Page 101 - Academic Press Encyclopedia of Physical Science and Technology 3rd Chemical Engineering

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Encyclopedia of Physical Science and Technology EN002C-86 May 17, 2001 20:36

Catalysis, Industrial 499

V. INDUSTRIAL CATALYST MARKETING TABLE IV Catalyst Quality Tests
Activity Laboratory activity test
Many companies that do industrial research on catalysis
choose not to make their own catalysts. Catalyst prepa- Surface area Gas adsorption
ration and marketing is a specialty chemical, high tech- Pore volume Water adsorption
nical service business. Manufacturers are under pressure Pore volume distribution Mercury porosimetry
to make their catalysts more active, more selective, and Metal surface area Selective gas adsorption
with a greater cost performance and lifetime than those Thermal stability Thermal gravimetric analysis
of their competitors. Development of a new catalyst or Crush strength Compression test
process historically has taken many years (5–10) which is Attition resistance Rotary drum test
a disadvantage in project economics. The overall catalyst Dimensions Measurement
business is expanding and catalyst life is finite. The chal- Particle size Sieve analysis
lenge is to make a cost-effective product with a sufficiently Density Weight per volume
high rate of return on investment. Purity Trace metal analysis
Catalysts are usually subdivided into homogeneous and Metal distribution Electron microprobe
heterogeneous classes. Homogeneous catalysts are solu- Lifetime Accelerated lab test
ble in the reaction media. Heterogeneous catalysts make Crystalline form X-ray
up the bulk of the catalyst market; they are the solid cata- Crystallite size X-ray
lysts that can be a support material, such as alumina, silica,
or silica alumina, but more often some metal salt is added
to a formed catalyst support. quality assurance. Common catalyst test procedures are
Petroleum catalysts constitute the largest catalyst mar- outlined in Table IV. Quality control testing by catalyst
ket,followedbyautomobileemissionscatalystsandchem- vendors and catalyst purchasers is vital for minimizing
ical catalysts. Catalytic cracking is the largest volume potential commercial problems. This is most important to
petroleum application, followed by alkylation, hydrotreat- the vendor, who develops a reputation (or lack thereof) for
ing, hydrocracking, and catalytic reforming. The highest excellence in product quality.
volume chemical catalysts in order are polymerization cat-
alysts, oxidation catalysts, ammoxidation, oxychlorina-
B. Proprietary Technology
tion, ammonia synthesis, methanol synthesis, hydrogena-
tion, and dehydrogenation. Proprietary information is often transferred between com-
panies after both sign a secrecy or confidentiality agree-
ment. Generally, the agreement defines what information
A. Scale-Up and Development
is to be exchanged, limits how long it is to be held confi-
Catalyst scale-up is a process in which a catalyst previ- dential (2–10 years is common), prohibits third-party dis-
ously made in small quantities in a laboratory is manu- closures, and provides exceptions. Common exceptions
factured in quantities of more than 100 lb with equipment are if the information transferred is already known or if
that performs the same operations as larger commercial the information becomes public at a later time.
equipment. If possible, this should involve equipment that Custom-catalyst manufacturers build a reputation based
simulates the series of unit operations that will be used in on keeping proprietary information confidential, and their
commercial catalyst preparation. overall performance in this area is excellent. The legal
In this scale-up stage an objective is to simplify the labo- departments of the companies involved agree to the ter-
ratory preparation while maintaining the essential activity minology of the agreement, and the agreement is signed
and selectivity of the catalyst. Unit operations available by a vice president or other senior company official. These
at most custom catalyst manufacturers include precipi- agreements permit joint projects to be undertaken between
tation, gel formation, filtration, washing, impregnation, catalyst inventors and catalyst suppliers in which catalyst
coating, kneading, drying, calcination, grinding and siev- recipes are transferred and optimized.
ing, dry-mixing, tableting, extrusion, beading, leaching,
melting, and activation. If special treatment of the catalyst
C. Licensing
is needed, it may add considerable expense to the catalyst
preparation. Catalyst formulations and technology can be licensed
A catalyst made in the laboratory or by a catalyst man- from inventors. The legal department of the company
ufacturer must be tested and meet quality control specifi- offering the technology draws up the license. It can be ex-
cations to ensure high quality and reproducibility. Cata- clusive or nonexclusive. For example, hydrocracking cat-
lyst companies are ISO 9002 certified which also provides alysts are usually licensed along with a process, whereas