ETE Newsletter Fall 2017 - Column: Cees Buisman

The focus on reducing the use of fossil fuels will have great influence on resource recovery. Many do not realize that carbon, including CO₂, will become a scarce resource if we stop using these fuels and transfer to renewable electricity. Many research projects, for example culturing microalgae or converting CO₂ into methane, depend on CO₂ sources from burning fossil fuels. Therefore, waste streams will become an important source of carbon instead. Consequently, environmental technologists need to develop new processes for more efficient recovery of carbon from waste. Anaerobic processes are well suited for this due to their efficiency.

The new factory of Chain Craft in Amsterdam, converting supermarket food waste into caproic acid, is such a process. Caproic acid, produced by anaerobic bacteria, can become a new source for chemicals. This process seems better suited for a carbon scarce world than the conventional anaerobic digestion, resulting in biogas.

Like carbon, also sulphur is harvested from fossil fuels. Therefore, also sulphur production will be limited when fossil fuels are not used anymore. The resulting carbon and sulphur scarcity comes on top of already limited resources like phosphorous and micro nutrients like zinc and selenium. Recovery of these resources will become crucial for future production of food and chemicals.