Preparation And Catalytic Performance Analysis Of Salix Carboniferous Solid Acid Catalysts

Acid catalyst has been diffusely used in the chemical industry,among which liquid acid is inexpensive,great catalytic effects and a wide range of applications.There are great advantages in the early stages of chemical industry.However,its disadvantages such as difficulty in separation and recycling,corrosion of equipment,and serious pollution of the environment can not be ignored.With the concept of "green chemistry" being put forward,the trend of developing heterogeneous solid acid catalysts(SACs)has been continuously developed in order to achieve environmental benefits and promote the sustainable development of the chemical industry.Of course,there are still many defects in the catalytic reaction of SACs:low density,low acid sites,low thermal stability,low catalytic activity,high cost,etc,which restrict the large-scale industrial application of SACs.Therefore,it is worthwhile to prepare a simple,environmentally friendly,and affordable solid acid catalyst for use in the catalytic reaction.The raw materials of this thesis are made of salix psammophila,the first step is pyrolysis carbonization,the second step is sulfonation process,Then the Salix carboniferous solid acid catalyst is prepared.The reaction of preparing oleic acid with methanol to prepare biodiesel is used to detect the esterification rate of the catalyst.The esterification rate was used as an indicator of the catalytic activity of the catalyst.Specifically,the following four different preparation factors were tested by single factor experimental exploration method:1.carbonization temperature and time,2.sulfonation temperature and time;The different pore sizes of the three types of samples of salix psammophila,the carbonized intermediate and catalysts were analyzed by the JW-BK static nitrogen adsorption instrument.The salix psammophila,carbonization intermediate and catalyst were characterized by the Spectrum65 type Fourier transform infrared spectrometer,the Hitachi scanning electron microscope,the Empyrean sharp X-ray diffractometer and the HCT-1 microcomputer differential thermal balance instrument.The results showed that:?In the single factor experiment,the esterification rate of Salix carboniferous solid acid catalyst in the reaction reached a maximum of 98.0%under the conditions of the carbonization temperature and time were 400?Cand 90 min,the sulfonation temperature and time were 95? and 90 min,respectively,which proved that the catalytic performance is optimal;the catalytic performance is optimal;?The catalytic properties of the Salix carboniferous solid acid catalyst have certain structure-activity relationship and effect on the pore structure.Salix carboniferous solid acid catalyst was prepared by sulfonation of concentrated sulfuric acid that "coal-like”carbonization intermediate from high-temperature hydrothermal carbonized salix psammophila.Specifically,the catalytic performance of the catalyst in the preparation of biodiesel and the influence of surface acid amount from oleic acid and methanol was analyzed by single factor method;The performance was optimized in the single factor exploration by response surface curve method.The salix psammophila and catalyst were characterized by Fourier transform infrared spectroscopy,EA300 elemental analyzer,scanning electron microscopy,X-ray diffractometer and differential thermal analysis.The results showed that:?The catalytic performance of the Salix carboniferous solid acid catalyst was optimal when the preparation conditions were carbonization temperature of 335?,carbonization time of 60 min,sulfonation temperature of 105? and sulfonation time of 90 min measured the esterification rate is 95.6%;?The sulfur content of the catalyst is greatly improved,and the sulfonic acid group is successfully loaded exhibited an amorphous carbon structure.It has a well-developed pore structure with great thermal stability and stability.The method of one-step carbonization of sulfonated salix psammophila with concentrated sulfuric acid was used to prepare a salix carboniferous solid acid catalyst.The prepared salix carboniferous solid acid catalyst is used to change the preparation conditions,and the catalytic performance of the catalyst is evaluated by a single factor method;On this basis,the catalyst was optimized by the response surface model.The optimized catalyst was were measured and characterized by Fourier transform infrared spectroscopy,microcomputer differential thermal balance and scanning electron microscopy,and the results were inferred and explained by analysis.Combined with catalyst catalytic mechanism analysis,the results were Explain the reasoning.