New Perspectives in Science Education

The steadily increasing consumption of limited fossil resources and the increasing threat of a progressing climate change direct more attention towards renewable energy sources. Despite the research activities in this field, a sustainable energy supply currently remains a rather long-term goal and many technical challenges still need to be overcome. One of the main problems of technologies such as solar and wind power is their unreliability and, more precisely, the lack of technical capabilities to store excess amounts of producible electric energy [1].

Until more advanced and affordable technologies and solutions to these problems become widely accessible, power-to-liquid-systems represent an interesting alternative which additionally incorporates the idea of sustainability. These systems enable the storage of excess energy from renewable energy sources, e.g. the synthesis of conventional energy carriers out of biomass, such as methanol. Especially so-called second generation biofuels are exclusively produced out of remaining organic waste and thus do not compete with food production (e.g. corn or rapeseed). Simply put, cellulose and other organic substances are converted into sugar, which is subsequently used to produce bioethanol via fermentation. Alternatively, it can be used to produce levulinic acid with little effort – this pathway has gained more attention recently, since a new method was presented describing the synthesis of octane via an easy Green Chemistry electrolysis out of levulinic acid [2,3].

In this contribution, a course design will be presented, reflecting the power-to-liquid-concept and the conversion from organic waste to biofuels. Aided by several (model) experiments, the key steps of this process can be illustrated using common chemicals and equipment, leading from the synthesis of levulinic acid out of cellulose up to the electrochemical synthesis of octane. Within this course design, several typical contents of the high school chemistry curricula such as electrolysis, alkanes, redox reactions and fermentation can be either introduced or deepened. Furthermore, the course topic offers several points of reference linking these concepts to students’ everyday lives. Finally, since two of the main challenges of the 21st century are said to be the supply and consumption of energy, the students’ consequent findings serve as the basis for discussions regarding the explored and further related topics.

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