DEVELOPMENT OF BORON RECOVERY SYSTEM FROM DESULFIRIZATION WASTEWATER OF COAL THERMAL POWER PLANT

燃煤热电厂脱硫废水硼回收系统的研制

• 批准号: 08650916
• 负责人: HANO Tadashi
• 金额: $ 1.41万
• 依托单位: OITA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650916/
• 关键词: BORON; SOLVENT EXTRACTION; COAL POWER PLANT; DESULFURIZATION WASTEWATER; DIOL; DENITRIFICATION; 脱硫廃水; 脱窯

The process for the recovery of boron in the wastewater from desulfurization unit of coal thermal power plant was investigated. The solvent extraction was selected as a most suitable method to recover boron from aqueous solution. Based on the extraction equilibrium study of various extractants, 2-buty, -2-ethyl-1,3-propandiol as an extractant and 2-ethylhexanol as a diluent were selected as the best extraction system of boric acid. The effects of various operating parameters such as extractant concentration, borate concentration and temperature were investigated to establish the optimum conditions. As a result, 1kmol/m^3 of extractant was found to be optimum from the viewpoints of extractability and easiness of phase separation after extraction. Boric acid extracted in the solvent could be stripped completely into aqueous alkaline solution. The effects of boric and concentration in solvent and the alkaline concentration was examined to determine the stripping conditions. A series of alkali well functioned as a stripping reagent. The continuous operation was also achieved using mixer-settlers. Various types of operation were investigated to find the optimum way that guaranteed a high concentration ratio of boron after recovery. The dissolution of extractant and solvent to aqueous phase during the contact between two phases causes another pollution problem if the effuluent after extraction and stripping is discharged without any treatments. We proposed to use the dissolved organic components as an organic carbon source of biological denitrification and obtained a satisfactory result.

对燃煤电厂脱硫废水中硼的回收工艺进行了研究。溶剂萃取法是从水溶液中回收硼的最佳方法。通过对各种萃取剂萃取平衡的研究，确定了以2-丁基-2-乙基-1，3-丙二醇为萃取剂，2-乙基己醇为稀释剂的最佳萃取体系。考察了萃取剂浓度、硼酸盐浓度和温度等操作参数对萃取效果的影响，确定了最佳萃取条件。结果表明，从萃取能力和萃取后相分离的容易程度来看，1 kmol/m^3的萃取剂是最佳的。萃取后的硼酸可被碱溶液完全反萃。考察了溶剂中硼浓度和碱浓度对反萃的影响，确定了反萃条件。一系列的碱很好地起到了反萃剂的作用。使用混合沉降器也实现了连续操作。研究了各种操作方式，以找到保证回收后硼的高浓缩比的最佳方法。萃取剂和溶剂在两相接触过程中溶解到水相中，如果萃取和反萃取后的流出物未经任何处理就排放，则会引起另一个污染问题。提出了利用溶解有机物作为生物脱氮的有机碳源，并取得了满意的效果。

项目成果

T.Hano: "Extractive fermentation of lactic acid with R.oryzae and L.rhamnosus" Values Adding Through Solvent Extraction. Vol.2. 1447-1452 (1996)

T.Hano：“用米根霉和鼠李糖进行乳酸提取发酵”通过溶剂萃取增加了价值。

T.Hano: "Extractive recovery of boron in wastewater from desulfurization plant" Proceedings of the Fourth Japan-Korea Symposium on Separation Technology,. 319-322 (1996)

T.Hano：《脱硫厂废水中硼的萃取回收》第四届日韩分离技术研讨会论文集。

T.Hano: "Recovery of phenols using liquid surfactant membranes prepared with newly synthesized surfactant" Separation and Science Technology. Vol.31. 107-124 (1996)

T.Hano：“使用新合成的表面活性剂制备的液体表面活性剂膜回收酚”《分离与科学技术》。

T.Hano: "Development of boron recovery system from desulfurization plant wastewater" Proceedings of Regional Symposium on Chemical Engineering 97. 233-237 (1997)

T.Hano：“脱硫厂废水硼回收系统的开发”化学工程地区研讨会论文集 97. 233-237 (1997)

Y.P.Tong, M.Hirata, H.Takanashi, T.Hano, M.Matsumoto and S.Miura: "Solvent screening for production of lactic acid by extractive fermentation" Separation Science and Technology. (in press).

Y.P.Tong、M.Hirata、H.Takanashi、T.Hano、M.Matsumoto 和 S.Miura：“提取发酵生产乳酸的溶剂筛选”分离科学与技术。