FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. Title of the Invention
A METHOD FOR PRODUCING METHYL ACETATE
2. Applicant(s)
Name Nationality Address
DALIAN INSTITUTE OF CHEMICAL
PHYSICS, CHINESE ACADEMY OF
SCIENCES
Chinese No.457 Zhongshan Road, Shahekou
Dalian City, Liaoning Province 116023,
China
3. Preamble to the description
The following specification particularly describes the invention and the manner in which it is to be performed
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A method for producing methyl acetate
Technical Field
The present invention refers to a method for producing methyl acetate and the derivatives
thereof by carbonylation of dimethyl ether.
Background
Accompanied with the rapid development of the modern industry, the confliction between
supplying and demanding of energy has become increasingly acute. China is a major energy
consumer and meanwhile a major country of energy shortage with an urgent desire for
searching replaceable energy sources. Ethanol is a clean energy source with a good mutual
solubility which can be used as blending component added into gasoline, to partially replace
gasoline and improve the octane number and the oxygen content of gasoline. It can also
promote gasoline burning sufficiently and decrease the emission of carbon monoxide and
hydrocarbons in vehicle exhaust. As a partial replacement of vehicle fuel, ethanol may make
the vehicle fuel in China more diversified. Currently, in China cereals, especially corns, has
mostly been used as a raw material to manufacture fuel ethanol. China has become the third
largest country of ethanol producing and consuming, after Brazil and America. However,
according to Chinese national condition, there are many unfavorable factors using cereals as
raw material to produce ethanol. In the future, non-cereal routes for producing ethanol will be
developed preferably in China.
Started with coal resources, producing ethanol via syngas is an important direction to
develope coal chemical engineering industry in China with a broad market prospect. It has
great strategic meanings and far-reaching impacts on clean utilization of coal resources,
relieving the pressure of lacking oil resources and enhancing energy security in our country.
Currently, there are mainly two process routes of preparing ethanol from coal, one of which is
preparing ethanol from syngas directly. However, a precious metal, rhodium, is needed to
serve as the catalyst in this route, so the cost of the catalyst is relatively high. Moreover, the
output of rhodium is limited. The other route is preparing ethanol from syngas through
hydrogenation of acetic acid, in which acetic acid is preformed by liquid phase methanol
carbonylation from the syngas, and then converts to ethanol by hydrogenation. The second
route is mature, but the device used in this route needed to be made of special alloy which is
anticorrosive, so the cost is high.
Using dimethyl ether as raw material, methyl acetate can be directly synthetized by
carbonylation of dimethyl ether, and methyl acetate can be hydrogenated to ethanol. Although
the route is still in research stage, it is a brand new route with great application prospect. In
1983, Fujimoto (Appl Catal 1983, 7 (3), 361-368) used Ni/Ac as catalyst to carry out a
gas-solid phase reaction of dimethyl ether carbonylation. It was discovered that dimethyl
ether can react with CO to generate methyl acetate when the molar ratio of CO/DME is in a
range from 2.4 to 4, with selectivity in a range from 80% to 92% and the highest yield of 20%.
In 1994, Wegman (J Chem Soc Chem Comm 1994, (8), 947-948) carried out a dimethyl ether
carbonylation reaction using heteropolyacid RhW12PO4/SiO2 as the catalyst. The yield of
methyl acetate was 16% and nearly no other side products were generated. In 2002, Russian
researchers, Volkova and her colleagues (Catalysis Letters 2002, 80 (3-4), 175-179) used a
cesium phosphotungstate modified Rh as catalyst to carry out the carbonylation reaction of
dimethyl ether and the reaction rate is an order of magnitude higher than the Wegman’s
reaction using RhW12PO4/SiO2 as catalyst.
In 2006, Enrique Iglesia’s research group in Berkeley (Angew. Chem, Int. Ed. 45(2006) 10,
1617-1620, J. Catal. 245 (2007) 110, J. Am. Chem. Soc. 129 (2007) 4919) carried out
dimethyl ether carbonylation on the molecular sieves with 8 membered ring and 12 membered
ring or 10 membered ring, such as Mordenite and Ferrierite. As a result, it was considered that
the carbonylation reaction happenes on the B acid active center of 8 membered ring. The
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selectivity of methyl acetate was quite good, reaching 99%, but the activity of dimethyl ether
carbonylation is very low.
American application US2007238897 disclosed that using molecular sieves with 8 membered
ring pore structure, such as MOR, FER and OFF, as catalyst for the carbonylation of ethers,
the pore size of the 8 membered ring should be larger than 0.25×0.36 nm. Using mordenite as
catalyst under the reaction conditions of 165 oC and 1 MPa, a space-time yield of
0.163-MeOAc(g-Cat.h)-1 was achieved. WO2008132450A1 (2008) disclosed a MOR catalyst
modified by copper and silver, whose performance is obviously better than unmodified MOR
catalyst, on reaction conditions of hydrogen atmosphere and temperature ranging from 250 oC
to 350 oC. WO2009081099A1 disclosed that the carbonylation performance of MOR catalyst
with smaller grains is better than MOR catalyst with bigger grains. WO2010130972A2
disclosed an MOR catalyst treated by desilication and dealuminzation, and the activity and
the reaction stability of the MOR catalyst can be significantly enhanced by an optimized
combination of acid treatment and alkali treatment. Moreover, CN103896769A disclosed a
method for preparing methyl acetate by carbonylation of dimethyl ether, in which mordenite
and/or ferrierite were used as the catalyst. CN101903325A disclosed a carbonylation process
of preparing acetic acid and/or methyl acetate in which the molecular sieves with MOR
framework structure were used as the catalyst. Wang Donghui (“Application of a
cocrystallization molecular sieve catalyst in preparing methyl acetate by carbonylation of
dimethyl ether”, Chemical Production and Techniques (2013), No.3, Vol 20, 14-18) disclosed
an application of a cocrystallization molecular sieve catalyst in preparing methyl acetate by
carbonylation of dimethyl ether, in which the catalyst was a cocrystallization molecular sieve
containing 2 phases of BEA/MOR. And cocrystallization molecular sieve containing 2 phases
of EMT/FAU was mentioned in the first paragraph, without being used for carbonylation of
dimethyl ether to methyl acetate. CN102950018A disclosed the reaction data of dimethyl
ether carbnylation on a cocrystallization molecular sieve of rare earth ZSM-35/MOR. The
results show that the activity and stability of cocrystallization molecular sieve was
significantly better than ZSM-35 catalyst, and the stability of cocrystallization molecular
sieve was significantly better than MOR catalyst. Xu Longya and his colleagues (RSC Adv.
2013,3:16549-16557) also reported the reaction properties of ZSM-35 treated by alkali in
carbonylation of dimethyl ether. The results show that after being treated by alkali, ZSM-35
has an apparent mesoporous structure, enhancing the diffusion effects of reactants and
products on the catalyst, and the stability and activity of the catalyst was improved.
In CN101613274A, pyridine organic amines were used to modify mordenite molecular sieve
catalyst, and it was discovered that the modification of molecular sieve can dramatically
enhance the stability of catalyst. The percent conversion of dimethyl ether was in a range
from 10% to 60%, and the selectivity of methyl acetate was over 99%. Moreover, the activity
of the catalyst remained stable after reacting for 48 h. Shen Wenjie (Catal. Lett. 2010,
139:33-37) and his colleagues made a research on preparing methyl acetate by carbonylation
of dimethyl ether, comparing the reaction activity on MOR and ZSM-35 catalyst. It was
discovered that ZSM-35 molecular sieve has better reaction stability and products selectivity,
and under the reaction conditions of 250 ℃、1 MPa，DME/CO/N2/He = 5/50/2.5/42.5 and
12.5 mL/min, the percent conversion of dimethyl ether could reach 11%, and the selectivity of
methyl acetate could reach 96%.
The above references has disclosed a lot of research results on dimethyl ether carbonylation,
and research on the catalyst has mainly focused on MOR, FER, and the like with a structure
of 8 membered ring. In the results reported publicly, those catalysts are very easy to become
inactivated with catalyst life of less than 100 h. And additionally, the reaction results cannot
meet the requirement of industrial production.
Summary of the Invention
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The purpose of the present invention is to provide a new method for producing methyl
acetate.
The inventors of the present invention found that the carbonylation reaction of low alkyl ether
is a typical acid catalyzed reaction, and the acidity and pore structure property of the catalyst
have a decisive influence on the carbonylation performance of the catalyst. EMT zeolite
belongs to the hexagonal system, the space group of P63/mmc with the cell parameters of
a=b=1.7374 nm and c=2.8365 nm, and the framework density of 12.9 T/nm3
. Its framework
structure is a simple hexagonal analogue of faujasite zeolite FAU, composed of 12 membered
rings, 6 membered rings and 4 membered rings. As a zeolite with a better topology structure
than FAU, it has a stronger acidity and a bigger acid quantity. At the same time, EMT has two
sets of intersecting cavities which are connected by 2 dimensional cross channels. Its superior
pore connectivity is more conducive to the adsorption of reactants and the diffusion of
product molecules.
Therefore, the present invention provides a method for producing methyl acetate, which
comprises a step carrying out a carbonylation reaction of dimethyl ether and a raw gas
containing carbon monoxide in the presence of a catalyst containing an acidic EMT zeolite
molecular sieve.
In a preferred embodiment, the molar ratio of silicon atoms to aluminum atoms in the acidic
EMT zeolite molecular sieve is in a range from 1.5 to 30. Preferably, the molar ratio of silicon
atoms to aluminum atoms in the acidic EMT zeolite molecular sieve is in a range from 2 to
15.
In a preferred embodiment, the acidic EMT zeolite molecular sieve contains a catalyst
promoter which is one or more metals selected from gallium, iron, copper and silver.
Preferably, the catalyst promoter is introduced to the acidic EMT zeolite molecular sieve by a
method selected from in-situ synthesis, metal ion exchange or impregnation loading.
Preferably, based on the total weight of the catalyst, the weight fraction of the catalyst
promoter calculated by weight of metal elementary substance is in a range from 0.01 wt% to
10 wt%. More preferably, based on the total weight of the catalyst, the weight fraction of the
catalyst promoter calculated by weight of metal elementary substance is in a range from 0.05
wt% to 1.0 wt%
In a preferred embodiment, the acidic EMT zeolite molecular sieve contains a binder which is
one or more compounds selected from alumina, silicon dioxide and magnesium oxide.
Preferably, based on the total weight of the catalyst, the weight fraction of the binder is in a
range from 0 wt% to 50 wt%.
In a preferred embodiment, the carbonylation reaction is carried out at a temperature range
from 160 ℃ to 250 ℃ and at a pressure range from 0.5 MPa to 20.0 MPa, and the feeding
mass space velocity of dimethyl ether is in a range from 0.05 h
-1
to 3 h
-1
, and the molar ratio
of carbon monoxide to dimethyl ether is in a range from 20:1 to 0.5:1.
In a preferred embodiment, the carbonylation reaction is carried out at a temperature range
from 170 ℃ to 240 ℃ and at a pressure range from 1.0 MPa to 15.0 MPa, and the feeding
mass space velocity of dimethyl ether is in a range from 0.1 h
-1
to 2.5 h
-1
, and the molar ratio
of carbon monoxide to dimethyl ether is in a range from 15:1 to 1:1.
In a preferred embodiment, the raw gas containing carbon monoxide contains carbon
monoxide, hydrogen and one or more inactive gases selected from nitrogen, helium, argon,
carbon dioxide, methane and ethane. Preferably, based on the total volume of the raw gas
containing carbon monoxide, the volume fraction of carbon monoxide is in a range from 50 %
to 100 %, and the volume fraction of hydrogen is in a range from 0 % to 50 %, and the
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volume fraction of the inert gas is in a range from 0 % to 50%.
In a preferred embodiment, the methyl acetate is hydrolyzed to acetic acid.
In a preferred embodiment, the methyl acetate is hydrogenated to ethyl alcohol.
In a preferred embodiment, the carbonylation reaction is carried out in a fixed bed reactor, a
fluidized bed reactor or a moving bed reactor.
The present invention provides a new method for producing methyl acetate. In the method of
the present invention, the carbonylation is carried out in the presence of the catalyst
containing the acidic EMT zeolite molecular sieve, and the reaction activity is high, and the
stability has been significantly improved, meeting the requirement of industrial production.
Detailed Description of the Embodiment
The present invention provides a method for synthesizing methyl acetate, which comprises a
step carrying out a carbonylation reaction of dimethyl ether and a raw gas containing carbon
monoxide and hydrogen on a catalyst containing an acidic EMT zeolite molecular sieve.
Preferably, the carbonylation reaction is carried out at a temperature range from 160 ℃ to
250 ℃ and at a pressure range from 0.5 MPa to 20.0 MPa, and the feeding mass space
velocity of dimethyl ether is in a range from 0.05 h
-1
to 3 h
-1
, and the molar ratio of carbon
monoxide to dimethyl ether is in a range from 20:1 to 0.5:1. More preferably, the feeding
mass space velocity of dimethyl ether is in a range from 0.1 h
-1
to 2.5 h
-1
, and the molar ratio
of carbon monoxide to dimethyl ether is in a range from 15:1 to 1:1, and the reaction
temperature is in a range from 170 ℃ to 240 ℃, and the reaction pressure is in a range from
1.0 MPa to 15.0 MPa.
Preferably, the molar ratio of silicon atoms to aluminum atoms in the acidic EMT zeolite
molecular sieve used in the present invention is in a range from 1.5 to 30. Preferably, the
molar ratio of silicon atoms to aluminum atoms in the acidic EMT zeolite molecular sieve of
the present invention is in a range from 2 to 15.
Preferably, the acidic EMT zeolite molecular sieve used in the present invention contains a
catalyst promoter which is one or more metals selected from gallium, iron, copper and silver
(which may exist in the form of metal elementary substance or metal compounds such as
metal oxides). For instance, the catalyst promoter is introduced to the acidic EMT zeolite
molecular sieve by a method selected from in-situ synthesis, metal ion exchange or
impregnation loading. Preferably, based on the total weight of the catalyst, the weight fraction
of the catalyst promoter calculated by weight of metal elementary substance is in a range from
0.01 wt% to 10 wt%. More preferably, the weight fraction of the catalyst promoter calculated
by weight of metal elementary substance is in a range from 0.05 wt% to 1.0 wt%.
Preferably, the acidic EMT molecular sieve used in the present invention contains a binder
which is one or more compounds selected from alumina, silicon dioxide and magnesium
oxide. Preferably, the weight fraction of the binder in the total weight of the catalyst is in a
range from 0 wt% to 50 wt%.
Preferably, the raw gas containing carbon monoxide used in the present invention contains
carbon monoxide, hydrogen and one or more inactive gases selected from nitrogen, helium,
argon, carbon dioxide, methane and ethane. Preferably, based on the total volume of the raw
gas containing carbon monoxide, the volume fraction of carbon monoxide is in a range from
50 % to 100 %, and the volume fraction of hydrogen is in a range from 0 % to 50 %, and the
volume fraction of the inert gas is in a range from 0 % to 50%.
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Preferably, the carbonylation reaction in the present invention is carried out in a fixed bed reactor,
a fluidized bed reactor or a moving bed reactor.
Examples
The present invention will be described in details by Examples, but the present invention is
not limited to these Examples.
In the examples, the calculation of percent conversion of dimethyl ether and selectivity of
methyl acetate was based on the carbon mole number:
Percent conversion of dimethyl ether = [(the carbon mole number of dimethyl ether in the
feed gas) - (the carbon mole number of dimethyl ether in the product)] ÷(the carbon mole
number of dimethyl ether in the feed gas) × (100%)
Selectivity of methyl acetate = (2/3) × (the carbon mole number of methyl acetate in the
product) ÷[(the carbon mole number of dimethyl ether in the feed gas) - (the carbon mole
number of dimethyl ether in the product)] ×(100%)
Four samples of Na-EMT zeolite molecular sieve whose molar ratios of silicon atom to
aluminum atom respectively are 2, 4, 15 and 25, a sample of Na-EMT zeolite molecular sieve
containing Ga whose molar ratio of silicon atom to aluminum is 4, and a sample of Na-EMT
zeolite molecular sieve containing Fe whose molar ratio of silicon atom to aluminum is 4
have been used in the Examples. All of them were produced and provided by Dalian Institute
of Chemical Physics.
Examples for preparing the catalyst
H-EMT Catalyst
100 g of a sample of Na-EMT zeolite molecular sieve was exchanged with 0.5 mol/L of
ammonium nitrate for three times and each time was for 2 hours. And then the solid product
was washed with deionized water, dried, calcined at 550 °C for 4 h, pressed, crushed and
sieved to 20-40 mesh used as the catalyst sample. Four samples of Na-EMT zeolite molecular
sieve with molar ratios of silicon atom to aluminum atom of 2, 4, 15 and 25 were used, to
obtain the samples of Catalyst 1#, Catalyst 2#, Catalyst 3# and Catalyst 4#, respectively.
Ga-EMT Catalyst
100 g of the sample of Na-EMT zeolite molecular sieve containing Ga (the molecular ratio of
silicon atom to aluminum is 4) was exchanged with 0.5 mol/L of ammonium nitrate for three
times and each time was for 2 hours. And then the solid product was washed with deionized
water, dried, calcined at 550 °C for 4 h, pressed, crushed and sieved to 20-40 mesh to obtain
the sample of Catalyst 5#.
Fe-EMT Catalyst
100 g of the sample of Na-EMT zeolite molecular sieve containing Fe (the molecular ratio of
silicon atom to aluminum is 4) was exchanged with 0.5 mol/L of ammonium nitrate for three
times and each time was for 2 hours. And then the solid product was washed with deionized
water, dried, calcined at 550 °C for 4 h, pressed, crushed and sieved to 20-40 mesh to obtain
the sample of Catalyst 6#.
Supported Catalyst of M/EMT
The supported catalyst of M/EMT was prepared using equivalent-volume impregnation
method. 4.32 g of Fe(NO3)3, 4.32 g of Cu(NO3)2·3H2O and 3.04 g of AgNO3·3H2O were
respectively dissolved in 18 mL of deionized water to form the Fe(NO3)3 aqueous solution,
Cu(NO3)2 aqueous solution and AgNO3 aqueous solution. 20 g of Catalyst 2# (H-EMT zeolite
molecular sieve catalyst) was added into the Fe(NO3)3 aqueous solution, Cu(NO3)2 aqueous
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solution and AgNO3 aqueous solution, respectively. After standing for 24 hours, the solid
products were separated by filtration, washed by deionized water, dried in the oven at 120 ℃
for 12 hours, and then the samples obtained were put into a muffle furnace whose temperature
was heated to 550℃ at a heating rate of 2 °C/min, calcined at 550 °C in air for 4 h to obtain
the samples of Catalyst 7#, Catalyst 8# and Catalyst 9#.
Ion Exchange Catalyst of M-EMT
20 g of Catalyst 2# (H-EMT zeolite molecular sieve catalyst) and 300 mL of 0.15 mol ferric
nitrate aqueous solution were placed in a flask, being stirred for 2 hours at 80℃ under the
condition of cooling and refluxing with solid-liquid ratio of 1:15. The solid product was
separated by filtration and washed by deionized water. Repeating the above steps for 2 times,
the sample obtained was dried at 120℃ for 12 hours, and the dried sample was put into a
muffle furnace whose temperature was heated to 550℃ at a heating rate of 2 °C/min, calcined
at 550 °C in air for 4 h to obtain the sample of Catalyst 10#.
Molded Catalyst of H-EMT
80 g of Na-EMT zeolite molecular sieve with molar ratio of silicon atom to aluminum of 4, 28
g of pseudo-boehmite and 10 % of diluted nitric acid were uniformly mixed, and then the
mixture was molded through extrusion. After being calcined at 550 ℃ for 4 hours, the molded
sample was exchanged with 0.5 mol/L of ammonium nitrate for three times (2 hours/time).
And then the solid product was washed by deionized water, dried, calcined at 550 °C for 4 h
to obtain the sample of Catalyst 11#.
80 g of Na-EMT zeolite molecular sieve with molar ratio of silicon atom to aluminum of 4, 20
g of magnesium oxide and 10 % of diluted nitric acid were uniformly mixed, and then the
mixture was molded through extrusion. After being calcined at 550 ℃ for 4 hours, the molded
sample was exchanged with 0.5 mol/L of ammonium nitrate for three times and each time was
for 2 hours. And then the solid product was washed by deionized water, dried, calcined at
550 °C for 4 h to obtain the sample of Catalyst 12#.
80 g of Na-EMT zeolite molecular sieve with molar ratio of silicon atom to aluminum of 4, 50
g of silicon sol and 10 % of diluted nitric acid were uniformly mixed, and then the mixture
was molded through extrusion. After being calcined at 550 ℃ for 4 hours, the molded sample
was exchanged with 0.5 mol/L of ammonium nitrate for three times (2 hours/time). And then
the solid product was washed by deionized water, dried, calcined at 550 °C for 4 h to obtain
the sample of Catalyst 13#.
Examples of synthesis
Comparative Example
H-MOR (molar ratio of silicon atom to aluminum atom Si/Al=6.7) was used as a comparative
catalyst. 10 g of the comparative catalyst was put into a tubular fixed bed reactor with inner
diameter of 28 mm, and then was heated to 550 ℃ at a heating rate of 5℃/min under nitrogen
gas. After being kept at 550 ℃ for 4 hours, the temperature was reduced to the reaction
temperature of 190 ℃ in nitrogen gas, and then the pressure was increased to the reaction
pressure of 5 MPa by introducing CO. The space velocity of feeding dimethyl ether was 0.10
h
-1
, and the molar ratio of carbon monoxide to dimethyl ether was 6:1, and the molar ratio of
carbon monoxide to hydrogen in the raw gas containing carbon monoxide was 2:1. The
results at the reaction times when the catalytic reaction ran on for 1 h, 50 h and 100 h, are
shown in Table 1.
Table 1: Results of the comparative catalyst
Time on stream (h) 1 50 100
Percent conversion of dimethyl ether (%) 35.7 23.8 9.8
Selectivity of methyl acetate (%) 99.8 78.2 25.3
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Example 1
According to Table 2, 10 g of the catalyst was put into a tubular fixed bed reactor with inner
diameter of 28 mm, and then was heated to 550 ℃ at a heating rate of 5℃/min under nitrogen
gas. After being kept at 550 ℃ for 4 hours, the temperature was reduced to the reaction
temperature of 190 ℃ in nitrogen gas, and then the pressure was increased to the reaction
pressure of 5 MPa by introducing CO. The raw material went through the catalyst bed from
top to bottom. The space velocity of feeding dimethyl ether was 0.10 h-1
, and the molar ratio
of dimethyl ether to carbon monoxide was 1:6, and the molar ratio of carbon monoxide to
hydrogen in the raw gas containing carbon monoxide was 2:1, and the reaction temperature
was 190 ℃. The results at the reaction time when the catalytic reaction ran on for 100 h are
shown in Table 2.
Table 2: Evaluation results of catalyst for dimethyl ether carbonylation
Catalyst Percent conversion of dimethyl ether ether (%) Selectivity of methyl acetate (%)
1# 7.5 95.3
2# 17.5 95.3
3# 23.5 97.7
4# 24.5 96.3
5# 27.5 91.6
6# 31.5 91.6
7# 24.5 91.6
8# 25.3 91.6
9# 24.2 91.6
10# 26.8 91.6
11# 17.5 98.3
12# 15.5 97.3
13# 14.2 97.3
Example 2
Reaction results of dimethyl ether carbonylation at different reaction temperatures
10 g of Catalyst 3# was used. The reaction temperatures were 70 ℃, 210 ℃ and 240 ℃,
respectively, and other experimental conditions were same as Example 1. The results at the
reaction time when the catalytic reaction ran on for 100 h are shown in Table 3.
Table 3: Reaction results at different reaction temperatures
Inlet temperature of reactor (℃) 170 200 230 240
Percent conversion of dimethyl ether (%) 15.7 42.1 76.0 87.8
Selectivity of methyl acetate (%) 97.8 99.7 94.5 90.4
Example 3
Reaction results of dimethyl ether carbonylation at different reaction pressures
The Catalyst 4# was used. The reaction pressures were 1 MPa, 6 MPa, 10 MPa and 15 MPa,
respectively, and the reaction temperature was 190 ℃, and other experimental conditions
were same as Example 1. The results at the reaction time when the catalytic reaction ran on
for 100 h are shown in Table 4.
Table 4: Reaction results at different reaction pressures
Reaction pressure (MPa) 1 6 10 15
Percent conversion of dimethyl ether (%) 18.3 29.3 41.8 52.3
Selectivity of methyl acetate (%) 98.7 99.1 99.4 99.8
Example 4
Reaction results of dimethyl ether carbonylation at different space velocities of dimethyl
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ether
The Catalyst 6# was used. The space velocities of dimethyl ether were 0.25 h
-1
, 1 h
-1
and 2h-1
,
respectively, and the reaction temperature was 190 ℃, and other experimental conditions
were same as Example 1. The results at the time on stream of 100 h are shown in Table 5.
Table 5: Reaction results at different space velocities of dimethyl ether
Space velocity of dimethyl ether (h-1
) 0.25 1 2
Percent conversion of dimethyl ether (%) 18.3 14.3 10.8
Selectivity of methyl acetate (%) 99.7 99.1 97.9
Example 5
Reaction results of dimethyl ether carbonylation under different molar ratio of carbon
monoxide to dimethyl ether
The Catalyst 5# was used. The molar ratios of carbon monoxide to dimethyl ether were 12:1,
8:1, 4:1 and 2:1, respectively, and the reaction temperature was 190 ℃, and other
experimental conditions were same as Example 1. The results at the reaction time when the
catalytic reaction ran on for 100 h are shown in Table 6.
Table 6: Reaction results under different molar ratio of dimethyl ether to carbon monoxide
Mole ratio of carbon monoxide /dimethyl ether 12 8 4 2
Percent conversion of dimethyl ether (%) 40.6 31.7 16.7 11.7
Selectivity of methyl acetate (%) 97.8 98.1 99.5 99.4
Example 6
Reaction results of dimethyl ether carbonylation when the raw gas containing carbon
monoxide also contains an inactive gas
The Catalyst 9# was used. The molar ratios of carbon monoxide to hydrogen was12 and 1.5,
respectively, and the space velocities of dimethyl ether was 0.1 h
-1
, and the molar ratio of
dimethyl ether to carbon monoxide was 1:9, and the reaction temperature was 190 ℃, and
other experimental conditions were same as Example 1. The results at the reaction time when
the catalytic reaction ran on for 200 h are shown in Table 7.
Table 7: Reaction results of dimethyl ether on H-EMT catalyst when the raw gas containing
carbon monoxide also contains an inactive gas
Volume fraction of
inert gas
Volume fraction of
CO
Percent conversion
of dimethyl ether
(%)
Selectivity of methyl
acetate (%)
1% (H2) 99% 33.5 96.8
48% (H2) 52% 13.9 97.8
1% (N2) 99% 33.5 96.5
48% (N2) 52% 12.6 95.2
20% (N2) + 28% (H2) 52% 13.1 96.7
20%(CO2)+28% (H2) 52% 13.2 96.7
Example 7
Reaction results in different type of reactors
The Catalyst 6# was used. The reaction temperature was 230 ℃, and the reactors were a
fluidized bed reactor and a moving bed reactor, respectively, and other experimental
conditions were same as Example 1. The reaction results are shown in Table 8.
Table 8: Reaction results on H-EMT catalyst in different type of reactors
Type of reactor fluidized bed moving bed
Percent conversion of of dimethyl ether (%) 95.2 94.5
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Selectivity of methyl acetate (%) 98.7 98.5
Example 8
Methyl acetate hydrolysis to acetic acid
The carbonylation product methyl acetate was hydrolyzed to acetic acid in the presence of
hydrolyzing catalyst. The ratio of water to ester was 4, and space velocity of methyl acetate
was 0.4 h
-1
, and loading amount of the catalyst was 10 g. The reaction results are shown in
Table 10.
Table 9: Reaction result of methyl acetate hydrolysis to acetic acid
Reaction temperature (℃) 50 60 70
Percent conversion of methyl acetate (%) 55.7 72.1 89.0
Example 9
Methyl acetate hydrogenation to ethanol
The carbonylation product methyl acetate was hydrogenated to ethanol in the presence of
hydrogenation catalyst. The reaction pressure was 5.5 MPa, and the molar ratio of hydrogen
tp methyl acetate in raw gas was 20:1, and the molar ratio of hydrogen to carbon monoxide
was 20:1, and the space velocity of methyl acetate was 3 h
-1
, and loading amount of the
catalyst was 10 g. The reaction results are shown in Table 11.
Table 10: Reaction results of methyl acetate hydrogenation to ethanol
Reaction temperature
(℃)
Methyl acetate hydrogenation
Percent conversion
of methyl acetate
(%)
Selectivity of
Ethanol (%)
Selectivity of
Methanol (%)
180 68.1 39.7 53.2
200 77.4 41.0 51.8
220 88.3 43.3 50.1
240 96.2 45.2 50.3
The present invention has been described in detail as above, but the invention is not limited to
the detailed embodiments described in this text. Those skilled in the art will understand that
other changes and deformations can be made without deviating from the scope of the
invention. The scope of the invention is limited by the appended claims.
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Claims
1. A method for producing methyl acetate, which comprises a step in which dimethyl ether
and a raw gas containing carbon monoxide go through a reactor loaded with a catalyst for
carrying out a carbonylation reaction; wherein the catalyst contains an acidic EMT zeolite
molecular sieve.
2. A method for producing methyl acetate according to claim 1, wherein in the acidic EMT
zeolite molecular sieve, the molar ratio of silicon atoms to aluminum atoms is in a range from
1.5 to 30;
preferably, the molar ratio of silicon atoms to aluminum atoms is in a range from 2 to 15.
3. A method for producing methyl acetate according to claim 1, wherein the acidic EMT
zeolite molecular sieve contains a catalyst promoter which is one or more metals selected
from gallium, iron, copper and silver;
preferably, the catalyst promoter is introduced to the acidic EMT zeolite molecular sieve by a
method selected from in-situ synthesis, metal ion exchange or impregnation loading;
preferably, based on the total weight of the catalyst, the weight fraction of the catalyst
promoter calculated by weight of metal elementary substance is in a range from 0.01 wt% to
10 wt%; more preferably, the weight fraction of the catalyst promoter calculated by weight of
metal elementary substance is in a range from 0.05 wt% to 1.0 wt%.
4. A method for producing methyl acetate according to any of claims 1 to 3, wherein the
acidic EMT zeolite molecular sieve contains a binder which is one or more compounds
selected from alumina, silicon dioxide and magnesium oxide;
preferably, based on the total weight of the catalyst, the weight fraction of the binder is in a
range from 0 wt% to 50 wt%.
5. A method for producing methyl acetate according to claim 1, wherein the carbonylation
reaction is carried out at a temperature range from 160 ℃ to 250 ℃ and at a pressure range
from 0.5 MPa to 20.0 MPa, and the feeding mass space velocity of dimethyl ether is in a
range from 0.05 h
-1
to 3 h
-1
, and the molar ratio of carbon monoxide to dimethyl ether is in a
range from 20:1 to 0.5:1.
6. A method for producing methyl acetate according to claim 1, wherein the carbonylation
reaction is carried out at a temperature range from 170 ℃ to 240 ℃ and at a pressure range
from 1.0 MPa to 15.0 MPa, and the feeding mass space velocity of dimethyl ether is in a
range from 0.1 h
-1
to 2.5 h
-1
, and the molar ratio of carbon monoxide to dimethyl ether is in a
range from 15:1 to 1:1.
7. A method for producing methyl acetate according to claim 1, wherein the raw gas
containing carbon monoxide contains carbon monoxide, hydrogen and one or more inactive
gases selected from nitrogen, helium, argon, carbon dioxide, methane and ethane;
preferably, based on the total volume of the raw gas containing carbon monoxide, the volume
fraction of carbon monoxide is in a range from 50 % to 100 %, and the volume fraction of
hydrogen is in a range from 0 % to 50 %, and the volume fraction of the inert gas is in a range
from 0 % to 50%.
8. A method for producing methyl acetate according to claim 1, wherein the methyl acetate is
hydrolyzed to acetic acid.
9. A method for producing methyl acetate according to claim 1, wherein the methyl acetate is
hydrogenated to ethyl alcohol.
10. A method for producing methyl acetate according to claim 1, wherein the carbonylation
DF170281PCT
11
reaction is carried out in a fixed bed reactor, a fluidized bed reactor or a moving bed reactor.