Effect of Reactor Temperature on Pyrolysis of Lignocellulosic Medical Waste in a Fixed Bed Reactor

Abstract

The lethargic modes of medical waste disposal in many developing countries have been a cause of concern to many regulatory agencies. In this study, effect of reactor temperature on pyrolysis of lignocellulosic medical waste in a fixed bed reactor was investigated. Gauze bandage was procured from AKOL Pharmacy, Ogbomoso, South-Western Nigeria. Samples of the gauze bandage, 40 g each at a time, were fed into a retort and the retort inserted into a developed fixed bed reactor for pyrolysis at different temperatures (300, 400, 500 and 600 o C) with a residence time of 15 minutes. Tar, gas and char yields were weighed using an electronic balance (WT20002T, RS232C) and were further expressed in percentage of the initial weight of the sample. Results showed that tar and gas yields increased with increasing reactor temperature while char yield decreased with it. Both intraand extra-particle secondary reactions were insignificant and therefore could not influence the yield spectra of products. The highest yield of tar, gas and char were 52.08, 28.42 and 52.7%, respectively while the lowest yield were respectively 30.50, 16.80 and 19.50%. Lignocellulosic medical waste can be a viable source of biofuels and raw materials respectively for sustainable development and for chemical industries.

Numerical Study of the Pyrolysis of Wood Chips for Biocharcoal Production: Influence of Chips Geometry and Initial Moisture Content

“…This reaction scheme depends on the mechanism of the heat and mass transfer between the reactor and the product. The dynamics of heat flux surrounding the wood chips, as heat is transferred from the surface to the core, are related to their shape [18,19]. Investigating some possible shapes of wood chips, the authors of [18,19] showed that the pyrolysis duration and the final mass fraction are shape dependent.…”

“…The dynamics of heat flux surrounding the wood chips, as heat is transferred from the surface to the core, are related to their shape [18,19]. Investigating some possible shapes of wood chips, the authors of [18,19] showed that the pyrolysis duration and the final mass fraction are shape dependent. The intra-particle structural dynamics of the wood chips are also affected by the shapes.…”

“…The shape of the biomass during pyrolysis can lead to differences in the characteristic length of the transport phenomenon for heat and mass transfer [20]. However, the authors of [18] simplified their choice of shapes for ease of numerical simulations. Considering the effect of the shape of wood chips on heat and mass transport phenomenon and product yield, Atreya et al [19] studied cuboids, cylinders, and spherical shapes.…”

“…They found that the duration for completion of the pyrolysis processes, mass loss measurement, iso-surface for internal pressure, and heat generation was highest for spheres and lowest for cubic shapes, and that these measures are affected by the shortest distance for heat and mass transfer. Okekunle et al [18] considered cylindrical, rectangular, equant, and disc-shaped wood chips in their pyrolysis studies. They observed high biochar yield for rectangular shapes at a lower temperature.…”