POWER UP A WINNER - Plant Services

By Terry McMahon,
Steve Walton and Jim Tatera
Despite
computerization,
skills are still
needed to achieve
the full benefits
Analytical instruments used for online chemical
analysis of process streams or plant environments are generally
called process analyzers. On-stream analytical data
have proven to be crucial to safe and efficient operation in
the petroleum, chemical, pharmaceutical, pulp and paper,
power and other industries. Historically speaking, these instruments
have been complex, even temperamental, systems
with relatively unique operational and maintenance needs.
If online instrumentation, sample-handling systems and
data-analysis software are to realize optimum performance,
they will require continual attention from the analyzer support
staff.
Increasingly, however, regulatory and high-priority
economic concerns such as operator health and safety,
emissions control and energy conservation are raising the
importance of analyzer reliability to normal operations.
Particularly with respect to regulatory and safety uses, the
time logged as out-of-limits because of an analyzer outage
can result in stiff fines.
In these situations, it’s important to be able to deal with
routine maintenance needs, as well as to recognize and
characterize maintenance needs that require more specialized
skills. Sourcing such specialized skills and an expedited response
to an incident frequently become high-priority items.
Looking back
A brief overview of analyzer history can put the current situation
into perspective. The technology for on-stream chemical
analysis dates back about 70 years. The first nondispersive
infrared (NDIR) photometers were developed and deployed
in the late 1930s at the Ludwigshafen Research Lab of I.G.
Farbenindustrie (German Chemical Trust later broken up by
the Allied Occupation Forces into BASF, Bayer and Hoechst).
A schematic of UltraRotAbsorptionSchreiber (URAS), the
first on-stream analyzer, is shown in Figure 1. The URAS
trade name belongs to the original manufacturer, Hartmann
& Braun, which is now a unit of ABB, a leading worldwide
analyzer supplier. When this work was discovered, its significance
was recognized immediately (British Intelligence
Operations Subcommittee Report #1007, 12 June 1946). The
report states that “I.G. Farbenindustrie’s development in recent
years of the infrared absorption meter and the magnetic
oxygen recorder represent a great advance.”
U.S. chemical and petroleum companies began using onstream
analyzers in the 1950s. By 1960, Standard Oil of New
Jersey’s (later Exxon) Baton Rouge Refinery had a significant
complement of on-stream analyzers (Table 1).
The emergence of real-time digital computers in the
1960s, followed by the microelectronics revolution and the
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