materials. n,n-diethylethanolamine (purity 99 %) and anhydrous piperazine (purity 98%) used in all experiments, were purchased from sisco research laboratories Pvt.Ltd.,Mumbai carbon dioxide, nitrous oxide, and nitrogen cylinders, with agiven purity of 99.95% were purchased from inox air products Ltd.,Mumbai all solutions were prepared using deionized water (conductity 0.054 us), which was supplied by a deionized water unit (millipore india Pvt.Ltd.,Mumbai)