Safety benefits of nitrogen generation via PSA technology
When an in-house PSA-based nitrogen generator is employed, the nitrogen that is generated is at the pressure and flow rate
that matches the requirements of the process. In contrast, when nitrogen from fractional distillation is employed, the external
storage tank may hold several hundred liters or more, depending on the individual circumstances, of pressurized liquid nitrogen
at –196 °C (–320 °F). A leak in the tank or the piping that leads to the reaction vessel could create significant problems
from the rapid evaporation of the liquid. A leak could possibly cause displacement of the air and reduce the oxygen required
for breathing. In addition, if an employee came into contact with liquid nitrogen, serious burns could occur.
Quality issues and the PSA nitrogen generator
Pharmaceutical companies periodically test incoming materials from outside suppliers to ensure that they meet specification
and avoid the possibility that the material will create problems in their manufacturing process. As a result, many test the
liquid gas being delivered. When a PSA nitrogen generator is employed, the user has complete control of the purity of the
gas, and the system's on-board oxygen analyzer provides a continual check of the oxygen content.
Environmental benefits of nitrogen generation via PSA technology
An in-house nitrogen generator based on the pressureswing-adsorption technique requires considerably less energy and therefore
has a considerably lower carbon footprint than fractional distillation of air and transportation of the gas from the distillation
site. A significant amount of energy is expended in the fractional-distillation process, and additional energy is required
to transport the nitrogen to the end-user. In contrast, an in-house PSA system simply requires a source of compressed air.
Because the nitrogen is generated locally with a small energy requirement, it is quite likely that conversion to PSA generation
of nitrogen will lead to a significant "green" credit for a pharmaceutical company that is not in the immediate vicinity of
a fractional distillation site. A green credit also arises from the fact that it is no longer required to transport liquid
nitrogen over significant distances. In addition, a significant amount of the power used to generate the nitrogen can be recovered
by using an energy recovery-type system with a water-cooled air compressor (i.e., the electric energy used in the compressor
can be transformed into heat and used elsewhere).
In-house generation of nitrogen for pharmaceutical manufacturing via the pressure-swing-adsorption technique can reduce the
economic and environmental costs of providing the gas compared with fractional distillation followed by transporting the gas
to the user's site. The magnitude of these benefits is especially significant when the manufacturing site is distant form
the location of the distillation site. An in-house pressure-swing-adsorption system with a two-vessel design with appropriate
valving and control system can provide the gas on a continuous basis. The system automatically responds to changes in the
nitrogen demand to minimize power consumption and valve usage.
Mario Bolivar is business development manager at Industrial Nitrogen Products, Filtration and Separation Division, Parker Hannifin, and
Peter Froehlich* is president at Peak Media, 10 Danforth Way, Franklin MA 02038, tel. 508.528.6145, firstname.lastname@example.org
*To whom all correspondence should be addressed.
1. M. Daly, American Environmental Laboratory, 6, 3 (1995).
2. P. Froehlich and R. Cardarople, American Laboratory News, 10, 3, 17 (2008).
3. Nitrogen Generation Systems Bulletin FNS-D, Parker Hannifin, Haverhill, MA, pp.37 (2010).