Sur la chaleur isostérique d’adsorption du dioxyde de soufre sur divers adsorbants carbonés ou non

Heats and Entropies of Adsorption of Sulfur Dioxide on Activated Carbon and Carbon Black

“…The tendency for the heats of adsorption to approach the value for the heat of liquefaction of sulfur dioxide at higher coverages is similar to that found by Debrun et al (1973) and Grillet et al (1974) for untreated carbons. Further, Nakada and Nozaki (1971) have reported a heat of adsorption of 5.2 kcal mol-1 for sulfur dioxide on a charcoal of low surface oxygen content.…”

“…Further, all forms of carbon are known to chemisorb molecular oxygen at room temperature and below (ZarifYanz et al, 1967; Vastola and Walker, 1961) and recent studies by infrared (Matson et al, 1970) and electron spin resonance spectroscopy (Harker et al, 1966) indicate approximately 90% of the surface oxygen is present as one of four types of functional group-carbonyl, carboxyl, phenolic, and lactone. It has been shown previously (Beebe and Dell, 1955; Grillet et al, 1974) that surface treatment of carbons with oxygen affected both the adsorption character-Ind. Eng.…”

“…This value is similar to that for untreated Spheron, an acidic carbon black which gave a heat of adsorption for sulfur dioxide of 15.5 kcal mol-1 at 0.2 /nmol m-2 (Beebe and Dell, 1955) compared to 15.0 at 0.16 /nmol m~2 on the present Elf material. Recently, Grillet et al (1974) reported heats of adsorption for sulfur dioxide on a number of carbonaceous adsorbents and those of high surface oxygen content gave heats of adsorption of the order of 9.0 to 20.0 kcal mol-1 at coverages approaching a monolayer. The activated charcoal used in the present study had a surface oxygen content of approximately 8 X 10-5 mol of oxygen g-1 of carbon and exhibited characteristically lower heats of adsorption than those obtained with the carbon black.…”

Adsorption of sulfur dioxide on heat treated .gamma.-aluminas at room temperature

“…Compacted samples of Alon were heated in air for. 5 h at 400, 500, 700, and 900 °C. The resulting thermally treated Alon samples will be referred to as Alon-4, -5, -7, and -9.…”

“…The nature of the interactions of S02 with -1203 at room temperature is less certain. Grillet et al 5 concluded that S02 is physically adsorbed on alumina and other oxides at 0-30 °C. Rosynek and co-workers,6,7 in their poisoning studies of -1203 with S02, observed no poisoning if S02 was adsorbed at room temperature, but observed a monatomic increase in the degree of poisoning with increasing S02 adsorption temperature.…”