Control of acidity on the external surface of zeolite Y for m-xylene isomerization using a mechanochemical neutralization method

Abstract

To improve the ortho-or para-xylene selectivity via the isomerization of meta-xylene, the acid sites located on the external surface of zeolite Y crystals were neutralized by using the intrinsic mechanochemical method, which resulted in reduced coke formation. Zeolite Y crystals were mixed in an agate mortar with alkaline earth metal oxides supported on micro spherical non-porous silica. The catalytic performances into o-or p-xylene from the m-xylene isomerization reaction were enhanced, especially with either the CaO-or MgO-neutralized catalyst, as verified by adsorption of bipyridine, which could not access the pore channel due to its bulky molecular size. These consistent changes in the reaction performance could be ascribed to the decrease in the number of acid sites on the external surfaces.

Spirulina platensisCulture with Flue Gas Feeding as a Cyanobacteria‐Based Carbon Sequestration Option

“…Recent research studies show growing interest in microalgal biofixation of CO 2 , on account of its promise as a viable CO 2 sequestration technology [13][14][15]. In fact, photosynthesis has been recognized as a means to sequester anthropogenic CO 2 , and algae have been identified as fast growing species whose carbon fixing rates are much higher than those of terrestrial plants [16]. In particular, microalgae or cyanobacteria, which convert CO 2 from a point source into biomass, use CO 2 efficiently because they can grow rapidly and can be readily incorporated into engineered systems such as photobioreactors [17][18][19].…”