The plans of Africa’s premier wet maize miller to produce a new range of high-value modified starch may be dashed as a result of inadequate municipal infrastructure, Engineering News can today report exclusively.

African Products is already at the detailed design stage of a project to produce a new range of modified starch to substitute imports and boost exports, but it may not be able to go ahead with what could be a R60-million investment at its Meyerton factory because the town’s sewage-and-effluent treatment plant is already exceeding its design capacity.

An environmental-impact study undertaken by Martizburg company Talbot & Talbot finds that Meyer-ton’s plant is already treating more sewage and effluent than its limit of 5 000 m3 a day and would need to be expanded. Technical support group manager Jaco Grobler tells Engineering News in an exclusive interview that the company has been diligently developing Meyerton as its preferred value-added starch-production facility for the past four years and that it would be a pity if the latest modified starch project had to be moved to one of the company’s other sites because of the town’s overloaded effluent infrastructure. A number of alternatives are currently under investigation to reduce the effluent load and possibly reallocate some of the modified starch production to other facilities.

Meyerton municipality has reported- ly drawn up a plan to build a pipeline to the Leeuwkuil treatment works in the Sebokeng area towards midyear in order to relieve pressure on its inad-equate plant, but it is still uncertain that budget approval for the pipeline will be forthcoming, which is now putting a question mark over the siting of the potential foreign-exchange saver and foreign-exchange earner. However, if the town’s infrastructural constraint is overcome, the company will most likely proceed with its plans to produce the high-value, low-volume modified starch that is used in tomato sauce, mayonnaise and other foodstuffs.

The investment could be as high as R60-million to supply the necessary plant and equipment to produce an additional 100 t of modified starch a day – more than double Meyerton’s current production of between 80 t/d and 110 t/d from its existing plant. The new plant would take nine to twelve months to build. Grinaker-LTA has been appointed as African Products’ technology partner to assist with the detailed design of the plant and process.

The raw material that will mainly be used is waxy maize starch, obtained from maize grown locally under contract using seed imported from Australian licensor, Penfords.

Normal maize has two starch poly-mers, one a branched chain carbo- hydrate polymer; amylopectin, and the other a straight chain carbohydrate polymer; amylase. While normal maize is 30% amylose and 70% amylopectin, waxy maize is 99%+ amylopectin, making the waxy maize starch easier to modify for specific food-grade applications. The proposed project involves using chemicals to produce the required cross-bonded starch. A dedicated chemical plant to process acetic anhydride and adipic acids will be built. Grobler cautions that great care has to be exercised in the handling of some of the chemicals used during the production of modified starches and reports that African Products’ personnel visited the Penfords facility in Australia to familiarise themselves with the process and chemical handling facilities to be incorporated into the new plant.

Due to the high chloride concentration during the production process, the equipment used is manufactured in special stainless steel, hastalloy and titanium. African Products is also implementing a number of other projects.

It is in the process of the final hot commissioning of an R11-million upgrade of its dextrose monohydrate facility in Germiston from 16 t/d to 25 t/d, an increase driven by local demand, but limited by the capacities of some of the key components installed during the previous upgrade. The plant was upgraded in 1998 from 10 t/d to the current 16 t/d. The product will be pneumatically conveyed to a new storage, packaging and palletising facility.

Such is the anticipated demand for the glucose-based dextrose monohydrate that Grobler already has his eye on the next step, which would involve a further expansion of the dextrose monohydrate production facility.

Dextrose monohydrate is supplied to the pharmaceutical industry for use in drips, as a 99,5%-pure deionised powder and is used as a bulking agent in pills.

In another growth project, African Products is upgrading the spray dryer and packing facility at its Germiston factory, again mainly to satisfy export markets, following the securing of supply agreements with global beverage and food companies, including giants like Coca-Cola and Nestl

To subscribe to Engineering News's print magazine email subscriptions@creamermedia.co.za or buy now.