Kapok-cotton Carbon Sponges for Oil Recovery

Carbonized natural fibers show great promise as sorbents because of their low fabrication costs, high surface area, high sorption capacity, and improved oil selectivity. Pyrolysis was performed on cotton and kapok fiber blends to produce carbon fiber sorbents. The carbon sponges showed improved mechanical properties with the addition of cotton. Pure carbonized kapok fibers were quite brittle, leading to challenges in recovery after use. The static water contact angle of carbonized kapok fibers, carbonized kapok-cotton blend (50K50C), and carbonized cotton fibers were determined to be 137.0°, 135.0°, and 135.9° respectively. This was an observed improvement from 127.9° for raw kapok and 0° for raw cotton. Sorption experiments revealed that the 50K50C fibers have sorption capacities about 25-27 times its original weight at 27.77 g/g, 25.72 g/g, and 26.01 g/g for motor oil, palm oil, and diesel, respectively.