Natural Solar Drying and Charcoal Production by Pyrolysis of Empty Shells of Cocoa Pods Using a Carbonisation Stove Fitted with a Chimney

The world’s production of cocoa highly has grown since 1960.In West Africa,the production reached about 3,000,000 tons in 2012.More than 50%of the world’s production of cocoa comes nowadays from Côte d’Ivoire and Ghana and Côte d’Ivoire is the biggest producer.After harvesting,the empty shells,considered as non-useful wastes,are abandoned in the fields where they become a source of pollution.That yields millions of tons of biomass that can be converted into charcoal,instead of being sources of pollution.In the present work,the drying kinetics of the empty wet shells were studied.Then,charcoal production by pyrolysis of those empty shells of cocoa pods was performed,using a carbonisation stove fitted with a chimney.The study showed that the empty shells have a high moisture content.The different phases of the drying were observed.The study compared the drying rates and the diffusion coefficients of a small sample and a big sample.Two experiences of carbonisation of the empty shells were successfully carried out.For the first experiment,the pyrolysis temperatures were recorded and the charcoal mass efficiency calculated.For the second experiment,the temperatures were higher and the result was colored charcoals.The colorations disappeared after some hours.

Coppicing ability of dry miombo woodland species harvested for traditional charcoal production in Zambia:a win–win strategy for sustaining rural livelihoods and recovering a woodland ecosystem

The miombo woodland is one of the most extensive woodlands in Africa, supporting livelihoods based on biomass fuel for millions of rural people. However, there are growing concerns about the sustainability of harvesting for biomass fuel （mainly charcoal）. Thus, the aim of this study was to examine whether regeneration by coppice is a viable option for sustainably managing miombo woodlands for biomass fuel production. We tested the hypotheses that （1） species, stump diameter, stump height and time since cutting significantly affect the number of sprouts per cut stump （coppice density） and mean sprout height （shoot vigour） and （2） higher coppice density reduces shoot vigour due to competition among coppice shoots in a given stump. In an inventory in areas that were harvested for charcoal production by the local people, 369 stumps of 11 species were recorded with mean coppice stumps ranged from 6 to 84. The mean coppice density ranged from 5 to 8 shoots per stump while the mean height of coppice shoots ranged from 46 to 118 cm with marked interspecific variations. Stump size was signifi- cantly and positively correlated with coppice density for some of the species, but not with shoot vigour for the majority of the species. However, shoot vigour was significantly positively correlated to time since cutting of trees for nearly half of the species. Coppice density had a significant negative correlation with shoot vigour for two species, and a positive correlation for one species. In conclusion, the results provide evidence about the importance of coppice management as a win-win strategy for sustaining charcoal-based rural livelihoods and recovering the miombo woodland ecosystem.

Effects of Charcoal Production on Soil Physicochemical Properties in Moro Local Government Area of Kwara State, Nigeria

Charcoal production is a major economic activity in rural Kwara State, North-Central Nigeria. Given that it generally involves the use of traditional earth kilns, this study was designed to investigate the effects of charcoal production on the physical and chemical properties of soil. Replicate soil core samples were collected within a depth of 0 - 20 cm from 19 charcoal kiln sites (CKS) and 19 adjacent control sites (ACS) across five administrative districts in the study area. These samples were subjected to laboratory analysis to determine their physical and chemical qualities and then t-test was used to statistically compare the CKS and ACS soils. There was no significant difference in soil texture between both sites. However, CKS soil pH and electrical conductivity significantly increased (p 0.05) due to charred biomass introduced to soils by the process of charcoal production. The CKS cation exchange capacity, Ca and Mg increased significantly (p < 0.0001) by 40.11%, 57.15% and 89.16%, respectively. Charcoal production significantly reduced Fe by 28.54%, while the concentration of other heavy metals remained similar between both sites. The findings showed that charcoal production using traditional earth kilns improves soil physical and chemical properties for agriculture purposes. However, further studies are suggested to understand its effects on vegetation cover and soil biota.

Design and Testing of a Solar Torrefaction Unit to Produce Charcoal

With increasing crude oil prices, fuels like kerosene and cooking gas have become unaffordable for many ordinary people in developing countries. For millions of Africans who need heat energy to cook their food, biomass like wood remains the easiest and cheapest source of fuel. Charcoal remains the most popular choice compared to wood since it can cook food much faster with very little smoke. Torrefaction of biomass is a mild form of pyrolysis at temperatures typically between 200℃ and 300℃ to produce charcoal. Torrefaction changes biomass properties to provide a much better fuel quality for combustion applications. A simple parabolic trough solar collector to produce charcoal by torrefaction process using solar energy has been designed from first principles. The device was fabricated and various locally available wood species were tested. The yield was found to be 21% to 35% with a production time of 90 minutes. The paper details the design procedure and the test results.

Charcoal kiln sites, associated landscape attributes and historic forest conditions:DTM-based investigations in Hesse(Germany)

Background： An examination of the distribution of ancient charcoal kiln sites in the forest landscape seems to be worthwhile, since general trends in the selection of suitable kiln site locations in the past might become obvious. In this way forest landscape elements with a more intense usage by charcoal burning can be identified. By doing this, we can expect to gain information on the former condition and tree species composition of woodland. Investigations on the spatial distribution of charcoal kiln sites in relation to landscape attributes are sparse, however, probably due to the high on-site mapping effort. The outstanding suitability of LiDAR-derived digital terrain models （DTMs） for the detection of charcoal kiln sites has been recently proved. Hence, DTM-based surveys of charcoal kiln sites represent a promising attempt to fill this research gap. Methods： Based on DTM-based surveys, we analyzed the spatial distribution of charcoal kiln sites in two forest landscapes in the German federal state of Hesse： Reinhardswald and Kellerwald-Edersee National Park. In doing so, we considered the landscape attibutes ＂tree species composition＂, ＂water supply status＂, ＂nutrient supply status＂, ＂soil complex classes＂, ＂altitude＂, ＂exposition＂, and ＂inclination＂. Results： We found that charcoal kiln sites were established preferably on hillside locations that provided optimal growing and regeneration conditions for European beech （Fagus sylvatico） due to their acidic brown soils and sufficient water supply. These results are in line with instructions for the selection of appropriate kiln site locations, found in literature from the 18th to the 19th century. Conclusions： We conclude that there were well-stocked, beech-dominated deciduous forest stands in northern Hesse before 1800, particularly at poorly accessible hillside locations. These large stocks of beech wood were utilized by the governments of the different Hessian territories through the establishment of ironworks and hammer mills. Our argumentation is well in line with findings which underline that not all Hessian forests were overexploited in the 18th century. Frequently repeated complaints about ＂wood shortage＂ seemed to be more a political instrument than reality, not only in Hesse, but all over Europe. Consequently, a differentiated assessment of woodland conditions in proto-industrial times is strictly advised, even if contemporary sources draw a dark picture of the historic situation.