Process for purifying (HYDRO)halocarbon compositions
A composition and technology of halogenated hydrocarbons, applied in chemical instruments and methods, preparation of halogenated hydrocarbons, organic chemistry, etc., can solve problems such as polluted products
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Embodiment 1
[0085] A small sample (about 50 mg) of each sorbent was accurately weighed into a 100 μl alumina crucible. The sorbent was first preconditioned by heating from 30°C to 350°C at 20°C / min under flowing nitrogen (125ml / min). The samples were then cooled to 40°C and exposed to 16.67% v / v HFC-152a in nitrogen for 2 hours, any uptake was monitored gravimetrically. Any adsorbent showing negligible HFC-152a adsorption capacity was then further screened for methyl chloride adsorption in the same manner.
[0086] The results are shown in Table 1 below.
[0087] HFC-152a is technical grade and is from Du Pont. The material was analyzed and found to have the following composition:
[0088] Chloromethane = 28ppm
[0089] Unknown 1 = 5ppm
[0090] 254fb (CF 3CH 2 CH 2 F) = 7ppm
[0091] E-1131 (CHF=CHCl)=1.2ppm
[0092] The remaining HFC-152a (99.9588%)
Embodiment 2
[0100] A 30 g sample of HFC-152a containing 28 ppm methyl chloride was prepared. The sample was treated with 0.5 g of Union Showa carbon molecular sieve in a glass pressure roller at room temperature and autogenous pressure while stirring with a magnetic stirrer. After a contact time of 8 hours, a sample of liquid HFC-152a was removed for gas chromatographic analysis. Residual methyl chloride was measured at 9 ppm.
Embodiment 3 to 4
[0102] A small sample (about 35 mg) of each sorbent was accurately weighed into a 100 μl alumina crucible. The sorbent was first equilibrated at 30 °C under nitrogen (100 ml / min) for 5 min, then preconditioned by heating from 30 °C to 350 °C at 20 °C / min under flowing nitrogen (100 ml / min) and held at 350 °C 5 minutes. The sample was then cooled at -20°C / min to 40°C, equilibrated under nitrogen (40ml / min) for 23.8 minutes, and exposed to 16.67% v / v HFC-152a in nitrogen (60ml / min) for 2 hours.
[0103] The HFC-152a supplied in Examples 3 to 4 was found to have a methyl chloride concentration of 24 ppm. The adsorption of HFC-152a and methyl chloride by the adsorbent was measured by thermogravimetric analysis. The results are shown in Table 2.
[0104] Table 2
[0105]
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