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Highly crosslinked thermoset plastic waste is generally regarded as unrecycled materials and dumped into landfills. To divert the waste from landfills, recycling thermoset waste as fine particles in cementitious composites is a potential approach. However, weak interface bonding between thermosets and cement hydrates causes significant strength degradation in cementitious composites, which has constituted a long-term stumbling block. Herein, we innovate a green recycling solution for recycling thermoset waste as fillers in order to engineer sustainable cement mortar with the help of a green surface adhesion promoter – a silane coupling agent. The feasibility of the proposed approach was experimentally validated in terms of workability performance and compressive strength in order to meet requirements in practice. The results show that thermoset waste can substitute for at least 15% of sand in cement mortar, following workability requirements. In addition, the optimal replacement level of thermoset waste for sand in cement mortars with the highest compressive strength is 5%, beyond which the compressive strength exhibits a continuing drop. The strength alteration mechanisms are elucidated by scanning electron microscope (SEM) analyses. We demonstrate that the developed thermoset cement mortars with 5% thermoset waste have the great potential to achieve a highly dense microstructure, robust interfacial transition zone, and better hydrate crystal growth, which are the microscopic origins determining the inherent strength enhancement. The findings of this study enable the design of eco-friendly cement mortar formulations, which can both benefit the construction industry and relieve the severe environmental burden caused by landfilling thermoset waste after its end-of-life use. • A novel strategy for recycling thermoset waste into cement mortars is devised. • The interfacial bonding between thermosets and hydrates is enhanced by silanization. • The workability and compressive strength of the cement mortars are evaluated. • The mortars with 10% thermoset show performances on par with control groups. • Microstructural origins behind variations in the compressive strength are revealed. [ABSTRACT FROM AUTHOR]

The conventional methods of waste disposal, namely landfill and recycling, are associated with environmental and economic inefficiencies. The associated policies and regulations are also found to be inadequate in relation to the current situation. The situation of plastic handling-related policies in India was reviewed in this regard. Alternative techniques such as liquefaction, biological treatment, pyrolysis and incorporation of plastics in road laying have received increased attention in recent years. This paper reviews the fundamentals of each process and offers a clear picture of plastic generation and disposal. The present review also focuses on the benefits and drawbacks of different disposal methods by comparing the methods over several economic, environmental and energy parameters. A comprehensive Energy, Economy and Environmental index (EEE index) has been developed in this study to compare the different methods and reconcile the various parameters based on which the comparison was performed. Incorporation of plastic waste in concrete structures and road pavements were found to be the best methods of plastic waste disposal, with an EEE index score of 42.85%. These two methods were followed by pyrolysis and liquefaction of waste plastic with scores of 23.08% each. Landfill, with an EEE index of −7.14%, was found to be the least holistic method of waste disposal and needs to be minimized wherever possible. [ABSTRACT FROM AUTHOR]

Waste-to-Chemicals production represents a sustainable pathway considering the new Circular Economy approach and the environmental problems related to waste disposal management. This paper concerns about the LDPE production starting from a nonrecyclable plastic waste feedstock, providing a solution to both plastic demand and plastic waste disposal. The proposed process combines different technologies starting from a high temperature gasification of waste, which leads to a no tar syngas production. The present paper provides a feasibility analysis in order to reach an interesting product yield and an innovative process configuration, reporting the overall plant block scheme and the Process Flow Diagram. The heat and material balances of the entire production chain, including the steam production, the byproducts separations and the plant furnace units, were developed via the simulation software Aspen Plus V8.0. The paper shows each simulator flowsheet of some significant plant sections, reporting all the necessary equipment and thermal recoveries and the properties of each plant unit outlet stream. Last but not at least a feedstock analysis is developed by comparing the mixed plastic feedstock to the RDF one, showing the resulting data and considerations. [ABSTRACT FROM AUTHOR]