Measuring the reduction limit of repeated recycling – a case study of the paper flow system

• Published in: Journal of cleaner production 2016-09, Vol.132, p.98-107
• Main Authors: Chen, Pi-Cheng, Chiu, Ming-Cheng, Ma, Hwong-wen
• Format: Article
• Language: English
• Subjects: Life-cycle stages; Lifetimes; Markov chain modeling; Material flow analysis; Recycling limit
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2015.04.023

Recycling and recovery of materials from used products is one of the major avenues to reduce material throughput. Ideally, all materials are anticipated for being reused by the economy an infinite number of times. In reality, recovery of secondary materials may be difficult because of high costs, or because of degraded quality compared with virgin materials. The search for potential reduction of throughput in material cycles should be based on a knowledge of the limits to repeated cycles. To gain understanding of recycling limits, we developed a method to estimate the actual reduction potential for each throughput in a material's multi-cycle life. First, we investigated the material flow system of paper in Taiwan, and developed a supply chain network of paper flows. Systematic elaboration of the flows revealed where paper can be recycled and where paper can be lost. Second, we estimated the reduction potential with a material input–output Markov chain model, which maps the distribution and loss of materials on the supply chain processes. The model estimated the quantities and the life pathways of recycled materials across continuous life-cycles. An indicator was used to quantify the total performance of the material across repeated life-cycles. This method offers an opportunity to examine practices that approach the limit of reduction. This case study shows that the use and separation of paper waste after discarding may need to be reformed to extend the life-cycles of the material. •A material input–output model depicting entire lifecycle stages is presented.•A metric sums the flows for a material input across all lifetimes.•A paper flow case study was examined to demonstrate the developed method.•Losses and exports influenced the succeeding circulation performance of economy.•Different circulation-improving scenarios were evaluated.