Scientists have successfully discovered a new approach to process a plant-derived material named nanocellulose, achieving a remarkable 21% reduction in energy consumption. This advancement was made possible through simulations conducted on supercomputers at the Oak Ridge National Laboratory.
A research team at the Department of Energy’s Oak Ridge National Laboratory has identified and effectively demonstrated an innovative technique for processing nanocellulose, a material sourced from plants, leading to a significant energy reduction of 21%. This method emerged from molecular simulations conducted on the lab’s supercomputers, followed by pilot testing and further evaluation.
This innovative method, which employs a combination of sodium hydroxide and urea dissolved in water, holds the potential to dramatically decrease the production costs associated with nanocellulosic fiber. This fiber is a robust and lightweight biomaterial, perfect for use in 3D printing applications, such as sustainable housing and vehicle construction. The research contributes to the development of a circular bioeconomy, where renewable, biodegradable materials replace petroleum-based alternatives, promoting decarbonization and minimizing waste.
Researchers from ORNL, along with collaborators from the University of Tennessee, Knoxville, and the University of Maine’s Process Development Center, worked on this project aimed at enhancing the efficiency of nanocellulose production. Nanocellulose, derived from cellulose found in plant cell walls, is a natural polymer that boasts strength comparable to steel.
The scientists aimed to optimize the fibrillation process, which is how cellulose gets broken down into nanofibrils—a step that usually consumes a lot of energy due to high-pressure mechanical methods in a water-based pulp suspension. They analyzed eight different solvents to identify a better pretreatment solution for cellulose. Using sophisticated computer models that simulate atomic and molecular behavior within solvents and cellulose, the team was able to explore this complex process without the need for extensive initial lab experiments.
The simulations were conducted by researchers associated with the UT-ORNL Center for Molecular Biophysics and the Chemical Sciences Division at ORNL, utilizing the Frontier exascale computing system—the world’s leading supercomputer for open science, situated within the Oak Ridge Leadership Computing Facility, operated by the DOE Office of Science.
“These simulations, which consider the interactions of every single atom, provide profound insights into the effectiveness of a process and detail the reasons behind its operation,” explained project lead Jeremy Smith, director of the CMB and a UT-ORNL Governor’s Chair.
After identifying the optimal solvent, the team conducted pilot experiments that validated the solvent pretreatment, confirming a 21% reduction in energy usage compared to water alone, as published in the Proceedings of the National Academy of Sciences.
With the selected solvent, the researchers estimated a potential energy savings of approximately 777 kilowatt hours for every metric ton of cellulose nanofibrils (CNF), comparable to the electricity required to power an average home for a month. Tests on the resulting fibers at the Center for Nanophase Materials Science, a DOE Office of Science user facility at ORNL, and at U-Maine, showed that they maintain similar mechanical strength and other desirable properties as conventionally manufactured CNF.
“We focused on enhancing the separation and drying stages, as they consume the most energy in producing nanocellulosic fiber,” stated Monojoy Goswami from ORNL’s Carbon and Composites group. “Thanks to molecular dynamics simulations and the advanced computing capabilities at Frontier, we accelerated progress significantly — what could have taken years of trial and error was achieved in a much shorter time.”
Optimal combination of materials and processes
“By merging our skills in computational science, materials science, and manufacturing, along with our nanoscience tools at ORNL, alongside the forestry knowledge from the University of Maine, we can reduce uncertainties in our research and develop more precise experimental approaches,” said Soydan Ozcan, who leads the Sustainable Manufacturing Technologies group at ORNL.
This project has received backing from the DOE’s Office of Energy Efficiency and Renewable Energy through the Advanced Materials and Manufacturing Technologies Office (AMMTO), in partnership with U-Maine, as part of the Hub & Spoke Sustainable Materials & Manufacturing Alliance for Renewable Technologies Program (SM2ART).
The SM2ART initiative aims to build future industrial-scale facilities that utilize sustainable, carbon-storing biomaterials to create a range of products, including housing, vehicles, and clean energy solutions such as wind turbine components, according to Ozcan.
“Creating robust, affordable, and carbon-neutral materials for 3D printing positions us to tackle challenges like the housing shortage,” remarked Smith.
Currently, constructing a house through traditional methods spans around six months. However, with the right materials and additive manufacturing techniques, it is possible to produce and assemble sustainable modular housing components in just a day or two, the researchers noted.
The team plans to explore additional methods for reducing the costs of nanocellulose production further, including new drying techniques. Future research is expected to utilize simulations to determine the best combinations of nanocellulose with other polymers for creating fiber-reinforced composites suited for advanced manufacturing systems currently under development at DOE’s Manufacturing Demonstration Facility (MDF) at ORNL. Supported by AMMTO, the MDF is a nationwide collaboration aimed at innovating and transforming U.S. manufacturing.
Additional scientists involved in the solvents project include Shih-Hsien Liu, Shalini Rukmani, Mohan Mood, Yan Yu, and Derya Vural from the UT-ORNL Center for Molecular Biophysics; Katie Copenhaver, Meghan Lamm, Kai Li, and Jihua Chen from ORNL; Donna Johnson from the University of Maine; Micholas Smith from the University of Tennessee; Loukas Petridis, currently with Schrödinger; and Samarthya Bhagia, currently with PlantSwitch.
