Much has been written and promised about the ‘super-material’ graphene. Graphene is an exciting material. Consisting of a single layer of carbon atoms arranged in a honeycomb lattice (an allotrope formed from a one-atom thick layer of graphite), the material is extremely stable, flexible, highly conductive, and of particular interest for electronic applications. Examples include a new generation of flexible displays, wearables, and other electronic devices.
However, is graphene environmentally sustainable? The short answer is ‘no’.
As assessed in IDTechEx’s latest report, “Graphene Market & 2D Materials Assessment 2023-2033“, the capacity for graphene easily exceeds 12,000 tpa (a measure of tensile strength). Nearly all of this comes from a graphite feedstock and uses a top-down approach, with liquid phase exfoliation and oxidation-reduction being dominant.
Each process carries with it a different impact, given the energy efficiency, water requirements, and chemicals used, but given the feedstock and general approach, IDTechEx do not think it is possible to call graphene a “green material”.
However, there are several arguments to be made for graphene’s green credentials being better than other industrial processes for materials. A number of these applications appear within the IDTechEx report.
There is a lower footprint and lower loading with graphene compared with other incumbent additives. This has been claimed by some companies, in which they state that against their petrochemical counterparts, such as carbon black, they have a lower carbon dioxide footprint per tonne, and the higher performance results in lower loading. However, this has been challenged by current research into graphene production.
It is also possible with graphene that alternative feedstocks be used. There is an emergent trend with some companies emerging to utilize waste, by-products, or renewable materials, and in several cases, coupling graphene manufacture with hydrogen production. Most of these are at an early stage in their commercial journey.
Graphene also carries a potential for making battery production more sustainable. With lithium-ion batteries, in the future silicon anodes will see significant adoption, and graphene is demonstrating itself as a potential enabling solution.
With another application, green polymers are a key topic that ranges from packaging to pipelines. Both recycled plastics and bioplastics have a consistent challenge with their mechanical performance compared with virgin incumbent material. Graphene is being explored as an additive to strengthen recycled plastics.
There are several other applications for graphene with environmental drivers, including filtration membranes, sustainable electronics, and replacing toxic additives. Each market landscape is different and at various stages of graphene commercialization.