Renewable Energy Global Innovations features: A techno-economic comparison of Fischer–Tropsch and fast pyrolysis as ways of utilizing sugar cane bagasse in transportation fuels production

Significance Statement

In recent years, critical issues such as energy security, petrol price upsurge and increasing consciousness of global warming, have all garnered attention from all walks of life to focus on the prospects of a bioenergy sector. The concept of biorefinery has recently emerged where biomass has already been identified as the sole source of renewable energy which has properties similar to fossil fuels. Sugarcane is currently the most cost-effective feedstock for the biofuel production and could become even cheaper and more advantageous if the waste bagasse would also be converted to biofuels. From various technoeconomic analysis, two techniques: the fast pyrolysis-hydro processing route and gasification coupled with Fischer–Tropsch synthesis, have been considered to be feasible for application in the large-scale production of bio fuels from the sugarcane bagasse.

In a recent paper published in Chemical Engineering Research and Design Stavros Michailos and Colin Webb from the School of Chemical Engineering and Analytical Science at University of Manchester in collaboration with David Parker at University of Exeter compared the economic and technological feasibility of the fast pyrolysis-hydro processing route (repurposed to enhance hydrogen production) and gasification coupled with Fischer–Tropsch synthesis processes. They aimed at resolving which between the two processes would deliver final products of fuels that can be directly used within the inherent technological infrastructure cheaply.

The adaptability of gasification followed by Fischer–Tropsch synthesis and fast pyrolysis coupled with hydro processing were examined against economic and thermodynamic criteria. Sugarcane bagasse was adopted as the feedstock at a flow rate of 100 metric tonnes per hour. The research team then utilized the Aspen plus process simulation software to build robust and thermodynamically rigorous simulations of the constituent processes of these biofuel conversion options processes. Mass, energy balance of the constituent processes, the overall thermochemical energy and economic efficiencies were calculated for each option based on the quantification and assessment of the yield.

From the comparative analysis of two near term biomass-to-liquid fuels conversion options, the researchers observed that the higher fuels productivity associated with the Fischer–Tropsch process resulted in in higher thermodynamic efficiencies than fast pyrolysis process. During fast pyrolysis, lignin is exploited in a steam cycle to generate electricity while in Fischer–Tropsch process, lignin is gasified and thereby it contributes to liquid fuels production. Moreover, almost forty percent of electricity generated by fast pyrolysis CHP unit is utilized to compress hydrogen. According to economic assessment Fischer–Tropsch process outplays fast pyrolysis process achieving higher values for all economic indicators. In addition, it is more lenient to variations of the elementary financial specifications. Conversely, the fast pyrolysis process delivers higher product diversity.

In light of the aforementioned remarks and outcomes, the choice of the best alternative conversion route depends on many aspects including factors aside from those enumerated in this study, such as market demand and location of the plant. However, at the moment and solely based on thermo-economic criteria Fischer–Tropsch process is more efficient than fast pyrolysis process mainly due to higher thermodynamic performance, minimal risk and substantial economic returns.

Reference

Stavros Michailos¹, David Parker², Colin Webb¹. A techno-economic comparison of Fischer–Tropsch and fast pyrolysis as ways of utilizing sugar cane bagasse in transportation fuels production. Chemical Engineering Research and Design. Volume 118 (2017) pages 206–214.

Show Affiliations

1. School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
2. School of Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK

 

Go To Chemical Engineering Research and Design Read more research excellence studies on: Renewable Energy Global Innovations (http://ift.tt/21cCPA4)

Renewable Energy Global Innovations features: Development of La(Cr,Co,Fe,Ni)O3 system perovskites as interconnect and cathode materials for solid oxide fuel cells

Significance Statement

Due to an increase in demand for sustainable energy sources, solid oxide fuel cells (SOFCs) have received more attention owing to their huge potential for power production in portal transport applications. Almost all solid oxide fuel cells are arranged either in parallel or series in order to facilitate voltage output. An interconnect is needed to connect the cells. It connects the cathode of one cell to the anode of the other, yet physically separates the cells.

An interconnect should be non-porous with 100% relative density to avoid the mixing of fuel and oxygen. Above all, it must be stable in oxidizing and reducing environments, have high electrical conductivity, chemical stability and sintering attributes. It can be metallic or ceramic. One desirable material for a ceramic interconnect in solid oxide fuel cell is the doped Lanthanum Chromite based perovskite material.

The cathode material should as well meet stringent requirements. Therefore, the shortcomings in perovskite oxide materials adopted for cathode and interconnect fabrication can be overcome through the synthesis of new materials by adding or modifying the transition metals in the current materials to enhance chemical stability, low sintering temperature, electronic and ionic conductivity, and thermal expansion coefficient.

Researchers led by Professor Rasit Koc at Southern Illinois University developed cathode and interconnect material for solid oxide fuel cells. Their main aim was to develop and evaluate cathode and interconnect materials for SOFC which will meet the exacting requirements of SOFC manufacturers.  These requirements are fabricability (sinterability) at temperatures 1400^oC and below at lower cost, high electronic conductivity, chemical stability in reducing and oxidizing conditions and coefficient of thermal expansion match with other cell components.  Dr. Zhezhen Fu of University of Maryland says “The developed sinterable materials with very high electrical conductivity are critical in the commercialization of low temperature solid oxide fuel cells (LT-SOFCs)”. The research work on La(Cr,Co,Fe,Ni)O₃ is now published in Ceramics International.

The authors prepared the powders through the Pechini approach. They mixed metal nitrates and lanthanum carbonate as starting materials in stoichiometric proportions. The resulting mixture was then mixed with ethylene glycol and citric acid forming a polymer that broke to form powder precursor. The precursors were calcined, ball milled, and pressed to form circular pellets. The microstructure developed completely in the course of the sintering process. The sintered samples were polished and thermally etched for microstructure analysis.

samples were prepared for electrical conductivity measurement. Each sample was subjected to resistance measurements. The pellets were then heated in a furnace and resistance measured as a function of temperature in the range of solid oxide fuel cell operation.

Through the Pechini polymer complexing approach, the authors were able to synthesize five compounds into a single phase of LaCo_0.7Cr_0.1Fe_0.1Ni_0.1O₃ (LCo7CFN), LaNi_0.7Cr_0.1Co_0.1Fe_0.1O₃ (LNi7CCF), and LaCr_0.25Co_0.25Fe_0.25Ni_0.25O₃ (LCCFN), LaFe_0.7Cr_0.1Co_0.1Ni_0.1O₃ (LFe7CCN), were sintered to a relative density of 98%, 82%, 94%, and 91% respectively at about 1400 °C for two hours in air. Transit liquid phases formed under the sintering conditions and contributed to the high relative densities. LaCr_0.25Co_0.25Fe_0.25Ni_0.25O₃ (LCCFN), posted the highest electrical conductivity.

Among the lanthanum perovskite oxides, LaCo_0.7Cr_0.1Fe_0.1Ni_0.1O₃ (LCo7CFN) and LaCr_0.25Co_0.25Fe_0.25Ni_0.25O₃ (LCCFN) appeared to comprise building blocks for interconnect fabrication owing to their high relative densities (94-98 %) and excellent electrical conductivity (>50 S/cm). LaNi_0.7Cr_0.1Co_0.1Fe_0.1O₃ (LNi7CCF) with high electrical conductivity and relative density of approximately 82% was selected to be a suitable candidate for the porous cathode.  Currently, these materials are being doped with Ca on the La site to further enhance their properties.

About The Author

Abhigna Kolisetty graduated from Southern Illinois University Carbondale with a Master’s degree in Mechanical Engineering. Her research interests are Material Science, clean energy, energy conservation, and energy efficiency. Under the guidance of her advisor, Dr Rasit Koc, Abhigna worked on developing interconnect and cathode materials for Solid Oxide Fuel Cells as her thesis topic. This research has been published in the journal “Ceramics International” as the article, “Development of La(CrCoFeNi)O₃ system perovskites as interconnect and cathode materials for solid oxide fuel cells.” She is currently a Mechanical Designer for AECOM, an engineering consulting firm in Cleveland, Ohio.

 

About The Author

Zhezhen Fu received his Ph.D. degree from Southern Illinois University in 2016. He is currently a Postdoctoral Associate at the University of Maryland. His research focuses on the processing and characterization of advanced ceramic materials such as: (1) titanium carbide and boride materials for structural application; (2) doped LaCrO3 perovskite for solid oxide fuel cell application; (3) lithium-ion conducting garnet-oxide for all-solid-state battery application.

About The Author

Dr. Rasit Koc is a Professor and Chair of Mechanical Engineering and Energy Processes (MEEP) Department at SIUC. Before coming to SIUC, Dr. Koc was a Senior Engineer at U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) in Golden, Colorado, where he conducted research in the areas of Processing and Characterization of Advanced Ceramic Materials and Composites. In 1995, his work on synthesizing nano-size SiC materials received R&D 100 award. During his graduate studies, he worked in cooperation with Dr. Harlan U. Anderson, in the areas of ceramic materials for Fuel Cells. Koc has authored/coauthored more than 100 papers and holds 3 U.S. patents. He served as the American Ceramic Society Rocky Mountain Chapter treasurer and he was an associate editor of the journal for 12 years.

Reference

Abhigna Kolisetty, Zhezhen Fu, and Rasit Koc. Development of La(Cr,Co,Fe,Ni)O₃ system perovskites as interconnect and cathode materials for solid oxide fuel cells. Ceramics International, volume 43 (2017), pages 7647–7652.

Department of Mechanical Engineering and Energy Processes, Southern Illinois University, 1230 Lincoln Drive, Carbondale, IL 62901, United States.

Go To Ceramics International Read more research excellence studies on: Renewable Energy Global Innovations (http://ift.tt/21cCPA4)

Renewable Energy Global Innovations features: Preferential positioning and phase exposure of granular particles at hydrophobic liquid-water interface

Significance Statement

Granular materials such as limestone and sand have been observed to exhibit an aptitude to aggregate with a hydrophobic phase, such as oil, thereby capturing substantial amounts of oil that floats on water surfaces. This unique phenomenon of selective positioning of the granular materials at the non-colloidal scale at the hydrophobic liquid-water interfaces is yet to be exhaustively studied and reported in the existing scientific literature. Consequently, it has therefore attracted profound interest as the comprehension of the granular particle behavior is needed for the possibility of utilizing readily available granular materials for capturing oil and curbing the mobility of floating oils as a treatment method.

In a recent paper published in Journal of Cleaner Production Daria Boglaienko and Berrin Tansel from the Department of Civil and Environmental Engineering at Florida International University proposed to analyze the observed variations in the positioning and behavior of the natural granular particles of limestone and quartz at the hydrophobic liquid-water interfaces. They also aimed at evaluating the dominant force impact on the particles behavior.

Foremost, experiments were carried out using dyed quartz and limestone particles with a 0.2-millimeter diameter for the fine particles and 0.5 millimeter for the medium sized particles. The researchers then used particles of different colors so that positioning of the particles with different sizes could be visually observed in the hydrophobic liquid water systems. They then selected silicon oil, tetradecane and crude oil for use as the hydrophobic liquid. Eventually, the researchers analyzed the behavior of the particles at the hydrophobic liquid and water interfaces through the application of the electrostatic image force theory.

By comparing theoretical and empirical results obtained, the researchers observed that the theoretical results did not support the assumption that the particle positioning at the liquid interface can be theoretically linked to gravitational force. The limestone which has active surface properties was observed to possess higher surface charge hence was able to cross the tetradecane-water interface abandoning the non-reactive tetradecane phase. They also observed that the zeta potentials of the aqueous limestone decreased upon addition of crude oil which explains why the limestone particles were held at the crude oil-water interface. These helped them conclude that the polar fractions of crude oil affected the surface charge and zeta potential of a particle.

The empirical observations have directed that the effects of the charge differences are more significant than the effect of the size difference in determining the position of a particle in a hydrophobic liquid, hydrophobic liquid-water interface and water phase. It is therefore important to note that slight differences in material composition affects surface characteristics thereby resulting in differences in the preferential positioning of the particles. The phenomenon presented here is of high interest and presents a new oil spills treatment technique which is inexpensive, simple and environmentally friendly.

About The Author

Dr. Berrin Tansel is a professor in the Civil and Environmental Engineering Department at Florida International University (FIU). She has over 30 years of experience in environmental engineering, water quality management, physical-chemical treatment methods, contaminant-surface interactions and water infrastructure. She has received her PhD degree in environmental engineering from University of Wisconsin-Madison.

Dr. Tansel is an elected Fellow of the American Society of Civil Engineers (ASCE) and Environmental and Water Resources Institute (EWRI). She is a Diplomate of American Academy of Water Resources Engineers, and Board Certified Environmental Engineer by the American Academy of Environmental Engineers. She is a registered professional engineer in the State of Florida, USA. She has published over 200 journal papers, book chapters, technical reports and two books. Dr. Tansel is the editor in chief of the Journal of Environmental Management.

About The Author

Daria Boglaienko received her PhD in Civil Engineering (with specialization in Environmental), Florida International University. She holds two Master’s Degrees: from National Technical University in Ukraine and from Florida International University, where she got Outstanding academic achievement award. Her overall research experience can be characterized as one with a broad interdisciplinary focus. She studied benefits of alternative energy sources with a specialization on biogas production in waste treatment and anaerobic digestion processes. For her second master’s thesis she integrated several important aspects of a cover crop study to clarify mycorrhizal status of a plant, to investigate the benefits after its incorporation into soil, and to assess and prove its economic value.

Daria’s dissertation research was on floating crude oil capture and encapsulation using granular materials. She analyzed oil-particle aggregation from different perspectives, proposing and developing recommendations for a new environmentally friendly and inexpensive method to capture floating oils. Daria received Outstanding doctoral award in Civil Engineering and Worlds Ahead Graduate award from Florida International University.

Reference

Daria Boglaienko, Berrin Tansel. Preferential positioning and phase exposure of granular particles at hydrophobic liquid-water interface. Journal of Cleaner Production volume 142 (2017) pages 2629-2636.

Department of Civil and Environmental Engineering, Florida International University, Miami, FL, USA.

 

Go To Journal of Cleaner Production Read more research excellence studies on: Renewable Energy Global Innovations (http://ift.tt/21cCPA4)

Renewable Energy Global Innovations features: Potential threshold of anode materials for foldable lithium-ion batteries featuring carbon nanotube current collectors

Significance Statement

Energy storage devices present a noteworthy challenge in creating a robust deformable system because they must be flawlessly integrated with intelligent wearable devices such as stretchable circuits, epidermal health electronics and flexible displays. The lithium ion batteries are the preferred source of power for such deformable functional devices if they can be compressed, rolled, stretched, buckled and folded. However, selecting an active material for convectional lithium ion batteries poses a major challenge since it easily delaminates or fractures upon being deformed. Moreover, the high-density attribute of the metal restricts the energy density of the lithium ion batteries. Therefore, replacing the metallic foils with light weight, flexible and highly conductive current collector can impart flexibility to the devices and may also rise the energy density of lithium ion batteries.

In a recent paper published in Journal of Power Sources, researchers led by professor Zi Ping Wu at Jiangxi University of Science and Technology in China proposed a study on Potential threshold of anode materials for foldable lithium-ion batteries featuring carbon nanotube current collectors. They aimed at providing a principle for the selection of an active material based on flexible current collectors for foldable lithium ion batteries.

First the research team prepared flexible carbon nanotube macro-film composed of carbon nanotube bundles by chemical vapor deposition. They then fabricated the electrodes by using slurry-based preparation technique. Next, they assembled coin-type half-cells in an argon filled glove box with bare flexible carbon nanotube macro-film disks as working electrodes, lithium titanium oxide and GPE that use copper foil as current collector for loading, lithium cobalt oxide that uses aluminum foil as current collector and lithium metal as reference electrode. These cells were then assembled in a de-humidified room with moisture content less than 2%. Eventually, cyclic voltammetry measurements were carried out using standard electrochemical instrumentation.

From the set up described it was observed that the electrochemical behavior characteristic for the two electrodes, lithium cobalt oxide -aluminum and lithium cobalt oxide – Flexible carbon nanotube macro-film was similar except for the current of oxidation peak. No notable difference was observed in their CV curves and galvano-static discharge/charge profiles. It was noted that when the anode material had a potential higher than 0.9V, good performance of the flexible carbon nanotube macro-film based foldable lithium ion batteries is obtained since the lithium ion passed the potential threshold and the flexible carbon nanotube macro-film retained its electrochemical inactivity. However, if the potential anode is lower than 0.9V several free lithium ions will be constrained. In return the capacity of the flexible carbon nanotube macro-film based electrode will be lowered and the cycling performance will be poor.

The flexible carbon nanotube macro-film based foldable lithium ion batteries generally performed well experimentally. Therefore, it is expected that the mechanism of potential threshold of anode materials will provide new impetus to both industry and academia to explore the development of lithium ion batteries in flexible and foldable energy storage devices.

About The Author

Dr. Wu is an associate professor at Jiangxi University of Science and Technology. He currently specializes on carbon nanotube macro-films for flexible batteries and electromagnetic shielding applications. Under his guidance, a folding insensitive and high energy density lithium-ion battery has been reported in 2015.

Reference

Qing Hui Wang, Sheng Wen Zhong, Jing Wei Hu, Ting Liu, Xian Yan Zhu, Jing Chen, Yin Yan Hong, Zi Ping Wu. Potential threshold of anode materials for foldable lithium-ion batteries featuring carbon nanotube current collectors. Journal of Power Sources volume 310 (2016) pages 70-78.

Show Affiliations

1. School of Materials Science and Engineering, Jiangxi University of Science and Technology, 86 Hong Qi Road, Ganzhou 341000, PR China
2. School of Materials Science and Engineering, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, PR China

 

Go To Journal of Power Sources Read more research excellence studies on: Renewable Energy Global Innovations (http://ift.tt/21cCPA4)

Renewable Energy Global Innovations features: The Influence of Periodic Wind Turbine Noise on Infrasound Array Measurements

Significance Statement

Wind turbine noise is a combination of audible acoustic and infrasonic components. Low infrasonic background noise is a prerequisite for infrasound detections of conceivable nuclear explosions in the atmosphere in the context of monitoring compliance with the Comprehensive Nuclear Test-Ban Treaty (CTBT). Aerodynamic noise emitted from the endlessly growing number of wind turbines in Germany is increasingly creating problems for the infrasound recording systems. During each revolution, the wind turbine blades encounter much variation in the air flow generated by changes in intensity and wind direction when flowing around the structural tower. As the wind turbine blade revolution process is repetitive, impulsive sound signals consisting of pure tones which are integer multiples of the fundamental blade-passing harmonic are generated. Consequently, studies on the intensity and frequency of the aerodynamic infrasonic noise signals produced have gained much interest.

In a recent paper published in Journal of Sound and Vibration Christoph Pilger and Lars Ceranna from The Federal Institute for Geosciences and Natural Resources (BGR) in Germany studied the influence of periodic wind turbine noise on infrasound array measurements. Their aim was solely focused on the effects of the infrasonic component of wind turbine noise on infrasound measurements by microbarometer arrays.

For the researchers to determine the emission of the infrasound signals by the wind turbines, a field campaign was carried out near a single 200kW horizontal axis turbine north of Hanover. Additionally, ten years of infrasound data recorded at the German infrasound array IGADE, were analyzed with respect to influences of nearby wind turbines. Theoretical models were then derived and validated by the field measurements using mobile microbarometer stations. Model computations on the influence of single versus multiple wind turbines and the effect of ducting and propagation on the sound pressure levels of infrasound observations were included and presented. Discussions and conclusions on least distances between wind turbines and infrasound arrays were derived from the model calculations of sound pressure levels in the infrasonic frequency range and verified by infrasound observations.

It was observed that at certain frequencies and during nearly all years and seasons, the aerodynamic sound waves of the BPH increased the SPL detected and quantified by the sensors. Blade-passing harmonics with multiples of 1 to 1.4Hz frequency were observed to occur during most of the observations and had the highest spectral increase compared to neighboring frequencies. From the model the researchers were able to estimate the generated sound pressure level of wind turbines and thus making it possible for specification of the minimum allowable distance between wind turbines and infrasound stations for undisturbed recording.

study demonstrated that a minimum distance of 20 km should be maintained between an infrasound station and a single wind turbine so as to guarantee unhindered recording and detection conditions. In the case of multi element wind farm, the distance would need to be increased to 50 km. However, if only occasional tropospheric ducts increasing the surface-near sound levels are considered, 5-10 km and 10-15 km would be adequate and sufficient to allow unhindered recording and detection conditions for a single turbine and a wind farm respectively.

About The Author

Dr. Lars Ceranna, Diploma in Geophysics at the Ruhr-University Bochum in 1997. PhD in Seismology at the Ruhr-University Bochum in 2002. Research fellow at the Federal Institute for Geosciences and Natural Resources (BGR) in Hannover from 2002 to 2008. Since 2009 unit head for “Monitoring and Verification” and deputy chief of the sub-department for “Seismological Central Observatory, Nuclear Test Ban”.

Previous scientific activities include studies on numerical simulations of seismic wave-propagation in inhomogeneous media, as well as simulations and analyses of infrasound propagation in the atmosphere generated by natural and anthropogenic sources. Moreover, activities include contributions to the Atmospheric dynamics Research InfraStructure in Europe (ARISE), and to compliances with the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Results have been published in Bulletin of the Seismological Society of America, Seismological Research Letters, Geophysical Journal International, Geophysical Research Letters, Natural Hazards and Earth System Sciences, Journal of Seismology, Journal of Geophysical Research, Pure and Applied Geophysics, InfraMatics, Journal of Sound and Vibration, and Nature.

Latest scientific studies include evaluations of the CTBT infrasound network performance to detect the 2013 Russian fireball event, as well as to monitor active volcanoes, and characterization of the influence of periodic wind turbine noise on infrasound array measurements.

About The Author

Dr. Christoph Pilger, Diploma in Mathematics at the University of Bonn in 2005. PhD in Atmospheric Physics at the University of Augsburg in 2011. Project scientist at the German Aerospace Center (DLR) in Oberpfaffenhofen from 2006 to 2012 and Research Associate at the German Federal Institute for Geosciences and Natural Resources (BGR) in Hannover since 2012.

Previous scientific activities include contributions to the German-Indonesian Tsunami Early Warning System (GITEWS), to the Network for the Detection of Mesosphere Change (NDMC) and to the Atmospheric dynamics Research InfraStructure in Europe (ARISE), as well as publications in the Journal of Atmospheric and Solar-Terrestrial Physics, Natural Hazards and Earth System Sciences, InfraMatics, Geophysical Research Letters, Journal of Geophysical Research and Journal of Sound and Vibration.

Current assignment at the German National Data Center of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) situated in BGR’s sub-department “Central Seismological Observatory, Nuclear Test Ban”. Research topics are infrasound data processing, acoustic noise characterization, detection capability estimation and seismo-acoustic studies. More than ten years of experience in infrasound, atmospheric wave dynamics and wave propagation modeling.

Latest scientific studies include quantifications of the CTBT infrasound network performance to detect the 2013 Russian fireball event and of the influence of periodic wind turbine noise on infrasound array measurements.

Reference

Christoph Pilger, Lars Ceranna. The influence of periodic wind turbine noise on infrasound array measurements. Journal of Sound and Vibration. volume 388 (2017) pages 188–200

Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Stilleweg 2, 30655 Hannover, Germany.

Go To Journal of Sound and Vibration Read more research excellence studies on: Renewable Energy Global Innovations (http://ift.tt/21cCPA4)

Renewable Energy Global Innovations features: Enhancement of the hydrolysis of bamboo biomass in ionic liquid with chitosan-based solid acid catalysts

Significance Statement

The ever-rising demand for clean fuels and environmental concerns arising from fossil fuels combustion has put a lot of pressure on the need to use renewable and clean sources of energy. Lignocellulosic biomass is a promising candidate for biofuels as well as production of chemicals. The most important step in the synthesis of biofuels and chemicals lies in the hydrolysis transformation of cellulose to fermented sugars. However, the sugars in the lignocellulose are resistant to chemical processes. Fortunately, it has been found that wood as well as cellulose can dissolve in 1-butyl-3-methylimidazolium chloride solvent, therefore, making the cellulose chains susceptible to chemical transformations.

Therefore, dissolution of lignocellulosic in different kinds of the chloride solvent implementing mineral acids has attracted numerous research attention. In a recent work is published in Bioresource Technology researchers led by professor Dan Wang from Chongqing University in China implemented sulfonated crosslinked chitosan immobilized with metal ions as excellent catalysts and an ionic solvent in the hydrolysis of cellulose. In their work, they realized that lignocellulosic materials could be effectively hydrolyzed and the chitosan solid acid catalyst would be removed from the hydrolysate easily.

The obtained bamboo samples were milled and their chemical composition determined. The authors prepared the 1-butyl-3-methyl-imidazolium chloride solvent as well as the crosslinked chitosan resin. They placed the reagents; the chloride solvent, bamboo powder, and sulfonated crosslinked chitosan (immobilized with metal ions) in the reactor. The mixture was stirred under normal atmospheric pressure for 24 hours. The authors drew samples from the mixture at different times and subjected them to sugar analysis.

After the hydrolysis process, the authors filtered the mixture and collected the retentate. They added anhydrous ethanol to the hydrolysate in order to recover the ionic liquid. The ethanol could dissolve the ionic liquid but not the reducing sugars. Ethanol was added until a turbid solution was obtained after which it was filtered to separate the ionic liquid from the solids of reducing sugar. The authors concentrated the liquid phase in order to recover the ionic liquid.

The authors observed that the impact of hydrolysis of the chitosan-based solid-acid catalyst on the milled bamboo powder was quite impressive. Chitosan-based solid-acid immobilized with iron (Fe³⁺) posted the best results. It yielded approximately 73.42% total reducing sugar. Catalysts immobilized with zinc and copper registered 62.43% and 68.75% total reducing sugars respectively, which increasing TRS yield by 68.47%, 43.25% and 57.76% respectively.

The effect of temperature was also investigated on the total reducing sugar yield and the rate of hydrolysis process. They found that 120 °C was the optimum temperature that gave a balance between energy consumption and the rate of hydrolysis and total reducing sugar yield.

The stirring speed and the amount of the chitosan-based catalyst used had an impact on the rate of hydrolysis and reducing sugar yield. The rate of hydrolysis and total reducing sugar yield increased towards a stirring speed of 20 RPM and dropped towards 30 RPM. Total reducing sugar yield increased when the amount of the chitosan-based catalyst was increased. The authors settled for an optimum ratio of 2:1 between the catalyst and the bamboo.

The proposed method of hydrolysis enhancement of the bamboo powder with solid acid catalyst required no pretreatments and enhanced the hydrolysis process. This could be a feasible method towards efficient conversion of biomass products into bio-based products and biofuels.

About The Author

Dr. Dan Wang is currently an associate professor at school of chemistry and chemical engineering, Chongqing University, Chongqing, P. R. China. She received the Bachelor’s degree from Sichuan University in 2005. After that, she received the Ph.D. in Biochemical Engineering from Institute of Process Engineering, Chinese Academy of Science in 2011. After a postdoctoral stay at the Department of Chemical Engineering, Rice University, she rejoined Chongqing University and became an associate professor for Chemistry in 2013. Her research focuses on Bio-based chemicals, green chemistry and chemical product process engineering.

About The Author

Jie Cheng is a Ph.D. candidate in the Bio-based Chemicals and Biomedicine Group at Chongqing University (Chongqing, P.R. China) under the direction of A.P. Dan Wang. He received his Bachelor’s degree from Chongqing University in 2014. His research interests focus on design and synthesis of novel materials for energy conversion, heterogeneous catalysis and biomass conversion.

Reference

Jie Cheng^1,2, Nan Wang³, Dezhou Zhao^1,2, Dandan Qin^1,2, Wenqing Si^1,2, Yunfei Tan^1,2, Shun’an Wei^1,2, and Dan Wang^1,2. The enhancement of the hydrolysis of bamboo biomass in ionic liquid with chitosan-based solid acid catalysts immobilized with metal ions. Bioresource Technology 220 (2016) 457–463

Show Affiliations

1. Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, PR China
2. Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, PR China
3. Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, KS 66045, United States

 

Go To Bioresource Technology Read more research excellence studies on: Renewable Energy Global Innovations (http://ift.tt/21cCPA4)