Team D22-005: Repurposing workshop waste

Empirical experience is indispensable for the engineer. In a bid to solve the world’s problems, a considerable slice of formative engineering education occurs in the workshop, affording students the opportunity to leverage conceptual knowledge and materialise what was hitherto purely theoretical. However, a requisite for such materialisation is the presence of physical material, and the unfortunate and inevitable consequence of said presence is waste.

Generally, workshop waste is almost dismissively disposed of, not from lack of awareness but for want of alternatives. The bulk of this refuse can be chalked up to perfectly usable wood and excess plastic from 3D printing, both of which possess substantial potential for reuse. According to Dr. Chandramohan George, research fellow at Imperial College London, reprocessing wood alongside plastic creates a flexible and sturdy composite, superior in mechanical properties with few requirements and fewer safety concerns.

The processes are not intricate, their execution far from laborious. Pulping via alkali extracts cellulose nanofibres (as well as expelling any external contaminants such as varnish) from wood, facilitating its integration with melted plastic, while delignification and hydration soften it to render it more ductile. Additionally, plastics might be utilised to laminate wood via oxidation, creating a protective layer with minimal resource usage. Of course, the individual compositions of different kinds of wood and plastic are of concern, and in some cases repurposing as opposed to recycling is the only recourse available. 1 kg of NaOH is merely a matter of £10, and the machine is unlikely to occupy much more space than the average broom closet. Notably, much of these extractions take place at low temperatures, their energy inflow minimal. Thus, at least in its fledgling stages, this idea is more than viable.

Measures to further the efficacy of this process are not altogether impossible to achieve. Per Ingrid Logan from ICL’s ACE workshop, people do adhere to bin etiquette, and a sufficiently well labelled and located container would take advantage of this. Feeding waste into the machine must be supervised, and machine maintenance does present added responsibilities, but none too severe in light of the procedure’s intrinsic merit. With access to the RCS chemistry labs, we can afford to put our ideas to the test and implement small scale prototyping ventures; spreading the concept across Imperial itself will undoubtedly propagate through the city’s wide network of colleges. As more institutions begin to adopt this system, it will burgeon and its cost will dampen. If something as ubiquitous as sawdust may be recycled so effectively, there is little doubt that this circular ecosystem can be implemented across a variety of regions, fields and materials.

In view of SDGs 9 and 12, our project engenders reflection on the repercussions of waste and its connection to responsible production. We are of the opinion that the best way the engineering sector may be made globally responsible is to create powerful, tangible and scalable solutions at the grassroots level, fostering a gradual yet deliberate change in the sustainability of the engineering enterprise.