Adsorbing 1, 3-butadiene and benzene by porous materials in gas stream and cigarette smoke

1, 3 -butadiene and benzene are the representing harmful volatile hydrocarbons in cigarette smoke. A variety of commercial porous materials need to be evaluated and selected in laboratory for the sake of seeking the optimal additive in cigarette filter to remove 1, 3 -butadiene and benzene. It is necessary to explore a suitable method which could reflect accurately the additives' actual performance in smoke. Temperature programmed desorption (TPD) and instantaneous adsorption (IA) are used to estimate the removal capacity of 1, 3 -butadiene and benzene by porous sorbents to select the suitable technique. Zeolites, mesoporous silica, activated carbon (AC), porous alumina and silica were chosen and evaluated with these two methods. In TPD tests, NaY zeolite showed the best removal capacity to 1, 3 -butadiene (1.80 mmol g-1) and benzene (1.07 mmol g-1), superior to AC (1.54 mmol g-1 for 1, 3-butdiene and 0.90 mmol g-1 for benzene). However, their adsorption of two targets in cigarette smoke was decreased and challenged by the harsh condition including the short contacting time plus the existence and competition of numerous other compounds in smoke. Fortunately, IA test can reflect the true performance of sorbents in cigarette smoke because it is performed in a similar high-speed air flow, in which AC captured more 1, 3 -butadiene (1.46 mmol g-1) than NaY zeolites did (1.06 mmol g-1). Acidic zeolites adsorbed 1, 3 -butadiene through the chemical interaction of acid center while other adsorbents trapped it by physical adsorption.