Half Orange Kiln (HOCK) for Producing Charcoal from Timber Leftovers Constructed at Prime Timber Sawmill Factory in Muheza District, Tanga Region    

By Shima Sago,TaTEDO

Biomass fuels and in particular firewood and charcoal, are main sources of household energy in rural areas and urban areas in Tanzania. Household sector is undoubtedly the largest energy-consuming sector in Tanzania, and more than 90% of household energy consumed in Tanzania is woodfuels. In rural areas where more than 80% of total population lives, woodfuels is used for cooking, water and space heating during the cold seasons. In urban areas, more than 80 percent of the population depend solely on charcoal for cooking and consume more than 10 million cubic meters of round wood per year in the form of charcoal.

 Improved Charcoal Production

In Tanzania, the popular way of producing charcoal is by using traditional earth kilns with charcoal recovery rate ranging between 10 and 12 percent on weight basis. This low rate of recovery means cutting more trees to obtain the same amount of charcoal. In efforts to improve charcoal production efficiency, TaTEDO started to compliment the efforts on improved charcoal production techniques to demonstrate and propagate wood saving techniques using the dome shaped Half Orange Brick Kiln (HOBK). The semi industrial charcoal production technology was introduced to utilize untapped resources such as sawmill residues and forest wastes for charcoal production with the aim of reducing extraction of wood from natural forests.

 Half Orange Kiln (HOK)

This is improved charcoal production kiln constructed using burnt bricks; it has efficiency of 25 – 35 %. Half Orange Kiln has the benefit of reducing wood wastage in the kiln and hence increase quantity of charcoal produced. Half Orange Kiln is applicable in fuel wood plantations where there is larger amount of raw materials (wood) for carbonization and in Saw mill industries. TaTEDO has been promoting this technology by conducting training to Technicians on construction and operation of HOK in sawmills industries and areas of large scale trees clearing for agriculture. This time TaTEDO Constructed one Kiln, at Prime Timber saw mill Industry in Muheza District. During the construction 3 TOT were also trained on how to construct HOK

 Site Selection and Preparation

Clearance of the site was done and it involves activities such as leveling the ground. This is very important stage in the whole process on the construction of Half Orange Kiln (HOK). Availability of logs or saw mill residue for improved charcoal production is also considered criteria for setting up of the Half Orange Kiln (HOK).

 Construction of Foundation

The construction of foundation 20cm of sand need was set surrounded the circle, thereafter the actual construction of the bricks up 40cm from the foundation. From there it is important to decide on which side of the Kiln to position the door depending on the geographic of the area such as the direction of the wind, and the size of the door it is recommended 55cm length after construction of foundation.

     Photo 1: Construction of foundation is in progress.

Straight Jacket.

This involves construction of double bricks together. The recommended height of straight jacket is 60cm after the foundation. This is very crucial wall because it gives the support to later level of the construction of bricks.

      Photo 2: Construction of the Straight Jacket.

Construction of Cupola

This start from the first raw of bricks after the straight jacket. The bricks are set 0.5cm, this is measured by radius rod. Thereafter, the measurement of 1cm up to the 6th raw.

It is very important to promote the construction of Half Orange Kiln to other site (Saw mill Industries) so as to promote improved charcoal production. 

It is very important to prepare all necessary materials before the construction process begin to avoid inconveniences.

·         More people should be trained on how to construct HOK most especially in the Saw mills sites.

·         Testing of the Kiln and hand it over to the entrepreneurs.

·         Promoting this technology and commercialize the improved charcoal production.

·         Finalize training resource materials on construction and operation of Half Orange Kiln