Developing a Model to Predict the Torrefaction of Biomass

2014 ◽  
Author(s):  
Ryan R. Mahutga ◽  
Stephen P. Gent ◽  
Michael P. Twedt
Keyword(s):  
Linear Equations ◽  
Chemical Species ◽  
Value Added ◽  
Product Formation ◽  
Reaction Model ◽  
Solid Mass ◽  
Yield Data ◽  
Arrhenius Kinetic Parameters ◽  
Mild Pyrolysis ◽  
Two Stages

With increasing fuel costs and more emphasis being placed on sustainable sources of energy, biomass from agricultural residues and energy crops are becoming an increasingly viable value-added resource for the rural economies in United States and throughout the world. Torrefaction, a thermochemical reaction process, is a form of mild-pyrolysis that improves the qualities of biomass feedstocks for use as a fuel similar to charcoal. This research presents a user-centered computational framework to predict the effects of torrefaction of biomass. The reaction model is based on recently developed models for the torrefaction of willow. The basis for this model is a two stage, solid mass loss kinetics reaction where Arrhenius kinetic parameters are estimated based on experimentally obtained TGA data. Utilizing these parameters along with solid product formation equations it is possible to determine the solid mass yield, as well as the yields of the two stages of pseudo-volatiles released during reaction. Chemical species composition of the volatiles is determined from a system of constrained linear equations based on calculated volatile yield data and experimental results. The reaction model is implemented into MATLAB R2012b as a standalone program with a graphical user interface to obtain inputs, and display numeric and graphic results. The overall goal of this model is to provide a guide for improving conversion efficiency of biomass to bio-char.

Intellectual capital and performance of listed companies: empirical evidence from Italy

2014 ◽  
Vol 18 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Domenico Celenza ◽  
Fabrizio Rossi
Keyword(s):  
Explanatory Power ◽  
Value Added ◽  
Listed Companies ◽  
Cross Sectional ◽  
Content Type ◽  
Accounting Performance ◽  
And Performance ◽  
The One ◽  
Two Stages ◽  
The Relationship

Purpose – The aim of this paper is to investigate the relationship between corporate performance and Value Added Intellectual Coefficient (VAICTM) on the one hand, and the relationship between the variations in market value and the variations in VAIC on the other hand. Design/methodology/approach – Starting from the VAIC model, 23 Italian listed companies were examined with the aim of investigating the relationship between VAIC and the performance of the firms in the sample. The analysis was divided into two stages. In the first stage, eight models of linear regression were estimated to verify the presence of a positive and statistically significant relationship between M/BV and VAIC and between accounting performance indicators (ROE, ROI, ROS) and the VAIC. In the second stage, six other models were tested, considering as an independent variable the variations in VAIC and the variations in profitability indicators. Findings – The outcomes of the application stress the importance of VAIC in the explanation of the variations in MV and its role as “additional coefficient” in the analysis of equity performance. Originality/value – This methodology highlights some very interesting aspects. In particular, whereas the relationship between M/BV and VAIC and between profitability indicators (ROI, ROE, ROS) and VAIC is statistically insignificant, the subsequent analysis highlights the importance of VAIC as a variable capable of increasing the explanatory power of the regression in a cross-sectional perspective.

Cascaded Biocatalysis and Bioelectrocatalysis: Overview and Recent Advances

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Yoo Seok Lee ◽  
Koun Lim ◽  
Shelley D. Minteer
Keyword(s):  
Value Added ◽  
Cascade Reactions ◽  
Product Formation ◽  
Deep Oxidation ◽  
Annual Review ◽  
Publication Date ◽  
Oxidation Reduction ◽  
Cascade Biocatalysis ◽  
Analyte Detection ◽  
Catalyst Systems

Enzyme cascades are plentiful in nature, but they also have potential in artificial applications due to the possibility of using the target substrate in biofuel cells, electrosynthesis, and biosensors. Cascade reactions from enzymes or hybrid bioorganic catalyst systems exhibit extended substrate range, reaction depth, and increased overall performance. This review addresses the strategies of cascade biocatalysis and bioelectrocatalysis for ( a) CO2 fixation, ( b) high value-added product formation, ( c) sustainable energy sources via deep oxidation, and ( d) cascaded electrochemical enzymatic biosensors. These recent updates in the field provide fundamental concepts, designs of artificial electrocatalytic oxidation-reduction pathways (using a flexible setup involving organic catalysts and engineered enzymes), and advances in hybrid cascaded sensors for sensitive analyte detection. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Development of a Continuous Process to Produce Ti via Metallothermic Reduction of TiCl4 in Molten Salt

2013 ◽  
Vol 551 ◽  
pp. 16-24 ◽  
Author(s):  
D.S. van Vuuren ◽  
S.J. Oosthuizen ◽  
J.J. Swanepoel
Keyword(s):  
Molten Salt ◽  
Fine Particles ◽  
Continuous Process ◽  
Scale Up ◽  
Product Formation ◽  
Current Status ◽  
Metallothermic Reduction ◽  
Process Route ◽  
Project Risks ◽  
Two Stages

After evaluating many different routes to produce titanium, the CSIR of South Africa selected a process to produce titanium powder continuously via metallothermic reduction of TiCl4 in molten salt. The project risks are being managed using the well-known STAGE/GATE method. The first two stages, viz, Route Selection and Preliminary Assessment have been completed and the next stage entailing campaigns extending over several days of uninterrupted operation, producing titanium at a rate of about 2 kg/h has recently begun. The rationale for selecting the process route is briefly reviewed and key process problems that had to be solved before embarking on scale-up and measures to do so are explained. Specific problems are: • Feed line blockages, • Titanium product formation and adherence to reactor internals, • Agglomerate formation; and • Production of very fine particles. Lastly the planned schedule and current status of the project are discussed.

Numerical Simulation of Natural Gas Combustion Process Using a One-Step and a Two-Step Reaction

2002 ◽  
Author(s):  
Angela O. Nieckele ◽  
Moˆnica F. Naccache ◽  
Marcos S. P. Gomes ◽  
Joa˜o N. E. Carneiro ◽  
Andre´ Augusto Isnard ◽  
...  
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Process ◽  
Chemical Species ◽  
Reaction Model ◽  
Gas Combustion ◽  
First Case ◽  
Natural Gas Combustion ◽  
Cylindrical Furnace ◽  
Global Reaction

The work evaluates the combustion of natural gas in a cylindrical furnace. The Generalized Finite Rate Reaction Model was selected for predicting the reactions. Two situations were considered. In the first case the combustion of the fuel was predicted by a single global reaction, and in the second case a two-step reaction was considered for predicting the combustion process. The conservation equations of mass, momentum, energy and chemical species were solved by the finite volume procedure, with the commercial software FLUENT. The turbulent flow was modeled by employing the two differential equation κ–ε model. The solutions obtained with the two reaction models, for the temperature and species concentration fields, were compared among them and against experimental data available in the literature. It was observed that the two-step reaction model represents better the physical phenomena, showing a better agreement with the experimental data.

scholarly journals Potential of Wastewater Valorization after Wet Extraction of Proteins from Faba Bean and Pea Flours

2020 ◽  
Vol 03 (02) ◽  
pp. 1-1
Author(s):  
Sofía Albolafio ◽  
◽  
María I. Gil ◽  
Ana Allende ◽  
Epameinondas Xanthakis ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Organic Matter ◽  
Environmental Impact ◽  
Faba Bean ◽  
Phenolic Content ◽  
Organic Matter Content ◽  
Oxygen Demand ◽  
Value Added ◽  
Matter Content ◽  
Two Stages

The present study aimed to characterize wastewater fractions obtained after the wet extraction of proteins from legumes. In addition, the suitability of wastewater fractions for the potential recovery of high value-added compounds was also examined, and consequently, the prevention of the environmental impact of these wastes was explored. Similar to the industrial production of proteins, wet alkaline and acidic extractions of proteins from faba bean and pea flours were performed in two stages of extraction. The different wastewater fractions were characterized by measuring their organic matter content, total solids (TS), total dissolved solids (TDS), electrical conductivity (EC), pH, and turbidity. The value-added compounds from these wastewater fractions were quantified, which included the protein content, carbohydrate content, phenolic content, and antioxidant activity. In addition, the phenolic compounds in these factions were identified and quantified. It was observed that the fractions obtained in the first extraction stage had 60%–90% higher organic matter content, measured as the chemical oxygen demand (COD), compared to the second fractions, indicating a higher environmental impact of the former in case of disposal. The results obtained for COD, TS, TDS, EC, pH, and turbidity demonstrated that microfiltration reduced only the turbidity (85%), and consequently, a decrease was observed in the particulate matter, while there was a practically negligible reduction in the soluble matter. Wastewater from faba exhibited the highest polyphenol content and antioxidant activity, and was, therefore, considered the most valuable fraction for potential valorization.

Implementation of Lean Manufacturing System in Bogie Assembly in Railway Coach Factory

2012 ◽  
Vol 248 ◽  
pp. 511-515 ◽  
Author(s):  
P. Arunagiri ◽  
A. Gnanavelbabu
Keyword(s):  
Lean Manufacturing ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Low Cost ◽  
Value Added ◽  
Layout Design ◽  
Design Calculation ◽  
Assembly Shop ◽  
Cost Calculations ◽  
Two Stages

Elimination of the non-value added activities in the bogie assembly shop during bogie assembly process. The various non-value added activities are found in the assembly shop such as excess distance between each assembly stages, excess cost to flow of material from one stage to another stage, waste of time and non-flexibility of shop. These types of non-value added activities occur due to the improper arrangement of bogie assembly stages. Implementation of lean manufacturing systems through layout design by the conversion of existing layout of bogie assembly shop into proposed layout. Analysing the existing layout by using the CRAFT method to find out the best optimized layout .Interchanges are made between each stages that help to correct the present layout. Design calculation are done for various stages .Interchanging of stages of different section are considered by distant matrix and total cost calculations .Various cost of all the pair wise interchanged stages are estimated to find the best low cost interchange. As per the design calculation best interchange between the two stages are considered and that lead to the development of new proposed layout in which all the non-value added activities are eliminated

scholarly journals Alkane and wax ester production from lignin derived molecules

2018 ◽  
Author(s):  
Milla Salmela ◽  
Tapio Lehtinen ◽  
Elena Efimova ◽  
Suvi Santala ◽  
Ville Santala
Keyword(s):  
Value Added ◽  
Product Formation ◽  
Wax Esters ◽  
Wax Ester ◽  
Acinetobacter Baylyi ◽  
Bacterial Host ◽  
Synthetic Pathway ◽  
Growth Product ◽  
Lignin Depolymerization ◽  
Value Added Products

AbstractLignin has potential as a sustainable feedstock for microbial production of industrially relevant molecules. However, the required lignin depolymerization yields a heterogenic mixture of aromatic monomers that are challenging substrates for the microorganisms commonly used in industry. Here, we investigated the properties of lignin-derived molecules (LDMs), namely coumarate, ferulate, and caffeate, in the synthesis of biomass and products in a LDM-utilizing bacterial hostAcinetobacter baylyiADP1. The biosynthesis products, wax esters and alkanes, are relevant compounds for the chemical and fuel industries. InA. baylyiADP1, wax esters are produced by a native pathway, whereas alkanes are produced by a synthetic pathway introduced to the host. Using individual LDMs as substrates, the growth, product formation, and toxicity to cells were monitored with internal biosensors. Of the tested LDMs, coumarate was the most propitious in terms of product synthesis. Wax esters were produced from coumarate with a yield and titer of 40 mg /gcoumarateand 221 mg/L, whereas alkanes were produced with a yield of 62.3 μg /gcoumarateand titer of 152 μg/L. This study demonstrates the microbial preference for certain LDMs, and highlights the potential ofA. baylyiADP1 as a convenient host for LDM upgrading to value-added products.

scholarly journals A Skeletal Kinetic Model For Biodiesel Fuels Surrogate Blend Under Diesel-Engine Conditions

2015 ◽  
Vol 15 (1) ◽  
pp. 52
Author(s):  
Chit Wityi Oo ◽  
Masahiro Shioji ◽  
Hiroshi Kawanabe ◽  
Susan A. Roces ◽  
Nathaniel P. Dugos
Keyword(s):  
Diesel Engine ◽  
Kinetic Model ◽  
Ignition Delay ◽  
National Laboratory ◽  
Chemical Species ◽  
Negative Temperature ◽  
Reaction Model ◽  
Reaction Products ◽  
Surrogate Fuels ◽  
Biodiesel Fuels

The biodiesel surrogate fuels are realistic kinetic tools to study the combustion of actual biodiesel fuels in diesel engines. The knowledge of fuel chemistry aids in the development of combustion modeling. In order to numerically simulate the diesel combustion, it is necessary to construct a compact reaction model for describing the chemical reaction. This study developed a skeletal kinetic model of methyl decanoate (MD) and n-heptane as a biodiesel surrogate blend for the chemical combustion reactions. The skeletal kinetic model is simply composed of 45 chemical species and 74 reactions based on the full kinetic models which have been developed by Lawrance Livermore National Laboratory (LLNL) and Knowledge-basing Utilities for Complex Reaction Systems (KUCRS) under the diesel like engine conditions. The model in this study is generated by using CHEMKIN and then it is used to produce the ignition delay data and the related chemical species. The model predicted good reasonable agreement for the ignition delays and most of the reaction products at various conditions. The chemical species are well reproduced by this skeletal kinetic model while the good temperature dependency is found under constant pressure conditions 2MPa and 4MPa. The ignition delay time of present model is slightly shorter than the full kinetic model near negative temperature coefficient (NTC) regime. This skeletal model can provide the chemical kinetics to apply in the simulation codes for diesel-engine combustion.

Coupled transport/reaction modelling of copper canister corrosion aided by microbial processes

2004 ◽  
Vol 92 (9-11) ◽  
Author(s):  
Jinsong Liu ◽  
Ivars Neretnieks
Keyword(s):  
Nuclear Fuel ◽  
Chemical Species ◽  
Reaction Model ◽  
Microbial Processes ◽  
Coupled Transport ◽  
Transport Reaction ◽  
Sulphate Reducing Bacteria ◽  
Bentonite Buffer ◽  
Reducing Bacteria ◽  
Local Depth

SummaryCopper canister corrosion is an important issue in the concept of a nuclear fuel repository. Previous studies indicate that the oxygen-free copper canister could hold its integrity for more than 100000 years in the repository environment.Microbial processes may reduce sulphate to sulphide and considerably increase the amount of sulphide available for corrosion. In this paper, a coupled transport/reaction model is developed to account for the transport of chemical species produced by microbial processes. The corroding agents like sulphide would come not only from the intruding groundwater, but also from the reduction of sulphate near the canister. The reaction of sulphate-reducing bacteria and the transport of sulphide in the bentonite buffer is included in the model. The local depth of copper canister corrosion is calculated by the model.

scholarly journals Layered dynamic regulation for improving metabolic pathway productivity inEscherichia coli

2018 ◽  
Vol 115 (12) ◽  
pp. 2964-2969 ◽  
Author(s):  
Stephanie J. Doong ◽  
Apoorv Gupta ◽  
Kristala L. J. Prather
Keyword(s):  
Regulatory System ◽  
Value Added ◽  
Fold Increase ◽  
Product Formation ◽  
Glycolytic Flux ◽  
Glucaric Acid ◽  
Dynamic Regulation ◽  
Fourfold Increase ◽  
Product Titer ◽  
K 12

Microbial production of value-added chemicals from biomass is a sustainable alternative to chemical synthesis. To improve product titer, yield, and selectivity, the pathways engineered into microbes must be optimized. One strategy for optimization is dynamic pathway regulation, which modulates expression of pathway-relevant enzymes over the course of fermentation. Metabolic engineers have used dynamic regulation to redirect endogenous flux toward product formation, balance the production and consumption rates of key intermediates, and suppress production of toxic intermediates until later in the fermentation. Most cases, however, have utilized a single strategy for dynamically regulating pathway fluxes. Here we layer two orthogonal, autonomous, and tunable dynamic regulation strategies to independently modulate expression of two different enzymes to improve production of D-glucaric acid from a heterologous pathway. The first strategy uses a previously described pathway-independent quorum sensing system to dynamically knock down glycolytic flux and redirect carbon into production of glucaric acid, thereby switching cells from “growth” to “production” mode. The second strategy, developed in this work, uses a biosensor formyo-inositol (MI), an intermediate in the glucaric acid production pathway, to induce expression of a downstream enzyme upon sufficient buildup of MI. The latter, pathway-dependent strategy leads to a 2.5-fold increase in titer when used in isolation and a fourfold increase when added to a strain employing the former, pathway-independent regulatory system. The dual-regulation strain produces nearly 2 g/L glucaric acid, representing the highest glucaric acid titer reported to date inEscherichia coliK-12 strains.

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