This project utilizes the high water-retention and biomass density of Opuntia (Cactus) stems to produce renewable energy. Cactus is an ideal energy crop for arid and semi-arid regions where other plants fail to grow. The study demonstrates that the anaerobic digestion of cactus stalks produces a high-methane yield, providing a sustainable alternative to fossil fuels while the digestate serves as a nutrient-rich organic fertilizer.
The cactus stalks are harvested, shredded, and fed into an anaerobic digester. Through a four-stage biological process (hydrolysis, acidogenesis, acetogenesis, and methanogenesis), microorganisms break down the complex organic matter in the absence of oxygen to release biogas. The gas is then scrubbed to remove CO2 and H2S, leaving high-purity methane.
Cactus fruit seeds are a byproduct of the food and juice industry. This research demonstrates the extraction of high-crystallinity cellulose nanocrystals (CNC) from these underutilized seeds. These nanocrystals possess exceptional mechanical strength and thermal stability, making them ideal building blocks for the next generation of high-performance, sustainable biomaterials.
The seeds are ground into a fine meal and pre-treated to remove hemicellulose and lignin. The purified cellulose is then subjected to controlled acid hydrolysis using sulfuric acid to remove amorphous regions. The resulting suspension is neutralized, dialyzed, and ultrasonicated to yield stable, rod-like cellulose nanocrystals.
