Bioenergy is part of a larger transition to a bioeconomy in which bioproducts will be competing by means of efficiency and price. The last 5 years have seen an astounding number of new technological developments for bioenergy that increase its performance in the environmental, food and energy security nexus including improvement of livelihoods. A wide array of technological pathways in hundreds of chemical and energy industries is expanding and maturing. Technological change that reduces costs combined with full biomass utilization for food, feed, energy, materials and chemicals may create a competitive industry focused on reduction of emissions and stimulate economic growth.
Almost half of such biomass projects are in the US and Brazil, with many initiatives underway in Germany, The Netherlands, Denmark and the UK, among others. The development of more efficient biomass conversion routes, especially routes that can convert lignocellulosic biomass into biofuels and biochemicals, will accelerate the transition towards a competitive biobased economy. Advanced biofuels have higher costs, compared to corn or sugarcane ethanol, typically related to pre-treatment and enzymatic hydrolysis processes and high cost of enzymes. Alternatives that could eliminate the need for enzymes such as ionic liquids pre-treatments can be expensive and require very high recovery efficiency for low cost products. Wastewater treatment when acid or base catalysts are present can also increase cost. Some pre-treatments require corrosion resistant materials, thus increasing capital costs. The conversion of soluble sugars to ethanol is limited by the tolerance of fermentative organism against inhibitors (e.g., furfural or 5-hydroxymethylfurfural) produced during pre-treatment and by contaminating organisms. The discovery of new detoxification methods and the development of more robust fermentative organisms are addressing this problem. In industrial conditions, current enzymes costs contribution to lignocellulosic ethanol is seven to ten-times higher than in the mature starch ethanol production. Costs are expected to decrease with increased operational time of industrial-scale plants and continued improvements in cocktails by enzyme manufacturers. Consolidated bioprocessing options are also in development.
Initial industrial scale operations of several lignocellulosic ethanol processes as first-of-a-kind plants started in 2013-2014. The positive outlook of advanced biofuels is conditional on accelerated deployment of whole supply chains, including harvesting, collection, baling, transport, drying, densification, storage and pre-treatment. Today there is an increasing awareness that sugarcane can be used for many applications, not only as a biomass feedstock for energy production but also for bioprocessing in a biorefinery into a wide range of chemicals including a variety of polymers. Life cycle analyses indicate that sugarcane would be highly competitive with other crops as a preferred feedstock for a biomass-based industry. Biorefineries that use wood are also underway.
The complex chemical makeup of wood (cellulose, hemicelluloses, lignins, pectins and extractives) makes it a good potential raw material to replace petrochemical-based fuels and chemicals. Integrated biorefinery systems that can produce fuels, chemicals, electricity, heat and other co-products are coming in many colors and formats. Hundreds of large-scale plants could be required to deliver energy in the scales needed, like power markets, while chemicals may not require as many. Urban centers may use flexible small-scale fuel production and some farm plants may be able to deliver multiple chemical products, changing our rural landscapes. It’s easy to imagine a completely different way of using land with multi-functional landscapes such as by substituting extensive inefficient pastures with integrated agro-forestry systems. Enough land is available that does not compete with our future food needs integrated food-energy systems possibly contributing to food security and energy access in developing regions.
Policies and energy prices are key drivers for current bioenergy and the emergent bioeconomy. As the bioeconomy is a promising but infant industry in most of the world, policies are needed to stimulate its development. Lessons learned on the implementation of biomass feedstock chains and conversion technologies have come a long way to decrease energy use, increase efficiency, decrease use of water and emissions. Regulation can deal with the indirect effects.
There is need for investment in advanced biosciences research-genomics, molecular biology, genetics and synthetic biology - for major platforms - sugar, syngas, methane and other bioproducts for fuels, including hydrogen, and chemicals. Over 70% of the costs of bioenergy are on the feedstock production side. Careful consideration is needed to define how best biomass is used, converted, scaled up and deployed to an appropriate level and in understanding the potential value of every single stream of organic matter - a no waste philosophy. The complete use of feedstocks must be sought to convert all primary energy content of the material to useful products. A new green revolution is on the way that includes not only increased yield and adaptation to the environment but also tailor-making biomass chemical composition to different applications including increased saccharification for second-generation biofuels and bio-based chemicals.
Contributed by Glaucia Mendes Souza, President of FAPESP Bioenergy Research Program BIOEN, University of São Paulo
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