Synthesis Of Mesoporous Carbon-based Solid Acid And Its Application In High Acid Value Of Biodiesel Raw Materials Pretreatment

Traditional catalytic solid acid catalyst has high activity, but the presence of a catalyst deactivation is easy, stability is not the disadvantages. High stability and high catalytic activity of the carbon-based solid acid, the researchers eager to become a hot research. The presence of low specific surface area, pore size distribution is poor, low acidity and other shortcomings common carbon-based solid acid catalyst. Pore structure of mesoporous material which is between the porous material 2-50nm between channels due to its highly ordered, with a high specific surface area, the most important field of catalysis become a catalyst and catalyst support. In this study, a porous carbon-based solid acid catalyst is a research object, using SEM, TEM, FT-IR, XRD, N2 adsorption-desorption technology for the structural properties of carbon-based solid acid materials were characterized and studied the catalytic effect of acid the value of the pre-esterification of biodiesel feedstock application.Specific contents are as follows:(1) In dodecylbenzenesulfonate as a surfactant and a sulfonating agent, one-step preparation of porous carbon-based solid acid catalytic activity is good, but the stability of the catalyst to be further enhanced and improved. The catalyst characterization results showed that carbon-based solid acid catalysts exhibit amorphous carbon structure, there are a lot of its surface pores.(2) Hydrothermal carbonization is used to prepare sulfonated carbon microspheres porous solid acid catalyst by two-step process for esterification high acid mixed fatty acid reducing reaction showed good catalytic effect.Carbon microspheres solid acid surface is smooth and uniform size of the microspheres and the microspheres are stacked together in the form of stacked hollow carbon spheres produced many interconnected structure, wide pore size distribution, and high catalytic activity, good stability(3) Soft template synthesis of mesoporous carbon, water reuse heat treatment sulfonated mesoporous carbon-based solid acid catalyst, sulfonated hydrothermally treated at 180℃ 22h obtained mesoporous carbon-based solid acid surface acid has the highest density of high-acid the value of mixed fatty acids showed better lipidated deacidification effect.Hydrothermal sulfonation better maintain the overall morphology of the material, pore size is slightly reduced.(4) Study Mesoporous carbon-based solid acid-catalyzed esterification catering Waste Oil Gas deacidification process conditions, the amount of catalyst 3wt%, reaction temperature 110℃, reaction time 90min equilibrium is reached. Response surface experimental design of pre-esterification reaction process was optimized to study the optimal level of the various reaction parameters and their interactions, the establishment of a quadratic polynomial mathematical model: Y=98.87+0.32A-2.44A2+0.98B-0.56B2-0.33C-2.36C2-0.015AB-0.073AC-0.38BC, R2=0.9928 (Y representative conversion rate, A representative the reaction temperature, B representative the reaction time, C representative the amount of catalyst).The reaction temperature and the ratio between the catalyst there is a significant interaction. According to model calculations to obtain the best conditions mesoporous carbon-based solid acid catalyzed gas-phase pre-esterification reaction:reaction temperature 110.65℃, reaction time 103.91min, the amount of catalyst 2.85%, fat rate forecast a maximum of 99.35%. Actual adjusted as follows:reaction temperature 110℃, reaction time 105min, catalyst 3%, then the conversion rate of 99.18%, when the acid value decreased l.OmgKOH · g-1, to meet the subsequent base-catalyzed lipid exchange reaction.