：multiple-effect membrane distillation organic acid ENRICHMENT performance ratio STABILITY 

分 类 号：TQ028.31[化学工程]