Solar Dehydrator in action
Nutrisea: Transforming Waste into Nutrients
Nutrisea: Transforming Waste into Nutrients
Artist Impression of our Solar dehydrator
Heat-generating film of the solar dehydrator
Convective airflow to promote evaporation
What it does
The Nutrisea kit is a simple and effective kit for communities to transform a coastal waste, Sargassum Seaweed, into a nutritious powder. The powder form is non-perishable and can be distributed inland, helping to alleviate micronutrient deficiency worldwide.
As a civil and environmental engineer, I learnt that large quantities of sargassum seaweed are consistently washed ashore in all tropical regions around the world. Many governments spend millions of dollars just to remove the seaweed from the coastlines, for subsequent incineration - what a waste! As fate may have it, I met Matthew and Syazana at an ideation workshop where they spoke passionately about wanting to tackle hidden hunger. So we thought - why not use one problem to solve the other! Through further research, we found that the seaweed is a superfood packed with nutrients.We then began our journey designing the Nutrisea Kit.
How it works
Each kit consists of 12 multi-purpose cages and one solar dehydrator. The multipurpose cages integrate all processes of washing, drying and grating. First, the wet seaweed is placed inside the cage, where water is run through it to remove sediments. It is then placed in the solar dehydrator for 10 hours. The solar dehydrator's cover has a heat-generating film that absorbs sunlight to produce heat, and the thermal insulation properties of the materials traps the heat inside. This greenhouse effect increases the temperature inside the dehydrator, while air vents at the top and bottom of the solar dehydrator promote convective airflow. The high temperatures increase evaporation rates while simultaneously killing bacteria. Furthermore, a thermochromic indicator changes colour when heat-sterilizing temperatures (60C) are reached internally. Lastly, dried seaweed is rubbed against the corrugated base of the multipurpose cage to powderize it.
Considering that the overgrowing Sargassum seaweed is widely distributed worldwide, we envision creating a global network of communities to convert this waste into a nutritious powder with significant market value. Based on this vision, emphasis was placed on creating a solution with three properties: effective, simple to use, and requires minimal maintenance. From our sketches, we proceeded to draw the Solar Dehydrator using solidworks to create an STL file. With that, we were able to 3-D print our solar dehydrator! Through iterative field tests, we were able to optimize the proportions and air vent sizes that maximized evaporation rate to 78% more than the original. To powderize the dried seaweed- we first tried pounding it using a mortar and pestle. However, this solution was too heavy, with the equipment made of rock! Next, a mill was then trialed. However, the low density of the dried seaweed made the process extremely inefficient. We then found out by accident that simply rubbing the dried seaweed against a grater was sufficient as it is brittle when dry! It is now down to material optimization. To prevent corrosion, porcelain-coated iron was chosen for the multi-purpose cages, and we are seeking a cost-effective material for the solar dehydrator meets our requirements.
How it is different
Conventionally, drying processes are employed on an industrial scale where highly energy-intensive methods are used. However, Nutrisea is a process that requires no external power, solely harnessing the power of the sun. It is intended to be easily utilized by poorer coastal communities to achieve a similar result, requiring just 1 hour per day to produce 6kg of seaweed powder, which is enough to meet the daily nutrient requirements of up to 600 people. Sargassum seaweed has never been commercially used as food. Through NutriSea, we are able to convert the seaweed into dry powder, ensuring that it does not decay, with an estimated shelf life of over 15 months. As opposed to traditional sun-drying, the use of a solar dehydrator also allows higher temperatures to be reached, allowing the eradication of bacteria, preventing illnesses. All this in a one-stop, maintenance-free solution, made possible with the Nutrisea Kit - flat packed for easy distribution.
Having had a 3-D printed prototype, we want to move forward to a life-size prototype with the correct materials to test its drying capabilities and maximum temperature achieved. We also seek engage NGOs to push out our product to coastal communities. In fact, we are currently in active discussion with Kopernik, a NGO based in Indonesia which is dedicated in connecting simple technologies to last-mile communities in order to alleviate poverty. We hope to fine tune our operations and distribution model based on the pilot testing, before we proceed to other global locations.
Shell Ideas360 Season 3: Global Finalist cum People's Choice award winner (Shell Ideas360 calls on young people to submit their own inventive solutions to the planet’s energy, water and food challenges. The idea beats almost 1,000 entries from 140 countries to land the Audience Choice Award. )