glass reactor,jacketed glass reactor,glass reactor vessel
Small stainless steel high-pressure reactor belongs to special equipment,should be placed in line with the explosion-proof requirements of the high-pressure operation room,high-pressure reactor and belong to the precision equipment,through the sealing ring using a tapered phase contact sealing form,through the tightening of the main bolts so that they are pressed against each other to achieve the purpose of sealing.It often appears in the process of using the problem is the reaction speed is slow,and even the reaction stops,must be filtered out of the catalyst,filtrate replenished with new catalyst to continue the reaction.For the reason of its slow reaction,let's analyse it briefly for your reference!
1、Impurities
Toxic chemicals,insoluble substances,metal ions and tars,excluding low molecular impurities,isomers and solvent residues.Raney nickel is generally more resistant to toxicity,toxicity is mainly for palladium carbon.The main toxicants are sulphur-phosphorus compounds,including various forms of substances containing elemental sulphur and phosphorus.Poisonous substances introduced into the pathway including raw materials,solvents,reactors and gases,etc.;insoluble substances are mainly inorganic substances and polymers,etc.,mainly deposited on the surface of the catalyst,so that the reaction site is blocked,the reaction slows down;metal ions,mainly heavy metals,copper ions,mercury ions,lead ions and cadmium ions,etc.,and the catalyst reaction,which slows down the reaction;the role of the mechanism of the tar and the insoluble substances are similar to,and may be the reaction is produced,so the reaction conditions generally can not be high;tar is similar to the mechanism,and may be generated.So the reaction conditions generally can not be high;impurity factors are difficult to analyse through the instrument,must be verified by experiment to know,which is easy to ignore in catalytic hydrogenation.
2、Stirring type
It is mainly the mixing effect of stirring on the bottom catalyst,because hydrogen is less soluble in the solvent,and mostly exists in gaseous state in the reaction system;the raw material is dissolved in the solvent,which is in liquid state;and the catalyst is in solid state.Microscopically,the reaction occurs on the surface of the catalyst,and good mixing can make the gaseous hydrogen and raw materials on the surface of the catalyst to pass and react quickly,and take the product away at the same time.Laboratory small test mostly use magnetic stirring,because the amount of small plus magnetic force has the role of grinding catalyst,generally fast reaction;pilot test,propelled stirring paddle under pressure mixed reaction system,the effect is better.Raney nickel due to heavier,by the stirring effect of the factors affecting the large;palladium carbon due to palladium metal adsorption on the activated carbon,relatively small impact;industrial production,the scale is larger,the stirring effect is poor,generally slower than the pilot reaction;traditional anchor stirring has no direction,bidirectional can be normal stirring;propulsive stirring paddle has a direction,the correct direction to have good stirring effect,the opposite direction of the effect of poor.
3、PH value
This factor is a key point that can be easily ignored when optimising the catalytic hydrogenation process,and the pH value affects the reaction rate by influencing the catalyst activity.The activity of Raney nickel is higher under alkaline condition and poorer under acidic condition,the alkalinity of reaction solution can be improved by adding amine;the activity of palladium carbon is higher under acidic condition and poorer under alkaline condition,the acidity of reaction solution can be improved by adding acetic acid.The above acidity and alkalinity should not be high,strong acid and alkali should not be used,and the stability of the equipment and the influence on the post-treatment need to be considered.
4.Reduced or unsuitable catalyst activity
If a catalyst has been used,the activity of the catalyst may have been reduced or the catalyst selected may not be suitable for the current reaction,which may result in a reduction in the reaction rate.In this case,consider replacing the catalyst with a new one or selecting a more suitable catalyst.
5、Scaling or pollution inside the reactor
After long-term use,scaling or pollution may occur inside the reactor,which affects the heat transfer efficiency of the reactor and the contact of reactants,thus reducing the reaction speed.Regular cleaning and maintenance of the reactor can reduce this situation.
6.Problems with the ratio of reactants
Incorrect ratios between reactants may also lead to slow reactions.It is important to check and make sure that the ratio of all reactants meets the requirements of the chemical reaction.
7、Equipment design or operation problems
The design of the reactor may not be suitable for the chemical reaction being carried out,or the operator may not be following the correct procedures,which may also result in a slow reaction.Equipment design and operating procedures should be re-evaluated.
In response to these potential causes,it is recommended that the reactor be thoroughly inspected and maintained,and that operating parameters be adjusted according to the specific situation to ensure that the chemical reaction can proceed at the expected rate.At the same time,attention should be paid to safe production to ensure that all operations are carried out within safety norms.
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