Renewable Energy Global Innovations features: Bimetallic Cu-Ni catalysts supported on MCM-41 and Ti-MCM-41 porous materials for hydrodeoxygenation of lignin model compound into transportation fuels

Significance 

Bio-oils are becoming alternatives to fossil fuels in view of the ever rising global energy demands, greenhouse emissions, and crude oil shortage. Bio-oils extracted from lignocellulosic biomass are composed of multicomponent molecules extracted from lignin, cellulose, and hemicellulose. The lignin component of lignocellulose is a promising renewable feedstock for the production of a number of chemicals and fuels. Lignin has an advantage over its counterparts hemicellulose and cellulose considering that bio-oils extracted from lignin can be upgraded to higher quality transportation fuels. This is in view of the high stability of the lignin aromatic structures with reference to resonance stabilization.

Fast pyrolysis has been an extensively applied method for converting lignin into bio-oil. Unfortunately, the potential of the resulting bio-oil is limited by the presence of a number of oxygenated functional groups, which in consequence lead to undesirable physicochemical attributes including low thermal and chemical stability, low heating values, easy corrosiveness and high density. In addition, lignin-extracted bio-oils are incompatible with either direct use or in combination with a petroleum fraction. This has forced researchers to look for alternative strategies which can enhance the commercial viability of lignin-extracted bio-fuels for use as a transportation fuel.

One method to remove chemically bonded oxygen from lignin-extracted oil and therefore enable the use of lignin-extracted bio-fuels is through catalytic hydrodeoxygenation processes. However, the direct application of catalysts in such processes is associated with numerous challenges owing to the complex nature of its oxygenated aromatic elements such as anisole, furan, benzofuran, and phenols. In order to overcome these issues, heterogeneous catalysts are attracting much attention, containing both a metal centre for the hydrogenation of the acidic support and an aromatic ring for the deoxygenation. While noble metals such as platinum, palladium, and ruthenium have been used in this process, their application is limited by the high cost and scarcity of these noble metals. Therefore, researchers have focused their attention on transition metal based catalysts including cobalt, nickel, iron, and copper-nickel.

Putla Sudarsanam and Suresh Bhargava at the Centre for Advanced Materials and Industrial Chemistry, School of Science, RMIT University in Australia in collaboration with Murtala Ambursa, Lee Hwei Voon, and Sharifah Bee Abd Hamid at the University of Malaya investigated the preparation, characterization and catalytic application of bimetallic Cu-Ni catalysts supported on Ti-MCM-41 for the hydrodeoxygenation of guaiacol. Their research work is published in the journal Fuel Processing Technology.

The authors prepared Cu-Ni catalysts supported on either Ti-MCM-41 or pure MCM-41 and compared their catalytic efficiencies for the hydrodeoxygenation of guaiacol. They performed the catalytic experiments in an autoclave reactor and investigated the effect of hydrogen pressure on guaiacol conversion as well as product selectivity.

Through the catalytic activity investigation, the authors observed that the CuNi/Ti-MCM-41 catalysts had a higher catalytic performance in guaiacol conversion as well as cyclohexane selectivity as opposed to a CuNi/MCM-41 catalyst. The high catalytic activity of the CuNi/Ti-MCM-41 catalyst was as a result of the cooperative function of the larger surface area, hexagonal pore geometry, medium-sized mesopores, adequate acidic sites, and excellent redox attributes. For this reason, Ti-MCM-41 is an efficient catalyst support for the hydrodeoxygenation of oxygenated elements to saturated hydrocarbons.

The research team also found that increased hydrogen pressures improved the guaiacol conversion and selectivity of the oxygenated compounds to hydrocarbons over the Ti-MCM-41 supported CuNi catalyst, increasing the impact of these catalysts within this important field of research.

About the author

Dr. Putla Sudarsanam obtained his PhD in chemistry at the CSIR-Indian Institute of Chemical Technology (Hyderabad, India) in 2015. He is currently working at the KU Leuven (Leuven, Belgium) as a Marie Curie individual post-doctoral fellow on the topic of designing nanostructured metal oxide based catalysts for the efficient conversion of agricultural bio-waste to produce biodegradable polymer building blocks and fuel grade chemicals.

He has been honoured for his work with many prestigious awards/fellowships including the Marie Skłodowska-Curie individual post-doc fellowship (2017); participation in the 67^th Lindau Nobel Laureate meeting (Germany, 2017); Leibniz-DAAD post-doc fellowship (Germany, 2016);  all India level best PhD thesis award (Catalysis Society of India, 2015); EFCATS PhD student award (XI^th EuropaCat conference, France, 2013); Australian endeavour research fellowship (Australia, 2013) and many others.

His expertise is mainly designing novel nanostructured metal oxide based catalysts for the 1) selective conversion of alcohols, olefins, and amines to useful fine chemicals; 2) transformation of renewable biomass feedstocks to value-added fine chemicals and bio-fuels and 3) efficient catalytic abatement of auto-exhaust pollutants (e.g., carbon monoxide, particulate matter, and nitrogen oxides). He has contributed over 44 refereed journal articles and 1 book chapter. He has in excess of 1170 citations with an h-index of 23 and an i10-index of 29.

About the author

Professor Bhargava is a world-renowned interdisciplinary scientist and is recognised for delivering research excellence that underpins significant industrial applications. As a passionate advocate in the application of technological science and engineering to innovation, he provides consultancy and advisory services to many government and industrial bodies around the world including BHP Billiton, Alcoa World Alumina, Rio Tinto and Mobil Exxon. He was also a member of the independent board of directors of one of the Aditya Birla group of industries. Out of his 7 patents, 5 have been adopted by the industrial partners and one has been licenced for commercialization.

During his distinguished career, Professor Bhargava has been awarded many prestigious national and international awards including the 2017 Non-Resident Indian of the Year Award by the TIMES Network. This award recognised him as the most outstanding Indian academic in the Asia-Pacific region, with the Bombay ceremony being broadcast to more than 110 countries around the world. Other notable awards he has received include the 2016 Khwarizmi International Award (KIA) by the Government of Iran, the 2015 CHEMECA medal (The most prestigious award in the chemical engineering profession in Australia and New Zealand), the highly esteemed Indian National Science Academy’s P. C. Ray Chair (distinguished lecture series 2014), RMIT University Vice Chancellor’s Research Excellence Award (2006 and 2014), and the Applied Research Award (2013) and the R. K. Murphy Medal (2008) from the Royal Australian Chemical Institute. He is also an elected fellow of six learned academies around the world including the Australian Academy of Technological Sciences and Engineering and the National Academy of Sciences, India.

Professor Bhargava has contributed over 410 refereed journal articles, 1 book and 10 book chapters. He has also co-authored more than 200 refereed full conference papers. He has in excess of 9,700 citations (5/day) with an h-index of 47 and an i10-index of 242.

He has strived over the years to create solid and sustainable global research partnerships to improve and advance Science and Technology. The establishment of the Indian Institute of Chemical Technology (IICT)-RMIT joint research centre, which is jointly funded by the Government of India (CSIR) and RMIT University, is one of the best examples of his international efforts. He has also applied this innovative model to connect RMIT University with the Academy of Scientific and Innovative Research (AcSIR), linking RMIT with a network of CSIR laboratories across India.

Reference

Murtala M. Ambursa, Putla Sudarsanam, Lee Hwei Voon, Sharifah Bee Abd Hamid, Suresh K. Bhargava. Bimetallic Cu-Ni catalysts supported on MCM-41 and Ti-MCM-41 porous materials for hydro-deoxygenation of lignin model compound into transportation fuels. Fuel Processing Technology, volume 162 (2017), pages 87–97.

 

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Renewable Energy Global Innovations features: Cellulose Biorefinery Based on a Combined Catalytic and Biotechnological Approach for Production of 5-HMF and Ethanol

Significance Statement

The need for development of sustainable technology that employs locally available sources of energy feedstocks for the production of motor fuels and valuable chemicals is on the rise. This can be attributed to the instability in the global energy and hydrocarbon feedstock markets. Sustainability, low power consumption and minimal carbon gas emission are among the contributing qualities towards this move. Lignocellulosic feedstock sources for biorefineries include energy crops, forestry and agricultural waste and residues which are made up of complex biopolymers such as cellulose, lignin and hemicellulose. Amongst, cellulose is relatively easy to process. Conversely, a flaw in its processing demands the need for the catalyst to be separated from the products and regenerated after the reaction which, however, can be averted by using carbon-based solid-acid catalysts to hydrolyze the cellulose.

Ksenia Sorokina and colleagues at the Boreskov Institute of Catalysis, in Russia, proposed a study to explore the potential of combining catalytic and biotechnological methods in a cellulose biorefinery. They aimed at examining the combination of one pot catalytic cellulose conversion into 5-hydroxymethylfurfura and glucose using a solid-acid catalyst and biotechnological glucose fermentation into ethanol with thermotolerant yeasts. Their goal was to produce 5-hydroxymethylfurfural and Ethanol. Their work is now published in the peer-reviewed journal, ChemSusChem.

The researchers commenced their empirical procedure by hydrolyzing the mechanically activated microcrystalline cellulose in the presence of a solid carbon-based catalyst that had been preliminarily oxidized with wet air. They then recovered the 5-hydroxymethylfurfural by isobutanol extraction from the mixture and the remaining sugar mixture was neutralized and concentrated for subsequent fermentation. The research team then selected the most effective ethanol producers by screening of the isolated thermotolerant yeast strains that were able to grow at 40⁰C.

The authors of this paper observed that hydrolytic dehydration of the mechanically activated microcrystalline cellulose over the carbon-based mesoporous Sibunt-4 catalyst resulted in moderate yields of glucose and 5-hydroxymethylfurfural. The 5-hydroxymethylfurfural was extracted from the resulting mixture with isobutanol and subjected to ethanol fermentation. The team also noted that among the isolated yeast strains, some exhibited high thermotolerance and resistance to inhibitors found in the hydrolysates.

Herein, a comprehensive study on the potential of combining catalytic and biotechnological techniques in cellulose biorefinery with an aim of producing 5-hydroxymethylfurfural and Ethanol has been presented. It has been shown that the use of the strains K. marxianus and O. polymorpha for the fermentation of processed catalytic cellulose hydrolysate has a relatively high efficiency since the strains are resistant to fermentation inhibitors. Therefore, the proposed combination of the catalytic processing of mechanically activated cellulose for the production of 5-hydroxymethylfurfural and subsequent fermentation of the extracted hydrolysate with thermotolerant yeasts is a promising alternative technique for ethanol production by fermentation and can be used to produce other valuable substances, such as bio-acids or bio-alcohols.

About The Author

Professor Valentin N. PARMON is an academician of the Russian Academy of Sciences (RAS), Dr.Sci. in chemistry, scientific director of the Boreskov Institute of Catalysis (Novosibirsk), Chairman of the Russian Scientific Council on Catalysis of the Russian Academy of Sciences, Chairman of the National Catalysis Society of Russia, the Russian National representative to the European Federation of Catalysis Societies (EFCATS) and International Association of Catalysis Societies (IACS). He is an expert in catalysis, photocatalysis, chemical kinetics in condensed phases, chemical radiospectroscopy, chemical methods of energy conversion, non-traditional and renewable energy sources, thermodynamics of non-equilibrium processes. Author and co-author of more than 800 papers in refereed journals, 9 monographs, 7 textbooks for universities, more than 100 patents. Editor-in-Chief of journals “Chemistry in Russia” (the Russian Chemical Society), “Catalysis in Industry” (Kalvis, Russia), “Catalysis Bulletin” of the National Catalysis Society of Russia, a Member of Editorial Boards of the “Russian Chemical Journal” (Russia), ), “Russian Chemical Review”, “Russian Journal of Physical Chemistry”, “Chemistry of Solid Fuels” and of the international journals “Chemistry for Sustainable Development” (SB RAS), “Catalysis Today” (Elsevier), “Catalysis Letters” (Springer), “Topics in Catalysis” (Springer), “Catalysis Reviews – Science & Engineering” (Baltzer), “Research on Chemical Intermediates” (VSP), “Chemistry & Technology of Water” (Ukraine), “Material Research Innovations”. Full Professor of the Novosibirsk State University (Chair of Physical Chemistry), Professor of the Tomsk State University and the Kazan State University.

About The Author

Ksenia Sorokina is a senior research scientist in biotechnology at the Boreskov Institute of Catalysis, Laboratory of Catalytic Methods of Solar Energy Conversion, Novosibirsk, Russia. Ksenia graduated from the Faculty of Natural Sciences of Novosibirsk State University, Russia in 2004, and defended her PhD in 2006.

Her primary research interests include the development biotechnological processes for enzymes and chemicals production from renewable biomass based on genetically engineered microorganisms.

About The Author

Professor Oxana P. Taran is Leading Researcher at the Boreskov Institute of Catalysis Siberian Branch Russian Academy of Science (BIC SB RAS) and Full Professor for Analytical Chemistry at the Novosibirsk State Technical University. She studied chemistry at the Novosibirsk State Technical University and completed her PhD with Prof. Valentin N. Parmon at the BIC SB RAS in 1999. She worked as visiting scientist at the Brookhaven National Laboratory (USA) with Dr. Sergei Lymar in 1998-1999 and at the IRCELYON (France) with Profs. Michele Besson and Pierre Gallezot in 2005. She is Professor of Russian Academy of Science since 2016. Her research focused on the development of catalysts and catalytic processes occurring in the aqueous solutions including: carbohydrates processing, wastewaters treatment, artificial photosynthesis and biomass catalytic treatment to produce fuels and chemicals.

Reference

Ksenia N. Sorokina, Oxana P. Taran, Tatiana B. Medvedeva, Yuliya V. Samoylova, Alexandr V. Piligaev, and Valentin N. Par. Cellulose Biorefinery Based on a Combined Catalytic and Biotechnological Approach for Production of 5-HMF and Ethanol. ChemSusChem 2017, volume 10, pages 562 – 574.

 

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Renewable Energy Global Innovations features: Probing the whole ore chalcopyrite–bacteria interactions and jarosite biosynthesis

Significance Statement

Chalcopyrite is considered the most abundant ore of copper sulfide. The ore has received significant attention owing to its vast ores with exploitation potential. Bioleaching that is environment friendly can be implemented for leaching copper ores employing sulfur and mesophilic oxidizing bacteria including Acidithiobacillus thiooxidans. The major oxidation product of chalcopyrite leaching has been found to be chalcocite that is further oxidized to yield covellite.

Chalcopyrite bioleaching initiates iron hydrosulfates precipitation coupled with metal-deficient layers that tend to minimize the entry of leaching components and bacteria to mineral surfaces. This in turn makes bioleaching inefficient. For this reason, finding a clarification of the approaches is necessary for optimizing chalcopyrite leaching and lessening the formation of jarosite passivation layers. Above all, researchers are yet to reach a consensus on the appropriate control procedures that must be followed in the bioleaching process.

Researchers led by professor Constantinos Varotsis from Cyprus University of Technology, Cyprus in collaboration with scientists at Hellenic Copper Mines, studied, for the first time, the formation of covellite from the bioleached surface of chalcopyrite, potassium, ammonia, ammonium ions, jarosites, and extracellular polymeric substances. They did the study in the microbial setting of the mines of copper. They applied FTIR micro-spectroscopies and Raman methods in a bid to establish a simple approach for assessing the formation of secondary minerals. Their work is published in peer-reviewed journal, Bioresource Technology.

The authors collected specimens from the copper mines of Hellenic and analyzed them by microscopy. They did bioleaching experiments in compact columns that were filled with solutions from the copper mines. The solutions contained microorganisms including Acidithiobacillus thiooxidans and Leptospirillum ferriphilum. They attached heating tapes around the testing columns in a bid to maintain the experiment at 35⁰C and this was done for four months. The authors performed infrared microscopies tests and collected Raman data.

The authors observed that the Raman spectra of chalcopyrite grain had a weak band of approximately 292cm^-1. In the spectra, this zone was obscured by light scattering because of focusing of the laser beam on the mineral surface, therefore, the authors were unable to detect this weak band. After one month of bioleaching, the authors recorded new bands of 469 and 226 cm^-1, which they assigned to Cu-S of covellite and FeO of K⁺ jarosite respectively.

At the end of two months of bioleaching, the authors recorded six more bands. However, by the end of the third month, they observed a drop in the intensity of the 469 cm^-1 band. This indicated that there was a drop in covellite concentration. However, at the fourth month, this band had disappeared altogether, and there was the formation of new marker bands.

From Raman data, the authors observed the formation of K⁺ Jarosite, which was then followed by NH₄⁺. They observed a color variation in the FTIR data, which indicated that microorganisms were attached on the surface of the mineral. A change in the intensity of the bands in the frequency range of 900-1140 cm^-1 confirmed the presence of biofilm conformations.

By analyzing the FTIR maker bands, the authors were able to understand the purpose of the extracellular polymeric substances to copper bioleaching.

Reference

Anastasia Adamou, Giorgos Manos, Nicholas Messios, Lazaros Georgiou, Constantinos Xydas, and Constantinos Varotsis. Probing the whole ore chalcopyrite–bacteria interactions and jarosite biosynthesis by Raman and FTIR micro spectroscopies. Bioresource Technology, volume 214 (2016), pages 852–855.

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Renewable Energy Global Innovations features: Landscape control of nitrous oxide emissions during the transition from conservation reserve program to perennial grasses for bioenergy

Significance Statement

Renewable fuels are an integral part of the liquid fuels portfolio of the United States and in fulfilling the stipulations of the federal threshold of 80 billion liters of ethanol produced from cellulosic sources by 2022. This will necessitate planting approximately 21 million hectares with cellulosic crops such as switchgrass, a perennial grass native to the United States. Land currently enrolled in the Conservation Reserve Program (CRP) – about 12 million hectares – might be suitable for energy crops. Some of this area is seasonally wet, environmentally sensitive, and with limitation for annual cropping. Converting these CRP lands to energy crops may increase the emissions of nitrous oxide, a potent greenhouse gas, particularly when converting lands that are seasonally wet due to soil or topographic attributes. Low carbon footprint is critical to accrue the benefit of energy crops. For such crops to qualify as renewable, their greenhouse gas emissions must be at most 50% of those from fossil fuels. Therefore, nitrous oxide emissions must be kept low in the feedstock production phase. Controlling nitrous oxide emissions from these energy crops requires an in-depth understanding of the interactive effects of landscape properties, crops growth rates, nutrient, and hydrology.

The research conducted by Debasish Saha and colleagues at The Pennsylvania State University identifies the potential of growing sustainable energy crops on these CRP landscapes without increasing greenhouse gas emissions. The researchers measured nitrous oxide emissions from plots converted from CRP to switchgrass and Miscanthus in central Pennsylvania. The physiography of the experimental site, representative of the Appalachian Ridge and Valley region with cropped uplands and wet bottomland that are occasionally under CRP. The emissions from the plots of energy crops were compared to the emissions from adjacent, unconverted CRP land under different landscape positions with varying soil and hydrologic properties. The researchers also established an autonomous network of 144 soil moisture sensors installed at three soil depths in 48 monitoring points in the landscape to continuously measure soil moisture, an important factor for nitrous oxide emissions. The monitoring period extended from May to September of 2013 growing season, which includes a summer storm that saturated the soil – the perfect conditions to expect nitrous oxide emissions. Their research work is published in GCB Bioenergy.

Nitrous oxide is produced by soil microbes when soil mineral nitrogen from organic/inorganic fertilizer and other sources exceeds plant demand and coincides with wet soil conditions usually after a storm or snowmelt event. “The transition phase from CRP to energy crops is critical for nitrous oxide emissions as soil disturbance may increase nitrogen availability in excess of demand when plants are small and the root system is not extensive,” said Saha.

The authors realized that nitrous oxide emissions from energy crops increased above the CRP control baseline only in the wetter footslope positions. “While near-stream footslope soils with prolonged subsoil wetness had higher nitrous oxide emissions from energy crops than CRP, a large portion of the landscape had comparable emissions to those of CRP. The footslope positions of the landscape occupy at most a third of the lower part of the watershed. For this reason, about two-thirds of the set-aside conservation area (CRP) could be used for energy crops production.” Saha further added, “It is expected that large emissions from the footslope can eventually be curtailed as the grasses get established.”

Saha said “Apart from carbon benefits of energy crops, growing energy crops in these seasonally wet CRP lands usually on steep areas of the landscape can offer additional ecosystem services. Energy crops in these landscapes can function as riparian buffers to provide water-quality benefits by curtailing nutrient as well as sediment loads to surface and groundwater. Owing to vigorous biomass production by these grasses and little disturbance of the perennial rooting systems, these crops can store carbon in the soil because of their extensive below-ground carbon allocation.”

The outcomes of their study revealed that managing the conversion from CRP to energy crops while maintaining low nitrous oxide emissions could be optimized by designing a sufficient transition process that curtails co-occurrence of high mineral nitrogen and wet soils.

This research was funded by U.S. Department of Transportation Sungrant, the USDA, and the Richard King Mellon Foundation. Other research team members include Armen Kemanian, associate professor of production systems and modeling and Felipe Montes, research associate in Plant Science, Penn State; Jason Kaye, professor of soil biogeochemistry in Ecosystem Science and Management, Penn State; Paul Adler, research agronomist with the Pasture Systems and Watershed Management Research Unit, USDA-Agricultural Research Service; and Benjamin Rau, former USDA-Agricultural Research Service soil scientist, now a research ecologist with the USDA, Forest Service.

About The Author

Dr. Debasish Saha obtained his BSc in Agricultural Sciences with specialization in Agricultural Chemistry and Soil Science in 2008 from Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India. As a Junior Research Fellow of Indian Council of Agricultural Research (ICAR-JRF), he received his MSc degree in Soil Science from Punjab Agricultural University, Ludhiana, India in 2010. In 2015, he received his Ph.D. in Soil Science and Biogeochemistry under the supervision of Dr. Armen Kemanian at the Pennsylvania State University. His dissertation research investigated nitrous oxide (N₂O) emissions, a potent greenhouse gas, during the transition from Conservation Reserve Program grassland to perennial energy crops switchgrass and Miscanthus for renewable biomass energy production.

He is currently (2015-2017) appointed as a post-doc at the Department of Plant Science at the Pennsylvania State University. His post-doc research is focused on the core theme of enhancing the sustainability of organic cropping systems by mitigating N₂O emissions from soils. His research combines chamber-based N₂O monitoring, N₂O isotopomers, and microbial molecular techniques to quantify soil microbial processes contributing to N₂O production in interaction with tillage, cover crop, and manure management practices in a Reduced-Tillage Organic System Experiments.

For more information: Google Scholar ,  ResearchGate.  

Reference

Debasish Saha, Benjamin M. Rau, Jason P. Kaye, Felipe Montes, Paul R. Adler, and Armen R. Kemanian. Landscape control of nitrous oxide emissions during the transition from conservation reserve program to perennial grasses for bioenergy. GCB Bioenergy (2017) 9, 783–795.

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Renewable Energy Global Innovations features: Subcritical carbon dioxide-water hydrolysis of sugarcane bagasse pith for reducing sugars production

Significance Statement

Sugarcane bagasse that is a byproduct of sugarcane extraction process is majorly used in the paper making process. Approximately 40% of this residue is considered small fiber, sugarcane bagasse pith that is eliminated from the pulp for papermaking. Compared to a good number of agricultural residues, sugarcane bagasse pith is also a lignocellulostic material composed of lignin, hemicelluloses and cellulose. A large proportion of this byproduct is normally used for electricity production, but this comes with more carbon dioxide emissions.

Therefore, most researchers have focused on how it can be used for biological fuel production as well as chemicals that can offer economic, strategic, and environmental advantage. Reducing sugars, a biomass precursor that can be changed to fuel alcohol by fermentation, appears to be the best high-added product that can be extracted from sugarcane bagasse pith.

In order to extract reducing sugars from the sugarcane bagasse pith, the hemicelluloses as well as cellulose should be hydrolyzed. Some of the methods for achieving this include, acidic, enzymatic and alkali hydrolysis. Nevertheless, implementing concentrated acids, for instance, hydrochloric and sulfuric acids demands corrosion resistant reactors. Long process time as well as high cost of enzyme production are the major bottlenecks for enzymatic hydrolysis.

Researchers led by professor Xiaopeng Chen from the Department of Chemistry and Chemical Engineering at Guangxi University in China investigated the subcritical carbon dioxide water hydrolysis of sugarcane bagasse pith in the production of reducing sugars. In their study, an orthogonal test method was used to optimize a combination of process parameters, which include stirring speed, reaction temperature, carbon dioxide initial pressure, total reducing sugars, and reaction time. Their work is published in peer-reviewed journal, Bioresource Technology.

The authors carried out the hydrolysis of sugarcane bagasse pith in a stainless steel reactor, which was equipped with a magnetic driven paddle agitator. The reactor was heated and the temperature inside measured and controlled at operating temperature. A magnetic stirrer was then used to continuously mix the content of the reaction.

For carbon dioxide reaction, a stainless steel tube was connected to a valve and fitted to the reactor to allow for controlled introduction of carbon dioxide from a gas cylinder. The initial pressure of the carbon dioxide was then controlled using a high-pressure reactor regulator.

The hydrolysis of the sugarcane bagasse pith to generate reducing sugars under subcritical carbon dioxide-water led to the highest total reducing sugars production of approximately 45.8% at the optimal conditions established by orthogonal design of 200 °C, 1MPa initial carbon dioxide pressure, 40 minutes reaction time, 500rmin^-1 stirring speed, and 50:1 liquid-to-solid ratio.

FT-IR analysis indicated that xylose, arabinose, and glucose were the major components in the hydrolysis liquor. Elementary kinetic processes of biomass solubilisation represented by severity factors could not adequately define the hydrolysis of the sugarcane bagasse pith. Decomposition of the reducing sugars, rate constants, and activation energy of reducing sugar formation were obtained on the first-order kinetic model of consecutive reactions.

About The Author

Professor Xiaopeng Chen’s higher education was at Guangxi University, China. He has been at Guangxi University, China since 1984 progressing to Professor in 2003.

His research activities focus on the Resources Processing and Process Intensification Technology of biomass. He has a special interest in the kinetics and thermodynamics analysis of oleoresin for hydrogenation, dehydrogenation, disproportionation, cracking, and isolation. Professor Chen has published over 200 papers/books/patents in these subjects.

About The Author

Dr. Jiezhen Liang, is a senior experimentalist in the Department of Chemistry and Chemical Engineering at Guangxi University, China. She received Ph.D. degree at the same university in 2017. Her current research focuses on High Efficient Utilization of agriculture waste.

Reference

Jiezhen Liang, Xiaopeng Chen, Linlin Wang, Xiaojie Wei, Huasheng Wang, Songzhou Lu, Yunhua Li. Subcritical carbon dioxide-water hydrolysis of sugarcane bagasse pith for reducing sugars production. Bioresource Technology, volume 228 (2017), pages 147–155.

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Renewable Energy Global Innovations features: Solid-binding peptides for immobilization of thermostable enzymes to hydrolyze biomass polysaccharides

Significance Statement

Immobilization of enzymes onto solid supports can be achieved by a number of physical and chemical methods including, covalent attachment, adsorption, crosslinking and encapsulation. Immobilized enzymes, as opposed to soluble enzymes, offer better stability and easier removal from reaction mixtures, enabling repetitive use in batch and continuous bioprocesses and rapid termination of reactions.

Unfortunately, typical enzyme immobilization approaches usually result in a non-uniform orientation of the enzyme as well as unwanted conformational changes that alter their active sites and may curtail the catalytic activity of the enzyme. Solid-binding peptides have binding affinity as well as selectivity to the surfaces of solid materials such as glass, polymers, silica, metals and zeolite, all support materials employed with biocatalysts.

Solid-binding peptides typically are used as molecular linkers for functional protein immobilization onto solid surfaces without the need for any chemical reactions or even physical treatments.

Researchers led by Professor Anwar Sunna at Macquarie University in Australia have presented the implementation of the solid-binding peptide-mediated immobilization of industrially-based enzymes onto a low cost solid zeolite matrix. The introduction of crosslinking of the immobilized enzymes to create single as well as multiple enzyme biocatalytic modules enabled the authors to highlight the feasibility of this technology for its integration in industrial-scale processes. Their work is published in Biotechnology for Biofuels.

The research team genetically fused the silica-binding linker peptide to three thermostable polysaccharide-degrading enzymes for potential application in industrial-scale biocatalysis. The linker had significant affinity for silica-containing supports allowing for directional immobilization of these enzymes onto the zeolite matrix. The enzymes were observed to retain their binding affinity for zeolite and their biological activity. The integration of the linker did not have adverse effects on the pH and temperature optima of the polysaccharide-degrading enzymes and the assembled single and multiple enzyme biocatalytic modules retained their specific hydrolytic activities upon several rounds of recycling at high temperatures.

Professor Sunna summarized the importance of this platform technology saying; “Despite the promising characteristics of solid-binding peptides, their practical application has been mostly in nanobiotechnology, where immobilization of biomolecules generally relies on exotic and expensive laboratory-based matrices that may not be realistic economically for large-scale processes. Inorganic bulk materials like zeolite and silica are excellent carriers due to their structural and operational stability and their lack of susceptibility to microbial degradation. The combination of solid-binding ability and low-cost bulk materials represents an ideal technology for production of industrial-scale biocatalysts.”

The linker system developed in their study minimizes the time wasted in choosing precipitants as well as crosslinking reagents. Its compositional and structural characteristics allows it to impart orientation and directionality to enzymes after crosslinking. This combination results in improved enzyme reusability. Therefore, this linker technology presents an inexpensive immobilization approach for industrially based enzymes.

About The Author

Andrew Care is a Research Fellow in the ARC Centre of Excellence for Nanoscale BioPhotonics, a transdisciplinary research centre that aims to develop innovative nanotechnologies to investigate complex living systems. He obtained his PhD from Macquarie University in Sydney, Australia.

His current research is focused on the use of solid-binding peptides to control the immobilization of proteins and enzymes onto solid matrices in a range of biotechnological applications, including biocatalysis.

About The Author

Kerstin Petroll obtained her Diploma degree in Food Chemistry at the Karlsruhe Institute of Technology (KIT) in Germany. She was awarded a Macquarie University Research Excellence Scholarship to join Macquarie University as a postgraduate student in 2015. Initially, she focused on analytical sciences of plant metabolites and proteins for medical applications before changing to the field of synthetic biology with a focus on environmental applications. Her PhD project aims at the assembly of a cell-free synthetic pathway to produce a platform chemical from renewable low-value compounds.

About The Author

Peter Bergquist is Emeritus Professor in the Biomolecular Discovery and Design Research Centre at Macquarie University. He has a PhD and DSc from the University of Auckland in New Zealand and has been a Postdoctoral Fellow and Research Fellow at Harvard Medical School, Yale and Oxford Universities and a Visiting Fellow at New York University School of Medicine.

He is one of the pioneers of cloning and expressing genes from extremely thermophilic bacteria. He has an interest in biofuels that stems from early studies of cellulolytic microorganisms and their enzymes for biomass breakdown. He has been on the editorial boards of several significant journals such as Applied and Environmental Microbiology and Journal of Bacteriology.

About The Author

Anwar Sunna is an Associate Professor in Synthetic Biology in the Department of Chemistry and Biomolecular Sciences at Macquarie University (MQ), Sydney, Australia. He obtained a PhD from the Hamburg University of Technology in Germany. He was manager of the Environmental Biotechnology Co-operative Research Centre at MQ and later was the recipient of the prestigious Vice-Chancellor’s Innovation Fellowship.

His recent research has been on the interaction between biomolecules and inorganic compounds including new synthetic peptide linkers with applications in enzyme immobilisation and functionalisation of nanomaterials. Anwar is a member of the MQ Biomolecular Discovery and Design Research Centre, MQ Biosecurity Futures Research Centre, Australian Research Council (ARC) Training Centre for Molecular Technology in the Food Industry and the ARC Centre of Excellence for Nanoscale BioPhotonics. He is also one of the directors of Synthetic Biology Australasia.

Reference

Andrew Care, Kerstin Petroll, Emily S. Y. Gibson, Peter L. Bergquist, and Anwar Sunna. Solid-binding peptides for immobilization of thermostable enzymes to hydrolyze biomass polysaccharides. Biotechnol Biofuels (2017) 10:29.

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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

 

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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

 

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Renewable Energy Global Innovations features: Effects of Geographic Area, Feedstock, Temperature, and Operating Time on Microbial Communities of Six Full-Scale Biogas Plants

Significance Statement

Organic waste can be converted to energy by making use of a process known as anaerobic digestion, which involves the breaking down of biodegradable materials by microorganisms in the absence of oxygen. They produce a rich quantity of methane which can be used for cooking, transportation and generation of electricity.

The conversion process, which could be either in mesophilic or thermophilic conditions depending on temperature, contains some certain predominant microbiomes. Therefore, it is important to understand the major phylotypes of Bacteria and Archaea in view of increasing the efficiency of the conversion process.

It is also important to note that different feeds and environmental factors should be considered as major influences of composition and physicochemical properties of the slurry, and their effects during the anaerobic digestion process shouldn’t be undermined.

A group of researchers led by Fabrizio Cappa from Università Cattolica del Sacro Cuore in Italy investigated the effects of different animal feeds at two separate regions and cheese production areas of Parmigiano Reggiano and Grana Padano on the microbiome of six-full scale biogas plants by using indexed Illumina sequencing to identify key phylotypes of Bacteria and Archaea, and a quantitative polymerase chain reaction to determine 16S rRNA gene of total bacteria, archaea, Clostridiales and methanogens populations. The work was published in the journal Bioresource Technology.

The authors observed the effects of feedstock on the production efficiency of methane during the anaerobic digestion process. In Grana Padano biogas plants, the feedstock containing cattle slurry manure, energy crops and agro-industrial by-products had the highest methane concentration with minute accumulation of volatile fatty acids and ammonium concentration.

Biogas plants of the two regions with feedstock containing only cattle slurry manure had the lowest value of specific methane production and volatile solid degradation efficiency. Coupled with the feedstock composition, they also indicated the effects of the hydraulic retention time, organic loading rate and mixing ratio of the substrate as they played a major role in degradation efficiency of volatile solid and specific methane production yield.

Results from the Illumina sequencing analysis while regarding bacterial communities showed that the geographical area, operating temperature and feedstock played a major role in determining of the plant microbiomes while time had a negligible effect. The most predominant phylotypes were discovered to be: Firmicutes, Bacteroidetes and Proteobacteria. Thermotogae phylum found only in the thermophilic biogas plant was clearly related to the hydraulic retention time.

When observing the 16S rRNA gene population of bacteria and Clostridiales, results from the real-time polymerase chain reaction indicated a slight difference between both biogas plants of the two separate regions and as a result, the effect of the geographical location area on bacterial diversity has nothing to do with the order of Clostridiales.

For that of the archaeal community, Illumina sequencing analysis indicated most predominant phylotypes to be Methanosarcina and Methanosaeta in mesophilic biogas plants while Methanoculleus was predominant in thermophilic biogas plant. The Methanosarcina was related to ammonium concentration in the biogas plant.

The mean 16S rRNA gene populations of archaea and methanogens indicated major difference in the archaeal population unlike that of the methanogens where no major difference was found.

This study provided important data on the effects of the geographical location area, feedstock and temperature on anaerobic digestion of organic waste in relation to microbiomes involved in the process.

About The Author

Alessandra Fontana completed Masters in Industrial Biotechnology at the University of Turin, Italy, in 2014. She is currently a PhD student at the Doctoral School on the Agro-Food System at Università Cattolica del Sacro Cuore (UCSC), Italy. Her research is mainly focused on recovery of dairy industry wastes for bioenergy production.

At present, she is also working as guest PhD student within the Bioenergy group at the DTU Environment Department (Technical University of Denmark), in a project involving the biogas upgrading by means of hydrogen produced by water electrolysis using excess electricity from wind mills.

About The Author

Vania Patrone is a postdoctoral research fellow at the Institute of Microbiology, Università Cattolica del Sacro Cuore (UCSC), Italy. Her research is focused on microbial ecology and aims at revealing the identity and physiology of microorganisms within selected environmental or medically relevant systems.
Specifically, her interests include the characterization of gut bacteria and archaea populations to decipher the connection between gut microbial community structure and the onset and progression of disease in both humans and livestock.

A second core research theme is represented by the study of food microorganisms, in particular those related to improving the food quality through fermentation processes, as well as those causing food spoilage. Her areas of expertise range from traditional culture-based microbiological analysis techniques to bio-molecular tools, including genotyping, gene expression, real-time PCR and metagenomics. Since 2016 she coordinates the activities in the microbiome research area of the Research Centre in Nutrigenomics and Proteomics at UCSC.

About The Author

Mirco Garuti completed Masters in Molecular and Industrial Biotechnology at the University of Bologna, Italy, in 2009. He then worked at the Microbial Biotechnology laboratory of Insubria University (Varese, Italy) to optimize fermentation processes aimed at the production of secondary metabolites in Streptomyces strains within a project funding by a private pharmaceutical company.

He is currently working as researcher at the Research Center on Animal Production (CRPA), Italy, focusing on full-scale biogas production improvements, pretreatment technologies, trace elements effects on anaerobic microbial communities, and valorization of agro-industrial by-products in biorefineries. At present, he is also attending a specialization course about Circular Bio-economy.

About The Author

Fabrizio Cappa completed Masters in Agricultural Sciences in 1988. He is a senior researcher at the Institute of Microbiology, Università Cattolica del Sacro Cuore (UCSC), Italy. His research is focused on food microbiology and dairy industry technologies. He is currently working on the role of clostridia in anaerobic digestion processes by means of both traditional culture-based microbiological analyses and molecular techniques. He is also focusing on the recovery of dairy industry wastes for bioenergy production.

Reference

Fontana, A.¹, Patrone, V.¹, Puglisi, E.¹, Morelli, L.¹, Bassi, D.², Garuti, M.³, Rossi, L.³, Cappa, F.^1,2  Effects of Geographic Area, Feedstock, Temperature and Operating Time on Microbial Communities Of Six Full-Scale Biogas Plants, Bioresource Technology 218 (2016) 980–990.

Show Affiliations

1. Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Via Emilia Parmense, 84, 29122 Piacenza, Italy
2. Centro Ricerche Biotecnologiche, Università Cattolica del Sacro Cuore, Via Milano, 24, 26100 Cremona, Italy
3. Centro Ricerche Produzioni Animali, C.R.P.A. S.p.A., Viale Timavo, 43/2, 42121 Reggio Emilia, Italy

 

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Renewable Energy Global Innovations features: Co-Combustion Characteristics of Hydrothermally Treated Municipal Solid Waste with Coal in a Fluidized Bed

Significance Statement

Co-combustion of municipal solid biomass wastes and coal at high efficiency has been a challenge in recent time due to the hazardous nature of the waste gases generated in the process. Utilization of bubbling fluidized beds reactors, that use coal, has been called into question due these pollution effects. Measures have been taken to try and solve this problem that originates from the use of coal. In this paper, numerical and experimental models have been adopted for the simulation of the combustion process, within a bubbling fluidized bed reactor, so as to determine temperatures at which coal could be substituted with hydrothermally treated municipal solid waste.

A research team led by Professor Kunio Yoshikawa from Tokyo Institute of Technology and Associate Professor Tamer Ismail from Suez Canal University in Egypt, with Dr. Liang, Dr. Abd El-Salam and Prof. Yuqi Jin investigated the co-combustion characteristics of hydrothermally treated municipal solid waste with coal in a fluidized bed reactor. Their aim was to present models that use composite fuel (coal and municipal solid wastes) at least reactor modification. Their work is now published in the peer-reviewed journal Fuel Processing Technology.

Foremost, experiments had to be conducted using reliable CFD in order to predict crucial results and critical requirements for curbing and ensuring efficiency. The three approaches that were available for numerical simulations were: Euler-Lagrange approach, Euler-Euler approach and Discrete Element Method. Euler-Euler approach was adopted where ratios of 10, 20, 30 and 50% of the hydrothermally treated municipal solid waste were chosen to be tested at 700°C, 800 °C and 900 °C so as to determine the temperatures at which coal could be replaced with the hydrothermally treated municipal solid waste.

The research team had to determine the right temperature and mixture of the system that had the least emissions and yet could be operated at the least cost. They observed that for mixing ratios of 10 and 20% of the HT MSW there was a significant reduction in the CO outflow emission during the co-combustion with coal. Additional mixing of coal with the HT MSW lead to a further decrease in SO₂ emission from the combustion. Low levels of HCL were recorded for all the mixtures displaying a positive effect of the mixture. Nitrogen levels were also kept to a minimal as the blending mixing ratios of the HT MSW were increased.  Initially, high levels of NO were recorded due to increase in temperature but with the mixing of the HT MSW to 30% level, a significant drop was observed for all temperatures.

This research paper shows that with accurate simulation, trends for co-combustion can be predicted for various emitted gas species in the bed. This research sheds light into a promising way to simulate the combustion of solid waste in bubbling fluidized beds when using minimal coal. This study also reveals the features of a detailed structure for the combustion process inside the solid bed. Finally, it indicates the possibility of accepting the mixing ratio of the hydrothermally treated municipal solid waste, co-combusted with coal up to 30% without major modification of the coal-fired bubbling fluidized beds reactor.

About The Author

Dr. Tamer M. Ismail is an associate professor of Department of Energy and Fuel Science, Suez Canal University, Egypt. He obtained PhD in 2010, in Mathematical Modelling of MSW Incineration. He is one of the expert in the field of CFD of solid combustion and gasification having several research in this field. He is considered the pioneer in this field in Suez Canal University. He has a patent for CFD simulation code called, COMMENT- Code. Also, in the field of waste to energy he has several special work in designing many reactors, such as, fluidized bed, chemical looping combustor and bioreactor fermentor.

His major research areas are energy conversion, thermal engineering, combustion, gasification, waste treatment technologies, and he wrote many papers in this field. He works as research associate in Harbin Institute of Technology, Tokyo Institute of Technology and nstituto Politécnico de Portalegre, Universidade de Trás-os-Montes e Alto for combustion and gasification technologies.

About The Author

Dr. Kunio Yoshikawa is a professor of Department of Environmental Science and Technology, Tokyo Institute of Technology, Japan. He graduated from Tokyo Institute of Technology and obtained PhD in 1986. After graduation from Tokyo Institute of Technology, Prof. Yoshikawa worked for Mitsubishi Heavy Industries for one year, and then went back to his home university to become a research associate, associate professor and professor.

His major research areas are energy conversion, thermal engineering, combustion, gasification, waste treatment technologies and atmospheric environmental engineering, and he wrote more than 200 papers. He is an associate editor of Applied Energy. His main awards are AIAA (American Institute of Aeronautics and Astronautics) Best Paper Award in 1999, ASME (American Society of Mechanical Engineers) James Harry Potter Gold Medal in 2001, JSME (Japan Society of Mechanical Engineers) Environmental Technology Achievement Award in 2006, Fellow of JSME in 2008 and Best Educator Award of Tokyo Institute of Technology in 2014.

Reference

Liang Lu¹, T.M. Ismail², Yuqi Jin³, M. Abd El-Salam⁴, Kunio Yoshikawa¹. Numerical and experimental investigation on co-combustion characteristics of hydrothermally treated municipal solid waste with coal in a fluidized bed.  Fuel Processing Technology volume 154 (2016) pages 52–65.

Show Affiliations

1. Department of Environmental Science and Technology, Tokyo Institute of Technology, G5-8, 4259 Nagatsuta, Midori-Ku, Yokohama 226-8502, Japan
2. Department of Mechanical Engineering, Suez Canal University, Ismailia, Egypt
3. State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China
4. Department of Basic Science, Cairo University, Giza, Egypt

 

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Renewable Energy Global Innovations features: Cultivation of Chlorella sp. with livestock waste compost for lipid production

Significance Statement

Microalgae have received significant attention as a biodiesel feedstock. This is in response to energy shortage, climate change and global warming. Microalgae offer many advantages for use in biodiesel production. They have high photosynthetic efficiency, which translates to high growth rate. Moreover, most algal species have high lipid content. Furthermore, it is possible to launch algal biorefinery facilities in lands with low economic value, such as saline and arid lands therefore microalgae cultivation does not compete with food production for farmlands.

Liandong Zhu and colleagues from University of Vaasa in Finland developed a method to determine algal biomass accumulation for biodiesel production when algal cultivation with livestock waste compost was combined. In their work, an optimal concentration level for algal cultivation was found, and the productivities of biomass and lipids was specified. The work is published in peer-reviewed journal, Bioresource Technology.

Chlorella sp. microalgae were used in this study. It was isolated from local fresh-water habits by Utex and grown in a BG11 medium. Livestock waste compost from a local collection point was used. Windrow composting technology was applied to compost cattle waste. The compost was immersed in water, and stirred with a magnetic stirrer. The mixture was then filtered to eliminate non-soluble particulate solids.

Livestock waste compost medium was diluted using fresh water to four varying concentrations (200, 1500, 1000 and 500 mg L^-1 COD). The undiluted media and four diluted media were applied as cultures for microalgal cultivation for 10 days. For comparison, BG11 media (control group) were also used to grow algae. The livestock waste compost with the variable chemical oxygen demand concentrations were introduced into 0.4L flasks.  The optical density of Chlorella sp. was measured every day using spectrophotometer.

The authors determined the lipid contents of chlorella sp. in five cultures with varying nutrient concentration. The culture with the initial chemical oxygen demand concentration at 500 mg L^-1 experienced the highest algal lipid accumulation (44.30% of dry weight). They attributed this to the fact that low biomass concentration in the culture could make more algal cells access and receive more light that triggered and benefited lipid storage. As the initial chemical oxygen demand concentration increased from 500 mg L^-1 to 2680 mg L^-1 the lipid content decreased from 44.30% to 33.90%.

The authors also found that about one third to one fourth of lipids would be converted into fatty acid methyl esters; efficient biodiesel ingredients. This is because some lipids such as phospholipid, chlorophyll and glycolipid are not efficient ingredients for biodiesel production.

This study successfully found the optimal concentration level for algal cultivation and productivities of biomass. The authors concluded the following parameters: specific growth rate of Chlorella sp. grown in the five cultures ranged from 0.275 to 0.375 day^-1. Initial nutrient concentration affected lipid accumulation, and the lipid content ranged from 33.90% to 44.30%. The 2000 mg L^-1 chemical oxygen demand culture was found to be the optimum medium for algal cultivation, since the highest biomass and lipid productivities were realized.

This study was possible with partial funding from TranAlgae. A network of relevant stakeholders within the algae industry in the Botnia-Atlantica region with the aim of implementing innovative solutions for the production of micro- and macroalgae biomass from waste streams at industrial scale.

About The Author

Professor Zhaohua Li is the Dean of the School of Resources and Environmental Science. He was born in 1964 at Hubei Province in China, educated at China, the U.K. and Germany. His research spans including plant ecology, aquatic ecology, and environmental ecology.

Professor Li is of broad members of Chinese Geographical Association and Chinese Association of Agricultural Resources and Zonning. He received an Honorary of National Advanced Workers from Chinese government and more than 10 awards from Chinese ministries and Hubei Province. He has published 22 research works and 176 papers.

About The Author

Dr. Liandong Zhu is an assistant professor at the Faculty of Technology of the University of Vaasa and Vaasa Energy Institute, Finland. Through Talent Program, he has also been selected as a professor in several leading Chinese universities. In January 2014 he graduated from the University of Vaasa as a doctor in the area of biofuels. He is also the recipient of the Åbo Akademi Award and Chinese Government Award for Outstanding Self-financed Student Abroad. His background is environmental engineering and his doctoral and current research resides in biodiesel production by integration of microalgae cultivation with wastewater treatment.

Until now, he has published more than 50 papers in many esteemed peer-reviewed scientific journals, such as Water Research, Renewable and Sustainable Energy Reviews, Energy, Bioresource Technology, Applied Energy, Biofuels, Bioproducts and Biorefining (Biofpr) and Ecological Engineering. In total, the current impact factor (IF) of his papers has reached up to 101 points. According to Google Scholar, his papers have been well cited and the current H-index reaches 13. According to the Web of Science (ESI), three of his papers were marked as highly cited papers. In addition, Dr. Zhu serves as the Lead Guest Editor of the BioMed Research International, Associate Editor of the JSM Environmental Science & Ecology and the reviewer for more than 40 journals including Environmental Science & Technology, Water Research, Energy, Applied Energy, etc.

Currently Dr. Zhu is working on TransAlgae project, receiving funding from EU’s Botnia-Atlantica Programme. Dr. Zhu’s previous research has also been well reported by two local Finnish newspapers (Pohjalainen and Ilkka) on their cover pages. Dr. Zhu’s research interests fall into the scopes of wastewater treatment, biofuels, waste recycling, and sustainable development. Dr. Zhu welcomes all kinds of cooperation in research, project application, publications and academic exchange or visits.

Journal Reference

L.-D. Zhu^1,2,5, Z.-H. Li¹, D.-B. Guo³, F. Huang⁴, Y. Nugroho², and K. Xia². Cultivation of Chlorella sp. with livestock waste compost for lipid production. Bioresource Technology, volume 223 (2017), pages 296–300.

Show Affiliations

1. Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, and Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China
2. Department of Energy Technology, Faculty of Technology, University of Vaasa, Vaasa 65101, Finland
3. School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
4. Laboratory of Tropical Agro-Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
5. Renewable Energy Research Group, Vaasa Energy Institute, Vaasa 65101, Finland

 

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