Synergistic effect, kinetic and thermodynamics parameters analyses of co-gasification of municipal solid waste and bituminous coal with CO.

Co-gasification of municipal solid waste (MSW) with bituminous coal (BC) is an attractive alternative to realize the harmless disposal and energy harvesting of MSW. In this work, co-gasification characteristics and synergistic interaction of MSW and BC with CO atmosphere are studied by thermogravimetric method, including analyses of thermodynamics, kinetic parameters and reaction mechanism function. Results indicate that MSW gasification process can be divided into four main stages, and that of BC has only three main stages.

Thermally Developing Flow and Heat Transfer in Elliptical Minichannels with Constant Wall Temperature.

Laminar convective heat transfer of elliptical minichannels is investigated for hydrodynamically fully developed but thermal developing flow with no-slip condition. A three-dimensional numerical model is developed in different elliptical geometries with the aspect ratio varying from 0.2 to 1.

Energy, exergy and economic analyses of a novel biomass fueled power plant with carbon capture and sequestration.

The biomass based power plants, especially those with the carbon capture unit, usually suffer the issue of low electric efficiency, which is adverse to their commercial application. As one approach to solving this issue, a novel biomass fueled power plant with carbon capture and sequestration (BFP-CCS) is proposed in this work. The BFP-CCS subunit models are first validated before the integrated model of BFP-CCS is built.

Pressure Drop of Microchannel Plate Fin Heat Sinks.

The entrance region constitutes a considerable fraction of the channel length in miniaturized devices. Laminar slip flow in microchannel plate fin heat sinks under hydrodynamically developing conditions is investigated semi-analytically and numerically in this paper. The semi-analytical model for the pressure drop of microchannel plate fin heat sinks is obtained by solving the momentum equation with the first-order velocity slip boundary conditions at the channel walls.

Lattice Boltzmann Simulation of the Hydrodynamic Entrance Region of Rectangular Microchannels in the Slip Regime.

Developing a three-dimensional laminar flow in the entrance region of rectangular microchannels has been investigated in this paper. When the hydrodynamic development length is the same magnitude as the microchannel length, entrance effects have to be taken into account, especially in relatively short ducts. Simultaneously, there are a variety of non-continuum or rarefaction effects, such as velocity slip and temperature jump.

Investigation on biomass steam gasification in a dual fluidized bed reactor with the granular kinetic theory.

The dual fluidized bed (DFB) reactor is promising to convert biomass into high-quality syngas efficiently. In this work, a three-dimensional model is built based on the granular kinetic theory to predict the biomass steam gasification in dual fluidized bed reactors. The model is firstly validated against a series of experimental results.

Characterization of a dual fluidized bed gasifier with blended biomass/coal as feedstock.

A one-dimensional model is built based on the commercial Aspen Plus software to kinetically simulate the biomass/coal co-gasification process in a dual fluidized bed gasifier. The synergistic effect on the co-gasification kinetics is allowed for, and is coupled with the gas-solid flow hydrodynamics. With the developed model, the effects of different key operating parameters including the biomass blending ratio (R), the initial bed temperature (T), the feedstock mass flow rate (F), the bed material flux (F) and the steam to carbon ratio (R) on the resultant syngas composition and the supplemental fuel mass flow rate (F) are investigated, and the operation parameters are optimized.

On a clean power generation system with the co-gasification of biomass and coal in a quadruple fluidized bed gasifier.

A clean power generation system was built based on the steam co-gasification of biomass and coal in a quadruple fluidized bed gasifier. The chemical looping with oxygen uncoupling technology was used to supply oxygen for the calciner. The solid oxide fuel cell and the steam turbine were combined to generate power.

Simulation of biomass-steam gasification in fluidized bed reactors: Model setup, comparisons and preliminary predictions.

A user-defined solver integrating the solid-gas surface reactions and the multi-phase particle-in-cell (MP-PIC) approach is built based on the OpenFOAM software. The solver is tested against experiments. Then, biomass-steam gasification in a dual fluidized bed (DFB) gasifier is preliminarily predicted.

Thermodynamic analyses of a biomass-coal co-gasification power generation system.

A novel chemical looping power generation system is presented based on the biomass-coal co-gasification with steam. The effects of different key operation parameters including biomass mass fraction (Rb), steam to carbon mole ratio (Rsc), gasification temperature (Tg) and iron to fuel mole ratio (Rif) on the system performances like energy efficiency (ηe), total energy efficiency (ηte), exergy efficiency (ηex), total exergy efficiency (ηtex) and carbon capture rate (ηcc) are analyzed. A benchmark condition is set, under which ηte, ηtex and ηcc are found to be 39.

Sphere Drag and Heat Transfer.

Modelling fluid flows past a body is a general problem in science and engineering. Historical sphere drag and heat transfer data are critically examined. The appropriate drag coefficient is proposed to replace the inertia type definition proposed by Newton.