Wheat straw and oat husk volumes and use in Finland | LAB Open

Wheat straw and oat husk volumes and use in Finland | LAB Open

Finland is a significant agricultural producer, but its crop residues like wheat straw and oat husk have historically remained underutilized. However, recent research projects led by LAB University of Applied Sciences (LAB) and VTT Technical Research Centre of Finland are exploring ways to harness these abundant biomass resources for higher-value applications in the bioeconomy.

Wheat Straw Characterization

Wheat is one of the major cereal crops cultivated in Finland, with an annual production averaging 770,000 tons over the past decade. Using the typical crop harvest index, this translates to a theoretical wheat straw potential of 770,000-1,160,000 tons per year. However, only 20-30% of this straw is currently collected and utilized in a sustainable manner, amounting to 150,000-350,000 tons annually.

The composition of wheat straw includes cellulose, hemicellulose, and lignin—valuable biopolymers that can serve as feedstock for various industries. Straw also contains nutrients like nitrogen, phosphorus, and potassium, making it a potentially useful agricultural input. However, the sustainability of straw removal must be carefully considered, as it can impact soil quality and carbon sequestration if not managed properly.

Oat Husk Characterization

Finland is the second-largest oat producer in Europe, harvesting around 1 million tons per year. Approximately 25% of the oat grain is composed of the protective husk, resulting in an estimated 400,000 tons of oat husk generated annually as an agricultural side stream.

Oat husk is primarily used for bioenergy and animal feed production in Finland, but emerging applications in the bioeconomy are also being explored. For example, oat husk is now being utilized for xylitol production and as a fertilizer ingredient. Plans are also underway to establish a biorefinery that will process both oat husk and wheat straw.

Utilization of Wheat Straw

The current utilization of wheat straw in Finland is predominantly focused on energy and fuel production, though the adoption of these applications has been limited compared to other European countries. Efforts to establish large-scale bioethanol and bio-oil plants using wheat straw as a feedstock have faced various challenges, including inconsistent straw availability and logistical complexities.

To enhance the valorization of wheat straw, researchers are exploring fractionation techniques to extract its key components—cellulose, hemicellulose, and lignin—for use in diverse industries, such as packaging, textiles, cosmetics, and food. This approach aims to maximize the economic value and resource efficiency of the straw, rather than solely focusing on energy generation.

Utilization of Oat Husk

Oat husk is primarily used as a fuel for bioenergy production and as an ingredient in animal feed in Finland. For instance, an oat mill in Rauma produces 35,000 tons of oat husk pellets annually for these purposes, while another mill in Utajärvi utilizes its entire 6,000-ton oat husk output for energy generation.

Beyond these traditional applications, oat husk is also emerging as a valuable feedstock for circular economy solutions. It is now being used in the production of xylitol, a natural sweetener, as well as in fertilizer formulations. Moreover, plans are underway to establish a biorefinery that will process both oat husk and wheat straw to extract their various biobased components.

Sustainable Management

The sustainability of straw and husk utilization is a critical consideration, as these agricultural residues play an important role in soil health, nutrient cycling, and carbon sequestration. Researchers have emphasized the need for diversified crop rotations, cover/catch crops, and other sustainable farming practices to maintain soil quality while allowing for the responsible collection of these biomass resources.

At the European level, the Directorate-General for Energy of the European Commission has provided recommendations on cultivation practices to ensure the sustainability of bioenergy feedstocks, including avoidance of burning field waste and liming of acidic soils. These guidelines could potentially be extended to the broader utilization of wheat straw and oat husk in the bioeconomy.

Emerging Trends and Opportunities

The growing interest in circular economy principles and biorefinery concepts is driving the exploration of innovative applications for wheat straw and oat husk in Finland. Beyond their traditional uses in energy, fuel, and animal feed, these agricultural residues are now being considered as feedstock for the production of high-value biobased products, including biochemicals, biomaterials, and biofuels.

The BioCarbonValue project led by LAB and VTT is a prime example of this trend, studying the suitability of high-value carbons derived from wheat straw, oat husk, and other biomass sources for use in energy storage systems, biocomposites, and water purification processes.

Challenges and Opportunities

While Finland has the technological capabilities to utilize wheat straw and oat husk almost entirely, the industrial-scale adoption of these applications has been limited due to various challenges, including:

  • Profitability: The economic viability of large-scale straw-to-biofuel or straw-to-biorefinery projects has proven difficult to sustain, leading to the cancellation or postponement of several initiatives.
  • Logistics: The seasonal nature of straw availability and the narrow harvest window pose significant logistical hurdles in terms of volume management and storage.
  • Sustainability: The environmental impacts of straw removal, including effects on soil quality and carbon sequestration, require careful consideration and mitigation measures.

To address these challenges, a holistic approach that integrates sustainable farming practices, advanced processing technologies, and innovative business models will be crucial for unlocking the full potential of Finland’s wheat straw and oat husk resources in the bioeconomy.

Future Outlook

As Finland and the wider European Union continue to prioritize the transition towards a sustainable, circular, and biobased economy, the valorization of agricultural residues like wheat straw and oat husk will become increasingly important. Through collaborative research, policy development, and private-public partnerships, the country is well-positioned to capitalize on these biomass resources and drive the bioeconomic transformation of its industrial sectors.

The European Future Energy Forum provides a platform for industry leaders, policymakers, and researchers to discuss the latest advancements and explore the future prospects of renewable energy, biofuels, and bioeconomy initiatives across Europe. By sharing knowledge and best practices, this forum can help accelerate the sustainable utilization of Finland’s wheat straw and oat husk, contributing to the broader goals of climate action and resource efficiency.

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