01/15/25 AM: SeaH4

Wednesday began with a site visit to  the facilities of SeaH4, a startup aiming to produce green biofuel from seaweed. We left Cape Town at 9:30 am and started the two hour journey to the SeaH4 production facility. Along the drive we passed by pastures and large mining plants. We briefly stopped at a gas station for refreshments. After another 20 minutes on the road we finally arrived at the town of Saldanha, located on the west coast of South Africa.

The SeaH4 production facility is currently a small scale proof of concept design to determine the viability of seaweed as a sustainable fuel source and for areas where traditional fuel production methods are not possible. If proved to be a success, SeaH4 plans to open a production plant in Namibia where the methane and carbon dioxide produced can be further processed and used as fuel sources. 

Prior to our visit there was a significant loss of seaweed supply due to a lack of supply water in the tanks. So the staff was working to regrow their stock supply. Different experiments were going on to improve the seaweed growth. For example, in a portion of the building where there was no sunlight, two different artificial lights were being tested to determine which was best for seaweed growth. 

To produce biofuel from seaweed, the seaweed is added to an anaerobic digester with cow manure. Using the seaweeds carbohydrates and bacteria from the cow manure, anaerobic digestion produces sulfur, methane (CH4), and carbon dioxide. The anaerobic digester is currently fed about 10 kg of seaweed per day and produces 200-500 liters of methane per day. 

The building GLCM students visited was previously used as a crayfish farm and was repurposed to grow seaweed. Series of open tanks contained green seaweed that was being supplied with  fresh seawater and air to promote growth. 

GLCM students got a hands on experience in the production process of turning seaweed into a fuel source by helping out with some steps of the process. About 5 kgs of seaweed was harvested from one of the tanks using a net. The seaweed was then blended with water into a pulp. 

Before the seaweed mixture could be added to the anaerobic digester, the built up gas in the tank had to be removed. Some of the methane was burnt off through a valve leading to a Bunsen burner, but the remaining gas had to be removed by applying pressure to the top portion of the tank. This proved to be a difficult and smelly task that required teamwork. 

Some of the liquid in the anaerobic digester also had to be removed. Containing many nutrients, the liquid was added into the seaweed growing tanks. 

Finally, the blended seaweed was added to the anaerobic digester to complete the process. 

After the tour of the facilities and helping with the production process we stopped by the ocean to take some photos in our PPE. On the drive back we enjoyed another lunch prepared with love by Ivy.