This video segment examines industrial greenhouse gas emissions and the potential for their
mitigation.
It's major points are number one, most of the greenhouse gas emissions from industry
are energy related, yet energy efficiencies of most industrial processes are less than
half of what is theoretically achievable.
Number two, electric motors, their controls and their transmission systems are primary
targets for energy conservation in the industrial sector Number three, greater efficiencies
in generating and delivering steam are readily achievable.
Number four, steel and cement production, the two largest industrial emitters, have
industry specific remedies.
Industrial emissions of greenhouse gasses, if one includes emissions from electricity
and steam generated off site, amounts to 3.3 billion kilograms of carbon equivalents per
year.
Industries with the highest emissions are A. metal smelting, especially steel, iron
and aluminum, B. extraction and refining of petroleum, C. cement manufacture, D. pulp
and paper processing, E. industrial nitrogen fixation to generate ammonium and F. synthesis
of ethylene, a precursor of many plastics.
As the human population and per capita income have grown, so has production of industrial
goods.
Since 1980, global annual production of steel has increased 84%, petroleum 40%, cement 271%,
paper 180%, ammonia 200%, aluminum 223% and ethylene 194%.
The industrial sector, however, has not expanded as quickly as some other sectors, such as
transportation.
And actually the industrial share of greenhouse gas emissions has declined from 40 percent
in 1971 to 37 percent in 2004.
Many heavy industries have relocated from developed countries to developing ones such
as China and India.
Indeed, industrial greenhouse gas emissions from China and India rose from twelve percent
of the world's total in 1971 to 42 percent in 2004.
Because expected lifetimes of manufacturing equipment (power lines, and pipe lines, and
power stations) extend from ten to 50 years, industrial facilities under construction now
in China and India will influence emissions for decades to come.
Over 80 percent of the greenhouse gas emissions from industry are energy-related, yet energy
efficiencies of most industrial processes are less than half of what is theoretically
achievable.
Increasing energy efficiencies in the industrial sector thus presents an excellent opportunity
for diminishing greenhouse gas emissions as well as saving money.
Strategies to achieve this include: upgrading equipment, optimitizing operating procedures,
improving equipment maintenance and maximizing capacity utilization.
Most industrial equipment, including pumps, compressors, fans, and conveyors, contain
electric motors.
These motors consume more than 60 percent of the energy in the industrial sector.
Therefore, the motors themselves, their controls, and their transmission systems, are obvious
targets for energy conservation in the industrial sector.
Premium motors have stronger magnets, higher conductivity pressures and better bearings
than their standard counterparts and are three to 30 percent more energy efficient but about
twenty percent more expensive.
In industrial applications that run motors for extended periods, the lower energy requirements
of premium motors compensate for their higher purchase price in less than three years.
Motors operate most efficiently when loaded up between 75 percent and 100 percent of their
capacity.
Electronic adjustable speed drives vary the frequency and voltage of the electricity supplied
to a motor to control its speed.
Adjustable speed drives are expensive.
Costing roughly the same as the motors they control, yet under variable loads they improve
energy efficiency by ten to twenty percent and the energy savings quickly compensate
for a higher capital cost.
Transmission systems connect motors to the load via belts, chains, or gears.
V-belts are the most common type and they reach efficiencies of 95 percent if properly
installed and maintained, but typically have efficiencies of less than 90%.
Replacing V-belts with cog belts or gears increases energy efficiencies by an average
of 4%.
In some circumstances, an adjustable speed drive permits a direct connection between
the motor and the load, eliminating the need for a transmission system.