Preparing Solid Acid For Manufacturing FAME By Tubular Reactor

With the depletion of non-renewable energy and growing environmental problems, optimized use of resources and sustainable development of the society become important challenges of the world. In recent years, biodiesel, as a kind of renewable and green energies becomes an attractive feature in the field of energy chemical industry, as biodiesel provides a possibility to solve the energy problem.With the development of the modern chemical industry, catalysts plays an important throughout almost every field of chemical reactions, and preparation of catalysts is the most important subject in the catalytic reactions, which is why the preparation of catalysts is also called the cornerstone of modern chemical industry.Homogeneous catalysts (liquid acid and alkali catalysts) are the main catalysts in current biodiesel production industry. However, homogeneous catalysts are corrosive, hard for products separation after reaction and often cause environmental pollutions. Therefore, the research of heterogeneous catalysts (solid catalysts) becomes more and more attractive and accepted. As researches showed, the solid acid catalysts can maintain functionality for a long time, have lower demand for raw oil feedstock, and can catalyze high acid value and high water content raw materials in one-step to produce biodiesel. All these indicate that solid acid catalysts could potentially be used widely in the biodiesel industry.The solid super acid catalyst S2O22-/ZrO2-SiO2 was developed in this studied. The catalyst was characterized by FT-IR, XRD, SEM, TG-DTA on catalysts. The process of using this catalyst in the tubular reactor for biodiesel production from raw oil feedstoce (Swida wilsoniana oil) was also studied. The process parameters were optimized and the fatty acid methyl ester profile of the biodiesel produced was analyzed using GCMS, and the physicochemical properties of the biodiesel were also tested. The results showed that:1. n(Zr):n(Si), preparation temperature, preparation time, concentration of (NH4)2S2O8 soaking liquid, soaking time, activation temperature, and activation time have effects on the functionality catalysts. Among these, activation temperature, activation time, and soaking time were the significant factors.2. A multivariable linear regression model was developed for the significant factors affacting the catalysts preparation, and a regression equation with good fitting and high confidence is shown below: Y=96.92-1.48*A-0.93*B-1.43*C+0.180*A*B-0.81*A*C-0.47*B*C-1.63*A2-2.26*B 2-0.29*C2Where A is the activation time; B is the preparation time; C is the activation temperature.This regression equation can repalce some of the actual reaction experiments in analyzing the experimental results.3. According to the experiment results, the best parameters for preparing the solid super acid catalyst S2O82-/ZrO2-SiO2 were:preparing temperature of 40℃preparing time of 12 h, n (Zr):n (Si) ratio of 1.5:1, n((NH4) 2S2O8) concentration of 1.0 mol/L, soaking time of 13 h, activation temperature of 500℃, and activation time of 4.4 h. At these preparation conditions, the catalysts produced for the esterification of high acid value Swida wilsoniana oil and methanol can produce a 97.0% converstion rate.4. The catalysts were characterized by FT-IR, XRD, and SEM, and the results showed that the catalysts have larger amount of acidic groups, super acidity, high specific surface area, huge gap levels, and high thermal stability, which ensured the catalysts to have stable and effective catalytic activity.5. The process of using the catalysts used in tubular reactor for producing biodiesel was also optimized, and the combined best production process parameters were:reaction temperature 220℃, reaction pressure 6 MPa, ratio of alcohol to the Swida wilsoniana oil (volume ratio) 3:1. The content of fatty acid methylester of biodiesel produced by this condition was 95.7%.6. The biodiesel produced from Swida wilsoniana oil was tested according to the national biodiesel standard, and the results showed that each index of the biodiesel met the requirement of the national standard GB/T20228-2004, and could fully take place of the petroleum diesel. 7. The reaction temperature affected the oxidative stability of the biodiesel produced, the oxidative stability of the biodiesel reduced with the increase of the reaction temperature.In summary, a solid catalyst S2O82-/ZrO2-SiO2, was developed, which is of super acidity, and worked well in tubular reactor for biodiesel production. This should have significant impact in biodiesel industry development.