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CATnapTM
Cat Tech is pleased to present
the CATnap® Catalyst Passivation
Process - an exclusive, patented technique for unloading
catalysts from petroleum processing units. CATnap technology
passivates pyrophoric or self-heating catalysts by the application
of a proprietary CATnap catalyst coating chemical. The catalysts'
surfaces (and equipment surfaces) are coated with an organic film
which retards oxygen penetration and reaction. The passivated
catalyst can be unloaded under air, thus eliminating many of the
hazards and expenses related to inert entry.
This passivating effect is demonstrated in Figure 1. The blue line
shows the heat release of a spent Co/Mo catalyst as it is gradually
heated in air to 400°C. The catalyst starts heating up at about
120°C when the metal sulfides begin to oxidize. A second reaction
representing the carbon burn commences around 300°C. Once the
catalyst is passivated by the CATnap process (red line), the
catalyst is stable to about 300°C.
Application of the CATnap technology involves the injection and
adsorption of a chemical inhibitor. Often, this procedure is a
departure from the norm because the unit is partially cooled under
oil. Although the details of the procedure must be customized for
each application, a generalized procedure is outlined in Figure 2.
Initially, the feed rate is reduced while the reactor starts cooling
down. When the unit is below reaction temperatures, a carrier oil of
prescribed viscosity and other properties is introduced to displace
the normal process feed. Once the feed oil is flushed out, the
carrier oil is put on total recycle and the CATnap catalyst coating
chemical is injected. The unit is then cooled to a target
temperature (typically 140 - 150°C). Oil flow is discontinued and
the reactor is further cooled under flowing gas. At this point the
unit may require evacuation or purging to reach permissible entry
limits for H2S, SO2, LEL, CO and Ni(CO)4. The working area is then
flushed with air and the catalyst is unloaded by conventional
techniques.
The benefits of the CATnap process are clear: Improved Safety, Time
Savings, Reduced Costs, and Intangibles. These are outlined on the
opposite page.
Clearly the most important feature of CATnap technology is that it
eliminates the life threatening nature of working in a nitrogen
atmosphere. In spite of this, reactor entry technicians (RET's) are
outfitted with full life support equipment. Safety is further
enhanced by handling passivated catalyst and minimizing the
hazardous dust normally present with catalysts removal.
Experience has shown that significant time can be saved with the
CATnap process. Elimination of a hot H2 strip and cooling down with
liquid circulation can significantly reduce shutdown time. Also, the
equipment and procedures used with CATnap technology can reduce the
actual unloading time.
The time savings and other features can provide substantial cost
savings. The expense of nitrogen for inert entry is significantly
reduced or eliminated. Many associated costs, such as equipment
rental and contract labor, are reduced due to the shortened
turnaround time. Probably the most significant value to the refiner
is having his unit back on stream quicker and minimizing production
losses.
Intangible benefits are difficult to quantify but are, nevertheless,
very important. Clearly, not having to deal with a life threatening
environment increases morale, productivity, and quality. A cleaner,
safer operation means less complications and distractions for all
personnel.
Another important feature of CATnap technology is that the catalyst
is fully regenerable. A variety of hydrotreating and hydrocracking
catalysts have been tested and qualified through laboratory studies
and commercial runs.
Cat Tech is proud to bring CATnap technology to the refining
community. We feel if offers a major breakthrough in catalyst
unloading technology and sets a new standard for safety in the
industry. If you would like to learn more about CATnap, please
contact your Cat Tech representative, call our office at
713-292-1141.
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