The molecular sieve is
a crystal aluminosilicate. With the uniform
pore size and great specific surface area,
it is provided with as many outstanding advantages
as listed below:
The selective adsorption according to the
different molecular size and shape, i.e. to
adsorb the molecules smaller than the pore
size of molecular sieve only;
The selective adsorption of small polar molecules
and unsaturated molecules, and its selective
adsorbability is greater in case of the greater
polarity and unsaturation;
The enormous water absorption. It maintains
a high water absorbing capacity even at a
high temperature, high air velocity and lower
water content.
Now the products that have been put into production
for industrial use mainly include 3A, 4A,
5A, 10X, 13X and copper molecular sieves.
1. 3A Molecular
Sieve
(1) product Description
Usually the pyrolysis gas contains 400 to
700 PPm moisture that will be frozen in
cryogenic separation, and at a high pressure
and low temperature, the white crystal of
hydrocarbon mixture will be generated from
water and low carbon paraffin hydrocarbon
(e.g. CH4, C2H6
and C3H8, etc.). In
addition, the crystal of ice and hydrocarbon
mixture will also lead to the blocking of
pipeline or equipment, resulting in the
shutoff of the system. In such a case, the
petroleum pyrolysis gas must be deeply dehydrated
and dried prior to the cryogenic separation
so that the moisture in pyrolysis gas could
be reduced to less than 5 PPm (i.e. its
dew point is lower than TMP -60 ). Now,
the best deep drying adsorbent that is commonly
used and generally recognized at home and
abroad is 3A zeolite molecular sieve. Since
it adsorbs only the moisture present in
pyrolysis gas and not the larger hydrocarbon
molecules (e.g. C3H6,
C2H4,C3H8
and C3H6 etc.), it
can prevent the coking of olefin compound
within the pore canal of molecular sieve
and prolong the service life of adsorbent.
(2) Main Technical Conditions of 3A Strip
Molecular Sieve
| Item |
φ1.5-1.7 |
φ3.0-3.3 |
| High-class |
Ist-grade |
Qualified |
High-class |
Ist-grade |
Qualified |
| Abrasion loss ，N/≥ |
20.0 |
18.5 |
15.0 |
20.0 |
18.5 |
15.0 |
Bulk density ，%≥
|
20.0 |
19.0 |
20.0 |
19.0 |
Grain size，%≤
|
98.0 |
94.0 |
90.0 |
98.0 |
90.0 |
80.0 |
| Static water adsorption，T/m3 |
0.64 |
0.60 |
0.55 |
0.64 |
0.60 |
0.55 |
| Compressive strength，%≤ |
0.25 |
0.55 |
0.50 |
0.60 |
0.80 |
1.00 |
| Static ethylene
adsorption，mg/g≤ |
3.0 |
| Water content
in package % ≤ |
1.5 |
(3)Technical Conditions of 3A Spherical
Molecular Sieve
| Item |
φ1.5-1.7 |
φ3.0-3.3 |
| 1st-grade |
Qualified |
1st-grade |
Qualified |
| Abrasion loss，%≥ |
20.0 |
15.0 |
20.0 |
19.0 |
Bulk density，T/m3
|
0.68 |
0.60 |
0.68 |
0.60 |
Grain size，%≤
|
96.0 |
95.0 |
96.0 |
95.0 |
| Static water adsorption，%≤ |
0.40 |
0.60 |
0.40 |
0.60 |
| Compressive
strength ，N/≥ |
44.0 |
59.0 |
| Static ethylene
adsorption，mg/g≤ |
3.0 |
| Water content
in package % ≤ |
1.5 |
(4) Typical applications:
● Dehydration of many kinds of liquids (say
ethanol).
● Dehydration of air.
● Dehydration of refrigerant.
● Dehydration of natural gas or methane.
● Dehydration of cracked gas ,ethylene , propylene
or butadiene.
2. 4A Molecular Sieve
(1) product Description
The pore size for 4A molecular sieve is
4A. It is mainly used to adsorb water, methanol,
ethanol, sulfureted hydrogen, carbon dioxide,
ethylene, propylene, does not adsorb any
larger molecular than 4A, and offen used
as desiccant in industrials.
(2) Main Technical Conditions
of 4A Molecular Sieve (Spherical)
| Index |
φ1.5-1.7 |
φ3.0-3.3 |
| First
grade |
Qualified |
First
grade |
Qualified |
| Abrasion ratio，%≥ |
21 |
20 |
21 |
20 |
Bulk density,g/ml>=
|
0.66 |
0.60 |
0.66 |
0.60 |
Granularity,%
>=
|
30 |
25 |
70 |
50 |
| Static water
sorption,% >= |
0.40 |
0.60 |
0.40 |
0.60 |
| Crushing strength,((N/particle)>= |
88 |
85 |
88 |
85 |
| Water
content in package =< |
1.5 |
1.5 |
1.5 |
1.5 |
(2) Typical applications:
● Deep drying of air, natural gas , alkane
and refrigerant.
● Generation and purification of argon.
● Static dehydration of electronic element,
pharmaceutical and unstable materials.
● Desiccant for paint, dope and foul etc.
3. 5A Oxygenating
(Oxygen-enriching) Molecular Sieve
(1) product Description
Application: As a high-efficient adsorbent
of oxygen and nitrogen separation in the
field of air separating oxygenation, and
the oxygen generated can be controlled from
50% to 90% in purity.
(2) Main
Technical Index
| SizeIndexItem
|
Bulk density |
Static water sorpion |
Crushing strength |
Coefficient
of O2, N2 separating |
Remaining value of O2,
N2, (ml/g) |
Abrasion ratio |
Water content in package |
| ≥T/m3 |
≥% |
≥N |
O2 |
N2 |
≤% |
≤% |
| Spherica |
φ2-3 |
0.66 |
21 |
25 |
2.40-2.75 |
2.6 |
8.0 |
≤0.50 |
≤1.5 |
| φ4-6 |
0.62 |
21 |
50 |
≤0.50 |
≤1.5 |
4. 5A Dewaxing Molecular
Sieve
(1) product Description
Application: Extensively applied in the
separation of normal paraffin hydrocarbon
(dewaxing) in petroleum and its distillate.
The dewaxed petroleum products are of the
superior property similar with aviation
kerosene at a low freezing point, and the
separated normal paraffin hydrocarbon (paraffin
wax) can be supplied as the chemical material
of synthetic detergent.
(2) Main Technical Index
| sizeIndexItem
|
Bulk
densityg g/ml >= |
Static water
sorption % >= |
Crushing strength,
N/mm2/particle >= |
Abrasion ratio,% |
n-Hexane sorption,
(P/ps=0.1% <= |
Water content
in package,% <= |
| Strip |
φ3-5 |
0.60 |
21 |
22 |
0.55 |
≤20% |
1.5 |
| Ball |
φ4-6 |
0.62 |
21 |
60 |
0.5 |
≤12% |
1.5 |
5. 13X Molecular
Sieve
(1) product Description
Application: For the desulfurization (H2S,
SO2, mercaptan and thiophene)
of petroleum gas and natural gas, and it
is also a good drying agent.
(2) Main Technical Index
|
sizeindexItem
|
Bulk
density |
Static
water sorption |
Abrasion
ratio |
Crushing
strength
|
Benzene
sorption |
Removal of
SO2% |
Removal ofH2S% |
Water
content in package |
0.7
mmHg |
12.0
mmHg |
696
mmHg |
0.5
mmHg |
11.0
mmHg |
400
mmHh |
| Strip |
φ1.6ⅹ（3-8） |
0.56 |
23 |
0.5 |
20 |
180 |
24.2 |
30.5 |
35.3 |
9.2 |
18.1 |
28.0 |
1.5 |
| Ball |
φ4-6 |
0.60 |
16 |
0.5 |
23 |
0.5 |
(3) Typical applications:
● Purification and removal of H2O
and CO2 .
● Dehydration and desulfuration of nature
gas , liquid petrol gas and liquid alkane.
● Deep dry of common gases.
(4) Note: φ1.5 to 1.7 mm strip molecular
sieve means the sample with a strip length
of 1 to 6 mm as its nominal length;
φ3.0 to 3.3 mm strip molecular sieve means
the sample with a strip length of 2 to 9
mm as its nominal length.
6.13X Air-separating
Molecular Sieve
(1) product Description
Application: For an extremely high efficient
purification of unstripped oxygen and nitrogen
in the air in the air separation industry,
able to thoroughly eliminate the small amount
of CO2 and H2O in
the air which affects the oxygen and nitrogen
separation, it is a special adsorbent necessary
in the air separation industry.
Main Technical Index:
|
sizeIndexItem |
Bulk
density>= g/ml |
CO2
sorption>= % |
H2O
sorption>= % |
Abrasion
ratio<= % |
Crushing
strength >= N/stripN/particle |
Water
content in package, % |
| Strip |
φ1.6ⅹ（3-8） |
0.58 |
16 |
23 |
0.5 |
20 |
1.5 |
| Ball |
φ4-6 |
0.60 |
16 |
23 |
0.5 |
20 |
1.5 |
7. Cu-13X Molecular
sieve
Application: Mainly used to eliminate the
minute amount of organic sulfur (thiaalcohol)
in aviation kerosene.
Main Technical Index:
|
sizeIndexItem
|
Bulk density>=
g/ml |
Static water
sorption %(weight) |
Crushing Strength>=
N/strip/Nparticle |
Abrasion ratio,
<= %(Weight) |
Cu content,
<= %(weight) |
Benzene sorption,>=
mg/g |
| Strip |
φ1.5-1.9 |
0.50 |
23 |
20 |
0.5 |
1.5-1.9 |
180 |
| φ3.0-3.3 |
0.50 |
23 |
35 |
0.5 |
1.5-1.9 |
180 |
The Cu-13X molecular sieve can be used
in the desulfurization of aviation kerosene
under the following technological conditions:
The temperature is higher than 130℃;
2 to 3 Kg/cm2 in pressure;
4 h-1 at air velocity.
Note:
(1)The nominal length of φ1.5 to 1.7 mm
strip molecular sieve is 4 to 12 mm;
The nominal length of φ3.0 to 3.3 mm strip
molecular sieve is 6 to 14 mm.
(2)The water content in package refers to
that before delivery from manufacturer.
8. 10X Molecular Sieve
Application: Mainly used in the adsorption
and separation of aromatic hydrocarbon and
refining of paraffin wax.
Main technical Index:
| size Index
Item
|
Bulk density>=
g/ml |
Static water
sorption %(weight) |
Crushing strength,≤N/mm/N/Particle |
Abrasion ratio
<= %(Weight) |
Benzene sorption≥mg/g |
Water content
in package,≤%(weight) |
| Strip |
φ5 |
0.58 |
16 |
23 |
0.5 |
20 |
1.5 |
| Ball |
φ4-6 |
0.60 |
16 |
23 |
0.5 |
60 |
1.5 |
9. Recycling Conditions
of Molecular sieve
250 to 320℃at inlet temperature of adsorption
tower, greater than or equal to 150℃at outlet
temperature of adsorption tower;
The recycled gas must be dry and free from
the components to be adsorbed by molecular
sieve (the dry nitrogen is recommended);
The duration of regeneration is only 3 to
4 hours at a constant temeperature;
The recycled gas is often used to cool down
the bed for a standby use.
10. Ordering Information
The molecular sieve is of great absorptivity.
To keep it in a dry place and avoid exposure
to the air. In case of the occurrence of
moisture absorption due to a long-term storage,
to recycle before used and its property
won’t be changed;
It is recommended to use the solution of
PH=7 or 11 in case of A or X type molecular
sieve, and the operating temperature should
not exceed 600℃, otherwise it will lose
its activity;
The Corporation would like to manufacture
the special molecular sieve to the request
of user;
If the user encounters the possible difficulties
in operation, the Corporation may dispatch
the technical personnel for a on-the-spot
service.
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