– Biorefinery and Pulp&Paper process integration (mass and energy balance) and its techno-economic analysis
– Process development for biomass biochemical treatment (pretreatment, mechanical refining, enzymatic hydrolysis)
– Process development for biomass thermal treatment (pyrolysis, torrefaction)
– Dissolving pulp characterization and application
- 2021 ~ current Professor, North Carolina State University
- 2017 ~ 2021 E.J. Woody Rice Associate Professor, North Carolina State University
- 2015 ~ 2017 Associate Professor, North Carolina State University
- 2011 ~ 2017 Adjunct Professor, Seoul National University
- 2009 ~ 2015 Assistant Professor, North Carolina State University
- 2006, Ph.D., Pulp and Paper, North Carolina State University
- 2001, M.S., Pulp and Paper, Seoul National University, Korea
- 1997, B.S., Forest Products, Seoul National University, Korea
- FB 760 Engineering Unit Operations for Biomass Conversion
- FB 595 Special Topic: Bioenergy Science and Engineering
- PSE 425 Bioenergy and Biomaterials Engineering
- PSE 417 Pulp and Paper Process Simulation
Growing concerns over climate change and the desire to stimulate a sustainable economy have renewed the urgency for developing substantial replacement of fossil feedstocks with renewable resources. Chemical and other commodity industries are gradually shifting from relying on petroleum to lignocellulosic biomass as feedstocks. To make biorefinery financially attractive, it is critically important to co-produce high-value chemicals and materials in addition to biofuel production. This lesson is clear from the petroleum industry in which petro-based chemical production generates similar cash value to fuel production, while only ~16% of crude oil is used for chemical production.
Our research at NC State University covers a broad spectrum of biorefinery development and is focused on the fundamental understanding of lignocellulosic biomass reactivity and engineering process development for both biochemical and thermochemical conversion processes into biofuels, biochemicals, and biomaterials. Please check our publications to follow research trends.
Area(s) of Expertise
Biorefinery development for biochemical and thermochemical conversion processes into biofuels, biochemicals, and biomaterials.
- Effect of ash in paper sludge on enzymatic hydrolysis , Biomass and Bioenergy (2022)
- Toughened Renewable Bio-polyester Blends Achieved through Crystallization Retardation by Acetylated Cellulose Fibers , ACS APPLIED POLYMER MATERIALS (2022)
- An eco-friendly approach for blending of fast-pyrolysis bio-oil in petroleum-derived fuel by controlling ash content of loblolly pine , RENEWABLE ENERGY (2021)
- Dynamic life-cycle carbon analysis for fast pyrolysis biofuel produced from pine residues: implications of carbon temporal effects , BIOTECHNOLOGY FOR BIOFUELS (2021)
- Effects of Mechanical Refining on Anaerobic Digestion of Dairy Manure , ACS OMEGA (2021)
- Techno-Economic Analysis of decentralized preprocessing systems for fast pyrolysis biorefineries with blended feedstocks in the southeastern United States , RENEWABLE & SUSTAINABLE ENERGY REVIEWS (2021)
- Techno-economic analysis of producing xylo-oligosaccharides and cellulose microfibers from lignocellulosic biomass , BIORESOURCE TECHNOLOGY (2021)
- Co-pyrolysis of biomass and plastic waste over zeolite- and sodium-based catalysts for enhanced yields of hydrocarbon products , Waste Management (2020)
- Decarbonizing agriculture through the conversion of animal manure to dietary protein and ammonia fertilizer , BIORESOURCE TECHNOLOGY (2020)
- Effect of cellulolytic enzyme binding on lignin isolated from alkali and acid pretreated switchgrass on enzymatic hydrolysis , 3 BIOTECH (2020)
Interdisciplinary Doctoral Education Program will be created to focus on Renewable Polymer production using Forest Resources to Replace Plastics. PDs from three colleges will work together to train three Ph.D. students.
Abstract: With the inevitable coming of the Green Economy, biomass valorization, use of renewable and bio-based materials and development of high-performance, recyclable, biodegradable and biocompatible products are nowadaysÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢ challenges and opportunities to welcome a more sustainable society. Yet, to hasten its arrival, we must answer the daunting question of how we transform these challenges to opportunities? By educating new generations of students to the multiplicity of opportunities or ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œmultiverseÃƒÂ¢Ã¢â€šÂ¬Ã‚Â of biomass, from a scientific and engineering perspective to an entrepreneurial vision. The Department of Forest Biomaterials has decades of expertise in conversion and valorization of biomass into new fuels/energies and high-performance biomaterials that offer solutions to greenhouse gas emissions, environmental and aquatic pollution and waste accumulation.We propose to leverage our graduate curriculum by adding an entrepreneurial and business competency to its strong scientific and engineering core. Our envisioned integrated program aims at educating Master and PhD students from NC State University, and others (via an online version) by training them in the principles, practices and methodologies of biomass valorization, conversion, and usage.
We will improve and validate the critical unit operations needed for producing high-value carbon materials (graphite and hard carbon) used for lithium ion and sodium ion batteries from a faction of the biocrude produced by biomass fast pyrolysis. This work will bring together two innovations, 1) production of high-value carbon materials from the biocrude heavy residues fraction, which are often difficult to convert into biofuels, and 2) process innovations that should lower the costs for producing these high-value carbons. In order to produce high-value carbons, the biocrude residues are sequentially heated to remove volatiles and oxygen, polymerize the biomass carbons into graphene sheets, and in a second step form either highly crystalline graphite or disordered hard carbon. The graphite can be used in as drop-in anode material in existing commercial lithium ion battery (LIB) applications such as portable electronics and electric vehicles (EVs), while the hard carbon can be used in emerging and advancing battery applications, such as sodium ion battery (SIB) for grid electrochemical energy storage and LIB for hybrid batteries in EV with high capacity and good rate capability. The team has demonstrated that both graphite and hard carbon can be produced from pyrolysis biocrudes at laboratory scale and has measured their electrochemical performance in batteries. This work will optimize the range of operating parameters, with a focus on the complex interactions between the chemical changes and the heat and mass transfer characteristics of the reactor and increase the production scale to obtain mass and energy balances that are relevant for modeling commercial potential. The performance of the carbon materials will be evaluated to define their values in commercial systems. Both techno-economics (TEA) and life cycle analysis (LCA) will be performed to understand the economic and environmental impact of the proposed technology. Preliminary revenue analysis suggests diverting 15-25% of the biocrude, essentially all of the heavy and less valuable fraction, into high-value carbons like graphite or hard carbon can significantly improve the profits of a biorefinery and lower the cost of making biofuels. The goal of this project is to optimize and scale-up the process for producing graphite and hard carbon that meet the requirement for LIB and SIB, respectively. Performance specification will be measured, including electrochemical performance under varying conditions (e.g., operating voltage range, current density, and c-rate) using coin-type and pouch cells. We will use a suite of advanced analytical tools to develop a more detailed understanding of 1) how the chemical composition of biocrude and the carbonization process impact the macromolecular ordering of the final products and 2) how the changes in carbon structure influence on the ion storage behavior (e.g., (de)insertion and adsorption/desorption) and subsequent electrochemical performance. In addition to the performance of the carbon materials, we will determine yields in order to close the mass and energy balances of the process. This data will be used to conduct rigorous TEA and LCA models to demonstrate the target FOA metrics such as $3.00/GGE fuel selling price and 60% reduction in emission. Successful completion of the scale up of bio-based graphite and hard carbon production will enable commercialization of these processes and will have an important impact on several sustainable technologies, 1) the low cost biocrude, the bio-based graphite will reduce the cost for LIB that can be used in EVs, 2) the low cost of hard carbon production will enable SIB for energy grid storage and LIB for advanced batteries for EVs, supporting continued growth of PV and wind electricity generation, and 3) commercial production of graphite and hard carbon as biorefinery co-products will improve the overall economics of producing biofuels.
The objective of this proposal is to develop an education program for a new generation of researchers who understand the entire spectrum of biomass oligosaccharide production, animal production, and its analysis through a life cycle approach. Faculty members from two departments are proposing to create joint doctoral education program to address this Targeted Expertise Shortage Area (Animal Production) with Relevant Disciplines of (A) Animal Science, (B) Biotechnology, and (C) Renewable Natural Resources.Five focus areas are (1) Biomass oligosaccharide production; (2) Purification of xylose oligosaccharide; (3) Manufacturing and processing of animal feed; (4) Animal feeding and management; and (5) Life cycle Analysis. This program incorporates cross-disciplinary teamwork/advising, coursework in multiple disciplines, Preparing Future Leaders program, internship at a commercial farm, and exposure to biotechnology experts in industry.
This project will merge NRELâ€™s highly robust biomass fractionation and fermentation technology and NCSUâ€™s highly robust graphitization technology to convert two waste streams that are increasingly problematic in the southeastern US and Caribbean states (hurricane-damaged wood waste and Sargassum seaweed) into Sustainable Aviation Fuel (SAF) and graphite for lithium ion batteries (LIB), as shown in Figure 1. NREL has developed fractionation technology for biomass and algae that solubilizes carbohydrates and proteins of varying composition into fermentable hydrolysates. Hydrolysates from woody biomass contain abundant carbohydrates but are typically nutrient-poor for fermentation and require added nutrients, such as nitrogen. Algae (both micro- and macroalgae) hydrolysates are also rich in carbohydrates but are often over-rich in nutrients. Thus, combining these two waste stream hydrolysates in an appropriate ratio will maximize fermentation productivity of SAF precursor (ethanol) while keeping wood waste and Sargassum out of landfills. NCSU and NREL have also demonstrated synthesis of battery-grade graphite from a variety of sustainable feedstocks, including pyrolysis oil, lignin, and cellulose using metallic iron catalysts. This technology is also expected to work well with the insoluble residues from the waste streams described above. The proposed fermentation pathway presents a viable pathway to helping reach BETOâ€™s goal of producing 3 billion gal/year of SAF and the graphite production is compatible with the rapidly growing market for LIB (20% per annum) for portable electronics and electric vehicles.
The objective of this project is to demonstrate catalytic processes for upgrading carbohydrates to hydrocarbon biofuels using two low-cost wet organic waste streams: Papermaking sludge and Post-sorted municipal solid waste. The work is based on the previous success of hydrocarbon production from corn stover in a bench scale via dilute-acid and enzymatic deconstruction followed by dehydration to furans, condensation, and hydrodeoxygenation to hydrocarbons. The project team will develop (1) a sugar production process and a removal strategy of non-carbohydrates that could poison catalysts during the conversion process, (2) isomerization and dehydration processes necessary to convert both glucose and xylose to furans in a single reactor, (3) an upgrading process of furans via aldol condensation with ketone and hydrodeoxygenation to diesel range hydrocarbons, and (4) a detailed techno-economic analysis to integrate and optimize the overall process. The developed process in this project will be demonstrated in a relevant pilot-scale and life cycle assessment will be evaluated.
We propose an integrated technology of low capital intensity that will capture, utilize and sequester carbon dioxide in wood pulping processes. CO2 (Carbon Dioxide) will be utilized by converting two waste streams to mineral carbonate fertilizer. The carbon in the mineral carbonates is derived from carbon dioxide generated in recovery boilers and lime kilns. Excess carbon dioxide that is not utilized as fertilizer will be pumped deep underground into suitable geological reservoirs for permanent sequestration. Retrofitting lime kilns to oxy-fuel will enable low-cost generation of high purity carbon dioxide. If fully implemented at every large chemical pulp mill in the United States, approximately 14 million metric tons of carbon dioxide will be captured, utilized, and sequestered per year.
The purpose of the Consortium on Sustainable and Alternative Fibers Initiative (SAFI) is to develop fundamental and applied research on the use of alternative and sustainable fibers for the manufacturing of market pulp, hygiene products and nonwovens. The idea for SAFI has grown out of societal needs for alternative yet sustainable materials. SAFI will study the potential of alternative fibers based on technical (performance), sustainable and economic principles.
The project will prepare a diverse group of college students and high school teachers with the knowledge and interdisciplinary tools necessary to advance the future of AmericaÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s bioenergy, bioproducts, and the bioeconomy. Distance courses will be developed and taught by faculty in the Departments of Forest Biomaterials & Environmental Resources, with guidance from the College of Education, undergraduate students are recruited from historically underserved institutions (HBCU, womenÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s college, community college), as are teachers from rural, high poverty NC high schools. Undergraduates will complete three of the five online courses in bioenergy & bioproducts, and complete an industry internship, and earn a certificate. Bioproducts and bioenergy industrial and research organization partners provide hands-on internship projects in the industry or in a research setting. Rural high school science teachers will complete three of the five online courses, earn a certificate, participate in professional development workshops, carry out lessons with their students during the school year, and conduct a career fair in bioproducts and bioenergy.
We are proposing to develop fundamental research on the effect of physico-chemical deconstruction of recycled textiles to facilitate enzymatic digestibility and optimize the production of bio-based building blocks as feedstock to manufacture value-added chemicals. This project is in the heart of the circular economy promoting the use of waste and recycled materials and thus reduce overall carbon footprint. Preliminary studies carried out by Cotton Inc. and North Carolina State University on the pre-treatment of recycled textiles show important synergy in the interaction of chemical pretreatments and mechanical defibrillation in bleached cotton textiles. In order to apply these preliminary findings to more complex textiles matrixes (i.e., dyed cotton and cotton blends with synthetic materials), it is crucial to understand the underlying mechanism affecting the enzymatic hydrolysis. Additionally, to improve the economics of the conversion process (and further reduce carbon footprint), the recyclability of residual materials (after enzymatic hydrolysis) and its possible use as feedstock in another conversion process will be considered. With the aim to develop a profitable process suitable for pilot demonstration, capital expenditure and operational costs will be monitored by conducting techno-economic assessments at the early state.