Renewable Energy from Waste: Investigation of Co-pyrolysis between Sargassum Macroalgae and Polystyrene

Co-pyrolysis of the seaweed Sargassum and polystyrene was investigated as a potential source of renewable energy. Sargassum is a brown macroalgae, posing a large disposal problem for beaches worldwide, and polystyrene is the plastic least recycled in the U.S. Although macroalgae bio-oil cannot be directly used as a result of a high oxygen content and low heating value, co-pyrolysis of macroalgae with low-oxygen-content waste polystyrene can enhance oil quality. Pyrolysis of pure Sargassum was conducted to determine the temperature producing the highest percent oil (600 °C). Co-pyrolysis of four different mixture ratios of Sargassum and polystyrene (5, 15, 25, and 33% by weight) was then conducted at 600 °C. Feedstocks and pyrolysis products (liquid oil and water, gas phase, and solid phase) were characterized using elemental analysis, thermogravimetric analysis, gas chromatography, surface area and adsorption isotherm analysis, and nuclear magnetic resonance. Co-pyrolysis with polystyrene improved the qua...