Over this series of articles, we have been exploring some of the big challenges facing human society as it continues to develop, and the solutions that the bioeconomy provides for us. Previously we have looked at the problems associated with plastic waste, and at the more intricate and subtle challenges presented by biomass resource provision and ecosystem service provision.
In this final article in the trilogy, we will explore arguably the most well-known problems that the bioeconomy approaches. These have become the primary challenges for any kind of sustainable or renewable project, and are the most widely known among the general public. They are, of course, decarbonisation, and sustainable fuel use. The solutions are myriad, and cross several industries, and the bioeconomy solutions presented here will only form part of a wider collage of change. Though these are technically two different problems, a lot of their solutions overlap, and so we will dovetail them.
Problem: Carbon Emissions and Unsustainable Fuel Sources
Above all the environmental problems the world faces, the most well known is global warming. The evidence that attributes this effect to unmitigated emissions of greenhouse gases is both overwhelming and damning. The chief culprit is well known to be fossil fuels: though these are efficient and effective fuels, burning them releases carbon dioxide, with no alleviation of said emissions “upstream” of the process. This result in a net increase of carbon dioxide in the atmosphere, proliferating the greenhouse effect, and causing the planet to warm, resulting in a rate of climate change rarely before seen on Earth. This problem is now common knowledge, and the scale of the problem is starting to percolate into the public eye, but while it is generally accepted that decarbonisation is a must, progress towards a solution is not as fast as required. There are lots of avenues being explored, but there needs to be more.
On the other side of the fossil fuels coin is the fact that such fuels are by definition unsustainable. There is no way of producing more fossil fuels, as they take millions of years to form, meaning that this kind of fuel is completely non-renewable, and will in theory one day run out. The concern is not, however, about the fossil fuels running out, as this will not happen for some decades yet. Where unsustainable fuels are concerned, the focus is much more on the need to develop low-carbon fuel sources. From a holistic point of view, this prevents depletion of the planet’s resources, but from a more practical perspective, it is a necessary change that humans must make eventually (before the fossil fuels do run out) and so it might as well be made now.
Solution: Biobased Fuels
This is among the most well-known aspects of the bioeconomy: the notion of using biomass as fuel, either directly or indirectly. This manifests itself most plainly in the bioenergy and biofuels sectors: in the former, solid biomass can be burned directly instead of coal to produce heat and power, whereas in the latter, biomass can be processed into liquid fuel sources such as biodiesel or bioethanol and these products burned as transport fuel. Even though these fuels also release carbon dioxide when they are burned, this burning does not cause a net-increase in greenhouse gas levels, since they are made from plant biomass. This is due to the effect, in life, that these plants had, absorbing CO2 from the atmosphere during photosynthesis, thus effectively offsetting the emissions when they are burned.
Of course, there are considerations to be made when utilising fuels like this: there are other technologies outside of the bioeconomy that provide energy on a “zero emissions” basis, such as wind and solar energy, or nuclear energy. The latter, however, is a massive up-front investment, and is not renewable, and the former two are both dependent on weather conditions. Bioenergy, however, does not have any of these flaws, since existing coal infrastructure can be relatively easily converted to handle biomass, and biomass energy is able to provide a constant output (this is evidenced in UK renewable generation stats, where bioenergy forms a consistent baseline, with wind and solar providing varying amounts of energy on top of this). Wind, solar, and nuclear also do not provide viable direct solutions for transportation either. The most viable alternatives for petroleum-based transport fuels are biofuels, with electric cars only recently being able to catch up with biofuel-powered vehicles for performance.
In this regard, the obviously ideal choice would be to use entirely zero-emissions technologies, but they have not yet developed to the required level of efficiency to shoulder the entire energy load. This is what makes bioenergy and biofuels such an attractive solution: they are well-developed technologies that will provide a guaranteed interim benefit while zero-emissions technology continues to develop, ready to take up the mantle in the long term.
But one area where biomass isn’t going to go away is in its use as a raw material alternative to petrochemicals. In the first article of this series we discussed the benefits of biobased plastic from a waste perspective, but they also provide a key renewable alternative to fossil-based plastics. Usually derived from sugar or starch, these plastics usually have identical properties to their fossil-based counterparts, but being derived from renewable resources are considered more environmentally friendly, as, being derived from plants, these plastics become a net carbon sink, resulting in a decrease in atmospheric carbon. However, as plastic waste, they would cause the same environmental damage as petrochemical plastics, but with proper management, as discussed in the first article in this trilogy, they provide a superior environmental option to petrochemical plastics.
Fossil fuels also remain the principal source of chemicals used in the chemical industry, being a readily available source of hydrocarbons. However, renewable, biobased alternatives are continuing to emerge, as the technology to produce chemicals from plant biomass – known as biorefining – continues to develop. This technology has potential to revolutionise the chemicals industry, hopefully reducing the need for fossil fuels as chemical sources to an absolute minimum.
Returning to bioenergy, biomass once again features, not by being the feedstock itself, but by turning provider. In additional to coal, nuclear, and biomass, gas is one of the most important energy sources, being able to provide consistent and reliable energy. This gas is obtainable as a fossil fuel and thus is not renewable, however, through anaerobic digestion of biomass, this gas, now known as biogas, can be produced renewably, with the same carbon-saving benefits of utilising the raw biomass. At smaller scales, this is a much more viable option for using some kinds of biomass to produce energy, and indeed the only option for some forms of biomass, such as animal waste.
But it is not always just raw plant biomass that can be utilised in this way: through biorefining it has recently become possible to produce fuels from waste, by extracting the organic material from said waste. These are known as advanced biofuels, and are arguably a preferable, more sustainable technology to traditional biofuels. The reasoning behind this is that they do not directly utilise any crop-based biomass, thus preventing any loss of cropland for food, or any land-use change in order to grow more energy crops, not to mention providing a useful option to utilise waste as a resource in itself.
Such considerations need to be made whenever using biomass in a process: it is very easy to simply assume that through using biomass instead of fossil fuels, the environmental impact is nullified, but the entire life cycle of the product/process must always be considered. There are always indirect sources of carbon emissions, whether through transport of biomass or fuel before use, or in the construction of plants where the biomass is processed. This, however, should not be a deterrent: as long as biobased processes remain aware of their complete impact – usually through Life Cycle Assessment – then they will be able to ensure the maximum sustainability of the process.
And so, we begin to see the potential scope of the bioeconomy’s impact, both in the short and long term. With proper management, technological development, and self-awareness, we can hope to one day minimise our reliance on fossil fuels. Biomass – and the bioeconomy – has a huge role to play in that transition.
Source: NNFCC, press release, 2018-03-16.
Author: Bob Horton