Handling of ozone

Miniaturized near-infrared sensors were developed and implemented for online analysis and automated process control to also meet the safety requirements for handling of ozone and halogenating agents [49,50]. A target is to reduce the time from process idea to production (time-to-market) as well as development costs and costs for installation of the production unit. As pharmaceutical industry relies on the manufacture of many different products on smaller scale, and intermediates in quantities ranging from some kilograms to tons per year a modular approach toward a multipurpose microreactor plant is demanded. 

CGA P-34 Safe Handling of Ozone-Containing Mixtures Including the... 

Since handling of ozone is inconvenient, it is often replaced by sodium periodate and a catalytic amount of osmium tetroxide for the cleavage of C=C bonds to give the... 

Pure ozone is made by fraetional distillation of the blue liquid resulting from the eooling of ozonized oxygen in liquid air. Commereially it is often supplied dissolved in ehlorofluoroearbons in stainless steel eyiinders at ea 475 psig eyiinder pressure at 20°C often transported ehilled with dry iee. These solutions ean be handled safely at vapour eoneentrations of ea 20% by volume of ozone. 

The above book [1] deals, in 26 chapters in 5 sections, with theoretical and practical aspects of the use and safe handling of powerful oxidants and their complementary reactive fuels. Materials include nitrogen pentaoxide, perfluoroam-monium ion and salts, nitronium tetrafluoroborate, hydrazinium mono- and diperchlorates, nitronium perchlorate, tricyanomethyl compounds, difluoramine and its alkyl derivatives, oxygen difluoride, chlorine trifluoride, dinitrogen tetraoxide, bromine trifluoride nitrogen fluorides, and liquid ozone-fluorine system. 

Continuous analytical methods (amperometric and UV-absorption methods) are advantageous. However, sometimes only discontinuous methods (titrimetric and some photometric methods) are available due to expense. In such cases it is important to measure immediately after sampling to avoid the decay of ozone and in the case of liquid ozone to avoid degassing. Discontinuous photometric methods requiring the addition of chemicals to the sample can be converted to a continuous method by combination with flow injection analysis (FIA). This analytical technique requires instrumentation and is not easy to handle. 

Because antiozonants and waxes, which to be effective must form a surface bloom, are used to enhance ozone resistance it is usual to condition test pieces in the strained state before exposure. The usual conditioning period is between 48 and 96h and the test pieces should be kept in the dark and in an ozone-free atmosphere. For this treatment to be effective, the test piece surface must not of course be touched in the course of subsequent handling. Where specifications wish to specifically exclude compounds which rely on an adequate wax film for protection, the conditioning period is dispensed with. Hill and Jowett47 in a criticism of ozone test methods strongly make the point that the conditioning process should be relevant to service conditions if a discriminating evaluation of waxes is to be made. 

Briefly, the test pieces are placed in the chamber at the required strain and ozone concentration and inspected at intervals. If opening the cabinet reduces the concentration for appreciable periods this will affect the results, although an automatically controlled cabinet should show a fast response. Some workers observe the test pieces through a window in the cabinet. This avoids disturbing the concentration and any handling of the test pieces but it is doubtful whether the inspection can be as thorough as when the test pieces are removed. 

Title VI Stratospheric Ozone Protection Title VI of the 1990 Clean Air Act Amendments established a program to implement the provisions of the Montreal Protocol, a worldwide agreement to reduce the use and emission of ozone-depleting substances. EPA s regulations adopted in response to Title VI outline a series of requirements for facilities that use equipment containing ODS compounds. Facilities must be certain that they handle and manage ODS compounds as prescribed in the rules. Only certified technicians and staff may maintain... 

Practical applications have been found for most of these compounds witli some exceptions such as liquid ozone as it is considered to be too dilficuh to handle, the only probable form of ozone safe enough is its mixture with oxygen (Vol m.p. 309). 

The writers are grateful to coworkers at Armour Research Foundation for many helpful suggestions on the handling of liquid ozone, especially to C. E. Thorp, L. C. Kinney, R. F. Remaly, and G. M. Platz. Thanks are also given to S. Jones, now of General Mills, Inc., for his help with the design of the viscometer. 

The tests described above showed that any of these concentrations of ozone could be handled safely with suitable precautions. 

The solvents that will be most affected in percentage terms are many of the chlorinates which, because of ozone depletion and toxicity concerns and improved handling are expected to show a marked decline in use over the next decade. Likewise, the use of aromatic and some aliphatic hydrocarbons will show a significant... 

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