Renewable energy has been a hot topic for a long time now. Many countries have set goals to reduce their dependence on non-renewable energy sources such as coal and oil. One such renewable energy source is biofuel, which is derived from plants, algae, and other organic sources. However, producing biofuels on a large scale can be challenging and expensive. One promising technology that can help address these challenges is photo-bioreactors. Ashlyn and Cade recently spoke at the NHSEMP Symposium on their work on developing a cost-efficient photo-bioreactor.
What is a Photo-bioreactor?
A photo-bioreactor is a closed system that utilizes photosynthesis to cultivate microorganisms such as algae, bacteria, or fungi. It can be used to produce a variety of products such as food, fuel, pharmaceuticals, and more. The microorganisms are grown under controlled conditions, such as light, temperature, nutrients, and CO2, to optimize their growth and productivity. The advantage of a photo-bioreactor is that it provides a controlled environment that maximizes the production of desired products, reduces contamination, and improves the quality of the final product. Additionally, photo-bioreactors have a smaller footprint compared to other production systems, making them suitable for urban environments.
The Challenge of Cost
Despite the advantages of photo-bioreactors, the cost of building and operating them can be a significant barrier to their widespread adoption. One major cost driver is the lighting system, which provides the necessary light for photosynthesis. Traditional lighting systems such as high-pressure sodium (HPS) lamps or light-emitting diodes (LEDs) can be expensive and energy-intensive, especially when operated for extended periods. Additionally, traditional lighting systems generate a lot of heat, which can be challenging to manage, especially in warm climates.
Another cost driver is the reactor vessel itself. A photo-bioreactor needs to be made of materials that are transparent to light, durable, and chemically resistant. Glass is a common material for photo-bioreactors, but it can be expensive and prone to breakage. Plastic is an alternative material that is cheaper and more durable but can be prone to discoloration and degradation over time.
Ashlyn and Cade’s Solution
Ashlyn and Cade’s research focused on addressing these cost challenges by developing a cost-efficient photo-bioreactor. They tackled the lighting system and reactor vessel separately.
The Lighting System
To reduce the cost and energy consumption of the lighting system, Ashlyn and Cade experimented with using low-cost LEDs. LEDs are energy-efficient and can last longer than traditional lighting systems, making them a promising alternative. However, LEDs emit light in a narrow wavelength range, which may not be optimal for all microorganisms. To address this, Ashlyn and Cade developed a custom LED panel that can emit light at different wavelengths, allowing for more flexibility in growing different microorganisms. Additionally, they implemented a system that can adjust the intensity of the light based on the growth phase of the microorganisms, further optimizing their growth and productivity.
The Reactor Vessel
To reduce the cost and increase the durability of the reactor vessel, Ashlyn and Cade experimented with using recycled plastics. They sourced plastic waste from local recycling centers and melted them down into sheets that could be used as a material for the reactor vessel. They found that recycled plastic was cheaper than glass and more durable than traditional plastics, making it an ideal alternative. Additionally, they added UV stabilizers to the plastic to prevent discoloration and degradation over time.
