煎炸废油加氢制备绿色柴油的催化应用及机理研究

发布时间：2018-03-30 09:53

本文选题：煎炸废油　切入点：预处理　出处：《合肥工业大学》2015年博士论文

【摘要】：全球经济的迅速发展加大了人类对石油能源的需求。石油能源具有不可再生性,因此开发有可持续来源的石油替代燃料具有重要的意义。柴油燃料是重要的石油能源产品之一,目前国内外学者对替代性柴油的研究主要集中在酯交换反应制备生物柴油,对于催化加氢制备加氢柴油的研究较少。加氢制备绿色柴油是以动植物油脂或废弃油脂为原料,通过催化加氢技术制备的新型燃料。原料油品质。催化剂催化特性和产品的改性是加氢制备绿色柴油产业的关键因素。本文以煎炸废油为原料,通过加氢催化制备绿色柴油,以实现煎炸废油的转化利用。确定煎炸废油预处理工艺。作为催化加氢反应的原料,煎炸废油较深的颜色是影响加氢产物品质的重要因素,研究采用分离除杂、脱胶、脱色、脱水的方法对煎炸废油进行预处理,并对煎炸废油的脱色步骤进行单因素及响应曲面分析。得到最优脱色工艺参数为：反应温度104℃,反应时间46min,搅拌速率300 r/min,脱色剂用量16wt%,煎炸废油脱色率可达75%。将处理前后的煎炸废油进行对比,酸值由18.7mg KOH/g下降至15.2mg KOH/g、水分由0.75%下降到痕量,磷脂含量由1.47%下降到0.12%,透光率由92%上升到98%,达到实验对原料的要求。利用设计的催化加氢装置研究硫化法活化NiMo/Al2O3和CoMo/Al2O3催化剂对煎炸废油的加氢催化规律,通过各因素全面实验考察反应温度、反应压力和液时空速对原料油转化率及液体产物得率的影响。研究了两种催化剂加氢产物的物理化学参数,其中十六烷值达到90左右,高十六烷值有助于与石化燃料调配使用。产物中硫含量超过40 mg/Kg,冷滤点也超过EN590标准,需进行进一步的改性。针对硫化催化剂催化产物的硫含量超标问题,用氢气活化处理氧化态NiMo/Al2O3和CoMo/Al2O3催化剂。利用氢化活化催化剂对预处理的煎炸废油进行加氢催化,采用全面实验对两种催化剂催化条件进行优化。考察反应温度、反应压力和液时空速对原料油转化率及液体产物得率的影响。氢化活化处理的催化剂表现出良好的活性。通过对反应产物的研究发现,氢化活化催化剂改善了硫化活化的缺陷,所得产物的硫含量低于1mg/Kg,产物中异构烷烃含量较高,无硫元素污染且具有更好的低温特性。共浸渍法制备了负载型催化齐NiMoLa/Al2O3,采用一系列现代分析手段对催化剂的形貌,结构和活性组分进行分析,将其应用于煎炸废油的加氢催化反应,与NiMo/Al2O3和CoMo/Al2O3催化剂进行了对比。得到了NiMoLa/Al2O3催化剂最优制备条件为,La(NO3)3负载量6%,焙烧温度500℃,焙烧时间4h；通过实验确定最佳催化条件为：反应温度340-360℃、反应压力4.0MPa、液时空速1.5h-1,H2/oil为100Nm3/m3,在获得相似转化率和目标产物得率的情况下,所需的反应条件更温和；在200h的使用时间内,催化剂仍保持较高的催化活性。研究了煎炸废油的催化反应路径,显示的反应顺序应为第一阶段甘油三酯的饱和反应；第二阶段饱和甘油三酯的分解；第三阶段脂肪酸的加氢脱水,加氢脱羰和脱羧反应；第四阶段烷烃产物的裂化和异构化；其中气体产物中还存在甲烷化和水煤气变换反应。通过催化不同类型原料研究NiMoLa/Al2O3催化剂的适应性和耐受性。结合产物的物理化学性质,气相色谱和红外吸收光谱分析得出：催化剂对脂肪酸有较好的耐受性,对同时含碱金属离子和磷脂的原料油也有一定的催化效果,但对含有单一高含量碱金属和磷脂的原料油耐受性较差；催化不同类型脂肪酸酯所得产物的组成成分及性质相差不大,催化剂有较好的原料适应能力。最后,测定并改善NiMoLa/Al2O3催化剂加氢柴油组分的理化特性。与矿物柴油相比,加氢柴油组分的十六烷值可达93,酸值小于0.1,硫含量低于1mg/Kg,但产物中异构烷烃含量在11.3-15.4%,产物的低温特性较差,冷滤点较高。采用添加降凝剂、与低凝点矿物柴油混掺的方法来改善加氢柴油组分的低温流动性。两种方法都能够在一定程度上改善产品的低温流动性。在-20#柴油中添加5-30wt%的加氢柴油组分,混合燃料的凝点从-20℃上升到-14℃,冷滤点从-14℃上升到-3℃。选择三种降凝剂改善混合燃料的低温特性,选择添加30wt%加氢柴油组分的混合燃料作为研究对象,效果最好的是Keroflux 6226,0.25‰的添加量能把混合燃料的凝点从-14℃降至-30℃,效果最差的是降凝剂B,1.0‰的添加量将混合燃料的凝点从-14℃降至-28℃。三种降凝剂降低冷滤点效果没有降低凝点明显。
[Abstract]:The rapid development of the global economy to increase the human energy demand for oil. The oil is not renewable energy, plays an important role in oil alternative fuel sources. Therefore the development of a sustainable diesel fuel oil is one of the important energy products, scholars at home and abroad for the generation of research mainly diesel biodiesel exchange reaction system in the study of ester, hydrogenation hydrogenation diesel less. Hydrogenation preparation is green diesel from vegetable oils and animal fats or waste oil as raw material, through the new fuel hydrogen preparation technology of catalytic hydrogenation. The catalytic characteristics of feedstock quality. And product modification is the key factor for preparing green diesel hydrogenation industry. Taking frying oil as raw material, preparation of green diesel through catalytic hydrogenation system, to achieve the transformation of frying oil by frying oil. Determine the pretreatment process. As catalytic hydrogenation The reaction of raw materials, deep fried oil color is an important factor affecting the hydrogenation product quality, research the separation and impurity removal, degumming, bleaching, dehydration pretreatment of frying oil, analysis of decolorization and steps of frying oil by single factor and response surface. The optimal parameters for the decolorization reaction temperature 104 C, reaction time 46min, stirring rate of 300 r/min, the dosage of decolorizing agent 16wt%, frying oil decolorization rate of 75%. was compared before and after treatment of the frying oil, acid value by 18.7mg KOH/g down to 15.2mg KOH/g, the water dropped from 0.75% to trace, the phospholipid content decreased from 1.47% to 0.12%, the light transmittance increased from 92% to 98%. To meet the requirements of raw materials of the experiment. The catalytic hydrogenation of NiMo/Al2O3 and activation of CoMo/Al2O3 catalyst for frying oil by catalytic hydrogenation device design of the curing method, through the comprehensive experiment The effects of reaction temperature, reaction pressure and liquid space velocity on the conversion rate of raw oil and liquid product yield were studied. The physical and chemical parameters of two kinds of catalysts for hydrogenation products, of which sixteen cetane number reached 90, sixteen higher octane help deployment and fossil fuel use. The 40 mg/Kg more than the sulfur content in the product also, cold filter point exceeds EN590 standards, the need for further modification. The sulfur content exceed the standard problem of the catalytic product sulfide catalyst, oxidation states of NiMo/Al2O3 and CoMo/Al2O3 catalysts for hydrogen activation. The activation catalyst for catalytic hydrogenation pretreatment of frying oil by hydrogenation, using two kinds of catalysts to optimize the comprehensive experiment. The influences of reaction temperature, reaction pressure and liquid space velocity on the conversion rate of raw oil and liquid product yield. The catalyst hydrogenation activation treatment showed good activity through the. The study of reaction products, improve the hydrogenation activation catalyst activation defects, the sulfur content of the product is less than 1mg/Kg, higher isoparaffin content in the product, no pollution and low temperature properties of sulfur has better. Prepared by CO impregnation of supported catalyst NiMoLa/ Al2O3, on the morphology of the catalysts by using a series of modern analysis methods the structure, and the active component of catalytic hydrogenation reaction is applied to the frying oil, compared with NiMo/Al2O3 and CoMo/Al2O3 catalysts were obtained. The optimal preparation conditions for NiMoLa/Al2O3 catalyst, La (NO3) 3 loading 6%, 500 C of roasting temperature, roasting time is 4H; the optimal catalytic conditions as the reaction temperature is 340-360 DEG C, reaction pressure 4.0MPa, liquid space velocity 1.5h-1, H2/oil 100Nm3/m3, in similar conversion rate and target product yield under the condition of reaction required A more moderate; in the use of 200H time, the catalyst still maintain high catalytic activity. The catalytic reaction path of frying oil, reaction order display should be the first stage of the reaction of saturated triglycerides; second stage decomposition saturated triglycerides; hydrogenation dehydration stage third fatty acid hydrogenation, decarbonylation and removal decarboxylation; fourth stage alkane cracking and isomerization products; methane and water gas shift reaction exists in product gas. Through different types of catalytic material research NiMoLa/Al2O3 catalyst adaptability and tolerance. Combined with the physical and chemical properties of the product, the absorption spectra of gas chromatography and infrared: catalyst for fatty acid tolerance well, have a catalytic effect on raw oil and alkali metal ions and phospholipids, but the single containing higher content of alkali metal and raw phospholipid Feed oil poor tolerance; the composition and properties of fatty acid ester catalyzed by different types of the products are similar, the catalyst with better material adaptability. Finally, determine and improve the physical and chemical properties of NiMoLa/Al2O3 catalyst for hydrogenation of diesel components. Compared with diesel, diesel hydrogenation component sixteen octane can reach 93, acid value less than 0.1, the sulfur content of less than 1mg/Kg, but the content of isoparaffin products in 11.3-15.4%, poor low temperature characteristics of products, cold filter point higher. By adding depressant, to improve the low-temperature fluidity of diesel oil with hydrogen component and low pour point mineral diesel mixed method. The two methods can improve the low temperature fluidity the product in a certain extent. The addition of 5-30wt% in diesel hydrogenation group -20# in diesel fuel mixture, pour point increased from -20 DEG to -14 DEG, cold filter point increased from -14 DEG to -3 DEG. Three kinds of improved mixed depressant Low temperature fuel characteristics, selection of blended fuel adding 30wt% hydrogenation diesel components as the research object, the best is Keroflux 6226,0.25% of the amount can be added to the mixed fuel pour point from -14 to -30 DEG C, the difference is depressant B, adding 1% of the mixed fuel from freezing -14 DEG C to -28 DEG C. Three kinds of depressant reduced cold filter point effect is not obvious to reduce the pour point.

【学位授予单位】：合肥工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TE667

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