Material Flow Analysis Of Car-steel Based On The Waste Input-output Table

To understand the change of car-steel’s post-recycling fate of China in the last 30 years, this study quantitatively traces the fate of steel recovered from end-of-life (EoL) cars produced in different years by using the MaTrace method (Nakamura et al., ES\&T 2014) and Chinese 10 tables from 1987 to 2012. In a dynamic setting, we consider different technology and economic structure scenarios by using IOTs of different years. To classify the destination of car steel, all the secondary sectors are grouped into 5 categories:cars, buildings, civil engineering, machines, and others, which are of significant importance for ferrous materials. We have got few important conclusions from the results. First, the recycling cycle of car-steel is opened. There exists a decreasing trend in the total amount of car-steel recovered from EoL products, indicating that it is impossible to recycle steel without any loss. Second, most of the car steels are first recycled into cars and machines. Third, once a unit of steel has been used in car production in 1987, the peak of the in-use stock of the steel recycled from these cars appears in 2000. It implies that the gap between production and reuse peak is 13 years. The corresponding gaps for the cars produced in the year of 1992.1997,2002, 2007 and 2012 are 11,11,15,15 and 15 years, respectively. Forth, the shorter the car life-span is, the higher and steeper the peek is. Fifth, economic structure such as consumption pattern has its effects on the destination of car-steel. Last, total amount of car-steel revered increased over years from 1987 to 2012. That is because more cars, machines and buildings are demanded during the last 30 years, as a result of that, more car-steel is reused into them; and the recovery rate of these three final products are higher than that of civil-engineering and others.