• Resources Recycling
• /
• v.24 no.5
• /
• pp.22-32
• /
• 2015

This study aims to discuss the concept of upcycling as it applies to diaper recycling. Upcycling is the process of converting waste materials into new products of better quality. Through benchmarking of upcycling examples, useless objects can be transformed into valuable materials. However, current upcycling examples determine value creation related to qualitative elements, so that it is difficult to establish any quantitative strategy of upcycled products. Therefore, this study expands a B2B (Business to business) product for improving market availability and establishes a direction using both recovered pulp and mixed plastic at the same time. As a result, the upcycling method for recovered pulp and mixed plastics, is the application of a cellulose insulator. Within the near future, the high quality insulator market will grow more than three times. An upcycling strategy targeting the high quality insulator market needs to be established.

• Journal of Energy Engineering
• /
• v.29 no.3
• /
• pp.34-41
• /
• 2020

Used disposable diapers have been considered for a long time as a type of waste difficult to recycle and valorize due to their composite nature including plastic, cellulose pulp, a super absorbent polymer and either urine, feces or both. Therefore, the fate of disposed diapers often is either incineration or landfill burial which both have various adverse environmental impacts. However, used disposable diapers contain nutrients: cellulose is an organic matter while urine and feces contain non negligible amounts of nitrogen, phosphorus and potassium which are primary nutrients included in most chemical fertilizers used in agriculture. In a scope of waste recycling and valorization, this study focuses on developing a method to achieve nutrient solution extraction from used disposable diapers. The experiment essentially consists in shredding the diapers and letting them macerate in solutions of sodium hydroxide with various concentrations to allow breaking down of the cellulose and super absorbent polymer and release of urine and feces before sterilizing the solutions in an autoclave to remove potential coliform bacteria. At the end of the experiment, a set of parameters is measured for the final solution to identify concentrations of nutrients as well as presence or absence of harmful substances. Results are discussed and directions for future studies are suggested, which include mechanization of the diapers shredding process or added aeration to enhance nitrification and absorption of extracted nutrients from plants.

• Resources Recycling
• /
• v.24 no.1
• /
• pp.43-50
• /
• 2015

An extensive literature survey and personal communication with relevant experts made it possible to understand economic and technical feasibility of disposable diaper recycling. Commercial level of soiled diaper recycling technology is currently available from a Dutch company, Knowaste Co., who owns a proprietary separation technology of the pulps, plastics and super absorbing polymer (SAP). In Korea, on the other hand, pre-consumer diaper recycling technology without material separation at its infancy converts manufacturing scraps into refuse plastic fuel (RPF), container/truck cargo boards or automobile boards/sheets. Although previous studies on feasibility of post-consumer recycling in Korea showed mutually contradictory implication, it was found out in this research that significantly positive economic feasibility can be obtained with pre-consumer diaper recycling. Subsequent recycling R&D including pre-consumer scrap and policy support may expedite 'Establishment of Sustainable Society.