consulting services for a technical assessment of the stills at the ...

Final Report 

CONSULTING SERVICES FOR A TECHNICAL ASSESSMENT OF 

THE STILLS AT THE OPUWO PROCESSING FACILITY 

25 th March 2011 

commissioned by the Millennium Challenge Account Namibia 

with funding from the Millennium Challenge Corporation

Submitted by: Werner Bester 

Essential Distillation Equipment CC 

Riebeek Kasteel, South Africa 

werner.ede@vodamail.co.za 

+27 21 448 1387 

+ 27 82 334 3324 

Ref: MCAN/COM/IC/3D01001-D

Table of Contents 

Executive Summary ..................................................................................................................................1 

1. Background .......................................................................................................................................2 

1.1 Scope of work ........................................................................................................................................... 3 

2. Methodology ....................................................................................................................................3 

2.1 Pre-processing and steam distillation trials with the Mopane steam still ............................................... 3 

2.2 Pre-processing and steam distillation of Commiphora ............................................................................ 4 

3. Main Findings ....................................................................................................................................5 

3.1 General ..................................................................................................................................................... 5 

3.2 Mopane trials ........................................................................................................................................... 6 

3.3 Commiphora trials .................................................................................................................................... 6 

4. Recommendations .............................................................................................................................7 

4.1 General facility ......................................................................................................................................... 7 

4.2 Mopane distillation ................................................................................................................................... 7 

4.3 Commiphora distillation ........................................................................................................................... 8

Executive Summary 

This assignment had two main tasks: 

i) Inspect the installation of both the Commiphora and mopane still; 

ii) Conduct small processing trials and rectify any problems immediately if possible; 

The tasks above were designed to lead to an assessment and identification of the technical problems as 

well as any recommendations as to how these might be practically solved in order to get the processing 

facility situated in Opuwo fully functional. 

It was also imperative to get both the oil distillation plants working and producing oil without too many 

changes to the current equipment, to train the staff on the operation and maintenance of the stills and 

to establish a basis for standard operating procedures for the facility. 

The assignment was carried out from the 22 nd to the 26 th of March 2011. 

Key Findings 

General facility 

• changes to the electrical supply and fittings is needed, 

• upgrading water quality and supply, 

• installation of drainage and waste removal for a safer working environment. 

Mopane distillation 

• pods needs to be pre processed using a suitable machine, 

• stainless steel baskets need a re-usable material cover to facilitate stilling, loading and unloading. 

Commiphora distillation 

• steam distillation is superior to hydro distillation for Commiphora extraction in oil yield, separation 

and cleaning of equipment after distillation, 

• hand pre processing is the easiest and most convenient method, 

• establish best seal and basket arrangement in the pot for the current use of the hydro still as steam 

still. 

Key Recommendations 

General facility 

• employing a contractor to make the necessary changes to the electrical system, 

• employing a contractor to make the necessary changes to the water supply system, 

Report on the Technical Assessment of the Stills at the Opuwo Processing Facility (April 2011) Page 1

• testing the water quality and making the necessary changes to supply the boiler with suitable quality 

water, 

• employing a contractor to make the necessary changes to the drainage for cleaner and safer 

working area, 

• establish standard operating protocols once the facility is fully operational. 

Mopane distillation 

• to send some mopane pods to a hammer mill supplier to test different size equipment to establish 

the best pre processing means before purchasing of equipment, 

• have a supplier make up some removable hessian covers for the chain baskets. 

Commiphora distillation 

• building custom sorting tables to facilitate the pre processing of the Commiphora, 

• acquiring more baskets and seals to use the full capacity of the current pot and to have an extra set 

to facilitate and speed up the loading, unloading and cleaning process of the pots and baskets, 

• look at acquiring a pot custom designed for the steam distillation of the Commiphora in the long 

term. 

1. Background 

In 2004, IRDNC started investigating the possibility of commercial harvesting of Commiphora resin. 

Commiphora wildii is endemic to north western Namibia and spontaneously produces large quantities of 

resin in response to environmental stresses. The resin is similar to myrrh but can be sustainably 

harvested. Attempts at marketing the resin have met with limited success. Current indications are that 

the market would prefer to purchase the essential oil rather than having to deal with extracting it from 

the raw resin. Also, processing it locally adds value to the product and reduces the high costs of 

transporting the heavy drums of resin. This was the motivation for applying for funding to ICEMA to 

build a processing facility in Opuwo. Similarly, the bulk of the bags of mopane seeds and the associated 

challenges with transportation and storage motivated the purchase of the mopane still. The building 

was erected at the IRDNC Training Centre on the outskirts of Opuwo, the town closest to the PPOs that 

produce the raw material. The building was jointly funded by IRDNC and ICEMA. 

In 2009 two steam distillation units, a hydro/water still and a direct injected steam still, were 

commissioned by the ICEMA project to process the Commiphora resin and the Colophospermum 

mopane seeds harvested by Kunene Producer and Processor Organizations. These were collected from 

South Africa and delivered to Opuwo in May 2010. Due to delays in the installation of the three phase 

electricity at the site, the equipment could not be connected and tested. The ICEMA High Value Plants 

Project ended in June 2010. 


Technical difficulties have been experienced with the operationalisation of the still. These technical 

difficulties need to be resolved and standard operating procedures need to be established to ensure 

that essential oils of a standardized quality are produced. The Opuwo Processing Facility is targeted for 

training support by the MCA-N INP Sub-activity (PPO number 1.1.12) in 2011 but before this can take 

place the facility needs to be fully commissioned. 

1.1 Scope of work 

2. Inspect the installation of both the Commiphora and mopane still 

3. Conduct small processing trials and rectify any problems immediately if possible 

4. Advise as to possible solutions for problems that cannot be rectified immediately 

5. Establish an outline and recommendations for standard operating procedures 

Although not required in terms of the scope of work for these consultancy services the consultant was 

requested by the IRDNC to manufacture trial components (baskets and seals) to make it possible for the 

small processing trials outlined above in point 2 to be carried out. 

In addition to the above work training of the staff on the operation and use of the equipment and the 

distillation procedure was also conducted during the trials. A short training video was also made. 

Through the above tasks it was expected that an assessment and identification of the technical 

problems would be made and that recommendations as to how these might be practically solved in 

order to get the processing facility fully functional would be addressed. 

2. Methodology 

On initial inspection of the processing facility it was decided to first clean the facility and equipment in 

order to start with a fresh approach. This was done by physical means and by use of the boiler to steamclean 

the plant, including the material pots, cooling condenser and oil/water separator of both the 

mopane and Commiphora distillation units. After cleaning the layout of the equipment was rearranged 

in a more permanent position to utilise the space more efficiently. 

Two main processing trials were conducted, one on the Mopane steam still and the other on the 

Commiphora hydro still. In the case of both trials the raw material to be distilled was weighed to 

correlate the weight to oil percentage for the different trials, as this will also have an effect on the final 

decision. All trials were conducted for a period of two hours. 

The components of these trials are described below. 

2.1 Pre-processing and steam distillation trials with the Mopane steam still 

Three trials were done using different pre-processed material with a piece of hessian on the basket 

using the same distillation process: 


1. Whole unprocessed pods 

2. Crushed pods with current hammer mill (on loan from CRIAA SA-DC) 

3. Hand shelled kernels 

The two pots that make up the mopane steam still 

2.2 Pre-processing and steam distillation of Commiphora 

Two trials were conducted on the Commiphora resin using the adapted hydro still. 

1. In the first trial 5 baskets, manufactured for these trials, were prepared with a covering of 5 

different types of material placed in them and then filled with different sized pieces of Commiphora 

resin and placed in the pot with seals of different sizes and materials. 

2. In the second trial and based on the findings of the first trial it was decided to establish whether it 

would be possible to use less seals and pieces of material. In this trial the bottom basket was 

covered with mutton cloth, filled with fine Commiphora powder and placed in the pot with a seal. 

The next three baskets where filled with bigger Commiphora pieces (according to the mesh size of 

the baskets) and placed in the pot without covering material and seals. The final basket with the 

finest mesh size was placed on top with a silicon seal. 


The Commiphora hydro still 

The Commiphora still was originally designed to work as a hydro still where the product is submersed in 

water in a single basket. After trials it was decide that this method was not sufficient for oil extraction 

and created great difficulty during the cleaning process. The modifications will allow the still to operate 

as a steam still; although not ideal it is a workable solution for the immediate future. 

3. Main Findings 

3.1 General 

During the inspection, cleaning and steam cleaning (running the distillation units with empty pots and 

no cooling) it was established that: 

1. The electric breaker in the actual distillation room and on the main box was insufficient and will 

need to be upgraded, 

2. The quality of the water feeding the boiler is not good enough and some form of purification will be 

needed. A water sample was taken and analysed by a lab where it was noted that it has a high lime 

content and Total Dissolved Solids (TDS) level, pending subsequent discussions with experts a 

solution needs to be implemented, 

3. Changes to the plumbing of the feed water to the boiler and to the cooling water for the condenser 

will be required, 

4. Drainage measures need to be taken to create a safe and clean working environment. 


3.2 Mopane trials 

The following are the main findings with respect to the trials conducted on the mopane steam stills. 

1. Distilling the whole unprocessed pods was not successful and no oil was recovered as the shells did 

not open during distillation, 

2. Distilling the pods that have been processed with the hammer mill produced a good amount and 

quality oil of about 2% when compared to the full weight of the crushed shell and kernel, 

3. It was calculated after weighing the empty shells and kernels that weight distribution is about equal. 

The kernels were then distilled and nearly no oil was recovered. 

3.3 Commiphora trials 

The following are the main findings with respect to the trials conducted on distilling the Commiphora 

resin. 

Using the hammer mill to pre-process the Commiphora resin was rejected due to the previous trials with 

the resinous mopane seeds and build up within the hammer mill. Hand pre-processing seems to be the 

easiest and best as the operators have enough idle time during distillation for this procedure; some 

extra tools may be needed and designed. 

During the first steam distillation trail of the Commiphora resin was successful and approximately ±6% 

oil was recovered/volume (i.e. 100kg myrrh = 6kg oil), which was good, comparable to results from trail 

distillation done in laboratory conditions. As there is no norm quantity of oil recovered only further trials 

will establish this. Of the material that was used to cover the baskets in this trail, the mutton cloth and 

hessian was the considered to be the most appropriate. The only seal that was re-usable was the silicon 

seal. Upon opening the pot after distillation it was established that the Commiphora resin boils and 

make bubbles that rise to certain height making it possible to determine the optimal amount of baskets 

that can be used in the hydro still. It was also established that the boiling myrrh bubbles could also 

possibly seal around the baskets negating the use of too many seals. This would be tested in the second 

trial. A few different cleaning methods for the baskets and still were also carried out. 

In the second trial approximately 5% oil was recovered. On opening and inspection it was found that the 

boiling myrrh did seal as quickly as expected and it would better to use more silicon seals to get a better 

yield in a shorter time. Based on this a final basket and seal layout determined (see below in the 

recommendations). Cleaning protocols were finalised. 


4. Recommendations 

4.1 General facility 

The facility, being built before the actual arrival and installation of the stills, will need some minor 

changes to create a user-friendly and safe working environment, based on the findings of this 

assessment it is therefore recommended that: 

1. The 5KA rating electrical breaker in distillation room and in the main box needs to be upgraded to a 

breaker with a 15KA rating due to the type of boiler used as it causes fluctuations in Amperage, this 

change was discussed with the contractor in Opuwo, 

2. The water supply system be modified to facilitate the movement of the boiler which has already 

been discussed with a contractor in Opuwo, 

3. Depending on the results of the water analysis a water purification unit (such as water softener to 

remove lime and Reverse Osmosis to bring down the TDS) to supply the boiler with suitable quality 

water needs to be installed, 

4. Upgrading of water tanks from 5000 ℓ -10000ℓ for sufficient water supply for cooling as there is not 

sufficient supply for a full day’s worth of operating the stills, 

5. After discussions with contractor in Opuwo a suitable solution was reached to modify the floor by 

cutting channels into so that the excess water (from the boiler and cleaning) can drain out of the 

processing room thus creating a safer working environment, 

6. Create a simple method for removing spent plant material from the facility and floor to a waste or 

composting site after each distillation procedure by creating some ramps for a flat bed wheel 

barrow type vehicle which can then be tipped into a waiting trailer for removal from the site, if 

necessary, not withstanding that this “waste material” could also be valuable on its own. Either way 

a suitable storage area or dump area will need to be identified; 

7. Standard operating procedures will have to be established to produce a product of uniform quality 

and to determine the cost of production in order to be able to calculate a sales price; 

8. A business plan should be put together for future changes to improve productivity and for the 

marketing of the oil. 

4.2 Mopane distillation 

The mopane distillation system seems to functioning well and only a couple of minor changes needs to 

be implemented on the pre-processing and on the baskets for loading and unloading, based on the 

findings of this assessment it is therefore recommended that: 

1. The crushed Mopane seeds are the best for distillation in yield/weight and ease and speed of 

processing, although more trials should be done with size of pre-processing, 

2. Oil samples should be tested for quality and also be sent to prospective buyers, 


3. Acquire a strong enough hammer mill with a suitable grid for processing the seeds, preferably only 

breaking the shell, not too fine, 

4. Making some clip or tie-on pre-fitted, re-usable hessian covers for the baskets. 

4.3 Commiphora distillation 

The Commiphora distillation plant, which was originally designed for hydro distillation, can be used to 

steam distil the Commiphora and based on the findings of this assessment it is therefore recommended 

that: 

1. Individual mesh (of the correct size) tables with catchment area below should be constructed to 

facilitate with pre-processing, 

2. Steam distillation will be used as it is superior to hydro distillation in the case of the extraction of oil 

from the Commiphora (time and quantity) and ease of cleaning after distillation, 

3. In longer term it would be better to acquire a pot and baskets designed to steam distil the 

Commiphora as current use of the hydro still does not use the steam supplied as effectively as 

possible and to facilitate with loading, unloading and cleaning, 

4. Oil samples should be tested for quality and also be sent to prospective buyers, 

5. Basket layout in pot will be nine baskets, the bottom basket and 5 th basket to be covered with 

material (mutton cloth or hessian) and 5 silicon seals for every 2 nd basket starting on the bottom, 

6. Two sets of 9 baskets with two sets of 5 seals to be acquired for ease of cleaning and re-filling, 

7. Lifting out of baskets and seals out of pot after distilling to be done while pot is warm, 

8. The pot to be physically cleaned at the end of day or when the build up of spent resin in the pot 

interferes with inserting of baskets for new distillation.

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