Modelling the generation of household automobiles scrap in the context of urban-rural disparity: A case study of Nanjing, China

Forecasting the trend of scrapped household automobiles (HAs) at the city level will help to improve the automobile recycling system, and further promote the implementation of the national circular economy strategy. Based on a stocks-driven model, we project the generation of HAs scrap in urban and rural areas of Nanjing city in 2019–2050, under different scenarios of population development and automobile ownership growth. The results show Nanjing will display a notable net addition demand for HAs, with the in-use stocks increasing from 1.83 million units in 2018 to 3.68–6.11 million units in around 2038, then declining slightly till 2050. Because of wide gap in population size and difference in ownership rate, urban residents will occupy nearly 90% of the total amount for the incoming 3 decades. During the studied period, the total amount of HAs scrap in Nanjing will grow continuously to around 2042, reflecting a peak of scrap within the following two decades; then it will show a slight slide till 2050. The cumulative amount of HAs scrap will reach approximately 12.5–18.7 million, roughly 1.4–2 times of the estimated HAs for the whole nation in 2018. Again, scrapped HAs will be dominated by urban area. Compared with prediction results for the whole nation, Nanjing is shown to hold higher level of HAs in-use stocks and scrap as expected. The study then discusses the scenario uncertainty from the perspective of potential evolve of HAs lifetime distribution and the development of new-energy automobiles. The recycling potentials of scrapped HAs are finally estimated.