Why methanol carbonylation is a very important aspect of developing one carbon chemistry

With the development of one-carbon chemistry, the types of reactions involved by carbon monoxide have gradually increased, and now in the presence of transition metal complexes (mainly carbonyl complexes) catalysts, the reactions that introduce carbonyl groups (> co) into organic compound molecules are classified into the category of carbonylation reactions, which are collectively referred to as carbonylation reactions. There are two main categories:1

Carbonylation of unsaturated compounds 2Carbonylation reaction of methanol.

The carbonylation reaction of methanol mainly includes:

1.Methanol carbonylation to synthesize acetic acid --- Monsanto method.

monsanto acetic acid process)2ch3oh + co --ch3cooh2.Methyl acetate carbonylation synthesis of acetic anhydride ---tennessce eastman method.

ch3cooch3 + co --ch3co)2o3.Methanol carbonylation synthesizes formic acid.

ch3oh + co--hcooch3

hcooch3 + h2o---hcooh + ch3oh4.Methanol carbonylation oxidizes oxalic acid or ethylene glycol.

By applying methanol carbonylation, many important organic chemical products can be synthesized. Methanol can be produced from coal or natural gas. Therefore, these reactions are a very important aspect of the development of one-carbon chemical products using coal or natural gas as raw materials.

The carbonylation of methanol can be used to point out that methanol is the conversion of gaseous nitric oxide into liquid fuel.

This can be used as an aspect of fuel applications.

environment friendly

Carbon monoxide. and hydrogen mixture were synthesized by catalyst at high temperature and high pressure, and the chemical equation is: CO+2H2 CH3OH

Methanol. The products after combustion are: CO2 and H2O

2CH3OH + 3O2 = ignition = 2CO2 + 4H2O

Methanol is prepared by synthetic method, and the products after combustion of methanol are: CO and HO, 2CH OH + 3O = ignition = 2CO + 4HO.

1.The production of methanol is mainly synthesized, and the chemical reaction formula of synthesis is: 2H + Co CH OH

2.The synthesized crude methanol is removed by pre-distillation to remove the methyl ether. (The high-pressure method was the first method to realize industrial synthesis, but because of its high energy consumption, complex processing, demanding material requirements, and many by-products in the product, it was replaced by the ICI low-pressure and medium-pressure methods and the LURGI low-pressure and medium-pressure methods.)

Almost all industrial methanol synthesis adopts the method of carbon monoxide pressurized catalytic hydrogenation, and the process includes gas production, synthesis and purification, methanol synthesis and crude methanol distillation. ）

3.Crude methanol is purified, and the purification process includes rectification and chemical treatment. Chemical treatment mainly uses alkali to destroy impurities that are difficult to separate in the distillation process and adjust the pH value; Distillation is mainly to remove volatile components such as dimethyl ether, as well as refractory ethanol, high-carbon alcohols and water.

The purity after crude distillation can generally reach more than 98%.

4.The water content of industrial methanol is reduced to the following by rectification. It is then treated with sodium hypoperiodate to remove the acetone in it. Pure methanol is obtained by rectification.

The preparation of grade methanol is mainly by the rectification process. Using industrial methanol as raw material, high-purity methanol products are obtained by distillation, ultra-clean filtration, and ultra-clean packaging. Generally, industrial methanol is used as raw material, and the water is removed by frequent pressure distillation, and the top of the tower is controlled 64 65, and the insoluble matter can be removed by filtration.

A mixture of carbon monoxide and hydrogen is synthesized by a catalyst at high temperature and pressure, and the chemical equation is: CO+2H2 CH3OH

The products after combustion of methanol are: CO2 and H2O

2CH3OH + 3O2 = ignition = 2CO2 + 4H2O

The main chemical reactions

co+h2——ch3oh(g)

When carbon dioxide is present, carbon dioxide reacts as follows to form methanol CO2+H2 - CO+H2O(g).

co+h2——ch3oh(g)

The total reaction formula of the two-step reaction is:

co2+3h2——ch3oh+h2o

2) Typical side effects.

2co+4h2---ch3och3+h2oco+3h2---ch4+h2o

The products of 4CO+8H2---C4H9OH+3H2O after full combustion are carbon dioxide and water, and the products of insufficient combustion are carbon monoxide.

44 gCO2 is 1 mol CO2, and 56 gco is 2 mol co, i.e. n(CO2): n(co) = 1:2.

Assuming that the CO2 coefficient is 1 and the CO coefficient is 2, the reaction formula can be written first: 3CH4O+7 2O2=CO2+2CO+6H2O, and multiply both sides by 2 at the same time, that is, 6CH4O+7O2=2CO2+4CO+12H2O

(1) The main chemical reactions

co+h2——ch3oh(g)

When carbon dioxide is present, carbon dioxide reacts as follows to form methanol CO2+H2 - CO+H2O(g).

co+h2——ch3oh(g)

The total reaction formula of the two-step reaction is:

co2+3h2——ch3oh+h2o

2) Typical side effects.

2co+4h2---ch3och3+h2oco+3h2---ch4+h2o

4co+8h2---c4h9oh+3h2o

Search: Write down the main chemical reactions and side reaction equations for the synthesis of methanol with hydrogen and carbon monoxide as raw materials.

The main reason for imitation involves the superconjugation effect, and the introduction at the secondary school level belongs to the super-syllabic content. It's good to just remember this result, and if you have more than enough energy, you can learn about it.

Let's start with the superconjugation effect, in which one bond on carbon in a tetrahedral configuration will bond with another carbon, and the bond, p orbital, because the electron cloud can partially overlap, allowing the electrons of the two to enter each other. After entering, the two will affect each other's electron cloud to the degree of looseness, that is, the degree of activation or stabilization of the other. This stabilizing or activating effect brought about by the bond is called the super-comic yoke effect.

Take 2-butanol elimination as an example.

There are two directions for the elimination of 2-butanol. If it is eliminated into 1-butene (i.e., compound 1), then only the carbon-hydrogen bond on the red methylene group can be superconjugated with the bond.

If it is eliminated into 2-butene (compound 2), then the superconjugated bond with the bond becomes all the carbon-hydrogen bonds on the two methyl groups.

The natural reaction goes in this direction.

Synthetic methanol is an important chemical reaction with a wide range of industrial applications. The reaction rate of methanol synthesis is affected by a variety of factors, including reactant concentration, catalyst type and quality, reaction temperature, reaction pressure, etc. The following is an analysis and discussion of these factors.

Reactant concentration.

The synthesis of methanol is a process of mass balance control of reactants, so the concentration of reactants is an important factor affecting the reaction rate. When the concentration of methanol or hydrogen increases, so does the reaction rate. However, an increase in the reaction rate will also lead to an increase in the consumption of methanol and hydrogen, and an increase in the rate of consumption of reactants will create new problems, such as catalyst deactivation.

Catalyst type and quality.

The reaction catalyst for the synthesis of methanol is usually metal oxides such as cobalt oxide and zinc oxide. The type and quality of the catalyst have a great influence on the reaction rate, such as the activity, selectivity, lifetime, and regeneration capacity of the catalyst. The choice of catalyst should also take into account aspects such as the cost and service life of the catalyst.

Reaction temperature and reaction pressure.

The synthesis of methanol is a high-temperature and high-pressure process, and the influence of reaction temperature and reaction pressure on the reaction rate is very important. An increase in the reaction temperature can increase the yield of methanol, but the inactivation rate of the reaction catalyst will also increase at high temperatures, and the deactivation rate of the catalyst will be faster at high temperatures. The increase in reaction pressure can increase the yield of methanol, but at the same time, the sensitive file will lead to an increase in equipment costs, and the safety of the reaction equipment at high pressure will also be affected.

How do you determine the process conditions for the synthesis of methanol?

Determining the process conditions for the synthesis of methanol requires a combination of factors, including reaction rate, yield, energy consumption, catalyst selection, etc. Generally speaking, selecting an appropriate catalyst, controlling the concentration and temperature of reactants, and appropriately increasing the reaction pressure can reduce energy consumption and improve the safety of reaction equipment while ensuring the reaction rate and yield.

In industrial practice, determining process conditions generally requires experimentation and optimization. First of all, it is necessary to conduct experiments on the concentration of reactants, reaction temperature and reaction pressure to determine the appropriate reaction conditions. Secondly, the appropriate catalyst and catalyst quality need to be selected to ensure the maximum reaction rate and yield.

In addition, factors such as energy consumption and plant safety need to be taken into account to determine the optimal process conditions.

In practical applications, the process conditions for the synthesis of methanol need to consider not only the reaction rate and yield, but also environmental and economic factors. For example, in the petrochemical industry, the selection of process conditions needs to take into account factors such as petroleum**, production costs, catalyst selection and regeneration. In addition, in order to reduce energy consumption and improve the safety of reaction equipment, it is also necessary to rationally design and optimize the reaction equipment.

In summary, the reaction rate of methanol synthesis is affected by a variety of factors, and a combination of factors needs to be considered to determine the optimal process conditions. In practical applications, it is necessary to reasonably design and optimize the reaction equipment and catalysts to ensure the maximization of the reaction rate and yield, while reducing energy consumption and improving the safety of the reaction equipment.