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Chemical Technology • June 2016
S
o called ‘damaged’ products, or those that have
exceeded their sell-by date, cannot be sold any-
more and must be returned to the manufacturer,
who in turn contracts a waste treatment company to
collect and dispose of the ‘food waste’. Value chains
where damage to goods can potentially occur include:
manufacturing; transportation; intermediary storage;
sales; and in the case of online shops, final delivery.
The wastage associated with consumerism is what
drove my partner, Neels Welgemoed, and me to start a
sustainability venture which would later become TerraServ
(Pty) Ltd, a South African-based company. We developed
and piloted a process to convert food waste into value-
added products such as hand sanitisers, whiteboard
cleaners and window cleaners, which sold as our EcoEth™
range of products. Wasted foodstuffs are used to create
products, which in turn are sold, and hence help stimulate
the economy.
We also noticed that many products contain hazardous
components either associated with the active ingredients,
or originating from the production process of an apparently
non-hazardous active ingredient. Applying our knowledge,
accumulated from working in the petrochemical industry
for years, we made one of goals to keep everything as
‘natural’ as possible while maintaining their efficacy.
This article focuses, in the main, on the practical ex-
perience gained in wrestling with a continuous distillation
column that had little or no electronic controls. Batch
distillation, as opposed to fully continuous distillation,
would have solved many of these issues, however, it was
of cardinal importance to me that I went through the ex-
ercise in order to learn the best way not to do continuous
distillation when you are on a budget.
Overall process
Our process involves our proprietary fermentation system,
including vacuum extraction of ethanol as our first purifica-
tion step. Next we apply packed bed distillation, avoiding
extractive distillation as we do not wish to introduce harm-
ful solvents into our products. (See business flow diagram).
Before final blending and packaging we filter our prod-
uct to remove any remnant odours. Our process is built
upon efficient use of resources and hence we recycle water
as effectively as possible. In addition to this we aim to
implement an optimum amount of solar heating to further
reduce our carbon footprint, which is already positive due
to the significant reduction in CO
2
equivalent emissions
that our process has on the lifecycle of sugary food waste.
Food waste to value-added
product process −
Continuous distillation
on a budget
by Willie Coetzee
In our consumerist society with its
desire for perfect products, most
consumers are generally not aware
of the wastage they are causing by
rejecting less than ‘perfect’ goods,
such as broken chocolate bars.