Integrating green chemistry into Austrian secondary education using the context of wood biorefinery

1 Introduction

The responsible use of resources is one of the defining challenges of our time. Climate change, environmental pollution and global health crises are intensifying, driven by human activities and unsustainable practices [1], [2], [3], [4], [5]. It is essential to develop and adopt sustainable processes and products to ensure the viability of the planet for future generations. Addressing this challenge requires collaboration across multiple sectors. These efforts must be grounded in a clear understanding of the issues and a commitment to practical solutions.

The chemical industry holds a dual role in this context. On one hand, chemical substances and processes have contributed to environmental damage and health problems through pollution, persistent toxins and resource-intensive production methods. Chemistry is often perceived negatively, fuelled by stereotypes and high-profile accidents that highlight its risks and dangers [6]. For example, a recent study on European consumers perception of chemistry, chemists and chemicals shows that nearly 40 % of the participants wanted to live in a world without chemicals, unaware that such a world does not exist [7]. On the other hand, chemistry also offers solutions. Not only scientists seem to recognise chemistry’s contribution to society, but some studies among laypeople also show a tendency towards a positive view of chemistry, chemists and chemicals [8].

The industry can create safer and more efficient material and processes by following the 12 Principles of Green Chemistry [9]. These principles pose a framework for minimising environmental and health impacts of chemical processes. They address aspects such as atom economy, hazard reduction, energy efficiency and the use of renewable feedstocks. Thus, they align with the United Nations Sustainable Development Goals (SDGs), particularly SDG 12 (Responsible Consumption and Production) and SDG 13 (Climate Action).

At the individual level, societal change relies on informed choices and responsible consumption behaviours [3], [4], [10]. While systemic challenges cannot be resolved through personal actions alone, individuals can contribute meaningfully by supporting sustainable products, advocating for change and adopting practices that align with environmental goals. This can be achieved through science education and its main goal of scientific literacy [11], [12]. Scientific literacy, defined as “the ability to engage with science-related issues […] as a reflective citizen” [13], provides the foundation for informed decisions and responsible actions [12].

2 A synergistic approach to getting GC in the chemistry classroom

Developing and evaluating teaching material requires a multifaceted approach involving diverse stakeholders. For this reason, we applied a collaborative model (depicted in Figure 1) uniting educational researchers, pre- and in-service teachers and experts in the field of GC.

Figure 1:

Schematic representation of all parties involved in developing and evaluating the TLS.

The primary aim of this collaboration is to design, develop and evaluate TLSs focused on GC for secondary students. These TLSs aim to increase students’ knowledge on GC and, in turn, increase their scientific literacy. The TLSs include digital learning environments as part of the SpottingScience project (www.spottingscience-vienna.at), experiments and practical lab activities, apt worksheets, presentations and lesson plans on GC topics.

Educational researchers ensure that the teaching materials meet educational standards and facilitate their dissemination through professional development courses. The teaching materials presented in this contribution were developed and evaluated in co-construction with pre-service teachers alongside educational researchers.

For pre-service teachers, engaging with GC topics in their final theses offers multiple benefits: First, it encourages them to reframe their subject knowledge or acquire new content knowledge through the lens of GC. Second, it helps them to consider their students’ prior knowledge, beliefs and concepts when designing teaching materials [2]. Finally, participation in the project equips pre-service teachers with scientifically accurate, pedagogically appropriate and evaluated teaching materials for use in their future classrooms.

To ensure scientific accuracy, we collaborate closely with experts from various fields. These experts contribute specialized knowledge and insights on advancements in GC. This collaboration further provides a platform for experts to share their findings with broader audiences and engage with educational stakeholders. In-service teachers contribute by offering insights into their classroom realities, including relevant topics, challenges encountered and instructional needs. Participation in professional development courses enables in-service teachers to acquire content knowledge about GC and gain guided access to our teaching materials. Finally, in-service teachers integrate GC practice in their lessons through their role as multipliers.

3 Biorefinery of wood: a context for teaching GC

The TLS was developed through the iterative process of educational reconstruction [28], integrating the three key components ‘Clarification of Science Content’, ‘Research on Students Perception’ and ‘Design of the TLS’. To ensure accuracy and relevance, the science content described in chapter 3.1 was clarified in collaboration with experts in the field of lignocellulose biorefineries.

Wood biorefineries were chosen as the central context because they intersect sustainability, chemistry and regional relevance. The transformation of wood into a variety of products provides opportunities to integrate selected aspects of the 12 Principles of Green Chemistry. The use of renewable resources is particularly tangible and accessible for upper secondary learners. Additionally, the topic has strong local relevance, as approximately two-thirds of Austria’s land area is covered by forest. Comparing wood biorefineries to conventional oil refineries offers a way to introduce general chemical concepts (e.g. structure-property relationships) in new contexts.

Similar to crude oil in an oil refinery, biomass is the raw material in a biorefinery. In this regard, a biorefinery is the “sustainable processing of biomass into a spectrum of marketable products (food, feed, materials, chemicals) and energy (fuels, power, heat)” [29].

Integrated biorefineries aim to create synergies by linking biomass processing, product manufacturing and energy supply. The advantages of such synergies include shared water, wastewater, waste and energy systems, greater production capacity and lower costs [30]. Although biomass is considered renewable, it is not unlimited: Cultivation areas are restricted, seasonal and often compete with other land uses, such as food production or nature conservation [30]. Economic factors must also be considered, as the resulting products must be competitive with existing products and production ways. Biorefineries must therefore utilise the available resources as efficiently as possible while balancing ecological and economic factors.

3.1 Clarification of the scientific content – the chemistry of wood biorefinery

Wood biorefineries, especially pulp production, serve as a well-known example for biorefineries. Wood is a suitable raw material for the chemical industry because the cell wall consists of different components, enabling different production chains. The components are categorised according to their extraction properties into cellulose, hemicellulose, lignin and extractives.

The most important product of wood biorefineries is cellulose, which is largely used to produce pulp and paper [31]. Cellulose is a biopolymer made of glucose monomers connected by β-1,4-glycosidic bonds. Wood contains 30–50 % cellulose, depending on the tree species [32]. In contrast to cellulose molecules, hemicellulose molecules are heteropolysaccharides consisting of glucose, mannose and galactose molecules [32]. Compared to cellulose, hemicellulose has a lower chemical and thermal stability. It can either be preserved or destroyed during wood pulping, depending on the conditions [33]. The content of hemicelluloses also varies depending on the plant species, ranging from 5 % in cotton to 20–30 % in wood [33]. Hemicelluloses and celluloses act as structural carbohydrates, providing stability and structure of the cell walls.

The third major component of wood are lignins, phenol-based macromolecules. Phenylpropanoids (phenols with a C3-substituted side chain) form the basic unit of lignins and can be present, for example, as coniferyl alcohol, cumaryl alcohol or sinapyl alcohol in a three-dimensionally cross-linked structure [33]. The crosslinking is created by aryl-ether bonds on the respective α- and β-terminal carbon atoms. Lignin enables plants their stability and resilience. Depending on the plant species, the lignin content ranges from 17 % (grasses) to 33 % (spruce) [33].

There are various methods for pulping, which differ depending on the raw material (e.g., different types of wood, straw or other agricultural residues) and the intended cellulose application (e.g., paper, fibres, derivatives). For instance, the Kraft pulping process is carried out under alkaline conditions at approximately 160–170 °C using the salts sodium sulphide and sodium hydroxide. Figure 2 shows the reaction of Kraft pulping [34].

Figure 2:

Reaction scheme of the Kraft pulping process. Source: Martina Zodl, based on Otromke et al. (2019).

First, the alkaline conditions cause the phenol function to be deprotonated. Then, the aryl ether bond in alpha position is cleaved and quinone methide is formed. Driven by the rearomatisation of quinone methide, a hydrogen sulphide ion nucleophilically attacks the α-carbon atom and a thiol is formed. The sulphide ion binds to the neighbouring β-carbon atom, as it is relatively large and has free electron pairs available. It is only at this point that the key step of the reaction takes place, namely the cleavage of the oxygen bond on the β-carbon atom. This creates a triatomic, unstable thiirane ring, which finally decomposes and a double bond is formed [34]. This method is primarily used to produce pulp for papermaking [35].

After primary refining, the so-called precursors cellulose, hemicelluloses and lignin are separated. During secondary refining, cellulose and hemicellulose can be treated with specific enzymes in a fermenter to produce monomeric sugars such as glucose and xylose [30]. These sugars can in turn be fermented to contribute to the biotechnological production of ethanol, acetic acid and furfural.

With regard to the Principles of GC, pulp production generates a large proportion of by-products in addition to cellulose. Most of these are used for energy rather than as materials [36]. Biorefinery products are diverse, ranging from paper applications and medical supplies to textiles, plastics and food products such as vanillin and xylitol. However, a recent study shows that one third of wood in Germany is used in the sawmill industry, almost 21 % is used as split wood in private households, while its use in the pulp and paper industry and other material uses is only 7.1 % and 0.1 %, respectively [37].

The insights into the utilisation of wood resources presented in this chapter informed the development of the teaching materials presented in chapters 3.3 and 3.4.

3.2 Clarifying learners’ perspectives on biorefineries

Following the thorough content clarification of biorefineries, research was conducted on teaching and learning about the topic ‘Wood Biorefinery’. A qualitative approach was employed to explore learners’ associations with the concept of biorefinery. Specifically, an association-test based on the Own-Word Mapping technique [38] was chosen. Participants were given a central term, ‘biorefinery’ and asked to write down associations within a spatial (one A4 sheet) and temporal (5 min) framework. This approach seemed particularly suitable for exploring learners’ associations in a rather unknown field, as it allows for the externalisation of cognitive structures and facilitated new insights into their conceptual frameworks. The survey was conducted between March and April 2023 with students (N = 231) from secondary schools in Vienna. The participants were in the 11th or 12th grade (ISCED 3) and came from both academic and vocational schools. Written informed consent was obtained from all participants, their legal guardians as well as the school community committee. The data was collected anonymously, and no personal information was collected.

The data was analysed using a qualitative, structured content analysis approach [39]. Inductive coding, with the option of assigning multiple codes, led to the development of a category system with 12 main categories such as ‘Principles of GC’, ’Raw materials and products’, ‘Production processes & Energy’, ‘Chemistry’ and ‘Nature, Environment, and Climate’ and 18 subcategories. Each category was defined with anchor examples and coding rules to ensure consistency and clarity. The coding process underwent iterative refinement, including feedback from pre-service teachers and lecturers to improve category validity and applicability. Interrater reliability was tested (κ = 0.73) based on Brennan and Prediger [40], measuring the agreement by chance based on the number of categories rather than marginal frequencies. This approach was appropriate because, with predefined segments, no segments remained uncoded by both coders.

The analysis revealed 1,766 associations with the term ‘biorefinery’. Prominent main codes included ‘Nature, Environment, Climate’, ‘Raw materials and products’, and ‘Production processes & Energy’. Less frequent associations included ‘Principles of GC’ and ‘Economy’ (Figure 3).

Figure 3:

Relative frequency of segments coded with at least one subcode from the respective main category.

Interestingly, the term ‘biorefinery’ was often associated with ’oil refinery’. This likely reflects students’ attempts to derive meaning from the unfamiliar term by associating it with their existing knowledge on oil refineries from other lessons. The study also revealed varying attitudes toward biorefineries. Some responses reflected positive associations, while others revealed negative connotations. The response depicted in Figure 4 shows internal contradictions between the terms ‘bio’ and ‘refinery’.

Figure 4:

A student’s associations with the word ‘biorefinery’, depicting internal contradictions between ‘bio’ and ‘refinery’ (translated version of original student’s writing by the authors).

Recognising students’ preconceptions is necessary for chemistry teaching, as these ideas can shape how they engage with new concepts [41], [42].

For this reason, we incorporated the findings in the TLS by starting with familiar concepts, like oil refineries, and then transitioning to biorefineries, highlighting their processes and sustainability implications.

4 Piloting the TLS

During the piloting phase, units one, four and five of the TLS were implemented in two 11th grade classes (N = 25) at a Viennese secondary school. These units were selected for evaluation due to their focus on GC, wood and wood biorefinery, while units two and three provided preparatory content. Unit six, which involves a student-led council, requires a different methodological approach for evaluation. To evaluate the TLS, a mixed-methods study was conducted, to examine how students’ conceptual understanding of GC evolved. The study aimed to determine how the TLS affected students’ conceptions about GC. To ensure consistency, the units were taught by a researcher with a degree in chemistry education, following the same procedure in both classes.

Using a pre-, post-, and follow-up design, students were asked to complete the sentence ‘I think green chemistry is …’ and, similar to the associations test described in chapter 3.2, list their associations with GC. A summative qualitative content analysis using deductive categories based on Armstrong [43] was employed to analyse their responses. We calculated interrater agreement of two raters across three measuring points: pre-test (88,37 %), post-test (92,86 %), and follow-up (80,95 %), with an overall agreement of 87,04. Subsequently, kappa coefficient [40] of 0.86 was calculated.

Initial pre-test data revealed that students’ associations with GC were mostly vague buzzwords with little explanation, like ‘sustainability’ or ‘environmentally friendly’. These results are similar to those of a broader group surveyed 2022 (N = 115) in a study by Lembens and colleagues [2]. Only one student mentioned an association linked to the 12 Principles of Green Chemistry.

After completing the TLS, more students provided associations tied to the GC Principles, while the use of vague keywords decreased. Three weeks later, during the follow-up test, the number of students referencing at least one of the 12 Principles increased further. Figure 5 shows the frequency of associations coded in four categories across the three measurement points. To further analyse these results, Wilcoxon signed-rank tests were conducted on selected categories, as the data did not meet the assumption of normality. No significant differences and small effect-sizes were observed for the categories ‘Incorrect Definition’ (z = 1.34, p = 0.182, r_rb = 0.25) and ‘Buzzwords Only’ (z = 1.51, p = 0.129, r_rb = 0.28). In contrast, the category ‘12 Principles of GC’ showed significant increases with large effect-sizes over time (z = 2.55, p = 0.011, r_rb = 0.60). While the effect sizes suggest potential growth in conceptual knowledge on GC, the small sample size calls for careful interpretation. However, these quantitative results align with the conclusions drawn from the qualitative data [44].

Figure 5:

Frequency of four coding categories across the three measurement points: pre, post and follow-up. Connecting lines between measurement points are introduced for visualization purpose only.

Additionally, situational interest [45] was measured across the units using a questionnaire with five Likert-scale items. The internal consistency of the scale is satisfactory, with Cronbach’s Alpha reported at 0.75. The item-total correlations range from 0.39 to 0.59. Item and scale descriptives, as well as the full questionnaire, are provided as supplementary material.

Figure 6 illustrates individual trajectories as well as the linear trend across all three measurement points on situational interest regarding the three units. Overall, mean situational interest remained consistently high across the three measurement points.

Figure 6:

Individual trajectories (N = 25) and linear trend of four-point likert-scaled items from the situational interest scale [45] across three measurement points: pre, post and follow-up.

5 Limitations, conclusion and implications

In the context of GC, understanding the environmental impact of chemical processes and products is essential for driving systemic change. Integrating GC into educational curricula is a critical step in preparing students to address global challenges. However, this contribution identifies significant barriers to incorporating GC into education, such as the lack of teaching resources. Our research on students’ prior concepts of biorefineries reveals that regardless of grade or school type, students have difficulties perceiving chemical processes as pathways to sustainability. The TLS on wood biorefineries demonstrates how ‘classical’ chemical content can be taught in a new context. By integrating GC into education, students can develop the scientific literacy needed to make informed and responsible decisions that align with environmental and societal goals [5], [13], [14].

The TLS encourages students to explore and analyse real-world issues, such as the environmental impact of fossil fuels and the benefits of renewable resources like wood. Through the SpottingScience digital learning platform, students engage in activities that promote critical thinking and problem-solving, such as examining biorefinery processes and evaluating acetic acid production methods. These activities align with competencies outlined in the European Sustainability Competence Framework GreenComp [18] and the PISA framework [13]. Moreover, the TLS enables students to practise making scientifically informed decisions and engaging in societal discourse on sustainability. By participating in debates and presenting recommendations to a student-led council, students rehearse justifying their decisions and communicating effectively.

Baseline findings from our initial study on students’ associations provided a benchmark for evaluating shifts in students’ associations during the pilot study. For example, the significant increase in references to the 12 Principles of GC observed in the pilot study suggests that the TLS addressed the gaps identified in the baseline data. Interestingly, the TLS did not appear to influence situational interest, as it remained consistently high throughout the lessons, including pre-survey. The mixed-methods study revealed that students’ initial associations with GC, at first peppered with buzzwords, became more detailed and aligned better with the 12 Principles of GC after completing the TLS. While students’ conceptual understanding of GC improved, it remains unclear whether this knowledge translates into long-term behavioural changes. This touches upon the well-documented knowledge-behaviour gap in environmental education, which suggests that awareness and knowledge alone are insufficient to foster pro-environmental behaviour [46], [47].

While the piloting phase of the TLS showed promising results, several limitations must be considered. First, the small sample size of 25 students from two classes limits the generalisability of the findings. Second, the absence of a comparison group means that the observed improvements in students’ conceptual understanding of GC cannot be definitively attributed to the TLS alone. Third, the involvement of an external instructor may have introduced a teacher effect, potentially influencing students’ engagement and learning outcomes [48]. Additionally, the novelty of the topic and the teaching approach may have contributed to the consistently high situational interest observed. These factors highlight the need for caution when interpreting the effectiveness of the TLS. Future studies should therefore explore how GC education can be designed to address motivational and contextual factors that mediate behaviour change.

Although the TLS aligns with the Austrian curriculum, its conceptual design and thematic focus are not limited to the national context. Its compatibility with international frameworks such as the GreenComp and the OECD PISA science framework, underscores its potential for transferability. However, a key limitation to broader application is that the teaching materials are currently available only in German. Translation and contextual adaptation would thus be essential for implementation in non-German-speaking settings.

Based on our piloting we want to give recommendations to support educators in designing a TLS that integrates GC. First, educators should identify key disciplinary concepts already embedded in their national curriculum and use these as a foundation for incorporating sustainability issues. Local challenges related to climate change, energy systems or resource use, can then serve as contextual entry points for anchoring GC. Moreover, the development of scientific literacy should be an explicit objective of a TLS. This entails integrating tasks that go beyond content acquisition and foster competencies such as argumentation skills, evidence-based reasoning and decision-making skills.

With this article we want to make a case for the urgent need to incorporate GC into educational frameworks. Ultimately, secondary students represent the primary beneficiaries of the GC education project presented in this contribution. By engaging with GC topics in chemistry lessons, students should not only learn about scientific phenomena. They should also build environmental awareness and understand the significance of sustainability in chemistry. This will help them acquire the competencies needed to become responsible citizens, participate in societal discussions and make informed decisions on global challenges.