When talking about a biobased economy, most people think biofuel. And who can blame them, since gasoline alone is good for about half of global petroleum use? A transition from petroleum to biomass as a source for fuel would put a serious dent in CO2 emissions, not to mention decrease our dependency on often politically unstable countries.

Gasoline however can also be replaced in other ways than by biomass, like hydrogen or electricity. This does not hold true for the petroleum-based raw materials used in the chemical industry.

Raw materials

Currently worldwide petroleum use is about 85 million barrels daily, of which 18 per cent is used for producing raw materials for the chemical industry. And while 18 per cent might not seem like much, it still amounts to around 2.4 billion litres of oil per day.

These petroleum-based raw materials are in turn used to produce pharmaceuticals, plastics, fertilisers and paint, among others. Biobased raw materials for these products are gaining ground, especially in plastics, but the fossil fuel industry still supplies over 95 per cent of the chemicals needed.

It has to be biomass

Unlike for gasoline there aren’t a lot of alternatives to make these materials from besides biomass. The good news is that the biomass can come from anywhere, from plants to algae, from insects to offal and from old newspapers to waste water.

The problem is that everybody is trying so hard to turn the available biomass into biofuel that it is nigh impossible to find a niche for the production of raw materials from biomass, except perhaps in the case of algae.

Algae

As opposed to plants, the growth of algae does not have to compete over available land with food crops, since algae can be grown virtually anywhere. Another big advantage of algae is that they can easily be programmed, or genetically modified, to produce certain chemical building blocks.

Although plants can make many of these building blocks as well, sometimes even without genetically modifying them, algae are more reliable in producing the exact chemical that is needed. We wouldn’t want a biobased medicine made from plant derivatives to do almost what we want it to do, now would we?

CO2

The biggest drawback for the growth of algae however is the need for constantly moving water. The water doesn’t have to be clean however and can even be salt water for many species of algae.

That just leaves the fact that the water has to keep moving to pump the algae around. They need this to get enough sunlight to photosynthesise. So they do need energy, but remove a lot of CO2 from the atmosphere as a payback.

Energy goals

The U.S. Department of Energy has set the goal to obtain a quarter of their industrial chemicals from biological sources by 2025. So here is a little tip for them and of course everybody else: leave the available land to food crops, maybe using plant waste as a biomass source. Use hydrogen and sustainably produced electricity for transportation and other energy needs and leave the raw materials to the algae.

It will most certainly take longer than 14 years to accomplish all this, but if we keep going as we do we will need three more Earths by 2050.

© Jorn van Dooren | www.bitsofscience.org