Vol.8 (2018) No. 3 ISSN: 2088-5334 Conversion of Polypropylene Plastic Waste Into Liquid Fuel with Catalytic Cracking Process Using Al2O3 as Catalyst Devi Rachmadena, Muhammad Faizal, Muhammad Said Chemical Engineering Department, Faculty of Engineering, Sriwijaya University, Palembang 30139, Indonesia E-mail: rachmadenadevi@gmail.com, mfaizal1405@gmail.com Abstract– Approximately 129 million tons of plastic are produced each year, and from that amount, almost entirely produced from petroleum, while the needs on fuel oil (BBM) is continuously increasing, leading to the depletion of oil and gas reserves. However, besides the problem of raw materials derived from petroleum, the use of conventional plastic as packaging material facing various environmental problems, such as cannot be recycled and cannot be degraded naturally by the environment, causing a pile of plastic waste that causes environmental pollution. Thus, it is crucial to find a solution that can solve both problems. One method of processing plastic waste is to convert it into hydrocarbon fuels. Conversion of plastic waste can be done with the catalytic cracking process which is often used because it utilizes a catalyst to reduce the high temperatures used in the thermal cracking process and save on energy consumption. In this research, the raw material that was used was polypropylene in the form of mineral water cups, and the catalyst used was Al2O3. The purpose of this research was to observe the effect of the cracking process’ length of time, catalyst weight (% catalyst) and range of temperature towards the mass, characteristics, and composition of the product. The length of the cracking time was varied into 20, 40 and 60 minutes, while the % catalyst was varied into 4%, 6%, and 8%, and the operating temperature was varied into 150, 200, 300 and 350oC. From the research, the highest mass of liquid product was obtained at the variation of 350oC, 4% of catalyst for 60 minutes, with the value of 87.3 gr, with a total yield of 17.5%. While the characteristics were 0.762 gr/mL for density, 0.778 for Spgr and 50.4 for oAPI Gravity. As for the other products from different variations had lower mass and yield of liquid, but the characteristics were still in gasoline range’s characteristics. Two samples were analyzed by its composition, and although showed the different value of percentage, both also showed that the liquid product was included into gasoline range (C5- C12). Keywords– plastic waste; polypropylene; catalytic cracking process; Al2O3 catalyst I. INTRODUCTION Community needs on fuel oil (BBM) which is derived from fossil fuels continually increasing. It leads to the depletion of oil and gas reserves. World oil reserves at the end of 2014 amounted to 1700.1 billion barrels, while Indonesia only has proven oil reserves of 3.7 billion barrels and the number is only 0.2% of the total oil reserves in the world [1]. Total oil production of 852 thousand barrels/day by consumption of 1.641 million barrels/day. From the above data, it can be seen that there is a gap between production and consumption [2]. Today, approximately 129 million tons of plastic are produced each year, and from that amount, almost entirely produced from petroleum. To produce the required amount of plastic, it needs approximately 12 million barrel of petroleum per year. This amount reaches 8% of the total oil produced [3]. Plastics are macromolecules, formed by polymerization and have the ability to be shaped by the application of the reasonable amount of heat and pressure or some other form of force [4]. Thus, humanity has to rely on the alternate/renewable energy sources like biomass, hydropower, geothermal energy, wind energy, solar energy, nuclear energy and others. Waste plastic to liquid fuel is also an alternate energy source path, which can contribute to depletion of fossil fuel as in this process liquid. Fuel with similar properties as that of petrol fuels is obtained [5]. However, besides the problem of raw materials derived from petroleum, the use of conventional plastic as packaging material facing various environmental problems, such as cannot be recycled and cannot be degraded naturally, by the environment, causing a pile of plastic waste that causes environmental pollution. Waste of plastics takes approximately 80 years to be degraded completely. Every year the plastic waste generated increases. In 2013, the carrying amount of plastic waste in Indonesia was 804 tons/day [6]. High consumption of plastic, plastic waste management that is inadequate and difficult to decompose causing all of the plastics to form a pile of garbage. The buildup of this waste could produce methane (CH 4 ), which 694