Proposing a New Route to Solve Marine Debris Pollution Issues: Low-Temperature Eco-friendly Pulverization System by Utilizing LNG Cold Energy
Abstract Developing an effective and efficient recycling process for marine debris (MD) is one of the most urgent issues to maintain Earth’s sustainability. However, the restricted circumstances for collecting and separating MD in the ocean limit proper MD recycling. Here, we proposed a complete eco-friendly low-temperature MD pulverizing system that utilizes excessive liquefied natural gas (LNG) cold energy (LCE) in an LNG propulsion ship to improve the efficiency and effectiveness of MD recycling. The prototype design of the low-temperature pulverization (LTP) system showed that consumable refrigerant (liquid nitrogen) up to 2831 kg per hour could be substituted. Furthermore, we estimated the additional refrigerant needed for desired MD disposal depending on the ship speed to determine the optimal energy requirement. In addition, LTP systems utilizing LCE can significantly improve the storage capacity by pulverizing bulky MD. To determine the feasibility of LTP for MD recycling, four types of plastics obtained from actual MD from a coastal area in Busan, Korea were classified and tested.