By Dr. Joseph K. Muiruri
I have always been fascinated by interactions between science, technology and environment from which I developed interest in value addition of natural resources. In 2013, while I was still a principal investigator in a project entitled ‘Value added products from banana pseudostems’, I won Singapore International Graduate Award (SINGA) to pursue my PhD in natural fibre composites.
I joined Prof. He Chaobin’s group at the National University of Singapore (NUS) Material Science Department and ASTAR-Institute of Materials Research and Engineering which is renowned for nanocomposites research. Here, I developed tough biodegradable polylactic acid-nanocellulose composites for high performance applications. While doing my PhD work, two interesting things happened; first, the government of Kenya issued a ban on single-use plastics, and second, a rumor about ‘plastic or artificial rice’ being sold in Africa was in the news. These two issues revolve around bioplastics research.
After the ban on single-use plastics in Kenya, manufacturers and consumers bridged the gap with non-woven bags as alternatives. However, these non-woven bags were also found to contain non-biodegradable components which are harmful to the environment. With this in mind, research and development should be geared towards production of 100% organic, biodegradable, and eco-friendly bags. These bags look like plastic but are made of materials like natural starch and vegetable oil derivatives. This way, users can throw them away without worrying about harming the environment. From 2018-2023 projections, bioplastics production sector was set to increase by 25% to 2.6 million tonnes1.
I, therefore, knew that my newly acquired knowledge and expertise in bioplastics and biopolymers would be very useful in Kenya and Africa. My vision after graduation was therefore to demystify materials science, apply and innovate.
As a bioplastic expert, I returned to Kenya and sought to make use of the new knowledge. Knowing that Kenya and Africa is well endowed with natural resources, I was spoilt for choice. Starch rivals cellulose as the second most ubiquitous natural resource obtained from sources such as cereals (rice, wheat and maize) and the root vegetables (potatoes and cassava).
Because of the abundance of cassava, a climate smart crop, its value addition remains the most viable and profitable avenue to be pursued by Kenya and Africa at large. I, therefore, chose to do value addition of cassava starch to make biodegradable plastics for different applications including packaging bags. On a lab scale, we have developed samples of cassava starch-based plastics which have a wide array of applications such as biodegradable carrier bags, food containers and cutlery, single-use drinking straws and so on. The production process involves solution casting of a recipe comprising cassava starch powder, polyglycerol (plasticizer), citric acid, vegetable oil, a suitable emulsifier and some natural fibers. The mixture is homogenized and cast on a glass plate to dry at ambient temperature. The plastic films are tested for strength, barrier resistance and biodegradability. Preliminary results have shown that the films are strong enough for packaging materials and can degrade in compost over 180 days.
In addition, we want to go further and develop not only biodegradable cutlery but also edible ones. Just like we eat the ice-cream holder, edible cutlery is the future of ecofriendly utensils and can reduce the amount of single-use plastic products disposed in the environment. Overall, mass production of biodegradable starch-based products can be achieved through investment in extrusion technologies or modifying already existing blow molding plastic processing units in the African countries.
Opportunities and Challenges
Besides using cassava as food, we can develop other products such as feed, bioethanol and bioplastics. However, ethical questions arise about the sustainability of such a venture. In a food insecure nation, do we produce cassava for food, feed, bioethanol or bioplastic industries? These pertinent questions can be answered if we adopt biorefinery approach for cassava-based industrial wastes. Such an approach will demand the use of modern biotechnology knowledge, which has been on an upward trend in Africa.
The development of a regional Bioeconomy Strategy for Eastern Africa which is at an advanced stage is also a step in the right direction in setting up biorefineries in the region. Another challenge in setting up biodegradable cassava starch-based plastics process line would be the huge capital investments required. However, this being a green enterprise financial support can be sought from partners who support green initiatives.
Cassava farmers would be the first beneficiaries of biorefineries approach because of the huge demand for the crop to sustain the production of diverse value added products. In addition, biotechnologists will have to come up with high yielding cassava cultivars. Other beneficiaries include students and cassava processing units.
More importantly, Kenya’s economic prosperity and wealth creation as envisioned in Kenya Vision 2030 and ‘Big Four Agenda’ initiatives is not just due to its ubiquitous natural resources and trained manpower, but due to its ability to transform natural resources into value added products. In the third Medium Term Plan (2018-2022), and ‘Big Four’ agenda, manufacturing has been identified under industrial cluster programme aimed at employment creation and access to employment opportunities especially for women and youth. In addition, innovations arising from value addition of climate smart crops such as biodegradable cassava starch-based plastics will save our planet from environmental degradation. My clarion call to governments, policy makers and stakeholders is to support green initiatives and products for sustainable development.
The writer is the head of Textile Division at Kenya Industrial Research and Development Institute (KIRDI). Dr. Muiruri holds a PhD in Materials Science and Engineering from National University of Singapore (NUS), Singapore.