一种脂肽类生物表面活性剂的理化性质及其对原油的作用

PHYSICO-CHEMICAL PROPERTIES AND EFFECT ON CRUDE OIL OF A BACTERIUM-PRODUCED LIPOPEPTIDE BIOSURFACTANT

从大港炼油厂污水中筛选到一株地衣芽孢杆菌NK X3,在含糖培养基中培养可产生一种脂肽类生物表面活性剂 ,该生物表面活性剂在 pH 4— 1 2的范围内和 40 0 0mg/L的高钙离子浓度及 1 5%的高盐浓度下仍维持原有表面活性。更为显著的特点是在 1 2 0℃的高温下不失活。该产物可将水的表面张力由 76.6降至 35.5mN/m。其乳化活性值为 1 .50 ,临界胶束浓度 (CMC值 )为 30 .0mg/L。对高含胶质沥青质油的降粘率高达 50 %以上 ,增溶与脱附作用显著 ,可使油水互溶而形成水包油型乳化小滴。可使高含蜡油有效地乳化分散。这些特点有利于原油的增采和输送。

A spore formed bacterium, NK X 3, is screened from Dagang Refinery waste water and identified as Bacillus licheniformis . By acid precipitation of the supernatant of its fermentation liquor, a mixed lipopeptide biosurfactant is acquired with CMC value —30 mg/L. Through a series of laboratory experiments it is shown that this biosurfactant and the fermentation supernatant highly surface active in wide pH value range(4—12), tolerent to Na + and Ca 2+ salts and heat resistant, can emulsify wax and resin asphaltene rich crude oils and thus reduces their viscosity and disperse wax in aqueous media. It is hoped that this biosurfactant be used in enhanced oil production and recoveriy.