Preparation of acid-modified bentonite for selective decomposition of cumene hydroperoxide into phenol and acetone

Abstract

Phenol is industrially produced by the Hock process, in which cumene hydroperoxide (CHP) is decomposed with sulfuric acid to obtain equimolar amounts of phenol and acetone. Use of the liquid acid requires subsequent neutralization and purification of the phenol at substantial cost, and a waste stream generation that could be avoided if an effective solid acid catalyst could be used. Modified clays exhibit attractive properties as solid acids. Acid treatment produces an increase in surface area and acidity. The present study was undertaken to modify bentonite clay by treatment with hydrochloric acid for the production of phenol and acetone via the decomposition of cumene hydroperoxide. The effects of various parameters such as acid activation, catalyst weight, concentration of CHP, reaction temperature and reusability of catalyst were studied. The results indicate that the acid-modified bentonite catalyst may be used instead of sulfuric acid for selective decomposition of CHP into phenol and acetone.

Effects of Bentonite Activation Methods on Chitosan Loading Capacity

“…Sulfuric acid has the ability to remove the soluble salts and impurities from the surface and interlayers of bentonite, and thus it increases the surface area, porosity, and the number of chitosan loading sites in bentonite [9,15,22]. Figure 7 shows that the chitosan loading onto bentonite first increased and then decreased with the concentration of sulfuric acid (within 3-20 %) used.…”

“…After 4 h of reaction, the mixture was centrifuged, and then the precipitate was washed until the filtrate reached a pH value of 7.0-8.0. The clay was then dried, grinded, and sieved (200 meshes, 0.075 mm sieve size) [15]. To activate the clay by calcination, 5 g of bentonite clay was placed by a griddle in a muffler furnace, and calcinated at given temperature between 150-750 °C for 2 h. After the oven cooled, the clay was grinded and sieved (200 meshes, 0.075 mm sieve size) [10].…”

Solid Acid Catalysts for the Hock Cleavage of Hydroperoxides

“…Furthermore, the leaching of Al3+ results in a decrease of strong Brønsted acid sites, but the overall concentration of weak Brønsted acid sites and the population of Lewis acid sites increases [47][48][49]. Bentonite treated with hydrochloric acid of different concentrations show a significant difference in Brønsted acid sites and according performance in a reaction system with CHP [50]. Treatment with low concentrated hydrochloric acid seems to increase the activity of the catalyst as more Brønsted acid sites are created, but treatment with highly concentrated acids leads to an elution of strong Brønsted acid sites.…”

Novel Reactive Distillation Process for Phenol Production with a Dry Cation Exchange Resin as the Catalyst

“…The phase equilibrium of the system was described by the NRTL equation, (8) where G ij = exp(−c ij τ ij ) and τ ij = a ij + b ij /T. However, there are no binary interaction parameters for CHP with other compounds in Aspen Plus, so the activity coefficient of CHP in the liquid phase is assumed to be 1.…”