Founder of
Raney Nickel
|
Murray Raney
(1885 -1966) |
|
|
|
Born in Carrollton, Ky.,
on October 14, 1885. Research Engineer. Business Executive.
University of Kentucky, B.S.M.E., 1909; Sc.D., 1951. Died,
March 3, 1966.
In 1950, he began devoting full time to the production
and sales of Raney Catalysts, and originated a catalyst
known to scientists throughout the world and took out
several patents on a number of chemical and metallurgical
processes. The company was acquired by W. R. Grace &
Company in 1963, to be known as W. R. Grace & Co.,
Raney Catalyst Division. In 1924, he discovered a method
of making nickel and cobalt hydrogenating catalysts from
alloys of nickel and cobalt, with silicon and aluminum.
In 1950, samples of the Raney Catalyst, a brief description
of the process, and his photograph were placed in the
Chandler Museum at Columbia University, Department of
Chemical Engineering.
He was awarded an honorary
Doctor of Science degree by the University in 1951. Other
honors included the Distinguished Service Medal given
by the American Chemical Society, Chattanooga Section,
in 1960. He was President of the Lookout Mountain Fairyland
Club, the Lookout Mountain Golf Club, and the Chattanooga
Kiwanis Club.
Murray Raney was named to
the Hall of Distinguished Alumni in February 1965.
TECHNICAL SPECIFICATION
OF RANEY NICKEL CATALYST (ACTIVE)
DESCRIPTION
: Black Slurry of finely divided metallic particles kept
under water.
Readily forms suspension on stirring. Ready to use catalyst.
SUPERNATANT WATER
| i) Clarity |
Clear to light milky. |
| ii) pH of Supernatant
water |
9.5 max. |
| iii) Chlorides |
Absent |
| iv) Sulphates |
Absent |
CATALYST
SLURRY
| i) Nickel
Content (w/w) ( on dry basis) |
88% min. |
| ii)
Bulk Density in gms/ ml. |
1.5 to 2.0 |
| iii)
Pyrophoric Rating |
3 to 5 |
| |
1 < 2 < 3 <
4 < 5 |
| |
POOR
EXCELLENT |
ACTIVITY
Rate of uptake of H2 in ml/minute
With O-Nitro Phenol (For 2 ml of Catalyst
slurry)
: 90
ml/ minute minimum
Note
: Use prescribed
test procedures for the above parameters.
DESCRIPTION:
GREY TO BLACK COLOURED SLURRY SUSPENDED IN WATER.
TESTS REQUIREMENTS
SUPERNATANT WATER
| i) pH |
Not more than 10.5 |
|
ii) CLARITY |
Clear transparent to
slight Hazy. |
| iii)
CHLORIDES
|
Absent |
| iv) SULPHATES |
Absent |
IGNITED OXIDISED CATALYST POWDER
i) SOLUBILITY IN ACID
MIXTURE
(80% HCl +20% HNO3) |
Not less than 99% |
| ii) NICKEL OXIDE (NiO)
CONTENT |
Not less than 83.5% |
WET
CATALYST
|
i) GRADE |
Fine/ Medium/
Coarse |
| ii)
NICKEL CONTENT |
Not less than
88% |
| iii) BULK DENSITY
IN g/ ml
|
1.5 to 2.0 |
| iv) WET SEIVING MATERIAL
RETAINED ON 400 MESH IS SIEVE
|
1]
Not more than 40% of the material should
be retained on 400 mesh
sieve for Fine grade. |
| |
2]
Material retained on 400 mesh sieve shall
be in the range of 40 to 50% for
Medium Grade. |
| |
3]
Not less than 50% of the material should
be retained on 400 mesh sieve for
Coarse Grade. |
| v) PYROPHORIC
RATING |
Shall be not
below two point in a five point rating scale.
1 < 2 < 3 < 4 < 5 |
| vi) ACTIVITY |
Poor
Excellent |
| |
|
| a]
With O-Nitro Phenol ( using
2.0 ml of Wet Catalyst slurry) |
Average uptake
of Hydrogen per minute shall be
not less than 110 ml for fine grade |
| |
100 ml for medium grade |
| |
90 ml for coarse grade |
|
(OR) |
|
| b] With 10
gm of Nitrobenzene using
1 gm (on dry basis)
of
catalyst |
Average uptake
of Hydrogen per minute
shall be not less than 75 ml for fine grade |
| |
70 ml for medium grade |
| |
65 ml for coarse grade |
Shelf life :
The activity of the catalyst does not drop
below the specified level upto a period of 6 months from
the date of manufacture if stored in a place where temperature
does not go above 300C. For best result use
within one month from the date of manufacture.
Note
: Use prescribed test
procedures for above parameters.
TEST
METHOD FOR CHLORIDE & SULPHATES IN SUPERNATANT WATER
OF RANEY NICKEL CATALYST
GENERAL:
Presence of chlorides & sulphates in supernatant
water indicates use of raw water or poor quality demineralised
water in coustic lye preparation and/or during washing
of catalyst for making it caustic free. Though small amount
of chlorides are not known to adversely affect the hydrogenation
capability of Raney Nickel Catalyst none the less, the
supernatant water from good quality of Raney Nickel Catalyst
should be fre of chlorides and sulphates.
TEST
METHOD : Take
5 ml each of filtered supernatant water in two 25 ml test
tubes. To the first tube add two drops of Hydrochloric
Acid. Now to the first tube and about 1 ml of 2% Silver
Nitrate solution and to the second tube add 2 ml of 10%
Barium Chloride Solution. Shake both the tubes. Warm the
second tube. Examine both the tubes after five minutes.
Absence of any ppt. in the first test tube indicates absence
of Chlorides; whereas absence of any ppt in the second
test tube indicates absence of sulphate in the supernatant
water.
TEST
METHOD FOR CHECKING CLARITY OF SUPERNATANT WATER OF RANEY
NICKEL CATALYST
GENERAL:
Incomplete washing of catalyst slurry can subsequently
cause development of milky or light milky turbidity in
the supernatant water of Raney Nickel Catalyst due to
precipitation of residual Sodium Aluminate or non metallic
impurities present in Aluminium though presence of Sodium
Aluminate does not adversely affect catalytic Activity
of Raney Nickel Catalyst yet clarity of supernatant water
in indicative of better overall quality of catalyst.
TEST
METHOD: Stir catalyst
with a clean metallic rod (preferably S.S.Rod). Allow
the catalyst slurry to settle. Take about 100 ml of supernatant
water in a clean Nessler Tube. Simultaneously fill up
another Nessler Tube with D.M.Water. See through both
the tubes in comment on the clarity of sample liquid as
clear Transparent / Hazy/ Slightly Milky/ Milky/ Turbid.
CRITERIA FOR ACCEPTANCE:
Upto slight milkyness in the supernatant water, the material
may be deemed as satisfying the requirement in respect
of clarity of supernatant water.
PACKING OF PRESCRIBED QUANTITY OF RANEY
NICKEL CATALYST
ON DRY BASIS
- Take a translucent bucket of capacity
almost double the quantity of catalyst to be packed
on dry basis. Thus for packing 10 Kg Raney Nickel
Catalyst on dry basis the bucket should be of 20 litres
capacity.
- Put a mark with an indelible marking
pen on the bucket at a level if 1˝times in liters
of quantity to be packed in Kgs. Thus for 10
kg catalyst to be packed put a mark at 15 liters level.
- Now weigh the bucket filled exactly
upto the mark with water.
- Now remove about half the quantity
of water from the bucket and start adding catalyst
slurry into the bucket and bring the water level upto
the mark by adding or removing the water as the case
may be. This process of addition or removal of catalyst
and addition or removal of water so as to maintain
water level upto the mark and at the same time weight
of catalyst slurry along with supernatant water to
attain a pre calculated value has to be done by trial
and error method. Stop this process when both the
conditions i.e. level of water and weight of slurry
with supernatant water have been satisfied. The entire
operation of weight and volume adjustment can be done
by keeping the bucket on the weighing platform of
the balance.
- For calculating value of pre calculated
weight information regarding Nickel content of the
catalyst is required and that is available from the
test report issued by the laboratory for that batch.
ACTIVITY OF RANEY NICKEL
CATALYST (ACTIVE)
Activity : Activity
of a Hydrogenation catalyst means rate of uptake of Hydrogen
in ml/minute per gm.
(calculated on dry basis) of catalyst by a prescribed
quantity of a specified substrate in a prescribed quantity
of a specified solvent at specified reaction conditions,
viz. pH, temp., pressure, rate of stirring etc.
The above definition envisages
that for Activity values of a Hydrogenation catalyst
i]
The substrate be specified
ii]
Quantity of substrate be specified
iii]
Solvent be specified
iv]
Quantity of solvent be specified
v]
Conditions affecting the rate of reaction, viz. temp.
pressure, pH, rate of stirring
etc. be specified.
The definition also envisages
that there should be provision of accurate measurement
of quantity of Hydrogen consumed, accurate measurement
of time taken and accurate measurement of catalyst quantity
used (on dry basis). Further for repeatable and reproducible
results one should always use same time for purging. i.e.
displacement of air by hydrogen, nearly same quantity
of catalyst in all experiments, standardized method of
catalyst addition to the reactor vessel, fixed speed of
agitation, same apparatus and trained operator.
For Raney Nickel Catalyst,
the substrate for activity determination is generally
a Nitro group carrying aromatic compound, viz Nitrobenzene
A.R.grade from a reputed manufacturer viz Qualigens, Merck,
Ranbaxy, s.d.fne etc. The quantity of substrate taken
is 10 gm. which on density consideration is equivalent
to 8.3 ml, Solvent used is L.R.grade. Methanol from company
of Repute, viz. Qualigens, Merck, Ranbaxy, s.d.fine etc.
and quantity used is around 150 ml. It may be noted that
variation of
about 10 to 15 ml in quantity of Methanol do not significantly
alter Activity values.
Since the substrate and
solvent used are non aqueous and of specified grade from
manufacturers of repute, pH automatically becomes a non
disturbing factor. Besides, catalyst is also used after
washing with water and Methanol.
Note : Some customers
opt for a solution of Sodium Salt of ortho Nitro Phenol
in water instead of Nitrobenzene.
Temperature and pressure
used are ambient temp. and atmospheric pressure since
slight difference in temperature due to variation in ambient
temperature and slight difference in atmospheric pressure
due to climate variation do not make much difference in
final activity values.
Rate of agitation plays
a vital role in activity values and therefore is always
kept constant in all experiments. One of the main cause
for variation of activity values of two different labs
is due to variation in rate of agitation. Besides, Nickel
particles being paramagnetic, the size of magnetic bar
used also becomes a major cause of variation in values
obtained in two different labs. Normally a teflon coated
magnet bar of 35 mm x 9 mm is used while using a reaction
flask of 500 ml capacity.
Purging time, i.e. time
allowed for displacement of air by Hydrogen is kept constant
at 3 min. with rate of Hydrogen flow maintained at above
200 ml/ minute.
Accurate measurement of
quantity of Hydrogen is done with the help of a graduated
measuring cylinder. Since time is measured for absorption
of fixed quantity of Hydrogen gas, viz. 300 ml, the marking
in measuring cylinder is done especially at 500 ml mark
and at 200 ml mark thereby making measurement of 300 ml
a precise phenomenon. Time is measured in seconds with
the help of stop watch or an electronic digital watch
having least count of one second or less.
The problem of weighing
1 gm. of Raney Nickel Catalyst on dry basis is tackled
in an ingenious manner.
Quality of Hydrogen gas
is kept uniform by using A.R.Grade Zinc and Sulphuric
Acid from manufacturers of repute or by using high purity
Hydrogen gas from Hydrogen gas cylinder.
Weighing
of 1 gm. of Raney Nickel Catalyst on Dry Basis:
First determine the slurry
density of the catalyst by following the method prescribed
for determination of slurry density of Raney Nickel Catalyst.
Also determine Nickel content by following the method
for determination of nickel content of Raney Nickel Catalyst.Nowcalculate
volume of Raney Nickel Catalyst which corresponds to 1
gm of catalyst on dry basis by using the formula
1513 + 6.2 x Ni%
1 gm. of Raney Nickel
Catalyst on dry basis
= ------------------------------------
ml
2403x(Slurry Density–1)
In a burette specially
designed and fabricated for measurement of volume of Raney
Nickel Catalyst as shown in diagram for activity apparatus,
suspend Raney Nickel Catalyst bit by bit and allowing
catalyst slurry to settle before addition of next installment
of catalyst slurry till the volume of settled slurry reaches
the rounded off value of the calculated volume.
Now weigh 50 ml empty,
Specific Gravity bottle with stopper on. Thereafter fill
up the specific gravity bottle with DM water and insert
the stopper. Wipe off the outer portion with tissue paper
and determine accurately the weight of bottle with water.
Calculate weight of 50 ml of water by difference. Let
this be W. Now empty out the bottle and charge the catalyst
slurry quantitatively from the special burette directly
into the specific gravity bottle. If required use additional
quantity of DM water for quantitative transfer of catalyst
into specific gravity bottle. Allow the catalyst particles
to settle inside the specific gravity bottle. Fill up
the specific gravity bottle with water. Insert the stopper.
Wipe out exterior of the specific gravity bottle with
tissue paper. Reweigh the bottle with stopper on. Let
this weight be G. Calculate the precise wt of catalyst
slurry on dry basis by using the formula.
D x
(G - W)
2403 x
(G-W)
Wt. of catalyst in grams =
----------------------
OR
----------------------------- gms.
D
–1 1513
+ 6.2 x Ni%
Washing of Catalyst :
Transfer the weighed catalyst into a 100 ml beaker carrying
some D.M water. Stir with a glass rod. Allow the catalyst
slurry to settle. Drain out three fourth of the supernatant
clear water. Now wash the catalyst with Methanol two times.
Use glass rod for stirring the catalyst. Do not stir vigorously
for longer time. Stirring should be done for 15 seconds
only. Minimize exposure to atmospheric air. Repeat washing
with methanol once again. Keep the catalyst
in methanol.
Setting up of Apparatus
: Set up the apparatus as shown in diagram.
Zinc and Sulphuric acid are used to produce Hydrogen gas.
In the reaction flask, 8.3 ml of AR grade Nitrobenzene
is pipetted out. 100 ml of methanol LR grade is poured
inside. Magnetic Bar is introduced sliding through the
sides. 100 ml separating funnel is fitted on to the reaction
flask. Initially Hydrogen gas produced through the action
of Sulphuric Acid on AR grade Zinc metal kept in Hydrogen
producer flask is collected into a 500 ml measuring cylinder
through displacement of water. During this process, stop
cocks connecting Hydrogen producer flask to the inlet
of reaction flask are kept in a closed position. Hydrogen
is collected in the Hydrogen measuring cylinder. Hydrogen
collected at the first instance is vented out and then
filled again with a view to completely flush out the air
present in the cylinder. After storing more than 500 ml
(about 550 ml) Hydrogen gas in the measuring cylinder
the stop cock connecting the inlet of gas to the measuring
cylinder is closed so as to lock the gas stored.
Now Stop-cock connecting Hydrogen producer flask and the
reaction flask are opened and stop cock of the separating
funnel kept over the reaction flask is kept partially
open. Few ml of methanol are kept in the separating funnel.
As the hydrogen gas is escaping out through separating
funnel, the air present in the reaction flask starts getting
displaced. This
operation is known as purging. The reactor system starts
getting filled with Hydrogen. This operation is continued
for three minutes. Thereafter the stop cock of separating
funnel is closed. The stop cock for inlet of Hydrogen
gas to the reaction flask is also closed and stop cock
for venting out Hydrogen gas is opened. Hydrogen gas being
produced in the Hydrogen producer flask is allowed to
vent out.
The apparatus is now checked
for leakage. Keep the stock cock connecting the Hydrogen
producer flask and the reaction flak closed. The stop
cocks connecting the Hydrogen measuring cylinder and the
reaction flask are opened and level of water inter-alia
Hydrogen gas in the cylinder monitored. Water level after
few seconds of opening of stop cocks should become stable
and there should be no change in water level inter-alia
gas level. Close
the inlet stop cock of measuring cylinder.
The apparatus is now ready
for transferring of catalyst from the beaker into the
separating funnel. Transfer quantitatively catalyst from
the beaker into the separating funnel. If required a small
portion from the balance quantity of 50 ml methanol can
be used.
Charging of the catalyst
into the reactor:
Carefully simultaneously open stop cocks of separating
funnel and gas inlet of the reactor for few seconds to
allow catalyst to be charged into the reactor. Close the
valves. Add residual quantity of 50 ml methanol into the
separating funnel. Again carefully open stop cock of separating
funnel and gas inlet for few seconds to allow remaining
catalyst particles to be transferred into the reaction
flask. Moment complete transfer of the catalyst has been
effected. Close both the stop cocks. Pour about 5 ml of
methanol into the separating funnel to help check leakage,
if any. Bubbles would be seen if there is any leakage
in the system.
Activity Measurement:
Open the stop cock of hydrogen measuring cylinder and
immediately start the magnetic stirrer pre adjusted to
a specified speed and immediately the volume of water
level starts rising. When the water level reaches level
of 500 ml mark, start the stop watch or alternatively
record the time in minutes and seconds from electronic
or any other reliable watch. The water level continuously
rises. When it reaches 200 ml mark. Stop the stop watch
or record the time in minutes and seconds. Stop the magnetic
stirrer.
Calculate in seconds, the
time taken for uptake of 300 ml (500 ml mark –200 ml mark
= 300 ml ) of Hydrogen by the substrate. Calculate rate
of uptake per second and thereafter per minute. Let this
be M.
Final Calculation:
D
-------
( G-W ) gm of catalyst cause uptake of Hydrogen
at M
ml/minute
D-1
\
1 gm of catalyst will cause an uptake of
( D-1 )
1
---------
x -------
x M
ml/minute
( G-W )
D
Activity of the catalyst with 10 gm of Nitrobenzene
=
ml/minute
per gm of catalyst.
Andhra Pradesh
Indenting Agent
Mr. Vijaya Bhaskar
Chowdary Medepudi
M/s. Jagisa Agencies
# G 3, Swarajya Residency,
Adj to "Vikas" The Concept School,
Sai Krishnaja Hills, Cococola X roads ( Maktha),
Miyapur to Bollarum route, BACHUPALLY, Hyderabad - 500 090. Andhrapradesh, INDIA
Ph: +91- 40 - 2304 6898 , 2304 8615 Fax: +91 40 2304 6530.
Mobile: +91 99514 -13683 / 92462-13683 / 98481-13683
Email: hyd2_Jagisa@sancharnet.in, mvijayabhaskar@yahoo.com
Visit us at: http://jagisa.net
VINEETH CHEMICALS
Unit No 1, Agarwals Industrial Estate No. 3,
Satvili Road,Vasai(East), Thane-401208
Tel: 0250-245 5454 / 245 5757; Fax: 0250-245 5544 /233
4230
Email: catalyst@bom5.vsnl.net.in
