【作者】 徐琳；

【导师】 隋红；

【作者基本信息】 天津大学 ， 化学工程， 2016， 硕士

【摘要】 油砂是一种储量丰富的非常规石油资源。传统应用于油砂分离的热碱水洗法在其工业化过程中存在能耗、水耗高等环境问题。溶剂萃取法以其低水耗、可回收等优势而被认为是最有可能取代水洗法的一种重要开采技术。然而,溶剂残留和助剂(离子液体等)回收等问题是限制该方法进一步应用的主要因素。因此筛选高效、易回收的助剂和实现清洁分离成为油砂分离工业领域一个重要研究方向。可逆溶剂是一种能够根据实际应用需要,使其理化性质发生特定改变的溶剂,因其绿色和智能性而备受关注。本文通过对油砂基本理化性质的分析,同时结合可逆溶剂在离子态与分子态之间的变化特性,提出采用叔胺类亲水性可逆溶剂(以下称为“亲水性可逆叔胺”)作为助剂,并将其应用于溶剂萃取油砂沥青工艺中,并依次从亲水性可逆叔胺盐的合成、实验室油砂萃取及工艺优化、叔胺盐辅助萃取微观作用机理和萃取体系中乳液性能四个方面展开研究。通过优化叔胺盐的合成条件发现,叔胺的pKa值和合成温度是影响叔胺盐合成反应速率和反应进程的主要因素。通过溶剂萃取工艺条件研究发现,采用甲苯为萃取剂时,在油砂矿:叔胺盐溶液:溶剂=1:3:4(g/m L/mL)、萃取温度35℃条件下,沥青回收率达97.9%,比单独采用甲苯溶剂萃取时提高5%。当采用复合溶剂(乙酸乙酯/正庚烷)进行萃取时,乙酸乙酯体积比30%,油砂矿:叔胺盐溶液:溶剂=1:1:4(g/m L/m L),萃取温度为25℃时,沥青回收率达87.6%,比单独采用复合溶剂萃取时提高6%。此外,加入叔胺盐溶液能够有效减少沥青中的细砂夹带量和残砂中的溶剂残留。为了获悉叔胺盐促进沥青回收的作用机理,本文通过分离沥青四组分、固体表面元素分析、润湿性测试、Zeta电位测试、QCM-D测试等表面化学分析测试发现叔胺盐对沥青及矿物颗粒表面具有良好的改性作用。叔胺盐阳离子(如[Et3NH]+)吸附在沥青表面形成离子对,从而有效减弱沥青组分(如沥青质等)与矿物表面的相互作用,改变矿物表面性质(更亲水),使沥青从矿物表面的脱离变得更加容易、彻底。通过对叔胺辅助萃取过程中形成的乳液性质和成因进行研究,发现萃取过程中溶剂相沥青质含量的增多和游离细砂的存在是造成乳化严重的主要原因。更多还原

【Abstract】 The widely distributed oil sands is an unconventional petroleum.The currently commercial process for minable ores is the water-based extraction(WBE)process which has caused high energy and water consumption.However the solvent extraction process also caused solvent residue problems and the recycling of the externally added functional chemicals(ionic liquids etc.)was found to be one of the most challenges which impeded the scaling-up of these hybrid processes.Therefore,searching for efficient and recyclable “green chemical additives” is an important research direction related to unconventional petroleum production.Switchable solvents which has been widely concerned due to its green and intelligence can change its physicochemical properties according to the practical application needs.Based on the analysis of basic physicochemical properties of oil sands and the properties of switchable-hydrophilicity tertiary amines(SHTAs)in their hydrophilic forms which can be recycled by hydrophilicity switching,SHTAs have been synthesized and applied to enhancing heavy hydrocarbons recovery from oil sands ores in the solvent extraction.In this paper,we researched on the synthesis of SHTAs,the extraction of oil sand in the laboratory scale,the mechanism of SHTAs-assisted solvent extraction and the properties of emulsion in turn.By condition optimization,we found tertiary amines’ pKa values and reaction temperature are the main factors which influenced the reaction rate and process of tertiary amine salt synthetic.Will tertiary amine salt solution is applied in solvent extraction,when toluene was used as extracting agent,the bitumen recovery improved to 97.9% while the ratio of toluene to SHTA solution to oil sands was 4:3:1 at 35℃;when using compound solvent(ethyl acetate / n-heptane)in extraction,the bitumen recovery increased to 87.6% while the ratio of compound solvent(30% ethyl acetate)to SHTA solution to oil sands was 4:1:1 at room temperature.At the same time,the addition of tertiary amine salt solution can effectively reduce the residual sand in bitumen and solvent in the sand.According to the surface characterizations by FT-IR,SEM-EDS,wettability test,zeta potential measurements,QCM-D(a surface material adsorption detection),it is found that the external addition of SHTAs solution plays an important role in modifying the bitumen and solids interfaces.The improved processability was mainly attributed to the absorption of cation ions(e.g.,[Et3NH]+)of SHTAs on bitumen surface,forming ions pairs.The formation of ions pairs reduced the interactions between bitumen components(e.g.,asphaltenes or other polar materials)and the solid surface,which changed the properties of the solid surfaces(significant increase in solids wettability).Consequently,the detachment of bitumen materials from the solid surfaces became much easier and more complete.Through the research on emulsion in the process of SHTAs-assisted solvent extraction,we found that the increasing asphaltene content in solvents is the main cause of serious emulsification.更多还原