纳米磺酸钙镁复合清净剂的合成、性能与机理研究

【作者】 梁生荣；

【导师】 樊君；

【作者基本信息】 西北大学 ， 化学工程， 2011， 博士

【摘要】 具有良好使用性能的纳米有机酸钙盐是目前应用最广的润滑油金属清净剂。近年来碱值高、灰分低、酸中和能力强的镁盐清净剂得到了快速发展。钙盐和镁盐复配具有良好的协同作用,因此在实际应用过程中两者经常采用复配的形式使用。磺酸盐是目前用量最大的一类润滑油清净剂,水杨酸盐是目前使用最多的一类无硫润滑油清净剂,两者也常采用复配的方式使用。而不同清净剂在复配过程中有时会出现沉淀现象。针对上述情况,本课题开展了直接合成纳米磺酸钙镁复合清净剂和磺酸水杨酸混合基质钙镁的研究工作。以玉门炼油化工总厂生产的轻质和重质磺酸铵及兰州石化公司生产的水杨酸为原料,采用单因素和正交实验,对两种磺酸铵合成纳米钙镁复合清净剂的合成工艺条件及重质磺酸水杨酸混合基质钙镁复合清净剂合成工艺中主要物料的加入量进行优化,并对纳米钙镁复合清净剂组成结构对其性能的影响进行了研究。最后对磺酸钙镁复合清净剂的合成机理进行了初步研究。研究内容及结论如下：(1)轻质和重质磺酸铵原料性质及组成结构的分析表明,两种磺酸铵都可用于合成润滑油清净剂,而重质磺酸铵更是一种理想的用于合成润滑油清净剂的原料。(2)轻质磺酸铵合成钙镁复合清净剂的最佳工艺条件为：在轻质磺酸铵为65g的条件下,氧化镁加入量22g、水加入量10mL、甲醇加入量16mL、碳酸化反应温度42℃、反应时间4h、二氧化碳通入速率120mL·min-1。可制备出碱值大于320mgKOH·g-1、运动粘度小于140mm2·s-1的高碱值纳米磺酸钙镁复合清净剂产品,产品中胶粒的平均粒径约为50nm,粒度分布较均匀。加入润滑油后能较好的改善润滑油的使用性能。(3)重质磺酸铵合成钙镁复合清净剂的最佳工艺条件为：在重质磺酸铵为80g的条件下,氧化镁加入量24g、水加入量12mL、甲醇加入量18mL、尿素加入量4g、碳酸铵加入量4g、碳酸化反应温度45℃、反应时间3h、二氧化碳通入速率为120mL·min-1可制备出碱值大于410mgKOH·g-1、运动粘度小于150mm2·s-1的超碱值纳米磺酸钙镁复合清净剂产品,产品中胶粒的平均粒径约为40nm,粒度分布较均匀,加入润滑油后能明显提高润滑油的使用性能。产品组成结构的表征表明,产品中金属磺酸正盐为磺酸钙,过碱性组分主要为碳酸镁,这与目的产品的组成结构是一致的。(4)重质磺酸铵与水杨酸合成混合基质钙镁复合清净剂工艺中主要反应物料的最佳加入量为：氧化镁量24g,水10mL,甲醇18mL,磺酸铵与水杨酸混合原料中水杨酸含量25%。可合成出碱值大于400mgKOH·g-1、运动粘度小于140mm2·s-1的超碱值磺酸水杨酸混合基质钙镁复合清净剂产品,产品中胶粒粒度分布均匀,平均粒径约为30m。加入润滑油后能明显提高润滑油的各项使用性能。(5)纳米钙镁复合清净剂组成结构对其性能的影响表明：①对于纳米磺酸钙镁复合清净剂,其正盐采用磺酸钙、适当增加产品中钙的含量、减小碱性组分中氢氧化物占碱值份额越小、提高产品碱值、采用较大分子量的磺酸基质,都可有利于提高产品的综合性能。②对于磺酸水杨酸混合基质钙镁复合清净剂,适宜的磺酸盐水杨酸盐比例,能够最大程度地提高混合基质钙镁复合清净剂的综合性能。③和国内外同类产品相比,轻质磺酸钙镁复合清净剂除碱值相对较低外其他性能相当；重质磺酸钙镁复合清净剂综合性能稍优于国内外同类产品；重质磺酸水杨酸混合基质钙镁复合清净剂的各项性能都达到或超过国内外同类产品,其综合性能明显好于同类产品。④磺酸钙镁复合清净剂的综合性能优于磺酸镁清净剂,而磺酸水杨酸混合基质钙镁复合清净剂的综合性能又优于磺酸钙镁复合清净剂,说明钙镁复合能够提高同基质的镁盐清净剂产品的综合性能,而选用合适的混合基质也可改善单一基质产品的综合性能。(6)通过对钙镁复合清净剂合成过程中反应体系化学组成、电导率、碱值变化情况的研究和分析确定了合成过程的宏观化学反应历程。对碳酸化反应过程动力学的初步研究表明,碳酸化反应过程受扩散控制。促进剂甲醇通过降低反相胶束界面膜的强度和磺酸钙正盐的临界胶束浓度来提高碳酸化反应的速度和最终产品的碱值。尿素和氨水通过提高水对氢氧化物的溶解度来加快碳酸化反应的速度。适宜的水量、合理的二氧化碳通入速率有益于碳酸化反应的顺利进行和最终产品碱值的提高。更多还原

【Abstract】 As lubricant metal detengents, possessing fairly good performance, calcium salts have been widely used at present. With higher total base number, lower ash content, stronger neutralization capability, magnesium salt detergents have been developing quickly in recent years. Because these two kinds of detengents have good synergistic effect, they are usually taken in a compound form in practical application. Presently, the most widely used lubricant detengents are sulfonates, while the sulfur-free lubricant detengents are salicylates. These two kinds of detengents are also taken in a compound form in practice. The sedimentation phenomena sometimes occur when detengents are compounded with each other. In view of the above circumstance, studies on direct synthesis of calcium-magnesium sulfonate composite detergents and calcium-magnesium sulfonate/salicylate composite detergents are carried out. Using the ammonium sulfonate(light and heavy) from Yumen petrochemical factory and the salicylic acid from Lanzhou petrochemical company as raw materials, the synthesis process conditions of the calcium-magnesium sulfonate(light and heavy) composite detergents and the calcium-magnesium sulfonate/salicylate composite detergents are optimized by single-factor and orthogonal experiments. The influence of composition and structre of calcium-magnesium composite detergents on their performance is studied. Finally, the synthesis mechanism of calcium-magnesium sulfonate composite detergents is investigated. The main contents and conclusions are summarized as follow:(1) The analytical results of chemical composition and properties of ammonium light sulfonate and ammonium heavy sulfonate indicated that they can be used to synthesize lubricant detengents. The ammonium heavy sulfonate is a good raw material for synthesis lubricant detengents.(2)The optimum conditions of synthesis calcium-magnesium light sulfonate composite detergents should be:ammonium light sulfonate 65g, magnesium oxide 22g, water 10ml, methanol 16ml, carbonation temperature 42℃, carbonation time 4 hours, carbon dioxide 120ml·min-1. The base number of product synthesized by the optimum conditions is higher than 320mgKOH·g-1, and its viscosity is lower than 140mm2·s-1. The distribution of colloidal particles in product is homogeneous. The average diameter of colloidal particles is about 50nm. The product can effectively improve the properties of the lubricating oil.(3) The optimum conditions of synthesis calcium-magnesium heavy sulfonate composite detergents is determined as follow:ammonium heavy sulfonate 80g, magnesium oxide 24g, water 12ml, methanol 18ml, urea 4g, ammonium carbonate 4g, carbonation temperature 45℃, carbonation time 3 hours, carbon dioxide 120ml·min-1. The base number of product synthesized by the optimum conditions is higher than 410mgKOH-g"1, and its viscosity is lower than 150mm2·s-1. The distribution of colloidal particles in product is homogeneous. The average diameter of colloidal particles is about 40nm. The properties of the lubricating oil can be improved obviously after addding this product. The composition and structure of the product are characterized. It is proved that the neutral salt is neutral calcium sulfonate and the overbasic components is mainly magnesium carbonate.(4) The optimal dosage of main materials in synthesis calcium-magnesium heavy sulfonate/salicylate composite detergents is determined as follow:magnesium oxide 24g, water 10ml, methanol 18ml, ammonium heavy sulfonate 60g, salicylic acid 20g. The base number of product synthesized by the optimum conditions is higher than 400mgKOH·g-1, and its viscosity is lower than 140mm2·s-1. The colloidal particles in product have even distribution of particle size and they are about 30nm of average diameter. The properties of the lubricating oil can be improved obviously after adding this product.(5) The influence of composition and structure on performance of calcium-magnesium composite nanodetergents is researched. The results show:①By using the neutral calcium sulfonate as neutral salt, appropriately increasing the content of calcium, decreasing the content of hydroxide in the basic component, enhancing the base number and using large molecular sulfonate, the comprehensive properties of calcium-magnesium sulfonate composite detergents can be improved.②Taking suitable ratio of sulfonate and salicylate in the calcium-magnesium sulfonate/salicylate composite detergents, the performance of products will be greatly improved.③Comparing with the same type of lubricant detergents, the calcium-magnesium light sulfonate composite detergents has equivalent performance except the base number, the calcium-magnesium heavy sulfonate composite detergents has better performance and the calcium-magnesium sulfonate/salicylate composite detergents has superior performance.④The comprehensive property of calcium-magnesium sulfonate composite detergents is superior to that of magnesium sulfonate detergents, while the comprehensive property of calcium-magnesium sulfonate/salicylate composite detergents is superior to that of calcium-magnesium sulfonate composite detergents. This indicates that calcium-magnesium composite detergents can improve the performance of magnesium salt detergents and the mixed substrate detergents can further improve the performance of single substrate detergents.(6) By researching and analyzing the changes of chemical structure, conductivity and the base number of the reaction solution, the reaction mechanism of synthesis calcium-magnesium composite detergents is definited. The studies of carbonation kinetics show that the diffusion was the control step of the carbonation process. The methanol, used as promoter, can increase the carbonation rate and improve the base number of product by lowering the interfacial film strength of reverse micelles and the criticalmicellar concentration of the calcium sulfonate. The urea and ammonia, used as co-promoters, can accelerate the carbonation rate by increasing the solubility of magnesium hydroxide in water. The fitting amount of water and the feasible flow rate of carbon dioxide are beneficial to carbonation process and to improving the base number of products.更多还原