Harvesting marine plastic pollutants-derived renewable energy: A comprehensive review on applied energy and sustainable approach

Abstract

The inevitable use of plastics in the existing standard of life makes its way to ecosystems, predominantly into the marine ecosystem. Recent research on energy recycling from marine discarded plastics through biological, chemical, and thermal processes is summarized, which degrade plastic debris and transform it into energy-efficient products. In a system-oriented approach, different boundaries like carbon efficiency, global warming potential, cumulative energy demand, and cost of the product have been evaluated. Even these technologies may successfully reduce the yearly volume of marine plastics by up to 89% while reducing greenhouse gas emissions by 30%. Conversely, recycling a ton of marine discarded plastics may save 915 cubic feet of landfill space, 6500 kWh of energy, and barrels of oil. Energy may be recovered up to 79% from waste plastics using various techniques. Up to 84% liquid fuel had been generated, with a maximum calorific power of 45 MJ/kg. It has been shown that in Asian countries, the power generation capacity of throw-away facemask wastes regularly varies from 2256 kWh/day to 18.52 million kWh/day. Hence, the conversion of marine plastics into biofuel, syngas, biochar, hydrocarbons, electricity, and value-added functional materials by various biotechnological and chemical processes like biodegradation, pyrolysis, gasification, methanolysis, and hydrolysis should be improvised as a source of alternative energy in the immediate future. Our review signifies the potential benefits of energy harvesting technologies from marine plastics pollutants to overcome the growing challenge of energy demands and provide a long-term solution to underdeveloped and developing countries as a sustainable source of energy. Endorsing current strategies to harvest energy from marine plastic wastes that enhance power generation technologies will help in building a more sustainable and greener environment that imparts a healthy and circular economy while shielding natural resources.

Keywords: Circular economy; Energy; Marine plastics; Microplastics; Recycling; Renewable energy.