Sample conditioning and standard preparation for synfuel gas analysis. [Especially reactive gases]

A goal of the work carried out subsequent to the field test was thus to develop a method of collecting and conditioning a gas sample which obviated these concerns. The method was to avoid exposing the gas to any liquid condensate, and was to be insensitive to high loadings of suspended dust or droplets, and should not be affected by pressure fluctuations which inevitably occur in a process line. For this purpose a volumetric gas dilutor was developed. This system extracts a fixed volume of gas at constant pressure and temperature and dilutes it with another inert carrier gas. The critical component of this system was designed and tested in the laboratory as described in Section 2 of this report. Finally, a detailed design for a fieldworthy gas conditioning system was completed to the level of individual components and vendors. A summary of this design was provided to LETC in the June 1983 monthly report, but the system was not developed further. The volumetric dilution system also appears to be a valuable method for preparing gas standards in the range 0.1 ppM to ca. 20%. In much of this range the accuracy of this standard can be traceable to NBS standards. Dilution of a fluid by means of repetitive injections of a fixed volume into a diluent stream requires that the resulting concentration spikes be averaged over time. This chapter shows that a single mixing chamber is normally inadequate, but that a column of 5 to 20 ''plates''or sub-volumes is optimum. 7 figs., 2 tabs.