Absorption of NO into Sodium Cobalt Phthalocyanine Sulfonate Solution

A study on nitrous mono oxide (NO) absorption into sodium cobalt phthalocyanine sulfonate (C0PCS) solution was carried out.The C0PCS solution absorbs NO and desorbs it easily on heating to have the absorption capacity restored, which makes the repeated cycle of absorption-desorption possible.The NO absorption rate with the C0PCS solution is far faster than that with the solid cobalt phthalocyanine reported by Ercolani et al., The rate is higher in the solution of organic solvents such as methyl-f ormamide, N-methye 2-pyrrolidone or dimethyl-sulf oxide compared with that in the aqueous solution.The coordination ratio of a NO molecule to a C0PCS molecule is estimated to be one to one in the organic solvents of high absorption capacity.Regarding other gaseous constituents that are supposedly contained in exhaust gas together with NO, none of oxygen, carbon monooxide and dioxide inhibits the NO absorption into the solution. However even a trace amount of SO2 inhibits the NO absorption into the aqueous solution of C0PCS. On the other hand SO2 does not exhibit any inhibition with the DMSO solution.The effects of absorption conditions such as pH and temperature of absorbent, C0PCS concentration and NO concentration were also investigated in the aqueous solution of C0PCS.