Evaluation of low-cost oxygen carriers for biomass chemical looping gasification

Biomass Chemical Looping Gasification (BCLG) is a cost-effective and efficient alternative to conventional gasification. The selection of appropriate oxygen carriers (OCs) is crucial for stable BCLG performance. These OCs need to possess high reactivity, selectivity, material strength, and resistance to sintering. The study investigated...

Biomass chemical looping gasification for high-quality syngas: A critical review and technological outlooks

Biomass chemical looping gasification (BCLG) offers significant advantages over the conventional biomass gasification process in terms of enhanced gasification efficiency, inherent CO₂ capture, process circularity, and mitigated emissions of pollutants. This review discusses the prevailing status of research and development of BCLG...

Multiscale modelling of wall-to-bed heat transfer in fixed beds with non-spherical pellets: From particle-resolved CFD to pseudo-homogenous models

We investigate forced convective heat transfer in packings of spheres, cylinders and Raschig rings, made of glass, steel and alumina, in relatively narrow tubes. A detailed comparison is made between resolved pellet-scale, azimuthally-averaged temperature profiles, and 2D-axially-dispersed pseudo-homogenous plug flow (2D-ADPF) predictions....

Supercritical water gasification of wet biomass residues from farming and food production practices: lab-scale experiments and comparison of different modelling approaches

Globally, large amounts of biomass wastes such as cattle manure, fruit/vegetable waste, and cheese whey residual streams are disposed of from farming and food processing industries. A promising approach to convert such biogenic residues into valuable biofuels is Supercritical Water Gasification (SCWG). A detailed investigation on SCWG of the...

Hydrodynamics of narrow-tube fixed bed reactors filled with Raschig rings

The local flow structure and pressure drop in random packings of Raschig rings are analyzed using sequential Rigid Body Dynamics (RBD) method and Computational Fluid Dynamics (CFD) simulation. Tube-to-pellet diameter ratios, N, between 3 and 6 are investigated for laminar, transitional and turbulent flow regimes (5 ≤ Re_p ≤ 3,000)....

Computational modelling and parameter estimation in fixed beds of non-spherical pellets

Fixed bed arrangements find wide applications, particularly in reaction engineering, where they are employed as multi-tubular catalytic reactors for the transformation of reactants into desired products. The importance of such complicated reactors can be realized by their extensive applications as the process workhorse in various industries, e.g...

Fixed bed reactors of non-spherical pellets: Importance of heterogeneities and inadequacy of azimuthal averaging

Despite the substantial simplicities inherent in pseudo-continuum models of fixed bed reactors, there is a continued interest in the use of such models for predicting fluid flow and transport scalars. In this paper, we aim to quantitatively address the inadequacy of 2D pseudo-continuum models for narrow-tube fixed beds. We show this by...

Rigid Body Dynamics algorithm for modeling random packing structures of nonspherical and nonconvex pellets

Despite the common use of nonspherical catalyst pellets in chemical engineering applications, the packing structures of such pellets have not been as systematically studied and characterized as spherical packings. We propose a packing algorithm based on rigid body dynamics to simulate packing of nonspherical and possibly nonconvex pellets....