Chemical Engineering Commons^™

Real-Time Observation Of Cellulose Biodegradation By Atomic Force Microscopy, Anthony Clarke, Amanda Quirk, Jacek Lipkowski, Darrell Cockburn, Dan Glickman

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Cellulose, the major structural component of plant cell walls, is a homopolymer of β-1,4-linked glucose residues. As cellulose is the most abundant biopolymer on Earth comprising approx. 50% of the bioshpere, it has attracted renewed interest as a potential source of energy through its biodegradation and fermentation to biofuels. The biodegradation of cellulose involves the concerted action of three types of enzymes, cellulases (EC 3.2.1.4, endo-β-1,4-glucanases), cellobiohydrolases (EC 3.2.1.91; cellulose 1,4-β-cellobiosidase), and β-glucosidases (EC 3.2.1.21; β-d-glucoside glucohydrolase). The former two classes of enzymes function to hydrolyze insoluble cellulose into soluble oligosaccharides which then serve as substrates for β-glucosidases to release …

Biofuels And Biochemicals: Investment Opportunities?, Fernando Preto

Bioenergy - II: Fuels and Chemicals from Renewable Resources

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A Novel Fast Gas-Solid Separator For Pyrolysis Reactors, Martin Huard, Cedric Briens, Franco Berruti

Bioenergy - II: Fuels and Chemicals from Renewable Resources

From escalating global concern over the exhaustion of non-renewable energy sources comes an imperative need for the use of renewable resources. Among possible renewable sources and subsequent conversion processes, biomass pyrolysis is a very promising alternative for fuel and chemical production. Previous work has shown that the most effective biomass pyrolysis processes employ downer reactors. Ongoing research at the Institute for Chemicals and Fuels from Alternative Resources (ICFAR) has led to the development of a new downer reactor design for the pyrolysis of biomass feedstock. However, this process requires a gas-solid separator that achieves a minimum spread of the gas …

Comparison Of Laboratory And Industrial Saccharomyces Cerevisiae Strains For Their Inhibitor Resistance And Xylose Utilization, Anli Geng, Wang Zhankun, Lai Kok Soon Tan Wei Yi Mark, Goh Kiow Leng Hedy, New Jen Yan

Bioenergy - II: Fuels and Chemicals from Renewable Resources

There are various kinds of stresses during the process of ethanol fermentation and more inhibitory factors are produced when lignocelluloses hydrolysate is used as the substrate. The pretreatment of lignocelluloses biomass before fermentation causes the increase in the amount of acids and thus the decrease in pH. Low-molecular weight aliphatic acids, furaldehydes and a broad range of aromatic compounds are produced during the pretreatment process. They are the inhibitors for the ethanol producers, such as Saccharomyces cerevisiae. Furthermore, besides glucose, lignocellulose hydrolysate contains other sugars, such as xylose, arabinose, galactose and mannose etc., among which xylose is taking the major …

Assessment Of Kinetics For Butanol Production By Clostridium Acetobutylicum, Fabio Napoli, Antonio Marzocchella, G. Olivieri P. Salatino

Bioenergy - II: Fuels and Chemicals from Renewable Resources

The economic scenario established at the beginning of the third millennium has revived the interest in Acetone-Butanol-Ethanol (ABE) fermentations. Recent developments in molecular techniques applied to solventogenic microrganisms in combination with recent advances in fermentation systems and downstream processing have contributed to improve ABE fermentation processes feasibility and competitiveness. The challenges raised over the last years as regards ABE production may be synthesized in: i) use of renewable resources as substrate; ii) selection of strains characterized by high ABE productivity; iii) development of new fermentation systems; iv) development of new downstream strategies for enhanced solvent recovery. The selection of unconventional …

Environmentally Sustainable Biofuels - Biodiesel, Palligarnai T. Vasudevan

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Biodiesel is a clean-burning fuel produced from grease, vegetable oils, or animal fats. Biodiesel is produced by transesterification of oils with short-chain alcohols or by the esterification of fatty acids. The transesterification reaction consists of transforming triglycerides into fatty acid alkyl esters, in the presence of an alcohol, such as methanol or ethanol, and a catalyst, such as an alkali or acid, with glycerol as a by-product. Due to diminishing petroleum reserves and the deleterious environmental consequences of exhaust gases from petroleum diesel, biodiesel has attracted attention during the past few years as a renewable and environmentally friendly fuel. Since …

Fast Pyrolysis Of Biomass Under Gasification Conditions: Influence Of Particle Size, Reactor Temperature And Gas Phase Reactions, Li Chen, Capucine Dupont, Sylvain Salvador, Guillaume Boissonnet, Daniel Schweich

Bioenergy - II: Fuels and Chemicals from Renewable Resources

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Suitability Of Wood Chips From Forestry And Different Biomass Feedstocks For Use In A Semi-Industrial Plant Of Btl Production By Gasification, Capucine Dupont, Sylvie Rouge, Alain Berthelot, Denilson Dasilvaperez, Ambroise Graffin, Françoise Labalette, Céline Laboubee, Jean-Claude Mithouard, Sophie Pitocchi

Bioenergy - II: Fuels and Chemicals from Renewable Resources

A semi-industrial plant of BtL production by biomass gasification is planned to be operating in 2011 in the Northern-East of France by a French Energy Research Centre, called Commissariat à l’Energie Atomique (CEA), and several partners. This demonstration plant will be a 50 MW plant, based on an entrained flow reactor, followed by different stages of syngas cleaning and a final stage of Fischer-Tropsch synthesis.

One study has been launched on the biomass regional resources that may be used as feedstock in the plant. The first task of this study deals with the availability of the resources and their feasibility …

Designing An Sscf Process For Bioethanol Production From Lignocellulosic Substrates By Co-Fermentation Of Xylose And Glucose, Kim Olofsson

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Different lignocellulosic materials, from e.g. forest industry and agriculture, are potentially interesting feedstocks for ethanol production. To meet desired overall yields during ethanol production from lignocellulosic materials, it is important to use both hexoses and pentoses. Saccharomyces cerevisiae, the most commonly used organism for industrial ethanol production, does not naturally ferment pentoses. Currently, genetically modified Saccharomyces cerevisiae strains are becoming available for xylose fermentation. However, simultaneous fermentation of xylose and glucose in genetically modified Saccharomyces cerevisiae requires a favorable ratio between these sugars.

In simultaneous saccharification and fermentation (SSF) of spruce, a potential feedstock in the northern hemisphere, the proportion …

Kinetic Assessment For Selective Production Of Furfural From C5 Sugars Contained In Biomass, Gianluca Marcotullio

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Furfural is nowadays one of the most important biomass derived chemicals having a market of roughly 300 ktonn/year. It finds application in many chemicals sectors, being used as a solvent itself, or as starting material for almost all the furanic compounds. In a biobased economy furfural could replace or substitute many oil derivatives as platform chemical and be a starting material for liquid fuels production: furanic biofuels have lately been addressed to represent a very interesting option to current biofuels showing advantageous qualities. Moreover, being furfural derived from the C5 sugars contained in biomass, its integration in a modern biorefinery …

Scale-Up Of The Milena Gasification Process For The Production Of Bio-Sng, Christiaan M. Van Der Meijden, Berend Vreugdenhil

Bioenergy - II: Fuels and Chemicals from Renewable Resources

The production of Substitute Natural Gas from biomass (Bio-SNG) is an attractive option to reduce CO2 emissions and replace declining fossil natural gas reserves. The Energy research Center of the Netherlands (ECN) is working on the development of a technology to convert a wide range of fuels into Bio-SNG. The ECN Bio-SNG technology is based on indirect gasification of biomass. The MILENA indirect gasifier is developed to produce a gas, which can be upgraded into SNG with a high efficiency. Because of the indirect heating of the gasification process no oxygen is required. Char and tar are removed form the …

Biocycle – Sustainable Polymer From Sugar Cane, Sylvio Ortega Filho

Bioenergy - II: Fuels and Chemicals from Renewable Resources

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Study Of The Behaviour Of A Catalytic Ceramic Candle Filter In A Lab-Scale Unit At High Temperatures, Eleonora Simeone, Manfred Nacken, Steffen Heidenreich, Wiebren De Jong

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Solid particles and tars are among the non-desirable products of synthesis gas produced during biomass gasification. Removal of fly ashes is necessary in order to comply with emission limits as well as avoid their deposition in downstream units. Condensation of tars, on the other side, can cause clogging. A catalytic hot gas filter can remove both solids and tars, when operating at temperatures as high as 850oC. Catalytic hot gas filter elements are under development in order to solve this issue.

A lab-scale filtration unit has been designed and constructed at Delft University of Technology. The unit contains one ceramic …

Historical And Recent Developments In The Enzymatic Hydrolysis Of Brazilian Feedstocks For Ethanol Production, Elba P.S. Bon

Bioenergy - II: Fuels and Chemicals from Renewable Resources

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Novel Design Of Multiphase Reactors For Biomass-To-Liquid Synthesis, Ahmed Youssef, Milorad P. Dudukovic Muthanna H. Al-Dahhan

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Generation of liquid fuels from renewable sources such as biomass has been practiced since early 1900’s. In view of the skyrocketing oil prices and the depleting reserves of natural gas, it has gained further interest. The Fischer-Tropsch synthesis is one of the main processes considered. It involves the reaction of syngas in presence of a catalyst to produce liquid fuels. Syngas sources are numerous ranging from waste gasification, anaerobic digestion to clean coal. The reactor of choice for gas to liquid conversion is a slurry bubble column. Although, these multiphase reactors offer several advantages including good heat and mass transfer, …

Gas Phase Mixing In Bubble Columns With Internals, Mohamed Hamed, Muthanna Al Dahhan

Bioenergy - II: Fuels and Chemicals from Renewable Resources

The use of renewable energy sources is becoming increasingly necessary, if we are to achieve the changes required to address the impacts of global warming. Biomass is the most common form of renewable energy, widely used in the third world but until recently, less so in the Western world. Latterly much attention has been focused on the conversion of biomass to liquid fuels; a process which would greatly increases the potential usefulness of biomass as a renewable resource.

Conversion of biomass to liquid is carried out by first gasification of biomass to yield synthetic gas. The synthetic gas can then …

Supply And Properties Of Agricultural Residues Suitable For Bioenergy Applications, Fernando Preto, Irene Coyle

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Agriculture is one of Canada’s largest industries and the residues left over from farming, milling and the off spec crops that are produced every year are present across the country. The quantity and quality of these residues as potential fuels have been analysed, including a comparison of the financial benefits and costs to selecting agricultural feedstocks for heat and power projects. A variety of fuels have been assessed, including raw and densified biomass, to understand the range in transportation costs, front and back end material handling and boiler selection. These fuels include: corn stover, corn cob, switchgrass pellets, whole canola, …

A Simulation Model Of Combined Biogas, Bioethanol And Protein Fodder Co-Production In Organic Farming, Piotr Oleskowicz-Popiel

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Anaerobic digestion based on animal manure and energy crops is very effective technology to provide energy and reduce green-house gasses emission, in particular ammonia and methane. Besides, utilisation of biogas contributes to reduction of CO2 emission. On the other hand, production of bioethanol from starchy or lignocellulosic materials can supply farmers with liquid fuel necessary for agriculture machinery. Therefore, there is a need for development an effective biorefinery for sustainable energy production in organic agriculture. Due to large amount of existing technologies and many ways for co-production of feed and fuel, the application of process engineering tools is required. The …

Fuels And Chemicals From Biomass And Waste, Esben Taarning

Bioenergy - II: Fuels and Chemicals from Renewable Resources

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Biofuel Production From Biomass-Derived Volatile Fatty Acid Platform, Ho Nam Chang, Nakjong Kim, Changmoon Joeng Jongwon Kang, Hyungshik Choi

Bioenergy - II: Fuels and Chemicals from Renewable Resources

The typical biorefinery platforms are sugar, thermochemical (syngas), carbon-rich chains, and biogas platform. The sugar platform uses hexose and pentose sugars extracted or converted from plant body. The thermochemical (syngas) platform is chemical or biological conversion process using pyrolysis or gasification of plant to produce biofuels. The carbon-rich chains platform is used to produce biodiesel from long-chain fatty acids or glycerides. Those platforms have unique advantages and disadvantages. Our group has concentrated on the biogas platform producing methane gas from municipal solid wastes through anaerobic digestion (AD) processs, which is composed of rapid acidogenesis and slow methanogenesis. This acidogenic and …

Increasing Corn Throughput In Dry Grind Process For Ethanol Process, Vijay Singh, Jameel Shihadeh, Kent D. Rausch, M. E. Tumbleson

Bioenergy - II: Fuels and Chemicals from Renewable Resources

In a conventional dry grind process, corn is ground and mixed with water to produce slurry. The slurry is cooked; starch in the slurry is liquefied, simultaneously saccharified and fermented to produce ethanol. Typical solids during slurry preparation range from 30 to 34%. Higher solids result in higher ethanol concentration. High final ethanol concentration improves plant profitability by increasing plant capacity and improving plant efficiency. Corn solids higher than 34% are not used in dry grind corn process due to high mash viscosity (after cooking), increase in sugar concentration during fermentation (substrate yeast inhibition) and high final ethanol concentration (product …

Biodiesel – Oxidation, Storage Stability And Materials Compatibility – The Brazilian R&D Experience, Eduardo Cavalcanti

Bioenergy - II: Fuels and Chemicals from Renewable Resources

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Hybrid Staged Thermolysis To Valorise Biomass, Paul J. De Wild

Bioenergy - II: Fuels and Chemicals from Renewable Resources

The need for a renewable ‘green’ chemistry is adamant because of the adverse effects of the increasing use of fossil fuels on our society, like global warming and the depletion of fossil fuel resources. Therefore, the use of ligno-cellulosic (woody) types of biomass as a renewable source for chemicals and energy is increasingly becoming important. Unfortunately, the heterogeneity of biomass presents a major obstacle to chemical utilization. The main constituents hemicellulose, cellulose and lignin are strongly interconnected by a variety of physico-chemical bonds that makes it difficult to extract individual chemicals in high yields. So an efficient and cost-effective fractionation …

A Novel Toa-Glycerol Based Extraction - Re-Extraction Process For The Separation Of Chemicals Produced By Acidogenic Fermentation Of Biomass, Juray De Wilde, Emilie Fockedey, Patrick A. Gerin

Bioenergy - II: Fuels and Chemicals from Renewable Resources

Acidogenic fermentation of biomass for the production of ethanol and acetic, propionic, butyric and lactic acids is a promising technology, in the sense that germ free conditions are not required, very diversified, less pretreated and cheap biomass can be used, and the molecules produced and their esters are consumed on a large scale by industries. The product recovery, separation and concentration steps downstream of the biomass transformation remain, however, a major challenge for the industrial application of acidogenic fermentation which produces very dilute (concentrations of only a few percent) and complex aqueous solutions of acids and ethanol. A novel extraction …

A Computational Study Of The Distribution Of Particles In A Lab-Scale Cfb Boiler, Kim G. Hansen, Tron Solberg, Bjorn H. Hjertager

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

When two-fluid modeling is used to predict riser flows there have been difficulties in predicting the solids hold up in risers represented by the correct pressure drop profile. A way of encountering this inherent problem in current Eulerian-Eulerian CFD modeling is to approximate the actual particle size distribution by using more particle phases instead of the current practice of using one mean diameter. For the lab-scale CFB investigated, CFD simulations show that a mal-distribution occurs in the CFB; the larger particles are retained in the riser, whereas the intermediate and small particles are distributed both in the return leg and …

Flow Structures In The Bottom Region Of Riser, Haiyan Zhu, Jesse Zhu

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

This paper studied hydrodynamic characteristics in bottom region of CFB risers with FCC particles over a wide range of operating conditions. Results included solids concentration, particle velocity, and probability density distributions. Comparisons were made between flow structures in riser bottom region and that in bubbling and turbulent fluidized bed.

Hydrodynamic Characteristics Of A Fluidized Bed With Rotating Distributor, C. Sobrino, S. Sánchez-Delgado, J. A. Almendros-Ibáñez, M. De Vega, U. Ruiz-Rivas, D. Santana

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

The performance of a novel rotating distributor fluidized bed is presented. The pressure drop and the standard deviation of pressure fluctuations, σp, were used to find the minimum fluidization velocity, Umf, and to characterize the quality of fluidization at different rotational speeds of the distributor plate. Experiments were conducted in the freely bubbling regime in a 0.19 m i.d. fluidized bed, operating with Group B particles according to Geldart’s classification. A decrease in Umf is observed when the rotational speed increases. Frequency analysis of pressure fluctuations shows that fluidization can be controlled by the adjustable rotational speed, at several excess …

Friction Between Gas-Solid Suspension And Circulating Fluidized Bed Downers, Xiaobo Qi, Hui Zhang, Jesse Zhu

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Friction between co-current downflow gas-solid suspension and the column wall was investigated. A new model to predict pressure drops due to friction between the gas-solid suspension in the fully developed section and the downer wall was developed. The results show that the friction between the gas-solids suspension and the downer wall causes a significant deviation of the apparent solids concentrations from the actual ones, especially for those operating conditions with higher superficial gas velocities and solids circulation rates. When the superficial gas velocity is greater than 8 m/s, the actual solids concentrations in the fully developed region of the downer …

Measurement Of Gas Velocities In The Presence Of Solids In The Riser Of A Cold Flow Circulating Fluidized Bed, James Spenik, J. Christopher Ludlow, Rex Compston, Ronald W. Breault

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

The local gas velocity and the intensity of the gas turbulence in a gas/solid flow are a required measurement in validating the gas and solids flow structure predicted by computational fluid dynamic (CFD) models in fluid bed and transport reactors. The high concentration and velocities of solids, however, make the use of traditional gas velocity measurement devices such as pitot tubes, hot wire anemometers and other such devices difficult. A method of determining these velocities has been devised at the National Energy Technology Laboratory employing tracer gas. The technique developed measures the time average local axial velocity gas component of …

Ozone Decomposition In A Downer Reactor, W. Song, Chigang Fan, Yong Zhang, Weigang Lin, Xiaotao Bi

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Catalytic ozone decomposition was conducted in an 8.20 m high, 0.09 m inner diameter downer. The ozone concentration profiles were measured under a series of operating conditions. It is found that the ozone distribution in a downer is generally more uniform both axially and laterally than in a riser, and that there exists a relatively significant non-uniform distribution in the entrance acceleration region of the downer.he increase of solid mass flow rate will slightly increase the ozone decomposition. In addition, the acceleration region has a great effect on the reaction.