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Due to perspective of biomass usage as a viable source of energy, this paper suggests a potential theoretical approach for studying multiregion nonadiabatic premixed flames with counterflow design crossing through the mixture of air (oxidizer) and lycopodium particles (biofuel). In this research, convective and radiative heat losses are analyticall...
Citations
... In Eq. (22), C a and C p are specific heat capacities of oxidizing gas and coal particles, respectively. Similar to the computations conducted in Ref. [27] and by using Taylor expansion, Q r can be linearized as below [27,28]: ...
... In order to present the mass and energy conservation equations in non-dimensional forms, following dimensionless parameters are considered [16,28]: ...
Biomass fuels have pivotal role in power generation decarbonization pathways due to zero-CO2 emission. In this paper, a biomass-fueled combustor integrated with a multi-generation system is scrutinized. The premixed wood combustion is modeled via asymptotic flame structure including preheat, drying, pyrolysis, flame, and post-flame zones. The conservation equations cover the impacts of combustor heat loss and flame inter-regional radiation. To produce electricity, fresh water and heat, the multi-generation system consists of one Brayton cycle, two steam Rankine cycles, and a multi-effect desalination (MED) unit is proposed. In addition to combustion examination, the multi-generation system is evaluated from the energy, exergy, economic and environmental (4E) viewpoints. The outputs are obtained for equivalence ratio, particle diameter, and ambient temperature ranges between 0.2 and 1, 400 and 1600 µm and 285 and 350 K, respectively. Results revealed that when the equivalence ratio increases from 0.2 to 0.8, the total cost rate and output power increase by 25% and 92%, respectively, whereas for increasing equivalence ratio from 0.8 to 1, these values are equal to 1000% and 16%. Also, decreasing particle diameter from 1600 to 400 µm results in an improvement in net output power from 3859.5 to 6611.4 kW and exergy efficiency from 15.97% to 31.12%.
Investigations into the magnetohydrodynamics of viscous fluids have become more important in recent years, owing to their practical significance and numerous applications in astro-physical and geo-physical phenomena. In this paper, the radial base function was utilized to answer fractional equation associated with fluid flow passing through two parallel flat plates with a magnetic field. The magnetohydrodynamics coupled stress fluid flows between two parallel plates, with the bottom plate being stationary and the top plate moving at a persistent velocity. We compared the radial basis function approach to the numerical method (fourth-order Range-Kutta) in order to verify its validity. The findings demonstrated that the discrepancy between these two techniques is quite negligible, indicating that this method is very reliable. The impact of the magnetic field parameter and Reynolds number on the velocity distribution perpendicular to the fluid flow direction is illustrated. Eventually, the velocity parameter is compared for diverse conditions α, Reynolds and position (y), the maximum of which occurs at α = 0.4. Also, the maximum velocity values occur in α=0.4 and Re=1000 and the concavity of the graph is less for α=0.8.
This research investigates the transient flame propagation and oscillation phenomenon in the flame speed of porous biochar dust cloud. Time-dependent mass, momentum and energy equations are solved in the spherical coordinate. The gas phase reaction includes the chemical reactions, thermodynamic properties, and multi-element transition properties. To account for the porosity effects of particles, the biochar dusts are modeled as spherical particles with unlimited number of pores (semi sphere) on the surface. The particle trajectory is governed by the equation of motion. The thermophoretic, gravitational, buoyancy and drag forces are employed in this model. In the energy equation, the absorption and radiation emissions by particles is considered. The results reveal that the inertia differences between the particles and gas causes a difference in the velocities of these two phases at the flame front—which is more evident at the early stages of flame propagation when there is a significant change in the density of dust particles. Moreover, the oscillation is further intensified by enhancing the oxygen concentration due to a higher reaction rate, and, as a result, higher velocity difference between the two phases.
In this study, adsorption of lactoferrin (Lf) and bovine serum albumin (BSA) nanoparticles on pellicular two-layer agarose-nickel immobilized by reactive blue 4 dye-ligand ([email protected]) was investigated. [email protected] was prepared using the three-phase emulsion method. The dynamic light scattering was first employed to quantify size distribution of Lf and BSA nanoparticles. Then, scanning electron microscopy (SEM) and atomic force microscope (AFM), respectively, were used to characterize structures of the two types of nanoparticles and adsorbent beads. SEM and AFM images demonstrate that shapes of the nanoparticles are globular and relatively uniform, where no adhesions were observed. Finally, adsorption behaviors of both Lf and BSA nanoparticles on [email protected] in affinity chromatography were investigated, with focus on the adsorption kinetics. Influences of contact time, pH, and initial concentration were analyzed to investigate the adsorbent behaviors in the expanded bed column. The influence of contact time on adsorption of Lf versus BSA nanoparticles indicates that 4 h is enough to adsorb protein models equal to 45%. Results indicate that Lf nanoparticles have a higher rate of around 83% than that of BSA nanoparticles. The increases in pH have negative effect on adsorption while opposite trend was found for initial concentration. Adsorption isotherm results reveal that the Langmuir and Freundlich isotherm models fit both adsorption kinetics of Lf and BSA very well.
In this study, a mathematical modeling using asymptotic solution method was performed to a multi-region premixed combustion of moist moso bamboo particles under adiabatic condition. The analytical model assumes and divides the modeling system into multi-regions as preheating, drying, pyrolysis, and homogeneous and heterogeneous reactions. The formulated mass and energy conservation equations were written for each region and solved analytically using specified jump and boundary conditions. The experimental validation using temperatures of homogeneous flame and heterogeneous reaction fronts confirmed that the prediction accuracy is promising. Then, combustion characteristics such as distributions of temperature and species mass fractions were clarified. Influences of particle diameter, gaseous fuel Lewis number, and equivalence ratio were finally explored on crucial quantities such as homogeneous flame temperature and heterogeneous reaction temperatures, burning velocity, and pyrolysis front location. The results showed that increasing bamboo particle diameter leads to lower burning velocity, lower flame temperatures, and prolonged reaction fronts. Fuel Lewis number showed similar trends for burning velocity and flame and reaction temperatures as those of particle diameter, while opposite conclusions were found for reaction front locations. The impacts of equivalence ratio are opposite for burning velocity, flame temperature, and reaction front locations as those of particle diameter.
