Selection of feedstocks from starch-based bio-refineries for development of an innovative and bio-based binder for wood-based panel boards

About SUSBIND project

Project SUSBIND was initiated with the goal to substitute fossil-based chemicals with those from renewable resources. The scope of the project was defined around feedstocks from the starch-based biorefineries and from the vegetable oil-based biorefineries already present in Europe. Meeting a first intermediate milestone end of December 2018, the carbohydrate-based feedstocks are now selected.

Following the vision of a sustainable European bioeconomy 

The role of the bio-based products as alternatives to fossil-fuel counterparts and their importance in developing a sustainable economy based on renewable materials has been recognized in the EU 2020 strategy. A sustainable European bioeconomy is necessary to build a carbon neutral future in line with the Climate objectives of the Paris Agreement. On top of that, a sustainable European bioeconomy aims to support the modernization and strengthening of the EU industrial base through the creation of new value chains and greener, cost-effective industrial processes (European Commission, Directorate-General for Research and Innovation, Unit F – Bioeconomy, 2018).

Selection of feedstock – starch as a possible sustainable alternative 

Starch is a carbohydrate extracted from agricultural raw materials such as wheat, corn and potato. In fact, besides cellulose, starch is the most abundant carbohydrate in nature. Because it is renewable and biodegradable it is a perfect raw material as a substitute for fossil-fuel components in numerous applications. According to Starch Europe, the carbon footprint of starch biorefinery streams is very low compared to traditional chemicals from the mineral oil industry. However, not all streams from a starch-based biorefinery are well suited for its use in the SUSBIND project.

Primarily, the selection of renewable feedstock for the synthesis of the binder to be developed must address the two important issues:

  • similar or lower cost in use than incumbent alternatives to a formaldehyde-free solution,
  • large availability (around 4 million tons of dry substance per year in EU).

Modern starch-based biorefineries, already present in Europe, are indeed able to deliver large volumes of cost-competitive renewable and “clean” feedstocks.

Figure 1: Starch production in the EU. Copyright: Starch Europe

The project team assessed the best starch-based carbohydrates as suitable candidates for the synthesis of wood binders with respects to the following criteria:

  • Economic considerations
  • Technical applicability
  • Sustainability
  • Ease of use
  • Reactivity

The applications of the criteria above to a large number of possible carbohydrates led to the following selection:

  • Fructose Solution, FF95
  • Glucose Solution, GU95
  • Maltodextrin, MDX17

All three proposed feedstocks are products from the liquefaction process of starch. Through depolymerization of the macromolecular starch polymers, solutions of oligomers or even monomers can be obtained and the insoluble starch is converted into liquid syrups. This liquefaction can be done either chemically and/or enzymatically and can be controlled very precisely so that a broad range of syrups can be produced.

Although evident from the process that the carbon footprint cannot be exactly the same for all the selected feedstocks, a fast assessment indicated that the differences are negligible. Fructose, glucose and maltodextrins are all well-established products of high purity in the industry with little complexity in handling and conveniently high level of dry solids around 70%.

The final selection

The final selection of the most suitable feedstock will then be done solely based on the chemical reactivity in the process to be developed. In order to have good coverage of the carbohydrate range, the two monomers fructose and glucose were selected as well as the oligomer maltodextrin, which could be considered a pre-polymer of glucose.

Samples of these selected feedstocks were shared with the project partner taking care of the carbohydrate conversion to reactive compounds for development of the final resin.

Author:

Thomas Luchsinger

Supervisor PPD-CoE Industrial Laboratory

PPD-CoE Industrial Specialist

Center of Expertise Industrial

Cargill Starches, Sweeteners and Texturizers

http://www.cargill.com/ 

List of references:

  1. European Commission, Directorate-General for Research and Innovation, Unit F – Bioeconomy (2018). A sustainable bioeconomy for Europe: strengthening the connection between economy, society and the environment, Updated Bioeconomy. European Union. Retrieved from: https://ec.europa.eu/research/bioeconomy/pdf/ec_bioeconomy_strategy_2018.pdf#view=fit&pagemode=none on 1.4.2019

List of figures:

  1. Starch Europe. Starch Production in the EU. Retrieved from https://www.starch.eu/the-european-starch-industry/#figures on 18.3.2019.