Table 7. Per capita woodfuel consumption in African regions (M3).

Source: adapted from Amous (1999) and Kir (1984).

All the charcoal consumed in Mozambique is produced by the traditional earth kiln method. The method consists on the following steps: (i) locating suitable trees; (ii) choosing the right place to build the kiln; (ii) cutting the trees and transporting them to the kiln site; (iv) gathering material necessary for kiln construction (grass, clay/sand and when available stones); (v) constructing the kiln; (vi) operating the kiln; (vii) unloading the kiln; (viii) putting the charcoal into bags (Fernandes et al. 1997).

In most households in Maputo, firewood has been replaced by charcoal, which has higher energy density and is thus cheaper to transport. In regulados, where forest resources are still abundant the processes of charcoal production consists on felling selected tree species and specific sizes and make a pile of logs and covered by earth.

The charcoal is made in earth kilns. The capacity of the kiln varies from 20 to 50 bags, very seldom 70 bags. The weight varies from 25 to 35 kgs depending on species used. This type of kiln requires only simple tools and labour. Where the traditional system persist, is drawn from household members or other producers co-operating for specific tasks in the production process. This casual labour although is co-operative is paid by a local beverage called wutchema (20 to 25 litres) (Vilanculos 1998). However, when the objective is commercial it requires chainsaws or two-men-cross-cut-saw and the bulk of the labour is from ex-soldiers and immigrants on wage earning basis. The time required to accomplish the whole process for either method is usually one month (Vilanculos 1998).

Most of the studies carried out in Mozambique took place in Maputo, probably due to the fact that exhibits the highest rate on woodfuel consumption in the country and acute shortage of biomass. Therefore, the charcoal production techniques discussed hereafter are those practised in the southern region of the country.

It is apparent that almost all the charcoal produced in this region is made by private burners. They operate in two major charcoal production areas supplying Maputo, namely the area south-west of Maputo broadly described as "Changalane", but including Changalane, Goba, Mahubo, Mazimunhara and Mafuiane, and the area Marracuene, to the north of Maputo (BTG, 1990).

The studies estimate that these areas provide almost 90% of the charcoal entering Maputo, divided almost equally between them 3 This is in agreement with DNFFB surveys conducted in 1985 and 1988 which showed that the majority of charcoal entering Maputo is transported through the Michafutene (on E.N.1) Matola-Rio (on E.N.2 or Matola Gare checkpoints (Mansur and Karlberg, 1986, Pereira, 1989).

The private producers can be divided into two categories: full-time professional burners operating on a large scale and non-professional burners operating on a small scale. Both categories make use of indigenous hardwoods as their raw material.

The full-time professional burners use large traditional earth mound kilns, while the non-professional burners produce only a few sacks at a time. Charcoal burning is discontinued during the rainy period (December to February). It was also apparent that many professional burner have generally been in the business for some time, often from childhood, and thus possess good charcoal burning skills.

3.2.1. Changalane Region

It is estimated that some 300 to 500 burners are operating in this area. They produce throughout the year except for an interval of approximately two months in the rainy season (December, January).

They produce by far the bulk of the demand in Maputo, utilising heavy and dense indigenous hardwood species such as Micaia, Inconola, Macuacua, Chivondzoane etc., many of them of the Acacia family.

Following a number of interviews, it became clear that all charcoal burners in this typical savannah woodland are operating the same type of earth mound kiln. The are triangular in shape, and of various sizes. The largest have a base of 4m and length of 7 or 8m, sloping from 1,40m to 0,20 - 0,50m at the firing point. Kilns half this size were also observed.

The volume of the large mounds is calculated at 14 mst (ca. 9 solid m3). Thus, as the species used - mainly Micaia (Acacia nigrescens) - combine high density with a relatively low moisture content when green, the total input is estimated at 11 tonnes for the bigger mounds.

The total number of days for the complete operation of one kiln varied between 9 and 22 days. Wood preparation required 2 to 14 days, depending on the use of power chainsaws or a simple bow - saw.

Construction of the mound varied from 1 to 3 days depending on the number of labourers available. Carbonisation time was recorded at 3 to 5 days, and finally a cooling time of 2 to 3 days. Yield varied from 35 to 45 kg, thus an average yield of 16% on weight basis, or 128-kg charcoal/mst wood. These professional burners operate in groups of 4 to 8 men, making at least 12 runs per year. Up to 21 runs per annum were recorded, when burners operate two or three mounds simultaneously.

3.2.2. Marracuene Region

This region is also an important supplier of wood charcoal to the capital, with an estimated capacity of approximately 3 000 tonnes/year. This is produced by dozens of professional burners and a multitude of occasional carbonisers, most of the latter women and youths.

Both professional and non-professional burners operate dame-shaped earth mound kilns. Small mounds, with a diameter of 1,50m and height of 0,90m, constructed and charred in their allotments by the occasional burners. These yield 1 to 3 bags of charcoal, usually from carbonised roots of Eucalyptus stumps or collected dry branches of indigenous trees. Whilst preparation of the raw material is rather time consuming - 3 to 7 days is not uncommon in this already largely denuded area the charring time is short and does not exceed 4 days. A cooling period of several days is usual.

The professional charcoal producers operate earth mounds with diameters ranging from 3 to 4 m, and heights of up to 2m, thus giving a total volume of ca. 7 m³. Their kilns yield approximately 10 sacks, of up to 60 kg each, per run. Total yield is ca. 500kg per run, i.e. 12% on weight basis or 72 kg charcoal/mst wood, somewhat lower than in Changalane. These burners sometimes take weeks to collect and prepare the raw material, mainly from wood with a high density. Construction of the mound, including coverage with coarse grass and sand takes 2 days and carbonisation time is, depending on the judgement of the operator (s), from 1 to 2 weeks. This is followed by a cooling down period of several days. Typical outputs are 50 sacks year for the small burners and 100 - 150 sacks/year for the remainder.

3.2.3. Charcoal Production at FO-2

When the FO-2 project commenced in 1977, a charcoal production-training programme was begun.

This made use of the material obtained from the clearing of the four areas to be afforested. Three carbonisation methods were introduced by Mabonga in 1981, the traditional long earth mound kiln, Mark V metal kilns and the Casamence kiln. Mabonga also considered Katugo brick kilns, Missouris, miniature retorts and continuous vertical retorts. These were rejected mainly on the basis of there being a lack of suitable construction materials.

The first kiln introduced, the traditional long kiln, an earth mound, typically measured up to 10 m in length, 2,5 m in width and 1 m in height. Charcoal yields of 49 kg/mst of input were recorded (Mabonga, 1981). However, the use of these kilns was suspended by the end of 1980, due to the labour intensity of kiln construction and charring control.

Portable steel Mark V kilns manufactured by Forjadora replaced the traditional long kilns. A total of 15 kilns were ordered but only half this number seem to have been delivered due to the lack of suitable materials. The remains of these kilns were found at Marracuene by the consultants. Yields obtained with the Mark V Portable Steel kiln averaged 106 kg/mst (Mabonga, 1981).

The Casamence earth mound kiln was introduced by Mabonga in March 1980. This kiln performed successfully and on the basis of this was recommended by Mabonga as the most suitable charring method for the charcoal production programme in the FO - 2 plantations. The average yield was 89 kg/mst (Mabonga, 1981). The charcoal burners employed by the FO - 2 project are still operating this type of kiln, though not as successfully as they did when under the supervision and guidance of Mabonga 4.

3.2.4. FO-2 Charcoal Production Levels

During the charcoal training programme, from 1979 - 1981 a total of 40,000 sacks of differing weights were produced, approximately 1,360 tonnes of charcoal. However, marketing seems to have encountered considerable difficulties as the light charcoal was not much in demand.

After 1981, when land clearing was almost complete, charcoal production dropped sharply for various reasons, the main one being a lack of raw material. However, improper kilning techniques and the impossibility of maintaining round the clock surveillance of carbonisation because of the security situation have also contributed. Thus for the last seven years only small quantities of charcoal have been produced (less than 100 t/yr.). In 1989, an all-time low of approximately 17 tonnes was reach.

The following table gives the actual production figures.

Table 8. Historical production of charcoal in Mozambique.

Source: Astorga et al, 1989

3.2.5. Charcoal Production at FO-4

According to the MONAP evaluation report, charcoal production at the FO-4 plantation near Beira has stopped. "Charcoal production does not pay its cost. It has therefore been given up" (Astorga ets 1989).

3.2.6. Charcoal Production at FO-5

Carbonisation at FO-5 near Nampula was exclusively performed in traditional long kilns measuring 8 in length, 1 m in width and 1 in height. From the gross 8 mst input, 12 to 14 sacks of charcoal each weighing approximately 45 was produced. This is about 10% lower than that obtained under supervision by Mabonga at FO-2. The production target for 1991 year is set at 30 tp 40 tonnes. FO-2 once fully committed, should contribute substantially more to the local markets.

3.2.7. Charcoal Production in Other Regions

In the Nampula region, charcoal produced by local burners, assisted by members of their family (household production) is obtained from circular, dome-shaped earth mounds, measuring 2 m diameter and 1 m in height. No records on yield were submitted.

Information received from a Canadian forester, operating in Gaza Province, indicates charcoal production in metal kilns, most likely of the Mark V type. In addition, small-scale domestic production in clay beehive kilns of limited capacity was observed. No specifications concerning wood species yield, total production, selling prices, markets etc. are available.