Algae used as roofing material
An experiment to test the use of algae in bitumen production has proved successful in multiple ways. The tests, recently completed in Groningen (NL), show that algae can be grown in the waste-stream of a bitumen factory, which consumes CO2. The test went further, demonstrating that these algae can then be used in the production of bitumen for roofing and other purposes.
The algae are grown using the gases from oil heaters. Warmed by these machines, they consume the CO2 that is released in the factory and double in volume every 36 to 48 hours. Part of the mass is scraped away and used for production. The algae contain a particular oil that can be used as a base ingredient for bitumen production. This cycle of using biomass for the production of bitumen materials has never been tested before.
The installation for growing the algae consists of ten large polymer sacks that are filled with water and pointed towards the sun. Each sack is 12 m long and filled with algae monocultures. The sealed sacks, spread over a 100m2 area, ensure that no organic or inorganic contamination spoils the culture. Fed by heat, light and CO2, the algae grow in short time. Previously, algae have been used as a design material. Now, the same organisms are being used and reused on an industrial scale.
Based on the success of these experiments, we could soon be growing most of the ingredients for our roofing material. The two companies involved, Algaecom and Icopal, state that this procedure is absolutely unique. The potential for use is large: bitumen products are used in the construction, transportation industries, among many others. We recently reported on another use of algae, this time as a source of energy in façades, by Arup and Colt.
This is a signal of a turning trend. It is well known that usage of non-renewable sources is under pressure. While current estimates of fossil fuel stocks vary, it seems prudent to concentrate on recycling and reuse of resources, particularly renewable sources such as algae. The method tested here is a green step in the right direction.
Images via Icopal and Algaecom.