干旱区生态环境知识资源中心(Arid): Recovery of propylene glycol from dilute aqueous solutions by reversible chemical complexation with organoboronates

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DOI	10.2172/95322
报告编号	LBL--36913
来源ID	OSTI_ID: 95322
	Recovery of propylene glycol from dilute aqueous solutions by reversible chemical complexation with organoboronates
	Broekhuis, R.R.; Lynn, S.; King, C.J.
英文摘要	Extractants consisting of an ion-pair of Aliquat 336 with phenylboronate or 3-nitrophenylboronate were prepared in various diluents (2-ethylhexanol, toluene, o-xylene or diisobutylketone). In batch experiments propyleneglycol (1,2-PD) was effectively extracted even at low concentrations. Heterogeneous complexation constants {beta}{sub 11} calculated at 25 C were 45-120 (mol/1){sup {minus}1} in 2-ethylhexanol, 34.8 (mol/l){sup {minus}1} in toluene, 37.6 (mol/l){sup {minus}1} in o-xylene and 14.4 (mol/l){sup {minus}1} in diisobutylketone. In 2-ethythexanol, there was no significant effect of extractant concentration on the complexation constant. Equilibrium water concentration in the extractants was 8-12 wt %, decreasing with 1,2-PD uptake. Nearly all extractant/diluent systems exhibited overloading (more than stoichiometric uptake of 1,2-PD). Evidence for aggregation of the ion-pair extractant in organic phase was found from water solubilization studies (molar solubilization ratios up to 10) and {sup 1}H NMR spectroscopy studies. Solubilization of 1,2-PD within hydrophilic aggregate interiors may explain the observed overloading. The complexation constant decreased with increasing temperature, but not enough to make back extraction after a temperature change attractive. Back extraction may be achieved after acidification with carbon dioxide to convert the organoboronate anion to the corresponding organoboronic acid. Up to 80% of the extracted 1,2-PD was backextracted in a batch extraction using C0{sub 2}. The extractant could then be regenerated by stripping carbon dioxide from solution at temperatures exceeding 110 C. However, at these temperatures the extractant appears to undergo a transformation in which color changes and extraction capacity is reduced to about 60% of original value.
出版年	1995
报告类型	Technical Report
语种	英语
国家	美国
来源学科分类	40 CHEMISTRY ; 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION ; GLYCOLS ; SOLVENT EXTRACTION ; MATERIALS RECOVERY ; ADSORPTION
URL	http://www.osti.gov/scitech/servlets/purl/95322
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/266130
推荐引用方式 GB/T 7714	Broekhuis, R.R.,Lynn, S.,King, C.J.. Recovery of propylene glycol from dilute aqueous solutions by reversible chemical complexation with organoboronates,1995.