G5 Doctoral dissertation (article)

SUSTAINABLE RECYCLING OF CRITICAL MATERIALS


Publication Details
Authors: Rahimpour Golroudbary, Saeed
Language: English
JUFO-Level of this publication:

Abstract

The world’s supply of critical materials
such as phosphorus (P), niobium (Nb), lithium (Li) and other strategically
important elements is under increasing pressure due to the rapidly growing global
demand in the recent years and limited possibilities of substitution. These
materials are used in producing a broad range of products in everyday life and
forming an integral part of many advanced and clean energy technologies. Hence,
such materials are significant for many industrial sectors and essential to
societal well-being. Therefore, the steady supply of critical materials starts
to be one of the key economic and environmental questions. Moreover, the
analysis of flows of those materials coming from mining and recycling starts to
evoke the growing interest.

A systematic understanding of how such
materials flow through the industrial and residential sectors is required. Such
awareness of materials’ inclusion in various products and their current stocks
in the anthroposphere improve the potential of recycling and reuse of those
materials as well as minimize overall waste.

This dissertation presents dynamic models for
critical materials such as P, Nb, and Li by using system dynamics methodology. It
considers all stages of supply chain by addressing material and energy flows as
well as greenhouse gas emissions. The main finding assists in optimizing for
environmentally sustainable operations in designing and modelling of the
critical materials supply chain.






The findings indicate a clear need to analyse
the recycling processes carefully. The obtained results show that recycling of
used products containing critical materials, in some cases, aims to prevent the
shortage of those materials and contributes to developing a robust circular
economy. However, the environmental sustainability of recycling procedures for
all materials could not be taken for granted, because it could differ based on
the type of the waste stream. For some critical materials, recycling can cause
more environmental damage than mining. Therefore, we should not treat critical
materials as a homogeneous group. Recycling carried out using the
existing technologies is a partial solution for some materials. In addition,
there are physical limitations to the increasing of the recycling rate for some
materials. The main limiting conditions of recycling can be economic,
environmental, and physical by nature. The lattermost means that even if
recycling is both more profitable and “greener” than mining, it is still
impossible to completely replace primary production with the secondary one.


Last updated on 2020-18-06 at 06:31