Evaluation of Four Types of Kilns Used to Produce Charcoal from Several Tree Species in Mexico

Abstract

Charcoal production is an activity that dates back over the years. The objective of the study was to determine the temperature and heating ramp in industrial carbonization processes using different kiln types and to quantify its impact on yield and quality of charcoal from different firewood species. The selection of sites, kiln types, and species investigated was based on those with highest production in Mexico. Brazilian beehive kilns using Arbutus xalapensis, Quercus durifolia, and Quercus sideroxyla species were analyzed; modified Brazilian beehive kilns with Pithecellobium dulce and Tamarindus indica; Argentine half-orange kilns with Quercus magnoliifolia and Q. sideroxyla, industrial metal kilns with Brosimum alicastrum, Vitex gaumeri, Manilkara zapota, and Pouteria unilocularis. The process time, temperature, heating ramp, production yield, and quality of charcoal produced were determined. Data were analyzed in a completely random statistical design. The industrial type kilns showed the highest production yield (>35%), and the Brazilian beehive kilns obtained the longest carbonization time (>240 h). On the other hand, the modified Brazilian beehive kilns obtained the best energetic characteristics (>75% fixed carbon and <16% volatile material). A carbonization process with a slow heating ramp (<1 °C min−1) and temperatures of 500–600 °C can generate a charcoal with export quality.

Quantification and Determinants of Carbonization Yield in the Rural Zone of Lubumbashi, DR Congo: Implications for Sustainable Charcoal Production

“…This disparity can be attributed, first, to the richness in tree species of the accessible miombo forest and, second, to an inefficient carbonization technique requiring an increased amount of wood for substantial charcoal production. It is noteworthy that controlling carbonization becomes increasingly challenging as its scale increases [54]. This observation aligns with the conclusions of Ref.…”

The Effect of Clay Insulator Use on Corn Cob Carbonization Reactor Heat Loss

“…The dimensionless Nusselt (Nu) and Gasthof (Gr) numbers are computed using Eqs. ( 5)- (12). The convection coefficients and heat losses are calculated using Eqs.…”

“…Moreover, simulations of char activation rotary kilns indicate that temperature distribution within the kiln is influenced by operational variables, including fuel and feed rate [6]. Furthermore, studies on industrial carbonization processes have shown that using slow heating techniques and maintaining the kiln or reactor temperatures distribute between 500 and 600℃ will produce high-quality charcoal suitable for export [12].…”

Comparison of Technical and Operational Conditions of Traditional and Modern Charcoal Kilns: A Case Study in Italy

“…The cooling phase represents one of the most time-consuming phases of the entire charcoal production cycle, with a duration similar to the carbonization process [35,91]. The natural cooling of the product requires a long time, drastically reducing productivity [1,22,24,25].…”

“…In the literature, several solutions are presented to accelerate the cooling process. Among the most common systems adopted are the use of water, inert gases, heat exchangers, the removal of insulation, and the use of different materials and thicknesses for the construction of kiln walls [22,72,78,91]. However, the implementation of additional components for cooling the material could cause an increase in investment costs and the use of natural resources such as water [22].…”