抄録
At present, hundreds of thousands tons of chlorofluorocarbons (CFCs) are regarded as harmful wastes because of their ozone layer depletion. To solve a problem, we are proposing a new process that these chlorinated wastes are converted into useful compounds. Especially, treatment of dichlorodifluoromethane (CFC12) gas seems to be a hopeful process. Photo-decomposition occurred by just bubbling CFC12 gas into methanol-NaOH solution under UV irradiation. After it dissolves in a methanol solution, it consecutively converts to chlorodifluoromethane (HCFC22) and finally to 1,1-diflourodimethyl ether which will be expected as the third generation refrigerant. To design a photochemical reactor, we need the solubility of fluorocarbons in a methanol solution. We already measured the solubility of CFC12 and HCFC22 in methanol (2000, 2001). However, we found that reaction rate decreases beyond our expectation. We thought that existence of NaOH caused decrease of solubility. In this work, we measured the effect of NaOH concentration on solubility or Henry's law constants of CFC12 and HCFC22 in methanol-NaOH solutions. As a result, Henry's law constants of CFC12-methanol and HCFC22-methanol systems were succeeded to correlate as a function of H = H0 exp(si [NaOH] ) . Where H0 is the Henry's law constant for a binary fluorohydrocarbon-methanol system at a temperature from our previous work, and si is a constant for fluorohydrocarbon.
