Researchers Recycle Cigarette Waste to Produce Green Fuel

A new study from the Lithuanian Energy Institute (LEI) and Kaunas University of Technology (KTU) presents a unique solution in recycling cigarette waste to produce cleaner fuels, addressing cost concerns and environmental impact.

In response to escalating environmental standards and the need for cleaner fuel alternatives, researchers are exploring innovative ways to generate biodiesel, a biodegradable fuel derived from vegetable oil or animal fat.

Despite its eco-friendly attributes, the high production costs and potential pollution associated with biodiesel production have hindered its widespread adoption, TechXplore reported.

Cigarette Butts for Green Fuel

Samy Yousef, a chief researcher at Kaunas University of Technology, highlighted the presence of triacetin, a compound commonly used in cigarette filters as a plasticizer. Cigarette butts, being rich in triacetin, offer a valuable source for this compound.

The researchers conducted experiments using pyrolysis, a process that thermally decomposes cigarette waste, to extract triacetin. The highest yield of triacetin (43%) was obtained at a reaction temperature of 750°C.

Globally, smokers purchase approximately 6.5 trillion cigarettes annually, resulting in over 1.1 million tons of cigarette waste each year. This waste comprises toxic chemicals, carcinogens, microplastic fibers, and radioactive elements, making it a significant environmental concern.

Yousef explained that their research group focuses on recycling and waste management, seeking abundant waste materials with unique structures. Cigarette waste, composed of tobacco, paper, and cellulose acetate fibers, fits these criteria, and its easy collection adds to its attractiveness for recycling, according to Yousef.

While previous attempts to recycle cigarette waste primarily focused on the thermal degradation of individual components, the Lithuanian scientists treated cigarette butts as a mixture. This approach sets their study apart, eliminating the need for pre-treatment to separate components, making the process more economically feasible.

The pyrolysis experiments yielded oil (38-39.5 wt%), char (25.7-27.7 wt%), and gas (33-36.4 wt%) from cigarette waste. The porous char, rich in calcium, has applications in fertilizers, wastewater treatment, and energy storage.

The gas produced can be used for energy purposes, and the oil, particularly rich in triacetin, can be added to biodiesel to reduce costs, as per Yousef.

Recycling Strategy

The researchers propose a waste collection system and recycling strategy involving the use of pyrolysis treatment at 750°C for cigarette butt recycling. Gaseous products could be used for electricity generation, char for absorbents, and oil as a biofuel additive.

Despite the potential benefits, the researchers noted that integrating such waste treatment technology into a circular economy system would require a comprehensive waste collection system, recycling strategy, and supporting infrastructure.

Yousef emphasized that their group continues to explore additional possibilities for utilizing cigarette waste, underscoring the potential for upscaling this technology in waste treatment and biofuel production. The study's findings were published in the Journal of Analytical and Applied Pyrolysis.