What is a biorefinery?
There are many definitions for a biorefinery. According to the US DOE, a bio-refinery is intended as “an overall concept of a processing plant where biomass feedstock is converted and extracted into a spectrum of valuable products”.
De Jong et al. (2012) defined that a biorefinery is sustainable processing of biomass into a spectrum of marketable products (food, feed, materials, chemicals) and energy (fuels, power, heat), using a wide variety of conversion technologies in an integrated manner. This definition is also employed by the Bio-based Industry Consortium. BIC defines a biorefinery as an “integrated production plant using biomass or biomass- derived feedstocks to produce a range of value-added products and energy”.
What is sustainability?
One of the most common definitions listed in the Brundtland report – “Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” This is such a wide definition that it raises the problem of how we can say for sure that all biorefineries are sustainable?
More practically sustainable means that we take care of at least three constituent parts: environmental, economic and social systems where the factory is and where the factory is to be built. Today the cultural things should be also covered.
In a normal investment the investors decisions making is still based mainly on the economic aspect. Adequate environmental matters are still determined by the authorities since they are assumed to only increase both CAPEX and OPEX costs. Social issues seem not to be such a high priority in the agenda, while cultural aspects are rarely taken into account. However, it is great that gradually responsible investors are demanding sustainability values other than purely economic in new greenfield and brownfield investments.
What things to consider when designing a sustainable biorefinery?
There is no simple answer for it, but at least the following things should be considered:
- The product portfolio should be wide – instead of one product there should be at least three separate ones. This essentially reduces market risk.
- The location of the mill should be near raw materials or near markets to avoid unnecessary transportation. This means lower carbon footprint of the products.
- The raw material should be collected as near as possible to the mill. Too long distance reduces raw material price (stump price) for their owners and increases the carbon footprint of the end products needlessly.
- The use of raw material should be based on utilisation of annual growth only. For example, in Europe about 70% of the annual forest growth is utilised and every year the forest is planted to replace what is felled. In addition to this the nutrients, trace elements and residue carbon (stumps and most of the logging residues) should be left or returned to support the growth of raw materials.
- The utilisation of side-streams from the mill should be considered in advance and the activities and new processes should have been taken into account in zoning. This follows the principle of zero waste.
- All energy possible should be taken out from organic raw material as heat and power if it can’t utilised as a material. Residual energy should be used for new and innovative ways to support ecosystems developed near the mill (for example: greenhouses and fish farming). This follows the principle of using energy locally, where the mill no longer heats the environment (air and water courses) unnecessarily.
- All greenfield and brownfield mill investments should be evaluated by using sustainability indicators as A. Azapagic And S. Perdan (2000) have presented. The minimum requirement is to calculate the carbon footprint of the products and compare them with similar products already on the market
- All investments (green or brown) should be formed around an ecosystem that creates more jobs for the region and thus contributes to the social well-being and economy of the region.
This list is not exhaustive, but it shows the breadth of the concept of sustainability. If the above elements are taken into account in the pre-design, we are already very close to a sustainable biorefinery.
 US DOE, 1997, Energy, Environmental and Economics (e3) Handbook, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Washington D.C.
 de Jong, E., Higson, A., Walsh, P., Wellisch, M., 2012. Bio-based Chemicals. Value Added Products from Biorefineries – Task 42 Biorefinery. http://www.ieabioenergy.com/publications/bio-based-chemicals-value-added-products-from-biorefineries. IEA Bioenergy – Task 42 Biorefinery
 A. Azapagic And S. Perdan, 2000. Indicators of Sustainable Development for Industry: A General Framework. https://doi.org/10.1205/095758200530763
Olli Dahl is professor of environmental technology within process industry at Aalto University, and takes a comprehensive view of biomass and sustainability related matters
Source: NC Partnering, Newsletter, 2021-03.
Author: Olli Dahl