U.S. patent application number 15/405292 was filed with the patent office on 2018-07-12 for method for preparing pentachloropyridine by utiilizing dctf rectifying short steaming residues.
This patent application is currently assigned to YANCHENG INSTITUTE OF TECHNOLOGY. The applicant listed for this patent is YANCHENG INSTITUTE OF TECHNOLOGY. Invention is credited to Zhaosheng Cai, Cheng Ding, Denghao Min, Huaihong Zhang, Xuemei Zhu.
Application Number | 20180194728 15/405292 |
Document ID | / |
Family ID | 62749498 |
Filed Date | 2018-07-12 |
United States Patent
Application |
20180194728 |
Kind Code |
A1 |
Cai; Zhaosheng ; et
al. |
July 12, 2018 |
METHOD FOR PREPARING PENTACHLOROPYRIDINE BY UTIILIZING DCTF
RECTIFYING SHORT STEAMING RESIDUES
Abstract
A method for preparing pentachloropyridine by utilizing DCTF
rectifying short steaming residues, comprising the following steps:
converting polymers in the residues through in situ catalytic
cracking and vacuum distillation by using the catalytic degradation
function of a catalyst formed by aluminum oxide, silicon oxide,
zirconia, 4A zeolite, magnesium oxide, mordenite and HZSM-5 zeolite
on the polymers in the DCTF rectifying short steaming residues into
small molecular compounds and obtaining
pentachloropyridine-containing crude oil; washing the
pentachloropyridine-containing crude oil by using an aqueous
solution of an alkaline assistant formed by sodium carbonate,
potassium carbonate, sodium bicarbonate, potassium bicarbonate,
ammonium bicarbonate and sodium hydroxide, carrying out reduced
pressure rectification, refrigerating crystallization, vacuum
filtration or centrifuging separation, solvent washing, and vacuum
drying method sequentially to obtain a pentachloropyridine product
with a mass percentage content greater than 95% at a yield being
1-15% of the mass of the DCTF rectifying short steaming
residues.
Inventors: |
Cai; Zhaosheng; (Yancheng,
CN) ; Min; Denghao; (Yancheng, CN) ; Ding;
Cheng; (Yancheng, CN) ; Zhu; Xuemei;
(Yancheng, CN) ; Zhang; Huaihong; (Yancheng,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
YANCHENG INSTITUTE OF TECHNOLOGY |
Yancheng |
|
CN |
|
|
Assignee: |
YANCHENG INSTITUTE OF
TECHNOLOGY
|
Family ID: |
62749498 |
Appl. No.: |
15/405292 |
Filed: |
January 12, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07D 213/04 20130101;
C07D 213/61 20130101 |
International
Class: |
C07D 213/04 20060101
C07D213/04 |
Claims
1. A method for preparing pentachloropyridine by utilizing DCTF
rectifying short steaming residues, characterized in that the
method comprises the following steps: mixing a catalyst formed by
aluminum oxide, silicon oxide, zirconia, 4A zeolite, magnesium
oxide, mordenite and HZSM-5 zeoliteon with the DCTF rectifying
short steaming residues; converting polymers formed by
chloropyridine compound, chlorofluoropyridine compound and
fluoropyridine compound under high temperature in the DCTF
rectifying short steaming residues into chloropyridine small
molecular compound and fluoropyridine small molecular compound
containing pentachloropyridine, 2,5,6-trichloro-3-(trifluoromethyl)
pyridine, 2,3-dichloro-5-(trichloromethyl) pyridine,
2,3,4,6-tetrachloro-5-(trifluoromethyl) pyridine,
2,3,6-trichloro-5-(dichlorofluoromethyl)pyridine,
2,3,6-trichloro-5-(difluorochloromethyl) pyridine,
5,6-dichloro-3-(hydroxymethyl)pyridine-2-phenol,
2,3-dichloro-5-(dichlorofluoromethyl)pyridine, and
2,3-dichloro-5-(difluorochloromethyl) pyridine through in situ
catalytic cracking and vacuum distillation under a condition of
0.001 MPa.about.0.101 MPa vacuum degree and 100.about.400 DEG C.;
separating polymers difficult to crack formed in rectifying short
steaming process with a reaction material containing DCTF, and
obtaining pentachloropyridine-containing crude oil; washing the
pentachloropyridine-containing crude oil by using an aqueous
solution of 0.01.about.20% of mass fraction of an alkaline
assistant formed by sodium carbonate, potassium carbonate, sodium
bicarbonate, potassium bicarbonate, ammonium bicarbonate and sodium
hydroxide to remove acidic material contained in the
pentachloropyridine-containing crude oil; carrying out reduced
pressure rectification on the alkaline washed
pentachloropyridine-containing crude oil sequentially, collecting
90.about.110 DEG C./100.about.1000 Pa fraction, conducting
refrigerating crystallization, vacuum filtration or centrifuging
separation to realize separation of pentachloropyridine with other
chloropyridine compounds and fluorochloropyridine compounds in the
crude oil and obtaining pentachloropyridine crude product; washing
the obtained pentachloropyridine crude product with a mixed solvent
formed by petroleum ether, diethyl ether isooctane, benzene,
methylbenzene and dimethylbenzene; and conducting vacuum filtration
or centrifuging separation on the washed pentachloropyridine crude
product to obtain a solid pentachloropyridine product, and drying
the obtained solid pentachloropyridine product under a condition of
0.001 Mpa.about.0.101 Mpa vacuum degree and 20 DEG C., and
obtaining pentachloropyridine product with a mass percentage
content greater than 95%.
2. The method for preparing pentachloropyridine by utilizing DCTF
rectifying short steaming residues according to claim 1,
characterized in that a mass ratio of the catalyst formed by
aluminum oxide, silicon oxide, zirconia, 4A zeolite, magnesium
oxide, mordenite and HZSM-5 zeolite is
0.01.about.50:0.01.about.60:0.001.about.10:0.01.about.80:0.001.about.10:0-
.01.about.30:0.01.about.10.
3. The method for preparing pentachloropyridine by utilizing DCTF
rectifying short steaming residues according to claim 1,
characterized in that a mass ratio between the catalyst and DCTF
rectifying short steaming residues is
0.01.about.20:0.01.about.90.
4. The method for preparing pentachloropyridine by utilizing DCTF
rectifying short steaming residues according to claim 1,
characterized in that a mass ratio of the alkaline assistant formed
by sodium carbonate, potassium carbonate, sodium bicarbonate,
potassium bicarbonate, ammonium bicarbonate and sodium hydroxide is
0.01.about.10:0.01.about.8:0.01.about.10:0.01.about.5:0.001.about.8:0.001-
.about.10.
5. The method for preparing pentachloropyridine by utilizing DCTF
rectifying short steaming residues according to claim 1,
characterized in that a mass ratio of the mixed solvent formed by
petroleum ether, diethyl ether isooctane, benzene, methylbenzene
and dimethylbenzene is
0.01.about.100:0.001.about.20:0.001.about.100:0.01.about.50:0.001.about.8-
:0.001.about.10:0.001.about.10.
6. The method for preparing pentachloropyridine by utilizing DCTF
rectifying short steaming residues according to claim 1,
characterized in that the pentachloropyridine product is obtained
at a yield being 1-15% of the mass of the DCTF rectifying short
steaming residues.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for preparing
pentachloropyridine by utilizing DCTF rectifying short steaming
residues, which is a new method for realizing efficient utilization
of recycling of chemical byproducts in preparation of fine organic
chemicals in fine organic synthesis field.
BACKGROUND OF THE PRESENT INVENTION
[0002] DCTF, chemical name 2,3-dichloro-5-(trifluoromethyl)
pyridine, CAS No. 69045-84-7, is a colorless and transparent liquid
with relative density of 1.55 (water is 1.0) under room
temperature. As an important pesticide and medicine intermediate,
DCTF can not only be used for production of fluoric herbicide such
as fluazifop-butyl, haloxyfop-ethoxyethyl and haloxyfop, but also
be widely applied in production of fluorine-containing benzoylurea
pesticides such as fluazuron and chlorfluazuron, insecticides such
as high efficiency fungicide fluazinam and fluorine-containing
medicines. These agricultural chemicals take DCTF as one of raw
materials, which has characteristics of high efficacy and low
toxicity, and distinctive characteristics of low pollution and
environmentally friendly, so DCTF is developed rapidly in more than
a decade.
[0003] Preparation of DCTF mainly includes following methods: (1)
taking 2-amino-5-methylpyridine as raw material, generating
2-amino-3-chloro-5-(trichloromethyl) pyridine by chlorination,
obtaining 2,3-dichloro-5-(trichloromethyl) pyridine by
diazotization and replacing diazo group by hydrogen in the presence
of the catalyst such as Cu2Cl2, and obtaining DCTF by the reaction
of 2,3-dichloro-5-(trichloromethyl) pyridine and hydrogen fluoride
in the presence of the catalyst such as mercuric oxide or mercuric
fluoride; (2) taking 2-chloro-5-methylpyridine as raw material,
carrying out side chain chlorination under photocatalysis to obtain
2-chloro-5-(trichloromethyl) pyridine, carrying out ring
chlorination to obtain 2,3-dichloro-5-(trichloromethyl) pyridine
catalyzed by the catalyst such as lewis acid, and obtaining DCTF by
the reaction of 2,3-dichloro-5-(trichloromethyl) pyridine and
hydrogen fluoride in the presence of the catalyst such as mercuric
oxide or mercuric fluoride; (3) taking 3-methylpyridine as raw
material, generating 3-(trichloromethyl) pyridine by the reaction
with chlorine under photocatalysis, carrying out ring chlorination
to obtain 2,3-dichloro-5-(trichloromethyl) pyridine catalyzed by
the catalyst lewis acid, and obtaining DCTF by the reaction of
2,3-dichloro-5-(trichloromethyl) pyridine and hydrogen fluoride in
the presence of the catalyst such as mercuric oxide or mercuric
fluoride; (4) taking 2-chloro-5-chloromethyl pyridine as raw
material, carrying out photochlorination to generate
2-chloro-5-(trichloromethyl) pyridine, generating
2,3-dichloro-5-(trichloromethyl)pyridine by heat-chlorination
catalyzed by the catalyst such as lewis acid, and obtaining DCTF by
the reaction of 2,3-dichloro-5-(trichloromethyl) pyridine and
hydrogen fluoride in the presence of the catalyst such as mercuric
oxide or mercuric fluoride. Among these methods, the process for
producing DCTF by taking 2-chloro-5-chloromethyl pyridine as raw
material is more widely applied in production of DCTF due to
various advantages such as low raw material cost, high reaction
selectivity and good product quality.
[0004] In the process for producing DCTF by taking
2-chloro-5-chloromethyl pyridine, 3-methylpyridine or
2-chloro-5-methylpyridine as raw material, the reaction material is
obtained by the reaction of 2,3-dichloro-5-(trichloromethyl)
pyridine and hydrogen fluoride in the presence of the catalyst such
as mercuric oxide or mercuric fluoride, the reaction material
should be primarily short steamed to generate short steaming liquid
containing DCTF, and DCTF product is obtained by further rectifying
the obtained short steaming liquid. However, in this process, DCTF
rectifying short steaming residues will be produced. Most of the
substances in these rectifying short steaming residues are
substituted pyridine compound containing multiple halogen atoms and
their polymers in molecular structure, however, they are difficult
to be harmless treated by simple incineration method due to no
combustibility or low combustibility. So how to treat DCTF
rectifying short steaming residues efficiently, realize separation
and purification or conversion of contained substances, reduce
production cost of DCTF and potential pollution and hazardous of
DCTF rectifying short steaming residues on environment, and
increase effective utilization of resources sufficiently have
become an important task of concerns gradually in recent years.
SUMMARY OF PRESENT INVENTION
[0005] A method for preparing pentachloropyridine by utilizing DCTF
rectifying short steaming residues of the invention is to carry out
efficiently treatment on the produced DCTF short steaming residues
in primary steaming before rectifying separation on the reaction
material containing DCTF after fluoridation in the process for
producing 2,3-dichloro-5-(trichloromethyl) pyridine by
photo-chlorination, heat chlorination and fluoridation and prepare
pesticide and medicine intermediate pentachloropyridine by taking
DCTF rectifying short steaming residues as one of basic raw
materials, thereby increasing effective utilization of resources,
reduce production cost of DCTF and potential pollution and
hazardous of DCTF rectifying short steaming residues on
environment.
[0006] The technical scheme of the invention is as follows: adding
a catalyst and DCTF rectifying short steaming residues respectively
into a reactor according to a mass ratio of
0.01.about.20:0.01.about.90 by using the differences in volatility,
solubleness and boiling point between polymers formed by
chloropyridine compound, chlorofluoropyridine compound and
fluoropyridine compound under high temperature in the DCTF
rectifying short steaming residues and chloropyridine compound,
fluoropyridine compound, and chlorofluoropyridine compound as well
as catalytic degradation function of a catalyst formed by aluminum
oxide, silicon oxide, zirconia, 4A zeolite, magnesium oxide,
mordenite and HZSM-5 zeolite according to a mass ratio of
0.01.about.50:0.01.about.60:0.001.about.10:0.01.about.80:0.001.about.10:0-
.01.about.30:0.01.about.10 on the polymers, stirring and converting
polymers formed by chloropyridine compound, chlorofluoropyridine
compound and fluoropyridine compound under high temperature in the
DCTF rectifying short steaming residues through in situ catalytic
cracking and vacuum distillation under a condition of 0.001
MPa.about.0.101 MPa vacuum degree and 100.about.400 DEG C. into
chloropyridine small molecular compound and fluoropyridine small
molecular compound containing pentachloropyridine,
2,5,6-trichloro-3-(trifluoromethyl) pyridine,
2,3-dichloro-5-(trichloromethyl) pyridine,
2,3,4,6-tetrachloro-5-(trifluoromethyl)
pyridine,2,3,6-trichloro-5-(dichlorofluoromethyl) pyridine,
2,3,6-trichloro-5-(difluorochloromethyl) pyridine,
5,6-dichloro-3-(hydroxymethyl) pyridine-2-phenol,
2,3-dichloro-5-(dichlorofluoromethyl) pyridine, and
2,3-dichloro-5-(difluorochloromethyl) pyridine, separating with
polymers difficult to crack formed in rectifying short steaming
process with reaction material containing DCTF, and obtaining crude
oil containing pentachloropyridine;
[0007] washing the pentachloropyridine-containing crude oil by
using an aqueous solution of 0.1% of mass fraction of an alkaline
assistant formed by sodium carbonate, potassium carbonate, sodium
bicarbonate, potassium bicarbonate, ammonium bicarbonate and sodium
hydroxide according to a mass ratio of
0.01.about.10:0.01.about.8:0.01.about.10:0.01.about.5:0.001.about.8:0.001-
.about.10 to remove acidic material contained in the
pentachloropyridine-containing crude oil, carrying out reduced
pressure rectification on the alkaline washed
pentachloropyridine-containing crude oil, collecting 90.about.110
DEG C./100.about.1000 Pa fraction, conducting refrigerating
crystallization, vacuum filtration or centrifuging separation to
realize separation of pentachloropyridine with other chloropyridine
compounds and fluorochloropyridine compounds in the crude oil and
obtaining pentachloropyridine crude product; washing the obtained
pentachloropyridine crude product after vacuum filtration or
centrifuging separation with a mixed solvent formed by petroleum
ether, diethyl ether isooctane, benzene, methylbenzene and
dimethylbenzene according to a mass ratio of
0.01.about.100:0.001.about.20:0.001.about.100:0.01.about.50:0.001.about.8-
:0.001.about.10:0.001.about.10, drying the obtained solid
pentachloropyridine product under a condition of 0.001
MPa.about.0.101 MPa vacuum degree and 10.about.50 DEG C., and
obtaining pentachloropyridine product with a mass percentage
content greater than 95% at a yield being 1.about.15% of the mass
of the DCTF rectifying short steaming residues.
DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a flow diagram of the method for preparing
pentachloropyridine by utilizing DCTF rectifying short steaming
residues.
[0009] FIG. 2 is Fourier Transform infrared spectroscopy (FT-IR)
diagram of pentachloropyridine.
[0010] FIG. 3 is Mass Spectrum (MS) diagram of
pentachloropyridine.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] The invention is further explained in conjunction with the
following embodiments.
Embodiment 1
[0012] Adding 1000 g DCTF rectifying short steaming residues and
100 g catalyst formed by aluminum oxide, silicon oxide, zirconia,
4A zeolite, magnesium oxide, mordenite and HZSM-5 zeolite according
to a mass ratio of 0.01:30:10:20:10:0.01:0.1 into a reactor,
stirring and realizing in situ catalytic cracking and vacuum
distillation of DCTF rectifying short steaming residues under a
condition of 0.01 MPa vacuum degree and 400 DEG C. Converting
polymers formed by chloropyridine compound, chlorofluoropyridine
compound and fluoropyridine compound under high temperature in the
DCTF rectifying short steaming residues into chloropyridine small
molecular compound and fluoropyridine small molecular compound
containing pentachloropyridine,2,5,6-trichloro-3-(trifluoromethyl)
pyridine, 2,3-dichloro-5-(trichloromethyl)
pyridine,2,3,4,6-tetrachloro-5-(trifluoromethyl) pyridine,
2,3,6-trichloro-5-(dichlorofluoromethyl) pyridine,
2,3,6-trichloro-5-(difluorochloromethyl)
pyridine,5,6-dichloro-3-(hydroxymethyl) pyridine-2-phenol,
2,3-dichloro-5-(dichlorofluoromethyl) pyridine, and
2,3-dichloro-5-(difluorochloromethyl) pyridine, separating with
polymers difficult to crack formed in rectifying short steaming
process with reaction material containing DCTF, and obtaining crude
oil containing pentachloropyridine; washing the
pentachloropyridine-containing crude oil by using an aqueous
solution of 0.1% of mass fraction of an alkaline assistant formed
by sodium carbonate, potassium carbonate, sodium bicarbonate,
potassium bicarbonate, ammonium bicarbonate and sodium hydroxide
according to a mass ratio of 0.1:8:0.01:0.5:4:5 to remove acidic
material contained in the pentachloropyridine-containing crude oil,
carrying out reduced pressure rectification on the alkaline washed
pentachloropyridine-containing crude oil, collecting 90.about.110
DEG C./100.about.1000 Pa fraction, conducting refrigerating
crystallization, vacuum filtration or centrifuging separation to
realize separation of pentachloropyridine with other chloropyridine
compounds and fluorochloropyridine compounds in the crude oil and
obtaining a pentachloropyridine crude product; washing the obtained
pentachloropyridine crude product after vacuum filtration or
centrifuging separation with a mixed solvent formed by petroleum
ether, diethyl ether isooctane, benzene, methylbenzene and
dimethylbenzene according to a mass ratio of
0.01:20:0.1:15:0.001:1:0.1, drying the obtained solid
pentachloropyridine product under a condition of 0.08 Mpa vacuum
degree and 30 DEG C., and obtaining a pentachloropyridine product
with a mass percentage content being 96% at a yield being 10% of
the mass of the DCTF rectifying short steaming residues.
Embodiment 2
[0013] Adding 1000 g DCTF rectifying short steaming residues and 50
g catalyst formed by aluminum oxide, silicon oxide, zirconia, 4A
zeolite, magnesium oxide, mordenite and HZSM-5 zeolite according to
a mass ratio of 0.1:2:1:0.1:3:0.1:0.01 into the reactor, stirring
and realizing in situ catalytic cracking and vacuum distillation of
DCTF rectifying short steaming residues under a condition of 0.05
MPa vacuum degree and 350 DEG C. Converting polymers formed by
chloropyridine compound, chlorofluoropyridine compound and
fluoropyridine compound under high temperature in the DCTF
rectifying short steaming residues into chloropyridine small
molecular compound and fluoropyridine small molecular compound
containing pentachloropyridine,2,5,6-trichloro-3-(trifluoromethyl)
pyridine,
2,3-dichloro-5-(trichloromethyl)pyridine,2,3,4,6-tetrachloro-5-(trifluoro-
methyl) pyridine, 2,3,6-trichloro-5-(dichlorofluoromethyl)
pyridine, 2,3,6-trichloro-5-(difluorochloromethyl)
pyridine,5,6-dichloro-3-(hydroxymethyl) pyridine-2-phenol,
2,3-dichloro-5-(dichlorofluoromethyl) pyridine, and
2,3-dichloro-5-(difluorochloromethyl) pyridine, separating with
polymers difficult to crack formed in rectifying short steaming
process with reaction material containing DCTF, and obtaining crude
oil containing pentachloropyridine; washing the
pentachloropyridine-containing crude oil by using an aqueous
solution of 1% of mass fraction of an alkaline assistant formed by
sodium carbonate, potassium carbonate, sodium bicarbonate,
potassium bicarbonate, ammonium bicarbonate and sodium hydroxide
according to a mass ratio of 1:0.8:0.1:5:0.4:0.5 to remove acidic
material contained in the pentachloropyridine-containing crude oil,
carrying out reduced pressure rectification on the alkaline washed
pentachloropyridine-containing crude oil, collecting 90.about.110
DEG C./100.about.1000 Pa fraction, conducting refrigerating
crystallization, vacuum filtration or centrifuging separation to
realize separation of pentachloropyridine with other chloropyridine
compounds and fluorochloropyridine compounds in the crude oil and
obtaining a pentachloropyridine crude product; washing the obtained
pentachloropyridine crude product after vacuum filtration or
centrifuging separation with a mixed solvent formed by petroleum
ether, diethyl ether isooctane, benzene, methylbenzene and
dimethylbenzene according to a mass ratio of 100:10:0.1:3:8:10:10,
drying the obtained solid pentachloropyridine product under a
condition of 0.10 Mpa vacuum degree and 30 DEG C., and obtaining a
pentachloropyridine product with a mass percentage content being
98.7% at a yield being 1% of the mass of the DCTF rectifying short
steaming residues.
Embodiment 3
[0014] Adding 1000 g DCTF rectifying short steaming residues and 10
g catalyst formed by aluminum oxide, silicon oxide, zirconia, 4A
zeolite, magnesium oxide, mordenite and HZSM-5 zeolite according to
a mass ratio of 1:0.2:1:0.01:15:10:10 into the reactor, stirring
and realizing in situ catalytic cracking and vacuum distillation of
DCTF rectifying short steaming residues under a condition of 0.09
MPa vacuum degree and 300 DEG C. Converting polymers formed by
chloropyridine compound, chlorofluoropyridine compound and
fluoropyridine compound under high temperature in the DCTF
rectifying short steaming residues into chloropyridine small
molecular compound and fluoropyridine small molecular compound
containing pentachloropyridine,2,5,6-trichloro-3-(trifluoromethyl)
pyridine, 2,3-dichloro-5-(trichloromethyl)
pyridine,2,3,4,6-tetrachloro-5-(trifluoromethyl) pyridine,
2,3,6-trichloro-5-(dichlorofluoromethyl) pyridine,
2,3,6-trichloro-5-(difluorochloromethyl)
pyridine,5,6-dichloro-3-(hydroxymethyl) pyridine-2-phenol,
2,3-dichloro-5-(dichlorofluoromethyl) pyridine, and
2,3-dichloro-5-(difluorochloromethyl) pyridine, separating with
polymers difficult to crack formed in rectifying short steaming
process with reaction material containing DCTF, and obtaining crude
oil containing pentachloropyridine; washing the
pentachloropyridine-containing crude oil by using an aqueous
solution of 5% of mass fraction of an alkaline assistant formed by
sodium carbonate, potassium carbonate, sodium bicarbonate,
potassium bicarbonate, ammonium bicarbonate and sodium hydroxide
according to a mass ratio of 10:0.01:10:5:4:10 to remove acidic
material contained in the pentachloropyridine-containing crude oil,
carrying out reduced pressure rectification on the alkaline washed
pentachloropyridine-containing crude oil, collecting 90.about.110
DEG C./100.about.1000 Pa fraction, conducting refrigerating
crystallization, vacuum filtration or centrifuging separation to
realize separation of pentachloropyridine with other chloropyridine
compounds and fluorochloropyridine compounds in the crude oil and
obtaining a pentachloropyridine crude product; washing the obtained
pentachloropyridine crude product after vacuum filtration or
centrifuging separation with a mixed solvent formed by petroleum
ether, diethyl ether isooctane, benzene, methylbenzene and
dimethylbenzene according to a mass ratio of
100:0.02:30:50:4:0.5:10, drying the obtained solid
pentachloropyridine product under a condition of 0.09 Mpa vacuum
degree and 20 DEG C., and obtaining a pentachloropyridine product
with a mass percentage content being 98% at a yield being 5% of the
mass of the DCTF rectifying short steaming residues.
Embodiment 4
[0015] Adding 1000 g DCTF rectifying short steaming residues and 5
g catalyst formed by aluminum oxide, silicon oxide, zirconia, 4A
zeolite, magnesium oxide, mordenite and HZSM-5 zeolite according to
a mass ratio of 30:60:0.01:40:3:15:10 into the reactor, stirring
and realizing in situ catalytic cracking and vacuum distillation of
DCTF rectifying short steaming residues under a condition of 0.09
MPa vacuum degree and 300 DEG C. Converting polymers formed by
chloropyridine compound, chlorofluoropyridine compound and
fluoropyridine compound under high temperature in the DCTF
rectifying short steaming residues into chloropyridine small
molecular compound and fluoropyridine small molecular compound
containing pentachloropyridine,2,5,6-trichloro-3-(trifluoromethyl)
pyridine, 2,3-dichloro-5-(trichloromethyl)
pyridine,2,3,4,6-tetrachloro-5-(trifluoromethyl) pyridine,
2,3,6-trichloro-5-(dichlorofluoromethyl) pyridine,
2,3,6-trichloro-5-(difluorochloromethyl)
pyridine,5,6-dichloro-3-(hydroxymethyl) pyridine-2-phenol,
2,3-dichloro-5-(dichlorofluoromethyl) pyridine, and
2,3-dichloro-5-(difluorochloromethyl) pyridine, separating with
polymers difficult to crack formed in rectifying short steaming
process with reaction material containing DCTF, and obtaining crude
oil containing pentachloropyridine; washing the
pentachloropyridine-containing crude oil by using an aqueous
solution of 10% of mass fraction of an alkaline assistant formed by
sodium carbonate, potassium carbonate, sodium bicarbonate,
potassium bicarbonate, ammonium bicarbonate and sodium hydroxide
according to a mass ratio of 10:4:5:5:3:10 to remove acidic
material contained in the pentachloropyridine-containing crude oil,
carrying out reduced pressure rectification on the alkaline washed
pentachloropyridine-containing crude oil, collecting 90.about.110
DEG C./100.about.1000 Pa fraction, conducting refrigerating
crystallization, vacuum filtration or centrifuging separation to
realize separation of pentachloropyridine with other chloropyridine
compounds and fluorochloropyridine compounds in the crude oil and
obtaining a pentachloropyridine crude product; washing the obtained
pentachloropyridine crude product after vacuum filtration or
centrifuging separation with a mixed solvent formed by petroleum
ether, diethyl ether isooctane, benzene, methylbenzene and
dimethylbenzene according to a mass ratio of
100:0.02:0.01:50:4:0.01:5, drying the obtained solid
pentachloropyridine product under a condition of 0.09 Mpa vacuum
degree and 20 DEG C., and obtaining a pentachloropyridine product
with a mass percentage content being 98.5% at a yield being 3% of
the mass of the DCTF rectifying short steaming residues.
Embodiment 5
[0016] Adding 1000 g DCTF rectifying short steaming residues and 3
g catalyst formed by aluminum oxide, silicon oxide, zirconia, 4A
zeolite, magnesium oxide, mordenite and HZSM-5 zeolite according to
a mass ratio of 50:30:0.1:37:5:18:9 into the reactor, stirring and
realizing in situ catalytic cracking and vacuum distillation of
DCTF rectifying short steaming residues under a condition of 0.098
MPa vacuum degree and 260 DEG C. Converting polymers formed by
chloropyridine compound, chlorofluoropyridine compound and
fluoropyridine compound under high temperature in the DCTF
rectifying short steaming residues into chloropyridine small
molecular compound and fluoropyridine small molecular compound
containing pentachloropyridine,2,5,6-trichloro-3-(trifluoromethyl)
pyridine, 2,3-dichloro-5-(trichloromethyl)
pyridine,2,3,4,6-tetrachloro-5-(trifluoromethyl) pyridine,
2,3,6-trichloro-5-(dichlorofluoromethyl) pyridine,
2,3,6-trichloro-5-(difluorochloromethyl)
pyridine,5,6-dichloro-3-(hydroxymethyl) pyridine-2-phenol,
2,3-dichloro-5-(dichlorofluoromethyl) pyridine, and
2,3-dichloro-5-(difluorochloromethyl) pyridine, separating with
polymers difficult to crack formed in rectifying short steaming
process with reaction material containing DCTF, and obtaining crude
oil containing pentachloropyridine; washing the
pentachloropyridine-containing crude oil by using an aqueous
solution of 15% of mass fraction of an alkaline assistant formed by
sodium carbonate, potassium carbonate, sodium bicarbonate,
potassium bicarbonate, ammonium bicarbonate and sodium hydroxide
according to a mass ratio of 9:8:7:5:8:10 to remove acidic material
contained in the pentachloropyridine-containing crude oil, carrying
out reduced pressure rectification on the alkaline washed
pentachloropyridine-containing crude oil, collecting 90.about.110
DEG C./100.about.1000 Pa fraction, conducting refrigerating
crystallization, vacuum filtration or centrifuging separation to
realize separation of pentachloropyridine with other chloropyridine
compounds and fluorochloropyridine compounds in the crude oil and
obtaining pentachloropyridine crude product; washing the obtained
pentachloropyridine crude product after vacuum filtration or
centrifuging separation with the mixed solvent formed by petroleum
ether, diethyl ether isooctane, benzene, methylbenzene and
dimethylbenzene according to a mass ratio of
100:0.02:0.01:50:4:0.01:5, drying the obtained solid
pentachloropyridine crude product under a condition of 0.09 Mpa
vacuum degree and 20 DEG C., and obtaining pentachloropyridine
product with the mass percentage content being 98.5% at a yield
being 3% of the mass of the DCTF rectifying short steaming
residues.
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