Progress in spherical packed-bed reactors: Opportunities for refineries and chemical industries

Giving the ever-increasing energy and raw material demand as a result of global economy growth, revisiting the traditional reactor configuration designs (which are considered to be the heart of chemical industries) can significantly reduce the capital and operational costs while addressing the larger market demand for chemicals. The spherical-reactor geometry is an attractive alternative design to traditional tubular reactors due to its lower pressure drop (which is due to feed distribution over a larger outer surface area in spherical reactors compared to the cross sectional area in conventional tubular reactors) and recompression costs as well as construction material investment (reduced wall thickness to half). This review summarizes numerical modeling and experimental research on spherical reactors from 1958 to date. Several configurations of spherical reactors have been described and categorized. A review has been performed on modeling results of numerous arrangements and combinations of tubular and spherical reactors for industrial-scale reforming processes. The superiority of spherical packed bed reactors is further discussed and additional recommendations are provided to be considered in future research. As a general conclusion, spherical reactors could be considered as a potential candidate for pilot and industrial scale reactors due to their cost-effective designs and flexibilityof operation conditions.