MHD Flow of a Uniformly Stretched Vertical Permeable Membrane in the Presence of Zero Order Reaction and Quadratic Heat Generation

We present a magneto - hydrodynamic flow of a uniformly stretched vertical permeable surface undergoing Arrhenius heat reaction. The analytical solutions are obtained for concentration, temperature and velocity fields using an asymptotic approximation, similar to that of Ayeni et al 2004. It is shown that the temperature field and the velocity field depend heavily on the thermal grashof numbers, heat generation/absorption, magnetic induction, chemical reaction parameters and reaction order. It is also established that maximum velocity occurs in the body of the fluid close to the surface and not the surface

Influence of Power-law Exponent on an Unsteady Endothermic Reaction

In [6], the solution of a steady Arrhenious endothermic chemical reaction where the exponential term was reduced to a power-law approximation was studied. A numerical solution obtained using a shooting technique with second order Runge-Kutta scheme showed that the minimum temperature of the reactant increases as the power-law index increases. In this paper, the scope of the work was extended to a solution of an unsteady Arrhenious endothermic reaction using shooting technique [3]. The result showed that the temperature of the reactant depends greatly on the power-law exponent. The temperature of the reactant increases as the power-law exponent α increase, whereas the temperature decreases as the Frank- Kamenestkii parameter β increases

Comparative analysis on temperature swing adsorption cycle for carbon capture by using internal heat/mass recovery

Due to relatively high energy consumption of absorption technology, adsorption carbon dioxide capture is gathering the momentum in recent years. This paper aims to further improve the thermal performance of a 4-step temperature swing adsorption cycle by integrating internal mass recovery and heat recovery. Exergy efficiency is evaluated by using adsorption characteristics of activated carbon and compared in terms of four different situations i.e. basic cycle, heat recovery cycle, mass recovery cycle, heat and mass recovery cycle, which could illustrate the advantages and disadvantages of different recovery technologies. Results demonstrate that heat recovery and mass recovery technologies are quite conducive to improve the up limit of cycle thermal efficiency. Under the conditions of different desorption/adsorption temperatures and pressures, exergy efficiencies using recovery technologies could be improved by up to 2.86 times when compared with that of basic cycle. Besides, in real application unused percentage of adsorption reactor and metal ratio have large influence on the cycle performance while mass recovery rate has a relatively small influence. One potential application of the proposed recovery technologies is direct air capture in building ventilation system since a largest improvement could be achieved at a low carbon dioxide concentration