The Rotary Trickle-Bed Reactor– A New Reactor Concept for Biological Gas Purification

Abstract

A new type of reactor employed to the biological gas purification is presented. The avoidance of clogging in the carrier packing is achieved by i) the use of a structured, rotating carrier packing, ii) a definite liquid irrigation regime during start-up, operation and clean-up time phases, iii) an on-line determination and control of the fixed biofilm mass. A uniform biofilm thickness is generated by an optimized liquid irrigation of the carrier packing with spray nozzles. The detachment of the fixed biomass is accomplished by liquid shear forces generated with jet nozzles. The time-scheduled operation regime of the reactor is founded on the on-line quantification of the immobilized biomass, which results in a new quality of process governing of biotrickling reactors applied to gas purification. This is proved by the experimental results of pressure drop, dynamic liquid holdup as well as the volumetric degradation rates. The degradation of styrene was investigated in laboratory and field experiments showing a maximal volumetric degradation rate of 150 g m-3 h-1 at a pollutant load of 200 g m-3 h-1. The feasibility of this reactor prototype is demonstrated by employing it to the elimination of industrial waste gas.