Dr. Zhaohui Tong
Zhaohui Tong’s work includes the full range of products that can be produced from renewable biomass. Her training gives her remarkable scope to work at all stages of biomass processing – from feedstock supply chain, conversion technologies, to final products and its process modeling. In addition to her work with biomass processes, Tong maintains an active research program in the area of novel polymer, nanoparticle, and biochemical development.
Biofuels and Biomass-based Products
The basic problems with petroleum are well known. Still the largest energy source in the U.S. (40%) and in the world (35%), petroleum results in many environmental problems, such as acid rain, global warming, and environmental degradation. Plus, petroleum and other nonrenewable energy sources are running out and will be depleted in the future. Part of the solution to these problems is the production of biofuels, and the U.S. government has mandated the production of 36 billion gallons of biofuels by 2022 and 60 billion gallons by 2030.
The development of new biofuel processes will be part of this solution. Tong helps to develop a $20 million biofuel production facility, which is located in Perry, Florida. Tong group has also developed several enabling technologies to convert lignin from biomass to high value aromatic precursors for jet fuel, food additives, and bioplastics. Tong is also interested in modeling and computational aspects of bio/chem process. She collaborates with Dr. Guanghui (George) Lan in the School of Industrial & Systems Engineering at Georgia Institute of Technology in an interdisciplinary research effort to simulate and optimize the biofuel/chemical processes.
But production of biofuels is not the whole story because petroleum is not just a fuel. Many chemicals and plastics are derived from petroleum. This is the “bioproducts” part of the program and one that Tong is eager to dig into. Replacing petroleum means both replacing petroleum-based fuels with biofuels and finding additional ways of reducing environmental pollution through complete utilization of current biomass and the production of high-value-added biomass-based products. Production of high-value-added materials from the three components of lignocellulose is a very interesting research area to Tong. She cites nanocrystalline cellulose, which can dramatically strengthen plastics, oligosaccharides as growth regulators for animals and plants, and lignin-based products, such as nanolignin with its UV-blocking properties.
Tong’s preparation for her current position is unique and especially appropriate. Her primary interests in school were mathematics and chemistry, but she has always been motivated by a strong desire to find work of benefit to human health, food security, and environment. Tong describes the many benefits gained from her past training and experience. Most importantly, her education and industrial experience in papermaking, packaging, and bioenergy process consulting dealt with lignocellulose and natural fibers, which are also the most interesting raw materials for bioproduct production. Lignocellulosic materials are not unfamiliar. This material makes up most of the mass of the plants all around us, in fact, lignocellulose is the most abundant organic material on earth. Tong explains that lignocellulose is composed mainly of three polymers. Cellulose is the main component of woody plants (about 40-45%) with lesser amounts of lignin (20-25%) and hemicellulose (15-25%).
In spite of the significant research effort devoted to renewable polymers over the past decade, the market of bio-based polymers is only a small fraction (<10%), compared to petroleum-based ones, because of their higher cost and inferior performance. To address these issues, Tong group has developed low cost nanocomposites, novel synthesis and self-assembling methods from bio-based molecules (lignin, cellulose, and glycerol) for the synthesis of several value-added functional materials. She will further explore this area by increasing sustainable portion, providing advanced functionality (e.g. preventing food spoilage bacteria), and investigating new polymer synthesis, processing, and self-assembling approaches.
In discussing the potential for novel products derived from biomass, Tong emphasizes lignin, which is the most abundant aromatic polymer in nature. Lignin has aromatic rings as the basic skeleton crosslinked via a variety of ether and carbon-carbon bonds. The selective depolymerization of lignin to produce high value aromatic monomers, hydrocarbon platform chemicals (e.g. jet fuel C8-C16) and low molecular weight chemicals (e.g. dicarboxylic acids) is very appealing and yet to be explored area of research. Tong has developed several low cost catalysts to effectively depolymerize lignin into low molecular weight aromatics under mild reaction conditions. The products could be further upgraded into hydrocarbon fuel precursors (e.g. jet fuel) that are compatible with current fuel infrastructure or high value aromatic chemicals (e.g. vanillin and benzonic acids), which have potential as the food additives or monomer precursors of polyesters.
Research and Extension
- Production, characterization and application of green nanocomposites
- Synthesis of sustainable latex of biopolymer encapsulated nanohybrid via miniemulison
- Development of high-value byproducts from biorefining waste and its applications in coating, packaging and agricultural areas
- Synthesis of cellulose-based biomimetic nanocomposite
- Conversion of lignocellulosic biomass to ethanol
- Synthesis of plant-based chemicals and materials
- ABE6654C/4655C: Biobased Products from Renewable Resources