AU634563B2 - A nickel based retaining material for removing arsenic and phosphorus contained in liquid hydrocarbon cuts - Google Patents

Description

634563

AUSTRALIA

PATENTS ACT 1952 COMPLETE SPECIFICATION Form

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: INSTITUT FRANCAIS DU PETROLE 4 AVENUE DE BOIS-PREAU 92502 RUEIL-MALMAISON

FRANCE

GRIFFITH HACK CO., 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.

Actual Inventor: Address for Service: Complete Specification for the invention entitled: A NICKEL BASED RETAINING MATERIAL FOR REMOVING ARSENIC AND PHOSPHORUS CONTAINED IN LIQUID HYDROCARBON CUTS -9S PREPARATION AND ITS USE.

The following statement is a full description of this invention including the best method of performing it known to me:- The invention concerns a retaining material, particularly for removing arsenic and/or phosphorus from a petroleum charge, its method of preparation and its use.

According to their source, crude petroleums may contain traces of many metallic compounds, generally in the form of organo metallic conplexes.

These organo metallic conpounds are poisons to the catalysts used in petroleum conversion processes.

The organo metallic compounds are chiefly contained in heavy cuts emanating from distillation of crude petroleum. More particularly, heavy cuts from distillation under vacuum contain many metals such as nickel, vanadium or arsenic and non-metallic elements such as phosphorus. However, organic phosphorus compounds will also be described as organo metallic by extension, as the phosphorus is contained in them in the cationic state. These heavy cuts normally undergo thermal or catalytic cracking treatments to convert them to lighter, unsaturated hydrocarbon cuts which can be upgraded better.

Metals such as nickel and vanadium are not generally contained in the effluents. On the other hand arsenic, which is much more able to form volatile copounds, is contained in lighter cuts such as C 2 and C 3 cuts containing ethylene and propylene; these are generaklly purified by selective hydrogenation on catalysts based on noble metals, which are respectively poisoned by arsenic reducing corpounds such as arsine and methylarsine.

French Patent 2619120 teaches that these reducing compounds can be absorbed, in gas phase or in liquid phase, on lead oxide deposited e.g. on alumina.

On the other hand if heavier cuts such as petrol or naphtha have to be treated, the arsines normally present have a boiling point higher than methylarsine and thus contain one or more hydrocarbon radicals in their molecule. Such compounds have a much weaker reducing power, and reactions for reducing lead oxide are not completed. Absorption materials containing metal oxides such as lead oxide are theni ineffective on liquid hydrocarbon cuts of this type. It is the same with organic phosphorus compounds, which cannot be eliminated in this way.

Patent FR 2617497 therefore proposes the use of an absorbent material, conprising nickel deposited on a carrier such as silica, magnesia or alumina. However, these retaining materials are found to have a limited effect and limited stability when they are regenerated.

Finally, patents GB-A-1144 497, EP-A-0239 687 and FR-A-2619 121 illustrate the state of the art.

The subject of the invention is a retaining material, particularly for removing arsenic and/or phosphorus, which is more effective than previously known materials. It is based on nickel, possibly associated with another metal such as palladium or platinum.

The invention also relates to a retaining material which can be regenerated and which is stable; that is to say, its effectiveness is restored by high terperature calcining treatments (generally from 300 to 600 0 C and preferably from 450 to 530 0 C) in air, a mixture of air and nitrogen or a mixture of air and steam, for 4 to 12 hours.

i r~wa. I 1 ~314~~; The invention thus concerns a retaining material, particularly for removing arsenic and/or phosphorus from a petroleum charge, characterised in that it conprises, by weight: a) from 60 to 97% of a porous carrier containing by weight: from 40 to 98.5% of at least one alumina from 1.5 to 60% of oxide of at least one metal A dissolved in alumina, in the form of aluminate, selected from the group formed by Mg, Ca, Sr, Ba, Mn, Fe, Co, Ni, Cu and Zn; b) from 3 to 40% of nickel oxide, with which the carrier is impregnated by exchange or depositing.

One feature of the invention is that the retaining material may further conprise from 0 to 1% and preferably 0.2 to 0.5% by weight of platinum oxide (counted as Ft02) and/or palladium oxide (counted as FdO), with which the carrier is inpregnated by exchange or depositing.

Another particularly advantageous feature is that the material for retaining arsenic and/or phosphorus may conprise, by weight: a) from 65 to 90% of said carrier, containing: from 60 to 96% of said alumina, from 4 to 40% of said metal oxide A; b) from 10 to 35% of nickel oxide, with which said carrier is inpregnated.

The alumina in the carrier is advantageously an alpha or gairrra alumina or a mixture of the two.

The alumina has a porosity generally from 20 to 150 and preferably from 50 to 120 cm 3 and a specific surface area generally from 10 to 300 and preferably from 70 to 200 m 2 /g.

Another feature of the invention is that for the purpose of utilising the material it may be subjected to reducing treatment in hydrogen at a temperature of 100 to 500 0 C, so that at least and preferably at least 50% of said nickel oxide is in metallic form.

A feature of the mathod of using the retaining material of the invention is that the operating conditions for absorption are moderate, namely a temperature of 110 to 280 and preferably 150 to 220 0 C and a pressure of 1 to 100 and preferably 5 to 50 bars.

The operation takes place in a hydrogen atmosphere, and the charge is preferably at least partly in liquid phase.

Thde charge may be a naphtha boiling generally at 40 to 200 0 C or a heavy condensate of liquefied gases boiling e.g. at from 20 to 480 0

C.

It has been found, surprisingly, that the fact that active nickel is deposited on an aluminus carrier, where the alumina is at least partly combined in aluminate form, makes the nickel substantially more active, and also more stable when the material is regenerated by combustion.

The aluininates used my be aluminates of magnesium, calcium, strontium, barium, manganese, iron, cobalt, nickel, copper or zinc, or mixed aluminates, e.g. those comrprising at least two of the metals A in the above-mentioned list.

Single aluminates or mixed aluminates of magnesium, calcium, cobalt, nickel and zinc are preferred, and nickel aluminate is even more preferred.

The above-mentioned aluminates generally have the stoichiometry (A A1 2 0 4 n Al 2 0 4 where n ranges from 0 to 10 and where A is at least one of the metals in the above-mentioned list.

The above-mentioned aluminates will generally be prepared by at least one of the methods described below. They may be: a) Aluminates obtained by impregnating an alumina carrier with an aqueous or non-aqueous solution of at least one salt of at least one metal A in the above list: by drying then thermally activating it at from about 500 to about 800 0 C, in order to combine at least part of the alumina in the carrier with at least one metal A and to form said aluminate.

The alumina carrier may advantageously be used preformed; for exarple in the form of spheres, obtained by bowl granulation, by coagulation in drops (oil drop, oil up) or, for exanple, in the form of extrudates obtained by any extrusion method known in the art.

b) Mass aluminates (aluminates massiques) obtained by hydrolysing at least one aluminium alkoxide and at least one alkoxide of at least one metal A in the above list. For exaple the procedure described in USP 3,297,414 can thus be used.

c) Mass aluminates obtained more generally by reacting at least one aluminium coipound and at least one compound of at least one metal A, to form a sol then a hydrogel by the sol-gel process, described e.g. in patents USP 4,018,834, USP 4,482,643, USP 3,408,159, USP 4,357,427, GB 1,296,049, GB 1,313,750.

d) Mass aluminates obtained by co-precipitation as described e.g. in Applicants' French Patent 2 523 957, from an aqueous solution containing at least one aluminium salt and at least one salt of at least one metal A in the above list, which is reacted with at least one carbonate and/or at least one hydroxide of at least one alkali metal or of armonium.

e) Mass aluminates obtained by coirplexing, as described e.g. in Applicants' French Patents 1 604 707 and 2 045 612.

The aluminates in the form of an intermediate compound, prepared by any of the procedures a) to e) above, can possibly be washed to free them, if necessary, from any troublesome irons which they may contain (alkaline, nitrate, other anions); they are then dried and finally activated by heat.

The aluminates may finally be: f) industrial aluminates such as aluminous csements of the calcium aluminate or the barium aluminate type, marketed by the French company LAFARGE, or strontium, magnesium or zinc aluminates, or mixed industrial aluminates including at least two of the metals A in the above list, such as mixed calcium and barium aluminates.

g) physical mixtures of at least two of the corrpounds in a) to f) above, which are subsequently formed.

Aluminates obtained by at least one of procedures a) to g) above will generally be formed, except for those obtained by procedure through inpregnation of a preformed alumina carrier.

The forming procedures are agglomeration in spheres (bowl granulation), extrusion, pelleting, coagulation in drops (oil drop, oil up) and spray drying to obtain micro grains.

The may be applied either to the moist product, or to the dried product, or to the thermally activated product, or to a mixture of at least two of these products.

Like the forming procedures, the conditions under which the aluminates are prepared are well known in the art, and it is not necessary to repeat them in describing the invention.

The above-mentioned thermal activation is generally carried out from 500 to 800 0 C and preferably from 600 to 750 0

C.

The quantity of metal oxide dissolved in the alumina in the form of aluminate may be controlled by X-ray diffraction.

The proportion of alumina combined in the form of aluminate of at least one metal A will be such that A/A1 2 0 3 0.05 to 1, and preferably 0.1 to 1 in atoms.

The nickel may be deposited on the aluminate carrier in any suitable manner, such as is known in the art, e.g. from one of its soluble salts, e.g. its nitrate, formate, acetate or acetylacetonate. The nitrate is generally preferred because of its great solubility in water. The nickel may be incorporated e.g. by "dry" irrpregnation (filling the porosity of the carrier with a volume of liquid equal to the pore volume of the carrier) from a nickel nitrate solution, so that the weight percentage of metal obtained on the absorbent material is 3 to 50% and preferably 10 to 40%, counted as nickel. After the impregnation the catalyst is dried to eliminate at least part of the water, chen calcined in air or in another atmosphere containing oxygen, at a temperature of from 300 to 600°C for 0.5 to 5 hours.

C~

To prepare the retaining material for use, both before its first use and after its regeneration, it is then subjected to reduction 'i molecular hydrogen or in another atmosphere containing hydrogen, such as a nitrogen-hydrogen, argon-hydrogen or helium-hydrogen mixture, at a temperature of 100 to 500 0

C.

The mixture of salts of metals such as palladium and/or platinum will be deposited in association with the nickel salt.

The salts should advantageously be chlorides, nitrates or acetylacetonates. The quantity of associated metal (palladium and/or platinum) with which the absorbent material is impregnated is from 0.1 to 5% and preferably from 0.3 to 1% by weight.

After the impregnation the catalyst is dried, then calcined and finally reduced under the same conditions as described above.

Once the absorbent material has been reduced it is put into contact with the charge to be purified, in any appropriate manner. For exaiple, the operation may be carried out in a fixed bed, in an absorption column of cylindrical shape, through which the naphtha to be decontaminated passes in an ascending or descending flow.

The volure of absorbing material can usefully be calculated according to the concentration of arsenic in the hydrocarbon charge, generally from 0.05 to 10 ppm by weight and advantageously from 0.1 to 1 ppm by weight in the case of a naphtha. It can also be calculated according to the concentration of phosphorus in the hydrocarbon charge; this may contain from 0.05 to 10 ppm "nd advantageously from 0. 1 to 1 ppm of phosphorus. Generally speaking, the liquid hourly spatial velocity (LHSV) relative to the volume of material is from 1 to 10 h 1 and the hourly throughput of hydrogen is from to 10 litres per litre of charge. Excellent results have been obtained with hourly throughputs (LHSV) and hourly hydrogen throughputs respectively from 5 to 10 h 1 and from 1 to 5 litres per litre of charge.

The following examples are unrestrictive and are given to illustrate the invention.

Exanple 1 (comparison) In this exanple an absorbent material is prepared on a carrier of gamma transition alumina. The specific surface area is 160 m 2 /g and the total pore volume 1.1 m 3 /g.

The macropore volume (pores larger than 0.1 micron) is 0.4 cm /g, 100 g of spheres of this carrier, with a mean diameter of 2 mm, is impregnated with a nickel nitrate solution with a volume of 110 cm 3 containing 20 g of nickel. After inpregnation the material obtained is dried at 120 0 °C for 4 hours, then calcined in air at atmospheric pressure and at 450 0 C for 2 hours.

cm 3 of the absorbent material is placed in a steel tuba 3 cm in diameter.

The material is then subjected to reducing treatment under the following conditions: 11 reducing gas hydrogen gas throughput 20 litres/hour pressure 2 bars temperature 400 0

C

duration 8 nours.

The retaining material is then cooled, when it has been subjected to the reducing stage up to the testing temperature of 180 0

C.

A charge comprising a naphtha boiling in the 50 to l30 0 C range, containing 500 ppm of sulphur and with 400 ppb of arsenic in the form of triethylarsine added to it, is then passed through in an ascending flow.

Operating conditions are as follows: tenperature 180 0

C

pressure 25 bars throughput of charge variable 200, 300, 400 cm 3 /h throughput of hydrogen variable 1, 1.5, 2.0 1/h.

The arsenic content of the product emerging after 300 and 600 hours is determined in each condition.

The results are set out in Table 1.

I Table 1 1 Throughput of Arsenic in the product naphtha in ppb cm3/h After 300 hours after 600 hours 200 <50 300 <50 325 400 150 400 It will be seen that the material only remains truly effective if the throughput of naphtha is limited to 200 cm 3 per hour, i.e. if LHSV 4 h Example 2 (conparison) After each 600 hour test the absorption column is purged of all the naphtha contained in it. The material is than subjected to "regeneration" in an oxidising atmosphere of air and steam under the following conditions: pressure 1 bar temperature 460°C steam throughput 500 g/h ait throughput 15 1/h The treatment is carried out for 8 hours.

After the oxidising treatment the absorbent material is again subjected to reducing treatment as in the previous exanple.

The absorption of arsenic contained in the said naphtha is then resumed under the same conditions.

The results of arsenic analysis after 150 hours are given in Table 2.

L-~

13 Table 2 Throughput of naphtha Arsenic in the product cm3/h in ppb 200 180 300 300 400 450 It will be seen that the oxidizing treatnent has not satisfactorily regenerated the absorbent material.

Exarrple 3 (according to the invention) 200 g of the alumina used in Exarple 1 above is impregnated with 220 cm 3 of a solution of magnesium nitrate containing 10 g of magnesium. The material obtained is dried at 120 0 C for 4 hours, then calcined in air at atmospheric pressure for 2 hours at 60G°C. The solid obtained is marked as solid A. A new solid B is prepared from 100 g of solid A, by inpregnating it with a solution containing 20 g of nickel in nitrate form and subjecting it to the same drying and calcining stages as in Exanple 1.

A solid C is prepared as follows: 200 g of the alumina used above is inpregnated with 220 cm 3 of nickel nitrate solution containing 10 g of nickel; the material obtained is dried at 120 0 C for 4 hours, then calcined in air at atmospheric pressure for 2 hours at 7 A new solid D is prepared from 100 g of solid C, by impregnating it with a solution containing 20 g of nickel in nitrate form. It is then subjected to the same drying and calcining treatment as in Exanple 1.

A new solid E is prepared from 100 g of solid C by impregnating it with a solution containing 20 g of nickel and 0.5 g of palladium in the form of nitrates. It is then subjected to the same drying and calcining treatment as in Exanple 1.

A solid F is prepared as follows: 200 g of the alumina used above is ipregnated with 220 cm 3 of nickel nitrate solution containing 4 g of nickel; the material obtained is dried at 120°C for 4 hours then calcined in air at atmospheric pressure, for 2 hours at 750°C.

A new solid G is prepared from 100 g of solid F, by impregnating it with a solution containing 20 g of nickel in nitrate form. It is subjected to the same drying and calcining treatment as in Example 1.

Finally, a new solid H is prepared from 100 g of solid C, by impregnating it with a solution containing 10 g of nickel in nitrate form. It is subjected to the sane drying and calcining treatment as in Exaple 1.

i j Analysis by X-ray diffraction shows that substantially all the j magnesium in solid A and substantially all the nickel is solids C and F are in the form of aluminate. The same test as in Exanple 1 is carried out with solids A, B, C, D, E, G and H, when they have been reduced in the sane way.

'ie composition of the solids is shown in Table 3.

Table 3 SoI i d Carrier Oxide of Ni Oxide of Pd.

Oxide of Alumina Metal A A 7.8% 92. 2 %4=100%) B 7. u% 92. 2 20.4% C 6% 94% (100%) D 6% 94% E 6% 94% 20.1% F 2.4% 97.6%0 (100%) G 2.4% 97.6% H 6%0 +94% 9% Arsenic analyses carried out af ter 10 hours, 300 hours and 600 hours are given in Table 4 below.

Table 4 Solid Throughput of naphtha CM3/h Arsenic in the product in ppb After 10 h Af ter 300 h After 600 h It will be seen that neither solid A nor solid C is even initially capable of removing the arsenic contained in the naphtha. On the other hand solids B, D and E are substantially more effective than nickel materials deposited on non-modified alumina.

It will also be seen that solid G, prepared with a hardly aluminated carrier, has a less good performance.

Example 4 (according to the invention) After each 600 hour test solids B, D, E, G and H are subjected to the same oxidising "regeneration" treatment with steam as in Example 2. The arsenic absorption test is repeated, and the results of analysing the effluent after 150 hours are given in Table 5 below.

Table Solid Throughput cm3/h 200 300 400 200 300 400 200 300 400 200 300 400 200 300 400 of naphtha Arsenic in ppm 200 400 300 the product ~I~LI~ ~I C In contrast with Exanple 2, it will be seen that the regeneration treatment has prolonged the effectiveness of absorption materials B, D and E. On the other hand, material G with little aluminate is less effective.

Exarple 5 (comparison) A series of tests is carried out on naphtha, boiling within the range of boiling points from 50 to 1800C, containing 500 ppm of sulphur and with 500 ppb by weight of phosphorus in the form triethylphosphine added to it. 50 cm 3 of the material from Exarple 1 is placed in a steel tube 3 cm in diameter and subjected to treatment in hydrogen under the following conditions: pressure 2 bars hydrogen throughput 20 1/h tenperature 400 0

C

duration 8 hours.

The charge from which the phosphorus has to be removed is passed through the bed of material in an ascending flow with hydrogen under the following conditions: throughput of charge 200 cm /h and 400 cm 3 /h tenperature 1800C pressure 2 5 bars throughput of hydrogen 1 1/h and 2 1/h.

The content of phosphorus in the product discharged after 100 and 450 hours is determined in each testing condition. The results are given in Table 5 below.

I I r~ n~nsr Table Throughput of naphtha cm3/h 200 400 Phosphorus in the product in ppb After 100 hours After 450 hours <100 225 <100 500 It is thus advantageous to limit the throughput of naphtha to 200 cm 3 /h.

Example 6 (comparison After each 450 hour test the material is subjected to "regeneration" treatment identical with that in Exanple 2. The absorbing material again undergoes reducing treatment as in Exanple 1, and the absorption of phosphorus contained in the naphtha is repeated, under the same conditions as in the previous example.

The results of phosphorus analysis after 100 hours are given in Table 6 below.

Table 6 Throughput of naphtha cm3/h 200 Phosphorus in the product in ppb 240

F'

Example 7 (according to the invention) Solids A, B, C, D, E and G from Example 3 are tested in the same way as in Exanple 6. Analyses of the phosphorus in the product after 10 and 400 hours are given in Table 7.

Table 7 Solid Throughput cm3/h of naphtha Phosphorus in ppb the product 200 400 200 400 200 400 200 400 200 400 200 400 200 400 500 500 <100 <100 500 500 <100 <100 <100 <100 <100 <100 <100 150 500 500 <100 200 500 500 <100 150 <100 <100 <100 180 <100 300 It will be seen that neither solid A nor solid C is even initially capable of removing the phosphorus contained in the naphtha. On the other hand solids B, D, E and to a lesser extent solids G and H are more effective than nickel materials deposited on non-modified alumina.

Exanple 8 (according to the invention) After each 400 hour test solids B, D, E, G and H are subjected to the same regenerating treatment as in Exanple 2. When they have been reduced again the phosphorus absorption test is repeated. The results of analysing the product after 120 hours are set out in Table 8 below.

Table 8 Solid Throughput of Naphtha cm 3 Phosphorus in in the product ppb <100 150 <100 100 <100 <100 <100 120 <100 300 The regeneration treatment can be seen to extend the effectiveness of the phosphorus absorbing material.

Claims (9)

1. A method of removing arsenic and/or phosphorus from an at least partly liquid hydrocarbon charge containing them, characterised in that said charge, molecular hydrogen and a retaining material are put into contact in a reaction zone, at a temperature of 110 to 250 0 C and a pressure of I to 100 bars, with an hourly throughput volume (LHSV) relative to the volume of retaining material, of from 1 to 20 h 1 and with an hourly throughput of hydrogen of 0.5 to 10 litres and preferably 1 to 5 litres per litre of charge, and said retaining material comprises, by weight: a) from 60 to 97% of a porous carrier containing by weight: from 40 to 98.5% of least one alumina from 1.5 to 60% of oxide of at least one metal A dissolved in alumina, in the form of aluminate, selected from the group formed by Mg, Ca, Sr, Ba, Mn, Fe, Co, Ni, Cu and Zn; b) from 3 to 40% of nickel oxide, with which the carrier is impregnated by exchange or depositing.

2. A method of removing arsenic and/or phosphorus according to claim 1, wherein the retaining material is regenerated by calcining it in an oxidising atmosphere at 300 to 600 0 C, and wherein the retaining material thus regenerated is subjected to a reducing stage in the presence of molecular hydrogen or a gas containing molecular hydrogen, at a temperature of 100 to 500 0 C.

3. The method of claim 1 or claim 2, characterised n that the retaining material further comprises from 0 to 1% a -c. by weight of platinum oxide and/or palladium oxide, with which the carrier is impregnated by exchange or depositing.

4. The method of any one of claims 1 to 3, characterised in that the retaining material comprises, by weight: a) from 65 to 90% of said carrier, containing: from 60 to 96% of said alumina, from 4 to 40% of said oxide of metal A; b) from 10 to 35% of nickel oxide, with which the said carrier is impregnated.

5. The method of any one of claims 1 to 4, characterised in that for the purpose of utilising the retaining material it is subjected to reducing treatment in hydrogen at a temperature of 100 to 5000C, so that at least and preferably at least 50% of said nickel oxide is reduced to the metallic form.

6. The method of any one of claims 1 to characterised in that the retaining material is prepared by a process including the steps of: either al) impregnating a preformed or non-preformed alumina carrier with a solution of at least one salt of at least one metal A as defined in claim 1 a2) hydrolysing at least one aluminium alkoxide and at least one alkoxide of said at least one metal A c i. a3) reacting at least one aluminium compound and at least one compound of said at least one metal A, to form a sol then a hydrogel by the sol gel process or, a4) reacting an aqueous solution of aluminium and at least one compound of said at least one metal A with an aqueous solution of at least one precipitating agent, to form at least one co-precipitate, possibly washing the product obtained in stage al), a2), a3) or a4), drying it, then thermally activa.-ng it at a temperature of 500 to 800 0 C, to form said aluminate; or using at least one industrial aluminate of at least one metal A such as calcium, barium, strontium, magnesium and zinc, forming the product obtained in stage al), a2), a3), a4), or a5) if it is not already formed, impregnating the product resulting from stage by exchange or depositing, with a solution of at least one nickel salt and D possibly with a solution of at least one platinum and/or palladium salt, under conditions such that said nickel oxide and possibly said platinum and/or palladium oxide is obtained impregnated onto the carrier, at least partly drying the water at a temperature of 80 to 200 0 C, calcining in the presence of a gas containing molecular oxygen at a temperature of 300 to 600 0 c, and recovering the retaining material.

7. The method of any one of claims 1 to 6, wherein the hydrocarbon charge is a naphtha or a heavy condensate of liquefied gases.

8. The method of any one of claims 1 to 6, wherein the hydrocarbon charge contains 0.05 to 10 ppm by weight of arsenic.

9. The method of any one of claims I to 6, wherein the hydrocarbon charge contains 0.05 to 10 ppm by weight of phosphorus. The method of any one of claims 1 to 6, wherein the hydrocarbon charge is a naphtha boiling at from 40 to 200 0 or a heavy condensate of liquefied gases boiling at 'from 20 to 480 0 C, containing from 0.05 to 10 ppm by weight of arsenic and from 0.05 to 10 ppm by weight of phosphorus. ij DATED THIS 21ST DAY OF DECEMBER 1992 INSTITUT FRANCAIS DU PETROLE By its Patent Attorneys: GRIFFITH HACK CO Fellows Institute of Patent Attorneys of Australia.