: s'_VIPao unreacted ethylene is discharged from the last 1 absorption tower and used as fuel gas after alkali washing or returned to the ethylene plant as feed.
System.
B' hydrolysis. The absorption liquid and water enter a water decomposer to hydrolyze diethyl sulfate. Working temperature so-} o,
At this temperature, the hydrolysis of ethyl bisulfate is very slow. The contact time of the hydrolyzer is about 2 minutes. The amount of water added to the hydrolyzer is about 100%.
After hydrolyzing diethyl acetate with the weight of 1- 1.4 times, the hydrolysis mixture is heated to }s0} and kept at a constant temperature of 1 hour to make it simple.
Hydrolysis of phenol. The stripper is essentially equivalent to the second hydrolyzer opening in the stripper, and ethanol and ether are diluted by stripping.
Steam it out with acid. After alkali washing and condensation, it is sent to the rectification section. The dilute acid at the bottom of the tower is sent to the acid concentration section.
C. rectification. After the ether is fractionated in the ether tower, the bottom liquid of the ether tower is sent to the purification tower, and 9pa (volume) is distilled from the top of the purification tower.
Ethanol products.
D. concentration of dilute acid. The concentration of dilute sulfuric acid is an expensive operation and the main cause of equipment corrosion. dilute sulphuric acid
It is sent to reboiler through two-stage vacuum evaporation system, and the acid concentration is raised to 9U Pa, and then it is mixed with 1U3 heptyl fuming sulfuric acid to make it
The content of sulfuric acid reaches 86-88%,
Hydrolysis' distillation and dilute acid concentration have equipment}}', the problem is that the general equipment materials are low carbon steel lined with green lead and ancestors.
Purification. Dilute ethyl 1} solution enters the middle of the light component removal tower, water is added to the top of the tower, and the dilute ethanol vapor is washed and flows at the top of the tower.
Acetaldehyde, ether and circulating gas all enter the hydration system to inhibit the formation of aldehydes and ethers. After the dilute ethanol solution at the bottom of the tower is exported, one
One part is vaporized and returned to the light removal tower, and the other part is sent to the rectification tower. Qualified ethanol is extracted from the upper side line of the distillation column and condensed.
Send to the finished product tank.
High-boiling substances enter the auxiliary rectification tower, and after ethanol is completely evaporated, it is discharged from the bottom of the tower for centralized treatment.
Distillation tower wastewater is pumped from the bottom of the tower, and part of it is used as washing water for washing tower and light component tower, and the other part is discharged into water.
Tao.
The highest concentration of ethanol obtained by distillation can only reach 95.fiojo, which is a * * * boiling mixture of ethanol and water. In the laboratory
When preparing anhydrous ethanol, 95.fi intestinal ethanol and calcium lime (CA0) can be heated to evaporate ss.s}o ethanol, and then magnesium can be used.
Principle, remove trace water, get ",95 intestinal ethanol. The preparation method of industrial anhydrous ethanol is as follows: adding 95. The ethanol of Ficus melo.
A certain amount of benzene is distilled to obtain ternary boiling point substances of benzene, ethanol and water (boiling point: 64. 85') is first distilled.
74.e intestine, B drunk 15.5 intestine, water 7.4 intestine), and then distilled binary * * * boiling substances of benzene and ethanol (boiling point 8}.25), ethanol.
32.4 1 intestine, benzene 67.59 intestine), and finally anhydrous ethanol (boiling point 78.3 0,
(c) process conditions
① temperature. The optimum temperature is the maximum ethanol yield, and the temperature is too low: the ethylene conversion rate is affected by the catalyst.
When the temperature is too high, the reaction is limited by equilibrium. 、
② pressure. Increasing the pressure will increase the speed of ethanol production, but it will also accelerate the formation of polymers, thus increasing the pressure.
There are certain restrictions.
③ The ratio of ethylene to water. The high molar ratio of ethylene to water is beneficial to the conversion of ethylene.
④ With the increase of airspeed and volumetric airspeed, the yield of ethanol will also increase, but relatively speaking, the cycle operation cost will also increase.
In addition
⑥ The ethylene concentration of raw materials, the higher the ethylene concentration, the better the reaction. Polymeric grade purity ethylene is usually used as a raw material, but
Considering the economy, 8} ethylene can also be used as raw material.
The above excerpt is from the second volume of organic chemical raw materials.
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