The product quantity and quality of etibylene production device not only is directly related with economic benefits but also influences the normal production movement and production quality of large downstreem production device (such as polyethylene device,polypropylene device,glycol device),as a result it accuplies a outstanding position in the quality (yield)control of enthylene production process. This text estabishes the pridict model of ethylene device cracking furnace according to orthogonal design method and stepwise regression method to predict control and optimization.Firstly, this text introduces mathematics model of the craft mechanism of the estabishment cracking furnace and then estabishes ethylene device cracking furnace’s simplified model according to orthogonal design method and stepwise regression method.The experiment deta is made use by the method of nonlinear regression method to get the simplified computer controlling model of ethlene and propylene.The analysis of variance and stastistics test of regression equation and regression coefifcient suggests the regression results is good ,the results of mechanism model and simplified model are very similiar and the exact rate of simplified model is very high,as a result this model can be made use to replace mechanism model which is used for computer control.Secondly,this test mainly introduces the soft measurement of the cracking furnace which has something with variables of cracking depth,the outlet temperature of cracking furnance,the production ability of cracking furnance and the raw materials ,and the steam dilution ratio control,in order to improve the yield of ethylene.In the end ,the cracking furnace gets optimal operated further on the basis of advanced control the ethylene device cracking furnace,in order to get the greatest average yield.This chaper establishes optimal proposition on the basis of constant conditions,applied network for fast training methods and algorithms ,decribes the operating characteristic idustrial pyrolysis process exactly and uses the optimal algorithms of simulated annealing for optimizing system.
Organic chemical Archive
Study on Microwave-Induced Synthesis、Spectra and Electrochemical of 4-Hydroxycoumarin and Its Derivatives
4-Hydroxycoumarin derivatives are of interest because of their bactericidal, insecticidal,anticoagulant and anti-HIV activities.They are also extensively used as optical brightening agents,dispersed fluorescent and laser dyes.For this reason,the optical and electrochemical propertities of novel derivatives,together with the development of new synthetic methods,are topics of growing interest for a great number of research groups.The synthetic progresses of coumarin and its derivatives were reviewed.Furthermore, a series of 4-hydroxycoumarin derivatives were synthesized and their optical and electrochemical propertities were studied.These studies would supply available informations and datas in life science.This thesis consists of four chapters,and the main contents are as follows:1.Coumarin derivatives have been playing important roles because of their important biological and optical activities.The recent advances in the synthetic methods of coumarin and its derivatives are reviewed.2.Three kinds of 4-hydroxycoumarin derivatives,3,3′-benzylidenedi-4-hydroxycoumarin、3,3′,3″,3′″-ethylenetetrakis-4-hydroxycoumarin and 4-hydroxycoumarin- 1,4-naphthaquinone have been synthesized from 4-hydroxycoumarin under microwave irradiation. Through change of reaction conditions,the best condition for the synthesis of 4-hydroxycoumarin was selected.Their structures were verified by elemental analysis、IR、1H NMR、MS spectroscopy and X-ray measurement.3.The fluorescence and UV properties of aimed compounds were preliminarily studied and the relationship was found between the compounds’ microcosmic structures and their corresponding optical properties.The results show that a bigπ-conjugated, symmetrical 3,3′,3″,3′″-ethylenetetrakis-4-hydroxycoumarin has better fluorescence in solution.When the concentration was in the range of 0.5～1.5×10-4mol·L-1,the fluorescence intensity linearly increased with decreasing concentration.In the range of pH 1.18 to pH 6.09 fluorescence intensity increases with increasing of pH,and in the range of pH 8.36 to pH 11.98 fluorescence intensity increases with decreasing of pH.Fluorescence enhancing was significantly observed in the presence of BSA、DNA.4.Electrochemical techniques were employed to study the electrochemical behavior in a KH2PO4-Na2HPO4 buffer solution of pH 7 and the interaction with BSA of 4-hydroxycoumarin. The experimental results show that the reduction wave detected in the solution was an irreversible reduction wave of 4-hydroxycoumarin involving 1e and OH+,and a complex was formed due to the reaction of 4-hydroxycoumarin and BSA.
At present,the main methods to produce epichlorohydrin chlorination are through allyl chloride route at high temperature or allyl alcohol route.But the two methods both use propylene as raw materials,which cost a large amount of non-renewable petrochemical resources and produce a large number of wastewater and waste residue.In this paper,we use glycerol as raw materials to synthesize 1,3-dichloro -2-propanol in tubular reactor under the conditions of circulation.The influence of different catalysts in the process of chlorination were researched,and on the basis, orthogonal experimental method was employed.The reaction temperature,the reaction time,the pressure and the amount of catalyst were used to find out the optimized conditions.The results were:1)The optimized catalyst was propionic acid.2)The optimized reaction conditions of initial chlorination were:reaction temperature 100℃,reaction time 1h,the amount of catalyst 3%（Mole ratio,to the amount of glycerol）,reaction pressure 5atm.Under these conditions,the conversion of the glycerin was more than 68%.3)The optimized reaction conditions of further chlorination were as follows: reaction temperature 130℃,reaction time 1h,the amount of catalyst 1.5%,reaction pressure 5atm.Under these conditions,the conversion of the glycerin was more than 98%and the yield was more than 50%.Meanwhile,1,3-dichloro-2-propanol made by the author was cyclized.And the influence of CaCl2 was studied,the results were as follows:1)Under the condition of the same amount of CaCl2 and ECH,as the temperature decreases and reaction time increases,the concentration of ECH in solution become lower.2)Under the condition of the different amount of CaCl2 and ECH,at the temperature of 75℃,as the Moore ratio and reaction time increase,the concentration of ECH become lower.
Amines are important intermediates for organic chemical industry. A large number of drugs, pesticides and dyes are made from them.Ethylenediamine was prepared by aminolysis of dichlorethane with a tubular reactor in this paper.The effects of several factors were investigated and the optimized conditions in the isothermal tubular reactor with inner diameter of 4mm and length of 13m were: the molar ratio of ammonia and dichlorethane 30:1, the concentration of the ammonia 60%, the volume velocity 2L/h, the reaction temperature 160℃, the system pressure 6MPa. Thus the conversion of dichlorethane was 98.7% per pass and the yield was 51.6%.The apparent kinetics of the reaction was studied on some assumed conditions as follows: the only by-product of the reaction is diethylenetriamine; the concentration of ammonia is regarded as constant; the fluid state in the reactor is ideal plug flow. The apparent kinetics equations were established as follows:in which CA was the concentration of dichlorethane, CB was the concentration of ethylenediamine, CC was the concentration of diethylenetriamine. The rate constant of main reaction k1=1.3211×106×e-53144/RT, the rate constant of side reactionk2=1.5594×108×e-73997/RT.The activity energy of the main and side reaction were53144J/mol and 73997J/mol respectively.The activity energy of the main reaction was lower than that of the side reaction according to the kinetics equations. It was known that higher temperature was favorable to the reaction which had higher activity energy. Therefore the non-isothermal reaction was considered to be suitable to improve the selectivity of ethylenediamine. High temperature was adopted in early period to improve the main reaction rate and low temperature was adopted in later period to restrain the side reaction. Compared to the isothermal reaction with the same length of the reactor pipe, the yield of the target product was increased by caculations based on the kinetics equations obtained above.By investigating the effects of several factors in the non-isothermal tubular reactor with inner diameter of 4mm and the overall length of 27m, the optimized conditions were: the temperature of the first reaction pipe 160℃, the reaction time 1.5min. The temperature of second reaction pipe 130℃, the reaction time 8.5min. The other conditions were the same as in isothermal reaction. Thus the conversion of dichlorethane was 98.6% per pass and the yield was 60.1%. To achieve the same yield in isothermal reaction, the suitable conditions were: the temperature 130℃, the reaction time 15min （the length of the pipe was 40m correspondingly）. The length of the reactor pipe was shortened by 33% compared to the isothermal reaction.The ethylenediamine solution with the concentration of 96% was obtained from the crude product through flash evaporation, neutralization, dehydration, azeotropic distillation and extraction.
Alkoxy benzoic acids are important intermediates in organic synthesis,applied in various areas of the fine chemical industry,such as herb antibacterial,pharmaceutical, pesticide,dye.This paper aimed to design a new synthetic route:starting from phenols,via acylation,Fries rearrangement,O-methylation,oxidation,getting corresponding alkoxy benzodic acids.The effect of temperature,time,the ratio of reactants and other factors were investigated and the improved reaction conditions were obtained as follows:1)In acylation reaction,the mole ratio of phenol and acetic anhydride was 1:2 with refluxing at 142℃,lasting 3～4 hours.2)In Fries rearrangement reaction,if the products were p-isomers,the mole ratio of phenol ester and aluminium chloride was 1:1.2 using nitrobenzene as co-solvent or without co-solvent at 30～40℃for about 10～12 hours(using co-solvent)or 1～2 hours(without solvent);If the products were o-isomers,the mole ratio of phenol ester and aluminium chloride was 1:1.5 using NaCl as co-solvent at 130～160℃for about 1.5～2 hours.3)In O-methylation reaction, the mole ratio of dimethyl sulfate and hydroxyl acetophenone was 1:3,with dimethyl sulfate dropping 20ml/h at 50～60℃,keeping pH 9～10.After dropping,kept temperature at 70～80℃for 1～2 hours.4)In oxidation reaction,using water as solvent refluxed at 80℃for 8～12 hours.The mole ratio of sodium hypochlorite and methoxyl acetophenone was 5:1.This route giving following advantages:1)it could apply to a series of alkoxyl benzoic acids of similar structures.2)In acylation reaction,by increasing the amount of acetic anhydride to replace the use of catalysts,the reaction yield was more than 98%.3)In Fries rearrangement reaction,the hydrolysis treatment for using nitrobenzene as co-solvent was putting strong base to become alkaline salts,then separated from organic phase,acidizing.It avoided the high-temperature steam distillation,and the product was of high purity;The hydrolysis treatment for using sodium chloride as co-solvent,put water first keeping 110℃for 1 hour,then cooling to 80℃,adding small amount of 36%hydrochloric acid.It greatly reduced the amount of hydrochloric acid.4)In oxidation reaction,using water as solvent,through appropriate extension of reaction time and intense agitation replaced the use of organic solvent and phase transfer catalyst to simplify operations and lower costs,and it was also favorable to the environment.The most overall yield was more than 50%,and the finally product was identified by melt point and ~1H NMR.This route is much of industrial value in cheap and easily gained material,the mild reaction conditions,convenient operation and environment benign.
Corn gluten meal(CGM),containing 40～60%protein,is the main by-product in the extraction of starch from corn.Because of its poor dissolvability,coarse-feeling and, moreover,lacking human body essential amino acids such as lysine and tryptophan,CGM was now mainly used as animal feed or just treated as a waste,only a few of it has found use in the food industry of mankind.The enzymolysis of CGM can be a very important approach for recycling CGM because it transforms the proteins into amino acids and oligopeptides.In this study,the optimum of the hydrolysis conditions for the acidic protease excreted by Aspergillus niger by the response surface method,the enzyme activity change during the hydrolysis of CGM and its causes,and the use of the hydrolyte for the synthesis of zeolite ZSM-5 have been studied.The following results are obtained:First,the optimized CGM enzymolysis conditions for the acidic protease excreted by Aspergillus niger given by the response surface method are specified by substrate concentration 100 g/L,hydrolysis temperature 55℃,acidic protease dosage 12%(based CGM substrate),hydrolysis time5 h.Under such conditions a HD value(hydrolysis degree)of 35%is forecasted,which agrees with the experimental value(34.84%)very well.This means that the response surface method is suitable for use in the hydrolysis of CGM.Second,the investigation of acidic protease activity change in the process of CGM hydrolysis was performed under the conditions of substrate concentration 100 g/L,acidic protease dosage 12%,and hydrolysis temperature 55℃.Results show that the hydrolysis of CGM substrate by acidic protease was characterized by fast increases of the degradation rate of the solid CGM and the hydrolysis degree of the proteins in the beginning period,slow increases in the middle period(ca.8 h after start),and no increases in the later period.The deactivation of the enzyme is considered to be the cause of the hydrolysis behavior.From parallel experiments it is concluded that two deactivation manners of the enzyme,i.e.,the product-inhibition and the enzyme denaturalization,occur during the hydrolysis of CGM.Third,ZSM-5 zeolite was synthesized hydrothermally by using CGM hydrolyte as additive.It is found that the hydrolyte of CGM has an obvious function of adjusting the morphology of the zeolite.
The apparent consumption of ethylene in China is over 10Mt. But considering the petroleum resources, it is unpractical to rebuild and extend the current ethylene facilities or construct the new petroleum cracking facilities. China is rich in crop straw resources. It will be a good plan to solve ethylene product shortage and also be sustainable development, if we get ethylene through ethanol which produces by crop straw fermentation. At present, rebuilding extension and process integration of the ethanol dehydration technology are beneficial to improve comprehensive utilization rate of energy and reduce production cost. The price of bio-ethylene with petro-ethylene will be equal or have better economic efficiency. The study on energy-saving process of ethylene from biomass ethanol would have more realistic significance.AnHui Feng Yuan Group newly builted a 17,000t/a ethanol dehydration unit in 2004. The process flow contains two parts: ethanol distillation process and ethanol dehydration process. The ethanol from biomass removes impurities, for example carbon dioxide, fusel oil ect, in ethanol distillation process, and then goes into the reactors for dehydration reaction in gaseous state after preheating vaporization.The current ethylene production from ethanol dehydration facilities, which was build after the fuel ethanol facilities, was dated and high energy consumption. In order to save costs and improve bio-ethylene’s competitive power in market, a series of energy-saving measures based on current facilities have been presented combining ethylene from biomass ethanol unit self characteristics. At the same time, a new molecular sieve catalyst which has lower reaction temperature and higher space velocity would be used in the process of ethanol dehydration. A new process suitable for this catalyst will be proposed and simulated, and then the economic efficiency of the two catalysts will be compared.Process simulation of both design condition and reconstruction condition of ethanol distillation and ethanol dehydration processes have been completed by using ASPEN PLUS software. Based on the results of simulation fitted with design data very well, the problem of current process will be analysed using the powerful functions of sensitivity analysis, parameter optimization of ASPEN PLUS. Then the key of process energy saving is found out and energy saving schemes are proposed. There is no stream added in the improved dehydration process, and 21.7% heat consumption is reduced comparing with the current process. If a molecular sieve catalyst is used, no stream added and the heat consumption reduced by 28.5%.
Liquid Catalytic Hydrogenation of Three Aromatic Nitro Compounds over Rapidly Quenched Skeletal Nickel
Aromatic amines are very important organic intermediates. They are widely used in dyestuffs, pharmaceuticals, agricultural chemicals, additives and surfactants. Most of the aromatic amines come from corresponding nitro compounds. Reducing the nitroarene to aromatic amines is an important reaction. Catalytic hydrogenation, especially liquid catalytic hydrogenation, greatly decreases environmental pollution and promotes the quality of products. With the increasing attention to environment problems, popularizing catalytic hydrogenation technology in the chemical industry will undoubtedly bring prominent economic and social benefits. So it is in urgent need of developing more efficient catalyst and replacing traditional methods with catalytic hydrogenation.In this thesis, we develop the rapidly quenched skeletal Ni catalyst and addition of molybdenum. Its characterizations are carried out with XRD and SEM. Rapidly quenched skeletal Ni is a new kind of skeletal nickel prepared by rapid quenching technique. Their activity, selectivity and thermal stability are tested in the preparation of two dye intermediates of aromatic amines by liquid catalytic hydrogenation.This thesis studied the appliance of the rapidly quenched skeletal Ni catalyst in the liquid catalytic hydrogenation of p-nitroacetanilide (p-NAT) to p-aminoacetanilide (p-AAT). Under the optimized conditions (60℃, 1.0 MPa, w(cat.)/m(p-NAT)=1/10 and methanol as solvent), 99.5% selectivity of p-AAT with 100% p-NAT conversion was obtained in 24 minutes. The apparent activation energy of the reaction is about 34 kJ/mol. It can be concluded that the rapidly quenched skeletal Ni catalyst shows higher activity and selectivity in the hydrogenation of p-NAT.In order to expand the use area of the rapidly quenched skeletal Ni catalyst and to test its catalytic performance further, it was also used in the preparation of 3-amino-4-methoxyacetanilide (AMA) from 3-nitro-4-methoxyacetanilide (NMA). The effects of reaction conditions such as different solvents, the amount of catalyst, reaction temperature and pressure were studied and all of them were optimized to serve for industrial application. Under optimized conditions (60℃, 1.0 MPa, m(cat.)/m(NMA)=1/10 and methanol as solvent), the conversion of NMA was 100% and the selectivity of AMA was as high as 99.9% in 40 minutes. The apparent activation energy of the reaction is about 52 kJ/mol. The catalyst was repeatedly used for 44 times and exhibited excellent catalytic activity and stability.Moreover, the reaction mechanism of liquid hydrogenation of 3-mononitrophenyl -β-hydroxyethyl sulfone to 3-aminophenyl-β-hydroxyethyl sulfone was studied. Based on the experimental observations by HPLC, a possible mechanism about the reaction catalyzed by the skeletal nickel catalyst was proposed.
4-Chlorophthalic anhydride is an important chemical intermediate which is broadly used in producing dyes, plastic, medicines, and pesticides. Currently, looking for some industrial potential synthesis routes, in which the technologcial conditions are reasonable and the materials can be easily obtained, has already become the point of research.Two routes that using phthalic anhydride and butadiene respectively as the starting material to synthesize 4-chlorophthalic anhydride are researched in this paper. In the route of using phthalic anhydride as the starting material, 4-chlorophthalic anhydride is synthesized through three consecutive reactions. Phthalic anhydride is firstly nitrified by oil of vitriol and nitric acid. Then the targeted product 4-nitrophthalic acid is separated from 3-nitrophthalic acid through two methods named extraction and esterification-hydrolysis. The optimum reaction conditions of both the two methods are obtained by orthogonal experiments. Under the optimum reaction conditions of the extraction method, the yield and purity of 4-nitrophthalic acid are of 53.4% and 83%, respectively. The relating results of the esterification-hydrolysis method are of 48.3% and more than 99%, respectively. 4-Nitrophthalic anhydride is obtained in 86.2% yield by the dehydration of 4-nitrophthalic acid. Finally, 4-chlorophthalic anhydride is obtained by the chlorination of 4-nitrophthalic anhydride and its acid. 3-chlorophthalic anhydride is found in the chlorination product by the analysis of HPLC/MS. The total yield of both the two isomers is of 89-95%.In the route of using butadiene as the starting material, tetrahydrophthalic anhydride is firstly synthesized by the Diels-Alder reaction of butadiene with maleic anhydride in a yield of as high as 99.1%. Tetrahydrophthalic acid is obtained by the hydrolysis of Tetrahydrophthalic anhydride in 85.9% yield. Then, tetrahydrophthalic anhydride and its acid are treated by chlorine in different solvents. The product of chlorination in water is 4,5-dichlorocyclohexane-1,2-dicarboxylic acid. Finally, the dehydrochlorination and aromatization reactions of 4,5-dichlorocyclohexane-1,2-dicarboxylic acid are explored in this paper.
Diisopropylbenzenes（DIPBs）will be formed as byproduct during manufacturing cumene by alkylation of benzene with propylene to in phenol-acetone plants,and meta-DIPB is an important raw material,which mainly can be oxidized to resorcinol. Recently with the need of resorcinol increasing in many industries,the need of m-DIPB is also increasing.However,the boiling points of the three isomers of DIPB are very close: ortho-DIPB 205℃,meta-DIPB 203℃,para-DIPB 203.5℃,so it is difficult to separate meta-DIPB from the other isomers using normal distillation.In this paper,the certain zeolites which have the shape-selective function will be used as catalysts to crack DIPBs selectively. They have the appropriate pore diameter in order to let para-DIPB go into the pores of molecular sieves and will be cracking to benzene and cumene with the acid centers inside,but meta-DIPB（larger diameter than para-）can not go inside and does not react.So 99% meta-DIPB can be producted though distillation using the obvious differences of boiling points of products,（benzene 80.1℃,eumene 152.5℃）.Shape-selective cracking of DIPB was investigated over zeolite catalysts,i.e.HZSM-5, HZSM-22、Hβand HY.The results showed that HZSM-5 zeolite appeared to be the most efficient catalysts for the reaction.Meanwhile,nano-HZSM-5 is the high-active catalyst for the reaction compared the different grain sizes of HZSM-5.The reaction conditions over nano-HZSM-5 were investigated,the cracking rate of para-DIPB can reach 93%,Content of m-DIPB in product DIPB 94%and the yield of meta-DIPB 75.7%at the optimum conditions: pressure 0.1MPa,reaction temperature 380℃,and weight hourly space velocity（WHSV）6h-1 with N2.Nano-HZSM-5 was modified with oxides of magnesium and lanthanum,the results show that the modified zeolites have the high activity during 40h,the stability is increasing,and the yielding of meta-DIPB is also increasing.The catalysts prepared with Mg（NO3）2 as the precursor of MgO have the higher cracking activity and stability than the catalysts prepared with Mg（CH3COO）2 as the precursor.Compared with the effects of different contents of lanthanum iron,the results indicate that 0.1%content the stability of catalysts increased obviously,and the cracking rate of para-DIPB can reach 92%,Content of m-DIPB in product DIPB 93%,the yield of meta-DIPB over 85%.Compared with modification by hydrothermal treatment in different time under the temperature of 160℃,the results indicate the catalysts modified by hydrothermal treatment in 2h hold high activity during 50h,and have the best stability.The stability of nano-HZSM-5 modified by hydrothermal treatment followed by lanthanum is better than modified by lanthanum followed by water,the cracking rate of para-DIPB can holding over 85%during 60h,Content of m-DIPB in product DIPB over 90%,the yield ofmeta-DIPB over 90%.