Homework #5 - Biomass Plant

Today’s visit to the biomass plant was interesting, and not only because of the smell. I was impressed by how thorough and resourceful the plant’s production was, with the plant using every part of the sugar cane to the fullest extent. From the stalk to the syrup to the hard sugar, every aspect was taken advantage of.

While it may seem like the stalks of the sugar cane may seem like trash to many, this plant put their waste to use. After extracting the syrup, the stalks were dried and fed into a boiler, where they were burned to collect energy from a typical steam-turbine system. While this may seem insignificant, it is anything but. This process produced about 40 MW, which is enough to keep the plant self-sufficient, and have a remaining 20 MW to sell to the grid. I was pleased to learn of this process because it alleviates one of the main issues of biomass production; biomass plants use nearly as much energy as they produce. At least by cutting down on the energy usage of the actual plant, the carbon weight of harvesting and transportation are not as detrimental. Likewise, the close proximity of the plant to the sugar cane fields lowers the impact of shipping the sugar cane.

Dried sugar cane stalk

Furthermore, the ethanol production process made sure that nothing was wasted. Through the five extraction processes, the plant is able to gather 70% of the syrup out of the sugar cane. This syrup was then brewed into the wine-like substance, and converted into ethanol which was distilled to 94% purity. While this pure ethanol does not smell very good, I was surprised by how clear it was. I always pictured a gold-ish liquid similar to gasoline, but even the color of ethanol gives it a purer feel than gasoline. We saw this sample in the on-site lab, which performed regular tests to ensure the quality of their product, ensuring the safety of their consumers. This is important when the plant outputs 300,000 Liters per day.

Test Distiller

Rationally, the plant also produces sugar from these sugar canes, which tasted great. The amount of sugar constantly being stored in that warehouse was staggering, with a ton sized bag of sugar coming in every minute or so.

Raw sugar cane

Our final stop was the sugar cane fields, where Josh, our fearless leader, rode in the harvester. This harvester was a behemoth, with blades on the upper arm to chop the excess leaves of the crop, and bottom blades that chopped the stalks before they were fed into the harvester. The harvester then sorted out a majority of the excess, leaving only the sugar cane stalks to be transported to the plant in a separate truck. This early sorting is just another example of the attention to detail in this process. However, it was disheartening to see the age and size of the equipment used at the farm, as these machines are certainly not clean burning, or high on mpg.

Harvester

Nevertheless, this is an expected cost, and it would be interesting to see if the extra efficiency of the sugar cane ethanol process makes up for this energy spending. Overall, I must say that I truly admire the self-sufficiency and total usage of the sugar cane at this plant. It was really SWEET to see such an efficient and well engineered facility.