液体石蜡乳化液的制备及对甲苯废气的吸收性能研究

以液体石蜡和水制备乳化液,以制备的乳化液吸收甲苯废气。考察了制备乳化液时油水质量比、乳化剂的质量分数、HLB值(亲水亲油平衡值)、乳化时间、乳化温度的选择及Tween 80、正辛醇、NaCl、Na2SO4对甲苯吸收效果的影响。结果表明,室温下油水质量比为7∶3,乳化剂质量分数为7%,HLB值为10,乳化时间为0.5 h时制备的乳化液稳定性最好。试验条件下乳化液对甲苯的初始吸收率可达96.53%,增加Tween 80的量和添加正辛醇能提高乳化液的吸收效果,添加NaCl和Na2SO4则降低乳化液对甲苯的吸收能力。

Preparation of liquid paraffin emulsion and its absorbability for toluene-latent waste gas

This paper is aimed at reporting our investigation findings of a kind of absorbent prepared for purifying VOCs from the exhaust gas,whose absorbent is emulsion existing in the raw material of water and liquid paraffin.Since the volatile organic compounds(VOCs) in the exhaust gas is the key factor responsible for the air pollution,we have been making efforts in testing the emulsion which is thought of benefit for heightening the absorptive efficiency of liquid paraffin.In doing so,we have investigated various conditions involved(such as the ratio of liquid paraffin and water,the amount of emulsifier,HLB of emulsifier,emulsifying time,as well as the emulsifying temperature) so as to promote our efficiency.At the same time,we have also explored the influence of additives(such as tween 80,capryl alcohol,sodium chloride and sodium sulfate) on the absorbability of emulsion.The experimental results show that the optimal condition for the said emulsion preparation can be stated as follows: the ratio of the liquid paraffin and the water component is 7:3,with the amount of emulsifier being 7%,HLB of emulsifier being 10,and the emulsifying time—0.5 h in the room temperature.The experimental data can actually be obtained by testing the volume fraction of emulsion after centrifuging 2 min at 3 000 r/min.The absorption of toluene-containing waste gas can help to increase the toluene concentration by gas chromatography.And then the removal ratio can be shown by means of the absorption curve in relation to the different time lengths.In so doing,it has been found possible to raise the original removal rate of toluene from the exhaust gas to 96.53% and keep the removing rate high level for several hours.In addition,the increase of Tween 80 and addition of capryl alcohol is found to be able to enhance the absorbability of the emulsion while sodium chloride and sodium sulfate can help to produce negative result.Therefore,it can be concluded that the liquid paraffin emulsion proves useful for purifying VOCs from the exhaust gas.