W-S Shih, M.A. Chappell, A.J. Kennedy
Brewer Science Inc.,
Keywords: carbon nanomaterials, carbon nanotube, nanoEHS, LCA, sustainable manufacturing
Summary:Responsible development of nanotechnology and fostering nanotechnology into products for commercial and public benefit are two of the four long-standing National Nanotechnology Initiative (NNI) goals . To achieve these goals, nanotechnology-related environmental, health, and safety (nanoEHS) efforts will need to consider the very early stages of research and development, captured within a “cradle-to-grave” life cycle assessment (LCA), Figure 1, to guide the technology development and to accomplish sustainable manufacturing of nanomaterials and nanotechnology-enabled commercial products. Through a public-private partnership, Brewer Science has been taking a proactive and systematic approach using nanoEHS and LCA methodologies to guide the development, manufacturing, and commercialization of carbon nanomaterials and devices. The nanoEHS assessment was conducted using a series of environmental risk assessments and decision-making tools developed at the Engineering Research Development Center (ERDC) of the U.S. Army Corps of Engineers , such as Nano-GRID (Nanomaterials Guidance for Risk Informed Deployment) . These tools facilitate and accelerate informed decision making for the product development and commercialization pathway with a systematic approach. The LCA methodology is deployed to guide the development and manufacturing of the carbon nanomaterials (carbon nanotubes, or CNTs) and devices (printed thermistors) to improve productivity while reducing the environmental impacts, as well as mitigating the health and safety risks to workers and the general public . An iterative approach was taken using the LCA methodology to identify critical areas for improvement and to quantitatively validate the reduction of the EHS impact, Figure 2. During the development of the CNT material and device manufacturing processes, detailed process technical data (life cycle inventory) were collected and populated into an LCA model developed at ERDC to identify the initial impact and risks and the major contributors to such risks. A mitigation plan was implemented to reduce or eliminate the major contributors, which in turn reduced the EHS impact. The overall performance and cost of the manufactured materials and devices should at least remain the same, or even be significantly improved. Through the nanoEHS and iterative LCA approaches, wastewater generation was reduced by an order of magnitude, and electricity consumption was reduced by more than 50%. Furthermore, carbon nanomaterial manufacturing throughput increased by more than 100% without any additional capital investment, and device manufacturing throughput increased by an order of magnitude. Details of these approaches and accomplishments will be presented at the conference.