A kinetic model for xylan hydrolysis in liquid hot water flow-through pretreatment was developed. The model utilized a declining xylan hydrolysis rate constant with increasing conversion in combination with direct xylooligomer degradation. The model was able to describe experimental results from flow-through pretreatment of corn stover and triticale straw at various pretreatment temperatures, a...

A study was made of the coking of a commercial fresh sulfide Ni-Mo/Al2O3 catalyst in a fixed-bed reactor. The catalyst was coked using different coke precursors in the gas oil under accelerated conditions at temperatures of 400 to 450°C to yield different deactivated catalysts containing 2-20 wt% C. Two cases were studied; crushed catalyst without diffusional ...

Polygalacturonases (PG) are pectinolytic enzymes that have technological, functional and biological applications in food processing, fruit ripening and plant-fungus interactions, respectively. In the present, a microtitre plate methodology was used for rapid screening of 61 isolates of fungi from Aspergillus section Nigri to assess production of endo- and exo-PG. Studies of scale-up were carrie...

Reductive treatments with pulses of CO-rich atmosphere have been used to increase and maintain the low temperature activity a Pt/CeO2-based oxidation catalyst. A combination operando infrared thermography spatiotemporal-resolved quick scanning extended X-ray absorption fine structure spectroscopy on fixed bed microreactor unraveled that, apart from pulse length, reaction atmosphere, reactor tem...

The problem of designing the pellet characteristics for existing fixed-bed reactors has been studied. The reactor is assumed to be a unidimensional, plug-flow, heterogeneous type. Three particle shapes, two intraparticle mass transfer mechanisms, two kinds of film resistance to mass transfer and two poisoning patterns have been considered. An economic balance to both product market price and pe...

Both types of biomass, despite some similarities, show also many differences. Probably as a result of complex relations (competition, migration, physical factors like flow velocity and biochemical factors like oxygen supply) the flocs and attached biomass can demonstrate many differences, e.g. texture, active surface, heterotrophs and autotrophs ratio, and especially biomass age. A compilation ...

The paper presents a simplified model of chemical looping combustion in a fixed bed reactor under isothermal condition. Both reduction and regeneration phases of the oxygen carrier are modeled in the single reactor model under the hypothesis of discontinuous feed and simplified reaction kinetics. This model is meant to be the simplest possible formulation for a description that incorporates all...