Adsorption kinetics of formaldehyde from aqueous solutions by carbon porous materials in presence of phosphoric acid. <...> Крайкин Григорий Андреевич Овчинников, Валентина Андреевна Горских, Ильяна Ильдусовна Фассалова, Денис Андреевич Кириллов, Вадим Салаватович Тухватшин ( ), Рифкат Фаатович Талипов Кафедра органической и биоорганической химии, Башкирский государственный университет, ул. <...> Валиди, 32, Уфа, Российская Федерация, 450076 E-mail: vadimtukhvatshin@yandex.ru ( ) Владимир Александрович Крайкин Уфимский институт химии Российской академии наук, просп. <...> Кraikin Grygori A. Ovchinikov, Valentina A. Gorski, Ilyana I. Fasalova, Denis A. Kirilov, Vadim S. Tukhvatshin ( ), Rifkat F. Talipov Department of Organic and Bioorganic Chemistry, Bashkir State University, Z. Validi st., 32, Ufa, 450076, Russia E-mail: vadimtukhvatshin@yandex.ru ( ) Vladimir A. Kraikin Ufa Institute of Chemistry of RAS, Pr. <...> Octyabrya, 71, Ufa, 450054, Russia ADSORPTION KINETICS OF FORMALDEHYDE FROM AQUEOUS SOLUTIONS BY CARBON POROUS MATERIALS IN PRESENCE OF PHOSPHORIC ACID In this paper we studied the adsorption kinetics of formaldehyde on porous carbon nanotubes and glassy carbon from aqueous solutions in the presence of phosphoric acid. <...> We found the influence of the contribution of external mass transfer and internal diffusion on the process of formaldehyde adsorption. <...> The time of establishment of sorption equilibrium was determined. <...> Key words: formaldehyde, carbon nanotubes, glass carbon, adsorption kinetics INTRODUCTION It is known that 4,4-dimethyl-1,3-dioxane is a key intermediate for the industrial synthesis of isoprene [1]. <...> It is obtained by condensation of the aqueous solution of formaldehyde with 2-methylpropene in the presence of phosphoric acid. <...> In the last decade, a porous materials has been used for the above process [2]. <...> However, in this work were not considered features of interaction of reagents and products of Prins reaction with porous materials. <...> Therefore, the aim of this work was to study the adsorption of formaldehyde from aqueous solutions by carbon nanotubes and glassy carbon in the presence of phosphoric acid. <...> EXPERIMENTAL We have used carbon nanotubes with a diameter 7-11Е ("Tomsk Catalyst Plant", Tomsk) and glassy carbon as sorbents [3, 4]. <...> Samples of a porous carbon sorbent [in the case used of nanotubes their weight was (0.10±0.01) g <...>