Method for recovering hydrochloric acid and phenol in p-hydroxybenzene hydantoin mother liquor

Abstract

The invention discloses a method for recovering hydrochloric acid and phenol from a p-hydroxybenzene hydantoin mother liquor. The method comprises the following steps: carrying out reduced-pressure distillation, condensation and sectional collection on the p-hydroxybenzene hydantoin mother liquor to obtain a condensate; absorbing concentrated hydrochloric acid steam via the condensate, wherein anabsorption liquid is obtained after the concentration of hydrochloric acid in the condensate exceeds a concentration threshold; and directly applying the absorption liquid to a synthesis reaction of p-hydroxybenzene hydantoin. According to the recovery method disclosed by the invention, the requirement for recovering phenol is met; meanwhile, HCl in the p-hydroxybenzene hydantoin mother liquor isfully absorbed, the purpose of simultaneously and indiscriminately applying phenol and HCl is achieved, a process route is shorter, operation is simple, other raw materials are not involved, treatmentcost is lower, the recovered phenol and hydrochloric acid can be directly used for synthesizing benzene hydantoin, and the method better conforms to the concept of green chemical production.

Description

technical field

[0001] The invention relates to the technical field of wastewater treatment, in particular to a method for recovering hydrochloric acid and phenol in p-hydroxyphenylhydantoin mother liquor. Background technique

[0002] P-Hydroxyphenylhydantoin is an important intermediate for the semi-synthesis of β-lactam antibiotics such as amoxicillin, ampicillin, and cephalosporins. There are generally two methods for its synthesis: (1) from p-hydroxybenzaldehyde and sodium cyanide and urea; (2) "One-pot" synthesis of phenol, glyoxylic acid, and urea; currently the "one-pot" synthesis process is mainly used. During the synthesis of dihydantoin, a large amount of phenol wastewater will be produced, with a concentration of about 10,000 ppm. 1 ton of dihydantoin will produce about 4 tons of wastewater containing phenol. Phenol is a highly toxic substance and has a great impact on the environment. Therefore, the dihydantoin industry is currently It has been listed as a rest...

Examples

Embodiment 1

[0026] Put 9.2L of mother liquor into a rotary evaporating flask. After the vacuum reaches -0.088Mpa, slowly raise the temperature to 60°C and collect in sections. At 20°C, collect 1.4L of the first condensate. At 20°C, Collect 4L of the second condensate, and remove the remaining 3.8L of the still residue for disposal, such as sending it to environmental protection for concentrated incineration.

[0027] Put the second condensate into the absorption bottle, control the temperature at 3°C, and fill the concentrated hydrochloric acid evaporation bottle with a volume of 1.5BV of the second condensate volume Concentrated hydrochloric acid (concentration of concentrated hydrochloric acid ≥ 31%), connect the device, open After vacuuming to -0.088Mpa, slowly raise the temperature to 45°C (internal temperature), absorb for 1.8h, and check that the concentration of hydrochloric acid in the absorbing liquid is > 31%, then hand over the absorbing liquid to Synthesis for use in the synthe...

Embodiment 2

[0036] Put 9.2L of mother liquor into a rotary evaporating flask. After the vacuum reaches -0.088Mpa, slowly raise the temperature to 69°C and collect in sections. At 20°C, collect 1.8L of the first condensate. At 20°C, Collect and obtain 5L of the second condensate, and remove the remaining 3.8L of the still residue for treatment, such as sending it to environmental protection for concentrated incineration.

[0037]Put the second condensate into the absorption bottle, control the temperature at 3°C, and fill the concentrated hydrochloric acid evaporating flask with concentrated hydrochloric acid (concentration of concentrated hydrochloric acid ≥ 31%) with a volume of 1.65 BV of the second condensate, connect the device, and turn on the vacuum After reaching -0.088Mpa, slowly raise the temperature to 52°C (internal temperature), absorb for 1.8h, and check that the concentration of hydrochloric acid in the absorption solution is >31%, then hand over the absorption solution to Sy...

Embodiment 3

[0044] Put 9.2L of mother liquor into a rotary evaporating flask. After the vacuum reaches -0.088Mpa, slowly raise the temperature to 66.5°C and collect in sections. At 20°C, collect 1.65L of the first condensate. At 20°C, Collect 4.6L of the second condensate, and remove the remaining 2.95L of still residue for treatment, such as sending it to environmental protection for concentrated incineration.

[0045] Put the second condensate into the absorption bottle, control the temperature at 3°C, and fill the concentrated hydrochloric acid evaporating flask with concentrated hydrochloric acid (concentration of concentrated hydrochloric acid ≥ 31%) with a volume of 1.65 BV of the second condensate, connect the device, and turn on the vacuum After reaching -0.088Mpa, slowly raise the temperature to 48°C (internal temperature), absorb for 1.8h, and check that the concentration of hydrochloric acid in the absorption solution is >31%, then hand over the absorption solution to Synthesis ...

technical field

[0001] The invention relates to the technical field of wastewater treatment, in particular to a method for recovering hydrochloric acid and phenol in p-hydroxyphenylhydantoin mother liquor. Background technique

[0002] P-Hydroxyphenylhydantoin is an important intermediate for the semi-synthesis of β-lactam antibiotics such as amoxicillin, ampicillin, and cephalosporins. There are generally two methods for its synthesis: (1) from p-hydroxybenzaldehyde and sodium cyanide and urea; (2) "One-pot" synthesis of phenol, glyoxylic acid, and urea; currently the "one-pot" synthesis process is mainly used. During the synthesis of dihydantoin, a large amount of phenol wastewater will be produced, with a concentration of about 10,000 ppm. 1 ton of dihydantoin will produce about 4 tons of wastewater containing phenol. Phenol is a highly toxic substance and has a great impact on the environment. Therefore, the dihydantoin industry is currently It has been listed as a rest...

Examples

Embodiment 1

[0026] Put 9.2L of mother liquor into a rotary evaporating flask. After the vacuum reaches -0.088Mpa, slowly raise the temperature to 60°C and collect in sections. At 20°C, collect 1.4L of the first condensate. At 20°C, Collect 4L of the second condensate, and remove the remaining 3.8L of the still residue for disposal, such as sending it to environmental protection for concentrated incineration.

[0027] Put the second condensate into the absorption bottle, control the temperature at 3°C, and fill the concentrated hydrochloric acid evaporation bottle with a volume of 1.5BV of the second condensate volume Concentrated hydrochloric acid (concentration of concentrated hydrochloric acid ≥ 31%), connect the device, open After vacuuming to -0.088Mpa, slowly raise the temperature to 45°C (internal temperature), absorb for 1.8h, and check that the concentration of hydrochloric acid in the absorbing liquid is > 31%, then hand over the absorbing liquid to Synthesis for use in the synthe...

Embodiment 2

[0036] Put 9.2L of mother liquor into a rotary evaporating flask. After the vacuum reaches -0.088Mpa, slowly raise the temperature to 69°C and collect in sections. At 20°C, collect 1.8L of the first condensate. At 20°C, Collect and obtain 5L of the second condensate, and remove the remaining 3.8L of the still residue for treatment, such as sending it to environmental protection for concentrated incineration.

[0037]Put the second condensate into the absorption bottle, control the temperature at 3°C, and fill the concentrated hydrochloric acid evaporating flask with concentrated hydrochloric acid (concentration of concentrated hydrochloric acid ≥ 31%) with a volume of 1.65 BV of the second condensate, connect the device, and turn on the vacuum After reaching -0.088Mpa, slowly raise the temperature to 52°C (internal temperature), absorb for 1.8h, and check that the concentration of hydrochloric acid in the absorption solution is >31%, then hand over the absorption solution to Sy...

Embodiment 3

[0044] Put 9.2L of mother liquor into a rotary evaporating flask. After the vacuum reaches -0.088Mpa, slowly raise the temperature to 66.5°C and collect in sections. At 20°C, collect 1.65L of the first condensate. At 20°C, Collect 4.6L of the second condensate, and remove the remaining 2.95L of still residue for treatment, such as sending it to environmental protection for concentrated incineration.

[0045] Put the second condensate into the absorption bottle, control the temperature at 3°C, and fill the concentrated hydrochloric acid evaporating flask with concentrated hydrochloric acid (concentration of concentrated hydrochloric acid ≥ 31%) with a volume of 1.65 BV of the second condensate, connect the device, and turn on the vacuum After reaching -0.088Mpa, slowly raise the temperature to 48°C (internal temperature), absorb for 1.8h, and check that the concentration of hydrochloric acid in the absorption solution is >31%, then hand over the absorption solution to Synthesis ...

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