Study On Preparation Of Butylene Glycol By Catalytic Hydrogenation Of Butanediol And Process Safety Analysis

2-butene-1,4-diol is one kind of important fine chemical,which can be used as pesticide and pharmaceutical intermediate.It also can be widly used in the industries,such as polymer materials,paper making,tobacco,electroplating.The method of preparing 2-butene-1,4-diol in industry is using Lindlar catalyst catalyze 2-butyne-1,4-diol hydrogenation,and the selectivity of 2-butene-1,4-diol had improved by doping lead in the active component of the catalyst for reducing the activity of the catalyst;However,the doped lead will pollute the environment and make the catalyst cost higher and easier to deactivate.Therefore,it is of great significance to study eco-friendly and economical catalyst to catalyze the reaction.There are two main ways to improve the hydrogenation catalyst of 2-butyne-1,4-diol,one is adding second kinds of metal to achieve a higher 2-butene-1,4-diol yield through its geometric effect and electronic effect of bi-metal;Another is the study of a new catalyst support,as a new type of porous material,MOFs has the advantages of super high specific area and larger aperture,which is beneficial to the active components of the catalyst dispersion;At the same time,its ordered nanometer sized channel can provide a micro reaction place for hydrogenation reaction and is helpful to the effective transmission of reaction substrates and products,so that it can achieve the purpose of high conversion rate and selectivity.Firstly,we preparaed double metal catalyst Pd-Cu/Fe₃O₄@C by impregnation method,which was characterized by some technical approaches such as XRD,X ray photoelectron spectroscopy（XPS）,Transmission electron microscopy（TEM）,VSM and so on.We also investigated the influencing factors of the hydrogenation reaction,which including Pd/Cu molar ratio,catalyst reduction methods,reaction solvent,and the ratio of the catalyst active center Pd to substance 2-butyne-1,4-diol,reaction temperature,H₂ pressure,reaction time.The results showed that the Pd-Cu/Fe₃O₄@C was successfully prepared by hydrothermal method,and the catalyst active component of Pd and Cu were well dispersed,it’s size was about 10.8±3.4nm.The saturation magnetic intensity of the Pd-Cu/Fe₃O₄@C catalyst was9.59emu/g,and there is basically no remanence,which prevented the catalyst from agglomerating;After optimizing the hydrogenation reaction conditions,the ratio of Pd/Cu material was 1:1,isopropanol as the reducing agent,methanol as the reaction solvent,the ratio of the catalyst active center Pd to substance 2-butyne-1,4-diol was 1:90000,the reaction temperature was 50℃,the H₂ pressure was 4.0 MPa,the reaction time was 25 min,the conversion of 2-butyne-1,4-diol and the selectivity of 2-butene-1,4-diol reached 95.2%and98.3%,respectively.Secondly,in this paper,Cu-Fc coordination polymer was used to load Pt and then it was calcinated in high temperature to get the 5wt%Pt-Cu/Cu_xFe_yO@C catalyst.The catalyst was characterized by XRD,N₂ adsorption and desorption,XPS,TGA and TEM-EDS.We also investigated the influencing factors of the hydrogenation reaction,which including the ratio of the catalyst active center Pt to substance 2-butyne-1,4-diol,reaction temperature,H₂ pressure,reaction time.The results showed that 5wt%Pt-Cu/Cu_x Fe_yO@C catalyst active components nano Pt,Cu particles,Pt-Cu alloy were surrounded by a large amount of amorphous carbon,and the catalyst had a larger specific surface area,which was favorable for the dispersion of the active components;After optimizing the experimental conditions,the proportion of catalyst active center Pt to substrate was 1:2000,the reaction temperature was 120℃,pressure was 4.0 Mpa,reaction time was 30 min,the 2-butyne-1,4-diol conversion rate was 100%,and the selectivity 2-butene-1,4-diol was 96.1%respectively.Thirdly,in this paper,RhCl₃ was impregnated on UiO-66-NH₂,which prepared by hydrothermal synthesis of ZrCl₄ and 2-amino terephthalic acid,and followed it was reducted by isopropanol to obtain the Rh/UiO-66-NH₂ catalyst,then it was characterized by some comprehensive technical approaches such as XRD,TGA,N₂ adsorption desorption instrument,infrared spectrometer.We also investigated the influencing factors of the hydrogenation reaction,which including the ratio of the catalyst active center Rh to substance2-butyne-1,4-diol,reaction temperature,H₂ pressure,reaction time.The results showed that UiO-66-NH₂ maintained good crystallinity and crystal structure during the preparation of5wt%Rh/UiO-66-NH₂ catalyst,and it had a good specific surface area,pore volume and pore size.The particle size of the UiO-66-NH₂ support was about 200 nm,and its morphology was a regular octahedral structure with uniform dispersion.After optimized by a single factor experiment,the conversion of 2-butyne-1,4-diol was 99.2%,the selectivity of2-butene-1,4-diol selectivity was 90.8%.Fourthly,this paper took the 500 ton/year 2-butene-1,4-diol product in a Chongqing chemical industry company as the research object,in order to achieve the purpose of safety production in chemical industry,the safety analysis of the process was carried out by the method of pre-hazard analysis,the material hazard and the dangerous and harmful factors involved in the hydrogenation process were identified and the corresponding preventive measures were made.