化学-酶催化法合成基于鱼鳞胶原蛋白的脂肽类表面活性剂及其在提高原油采收率中的应用

Chemo-enzymatic Synthesis of Lipopeptide Surfactants from Fish Scale Collagen and Their Application in Enhanced Oil Recovery

利用碱性蛋白酶Protex 6L或6 mol/L HCl对鱼鳞胶原蛋白进行水解,获得水解度为0,5%,10%和100%的多肽水解产物,分别用不同链长的烷基酰氯(油酰氯、月桂酰氯和癸酰氯)和苯甲酰氯对多肽进行酰化修饰,制备出16种具有不同亲水基和亲油基的脂肽表面活性剂,对其乳化性能、静态洗油和动态驱油性能进行评价.结果表明,与常用于驱油的化学表面活性剂十二烷基苯磺酸钠(SDBS)的乳化指数E_(24)最大仅20%相比,脂肽的乳化性能更好,500 mg/L水解度5%的油酰脂肽的E_(25)达60%以上.pH值11.0、水解度10%的油酰脂肽和月桂酰脂肽的洗油能力最强,40℃下150 r/min转速20 min内可将35%以上的原油从油砂上洗脱,远高于SDBS的洗油率(<10%).水驱采油后注入水解度10%的油酰脂肽或月桂酰多肽,可显著提高原油的采收率,增产油率分别达52.35%和41.18%.

Fish scale collagen was hydrolyzed by alkaline protease Protex 6L or 6 mol/L HC1 to obtain peptides with the hydrolysis rate of 0, 5%, 10% and 100%. The peptides were then acylated with oleoyl chloride, lauroyl chloride, decanoyl chloride or benzoyl chloride to prepare 16 lipopeptide surfactants with different hydrophilic and hydrophobic groups. The measured results of emulsion index （E24） showed that the synthesized surfactants had stronger emulsifying capacity, such that E24 of 500 mg/L oleoyl peptide （hydrolysis rate 5%） reached to 60%, while the maximal E24 value of chemical surfactant sodium dodecyl benzene sulfonate （SDBS） was only about 20%. Lipopeptides also showed much higher crude oil removal capacity than SDBS. Oleoyl peptide （hydrolysis rate 10%） and lauroyl peptide （hydrolysis rate 10%） ofpH 11.0 could wash about 35% of crude oil from oil sand within 20 min at 40 ~C and 150 r/min shaking, while the oil removal rate with SDBS was less than 10%. The results of sand pack column experiments showed that injection of oleoyl peptide （hydrolysis rate 10%） or lauroyl peptide （hydrolysis rate 10%） after water flooding could significantly enhance oil recovery, additional oil recovery rate after surfactant flooding reached 52.35% and 41.18%.