RESEARCH PAPER The Engineering of Hydrogen Peroxide Decontamination Systems Stefan Radl & Stefanie Ortner & Radompon Sungkorn & Johannes G. Khinast Published online: 16 June 2009 # International Society for Pharmaceutical Engineering 2009 Abstract In this article, the latest developments for designing hydrogen peroxide decontamination systems are analyzed. Specifically, focus is given to the accurate calculation of hydrogen peroxide condensation phenomena and discussion of a new correlation for its accurate prediction. A procedure for calculating the condensate composition or the dew point out of this correlation is detailed, and an h–x diagram for moist, hydrogen peroxide- laden air, which is of fundamental importance for the rational design of hydrogen peroxide decontamination systems, is proposed. Also presented are theoretical results that illustrate the effect of condensation and evaporation in these systems. Finally, some perspectives for improving hydrogen peroxide systems, and the role computational fluid dynamics (CFD) may have in this field, are provided. Keywords Hydrogen peroxide . Decontamination . Pharmaceutical engineering . Condensation . Mollier h–x diagram Notation Latin letters A DHP Total inner surface area of the DHP chamber [m²] B j Parameters of the Redlich–Kister equation [J/kmol] c i Concentration of species i in the gas phase [mg/l] c i sat Saturation concentration of species i over the liquid film [mg/l] c p,i Heat capacity of species i in the gas phase [kJ/kmol . K] c p,chamber Heat capacity of the chamber wall material [kJ/kg.K] C Dimensionless concentration of inlet gas C μ , C 1ε , C 2ε Constants for the turbulence model D i Diffusion coefficient of species i in air [m 2 /s] f Target function for the dew point iteration [Pa] g Gravitational acceleration [m/s 2 ] h Specific enthalpy [kJ/kmol] h 1+ x Enthalpy [kJ/kg dry air ] ΔH v,i Heat of vaporization of species i [kJ/kmol] k Turbulent kinetic energy [m 2 /s 2 ] MW i Molecular weight of species i [g/mol] m chamber Mass of the DHP chamber walls [kg] Á N cond;i c i ð Þ Molar condensation rate of species i [kmol/s] N l,i Molar amount of species i in the liquid phase [kmol] Á Q loss Heat loss [W] p Pressure [Pa] p i Vapor pressure for species i in a liquid mixture [Pa] p i sat Vapor pressure of pure species i [Pa] p tot Total pressure [Pa] ~ R Reynolds stress tensor [m 2 /s 2 ] R Molar gas constant, 8.314472 [J/mol . K] R gas Gas constant for air, 287.05 [J/kg.K] Ra Rayleigh number J Pharm Innov (2009) 4:51–62 DOI 10.1007/s12247-009-9057-3 S. Radl : R. Sungkorn : J. G. Khinast (*) Institute for Process and Particle Engineering, Graz University of Technology, 8010 Graz, Austria e-mail: khinast@TUGraz.at URL: http://ipt.tugraz.at S. Ortner Ortner Cleanrooms Unlimited, Uferweg 7, 9500 Villach, Austria