A Systematic Review of Fuel-Briquettes from Plastic Waste and Biomass: Material Composition and Performance Analysis

Indonesia, as a developing nation with a rapidly growing population, is concurrently grappling with two critical challenges: a widening energy deficit and escalating waste management issues. Energy demand continues to increase due to industrialization and urbanization, while plastic and organic waste volumes exceed current handling capacities. As a response, the development of waste-to-energy (WTE) solutions, particularly in the form of solid fuel briquettes made from plastic waste and biomass, has emerged as a dual-benefit strategy to address both environmental and energy crises. This paper systematically reviews recent experimental studies on the production and performance of solid waste-derived fuel briquettes composed of plastic waste and organic binders, with a particular focus on cassava peel, an abundant agricultural byproduct in Indonesia. The review compiles and analyzes technical parameters including calorific value, compressive strength, moisture content, ash content, and volatile matter, all of which are critical in determining the quality, efficiency, and feasibility of briquettes as alternative fuels. Experimental findings show that plastic-based briquettes, especially those incorporating Polypropylene (PP), Polyethylene Terephthalate (PET), and Low-Density Polyethylene (LDPE), exhibit superior calorific values, often exceeding 7000 cal/g, when compared to conventional biomass briquettes. Moreover, the addition of natural starch-based binders, such as cassava peel, significantly enhances compressive strength and combustion efficiency while maintaining environmentally acceptable ash levels. The reviewed studies highlight that optimized formulations, such as PET blended with rice husk or dried leaves and bound with 20% starch, can achieve both high thermal performance and mechanical stability. In parallel, studies exploring the integration of agricultural and industrial waste materials (such as corn cobs, sawdust, palm fronds, tannery waste) further validate the versatility of briquette technology. Desulfurization efforts using calcium-rich additives, along with binder variation and compaction parameters, were also shown to influence emission profiles and combustion behavior. Despite the breadth of individual studies, few have synthesized the data within a structured comparative framework. This review fills that gap by consolidating diverse findings and assessing their implications for scalable implementation in household and small-scale industrial applications. The results support the potential of plastic-biomass briquettes as a viable and sustainable energy alternative for developing countries, offering a circular solution that concurrently reduces waste and enhances energy security.