Oxytree Pruned Biomass Torrefaction: Process Kinetics

Oxytree is a fast-growing energy crop with C4 photosynthesis. In this research, for the first time, the torrefaction kinetic parameters of pruned Oxytree biomass (Paulownia clon in Vitro 112) were determined. The influence of the Oxytree cultivation method and soil class on the kinetic parameters of the torrefaction was also investigated. Oxytree pruned biomass from a first-year plantation was subjected to torrefaction within temperature range from 200 to 300 °C and under anaerobic conditions in the laboratory-scale batch reactor. The mass loss was measured continuously during the process. The relative mass loss increased from 1.22% to 19.56% with the increase of the process temperature. The first-order constant rate reaction (k) values increased from 1.26 × 10−5 s−1 to 7.69 × 10−5 s−1 with the increase in temperature. The average activation energy for the pruned biomass of Oxytree torrefaction was 36.5 kJ∙mol−1. Statistical analysis showed no significant (p < 0.05) effect of the Oxytree cultivation method and soil class on the k value. The results of this research could be useful for the valorization of energy crops such as Oxytree and optimization of waste-to-carbon and waste-to-energy processes.

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A Technique to Determine Unsteady-State Inhibition Kinetics in the Activated Sludge Process

Water Science & Technology ◽

10.2166/wst.1989.0261 ◽

1989 ◽

Vol 21 (6-7) ◽

pp. 593-602 ◽

Cited By ~ 3

Author(s):

Andrew T. Watkin ◽

W. Wesley Eckenfelder

Keyword(s):

Activated Sludge ◽

Kinetic Parameters ◽

Curve Fitting ◽

Glucose Utilization ◽

Batch Reactor ◽

Synthetic Data ◽

Utilization Rate ◽

Fitting Algorithm ◽

Test Reactor ◽

Two Parameter

A technique for rapidly determining Monod and inhibition kinetic parameters in activated sludge is evaluated. The method studied is known as the fed-batch reactor technique and requires approximately three hours to complete. The technique allows for a gradual build-up of substrate in the test reactor by introducing the substrate at a feed rate greater than the maximum substrate utilization rate. Both inhibitory and non-inhibitory substrate responses are modeled using a nonlinear numerical curve-fitting technique. The responses of both glucose and 2,4-dichlorophenol (DCP) are studied using activated sludges with various acclimation histories. Statistically different inhibition constants, KI, for DCP inhibition of glucose utilization were found for the various sludges studied. The curve-fitting algorithm was verified in its ability to accurately retrieve two kinetic parameters from synthetic data generated by superimposing normally distributed random error onto the two parameter numerical solution generated by the algorithm.

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Windblown Sand-Induced Degradation of Glass Panels in Curtain Walls

Materials ◽

10.3390/ma14030607 ◽

2021 ◽

Vol 14 (3) ◽

pp. 607

Author(s):

Yuxi Zhao ◽

Rongcheng Liu ◽

Fan Yan ◽

Dawei Zhang ◽

Junjin Liu

Keyword(s):

Visible Light ◽

Mass Loss ◽

Effective Area ◽

Area Ratio ◽

Light Transmittance ◽

Relative Mass ◽

Impact Time ◽

Windblown Sand ◽

Glass Panels ◽

The Impact

The windblown sand-induced degradation of glass panels influences the serviceability and safety of these panels. In this study, the degradation of glass panels subject to windblown sand with different impact velocities and impact angles was studied based on a sandblasting test simulating a sandstorm. After the glass panels were degraded by windblown sand, the surface morphology of the damaged glass panels was observed using scanning electron microscopy, and three damage modes were found: a cutting mode, smash mode, and plastic deformation mode. The mass loss, visible light transmittance, and effective area ratio values of the glass samples were then measured to evaluate the effects of the windblown sand on the panels. The results indicate that, at high abrasive feed rates, the relative mass loss of the glass samples decreases initially and then remains steady with increases in impact time, whereas it increases first and then decreases with an increase in impact angle such as that for ductile materials. Both visible light transmittance and effective area ratio decrease with increases in the impact time and velocities. There exists a positive linear relationship between the visible light transmittance and effective area ratio.

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Investigation of the Biological Treatability of Pistachio Processing Industry Wastewaters in a Batch-operated Aerobic Bioreactor

10.21203/rs.3.rs-448821/v1 ◽

2021 ◽

Author(s):

Sevtap Tırınk ◽

Alper Nuhoğlu ◽

Sinan Kul

Keyword(s):

Kinetic Parameters ◽

Growth Rates ◽

Specific Growth ◽

Batch Reactor ◽

The Other ◽

Batch Experiments ◽

Processing Industry ◽

Specific Growth Rates ◽

Biological Treatability ◽

Best Fit

Abstract This study encompasses investigation of treatment of pistachio processing industry wastewaters in a batch reactor under aerobic conditions, calculation of kinetic parameters and comparison of different inhibition models. The mixed microorganism culture used in the study was adapted to pistachio processing industry wastewaters for nearly one month and then concentrations from 50-1000 mg L− 1 of pistachio processing industry wastewaters were added to the medium and treatment was investigated in batch experiments. The Andrews, Han-Levenspiel, Luong and Aiba biokinetic equations were chosen for the correlations between the concentration of pistachio processing industry wastewaters and specific growth rates, and the kinetic parameters in these biokinetic equations were calculated. The µmax, Ks and Ki parameters, included in the Aiba biokinetic equation providing best fit among the other equations, had values calculated as 0.25 h− 1, 19 mg L− 1, and 516 mg L− 1, respectively.

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The Behavior of Tar Sand Fragments in Steady Streams of the Products of Combustion of Lean CH4-Air or H2-Air

Journal of Energy Resources Technology ◽

10.1115/1.3231375 ◽

1988 ◽

Vol 110 (3) ◽

pp. 151-156

Author(s):

G. A. Karim ◽

G. Ishola ◽

A. Hanafi

Keyword(s):

Mass Loss ◽

Kinetic Parameters ◽

Ignition Delay ◽

Low Temperatures ◽

Low Velocity

The behavior of tar sand fragments, molded into either slabs or spheres, was examined when exposed to low-velocity streams of the products of combustion of lean CH4-air mixtures, at temperatures of 700 K to 1200 K or lean H2-air mixtures at temperatures of 700 K to 1000 K. The processes of volatilization followed by slow oxidation were identified at low temperatures while autoignition and subsequent combustion of the volatiles complemented and enhanced the volatilization stage at higher temperatures. Some gross kinetic parameters of the processes involved are then evaluated using the mass loss and ignition delay data obtained.

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Decomposition of Organic Chemical Components in Wood by Tropical Xylaria Species

Journal of Fungi ◽

10.3390/jof6040186 ◽

2020 ◽

Vol 6 (4) ◽

pp. 186

Author(s):

Takashi Osono

Keyword(s):

Mass Loss ◽

Leaf Litter ◽

Tree Species ◽

Chemical Components ◽

Organic Chemical ◽

Klason Lignin ◽

Wood Decomposition ◽

Recalcitrant Compounds ◽

Initial Content

The ability of Xylaria species obtained from tropical wood and leaf litter to cause a mass loss of lignin and carbohydrates in wood was examined in vitro with pure culture decomposition tests. The mass loss of wood of four tree species caused by nine Xylaria isolates ranged from 4.5% to 28.4% of the original wood mass. These Xylaria isolates have a potential ability to decompose lignin and other recalcitrant compounds, collectively registered as acid unhydrolyzable residues or Klason lignin in wood. The origin of isolates (i.e., isolates from wood versus leaf litter) did not affect the mass loss of acid unhydrolyzable residue in wood. The Xylaria isolates tested generally caused a selective decomposition of polymer carbohydrates in wood in preference to acid unhydrolyzable residue. The mass loss of acid unhydrolyzable residue caused by Xylaria isolates varied with the tree species of the wood and was negatively related to the initial content of acid unhydrolyzable residue in wood, implying the limiting effect of lignin and recalcitrant compounds on wood decomposition by Xylaria isolates.

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Pyrolysis and CO2 Gasification of Composite Polymer Absorbent Waste for Syngas Production

ASME 2019 Power Conference ◽

10.1115/power2019-1884 ◽

2019 ◽

Author(s):

K. G. Burra ◽

P. Singh ◽

N. Déparrois ◽

A. K. Gupta

Keyword(s):

Energy Production ◽

Batch Reactor ◽

Fixed Bed ◽

Waste To Energy ◽

Composite Polymer ◽

Co2 Gasification ◽

Compositional Evolution ◽

Absorbent Material ◽

Syngas Production ◽

The Impact

Abstract Development of alternative carbonaceous sources for energy production is essential to alleviate the dependence on depleting fossil fuels which led to increasing atmospheric CO2 and thus global warming. While biomass utilization for energy and chemical production has been extensively studied in the literature, such studies on municipal solid wastes is difficult to interpret due to the heterogeneous nature of the waste. Understanding of the influence of individual components is necessary for comprehensive development of waste-to-energy pathway. One such waste that is complicated and has often been ignored in the literature is composite polymer absorbent material waste which can also be considered as a potential feedstock for thermochemical pathway of energy production. Composite polymer absorbent materials are ubiquitously used these days in the form of sanitary napkins, diapers, water blockers, fire blockers and surgical pads due to their high water-absorptive nature. Pyrolysis and CO2 gasification is ideal for such materials due to its versatile feedstock intake and uniform product output in the form of syngas with adjustable composition. CO2 gasification also provides the added benefit of CO2 utilization which provides carbon offset to this process. In the present study, a mixture of cellulose, absorbent material (sodium polyacrylate), polypropylene and polystyrene in a fixed proportion, to model approximate composition of a diaper, was examined for its pyrolysis and CO2 gasification capability for viable syngas production. The influence of individual components into the syngas yield from the composite waste gasification was also investigated. A fixed-bed, semi-batch reactor facility along with gas chromatography was employed to analyse the syngas yield and compositional evolution. Pyrolysis was done under nitrogen atmosphere and gasification was done under CO2 atmosphere. CO2 gasification provided net CO2 consumption which means a net reduction in carbon emissions per joule of energy produced. The sample was tested under four isothermal conditions of 973, 1073, and 1173 K to understand the impact of operational conditions on the syngas yield. Influence of individual component of the composite absorbent waste on the syngas yield and composition was also analyzed by comparing these syngas characteristics with that of the yield from gasification of its individual components separately at 1173 K. These investigations provided us with novel results on the behavior and capabilities of these composite polymer absorbent wastes and which opens up a new avenue towards efficient utilization of solid waste resources for sustainable energy production in the form of syngas which can also be used for various chemicals production such as methanol, gasoline and other petrochemical products.

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Degradation and erosion mechanisms of bioresorbable porous acellular vascular grafts: an in vitro investigation

Journal of The Royal Society Interface ◽

10.1098/rsif.2017.0102 ◽

2017 ◽

Vol 14 (132) ◽

pp. 20170102 ◽

Cited By ~ 8

Author(s):

Piyusha S. Gade ◽

Keewon Lee ◽

Blaise N. Pfaff ◽

Yadong Wang ◽

Anne M. Robertson

Keyword(s):

Mechanical Properties ◽

Mass Loss ◽

Mechanistic Model ◽

Vascular Grafts ◽

Damage Function ◽

Surface Erosion ◽

Outer Diameter ◽

In Vitro Investigation

A fundamental mechanism of in situ tissue regeneration from biodegradable synthetic acellular vascular grafts is the effective interplay between graft degradation, erosion and the production of extracellular matrix. In order to understand this crucial process of graft erosion and degradation, we conducted an in vitro investigation of grafts ( n = 4 at days 1, 4, 7, 10 each) exposed to enzymatic degradation. Herein, we provide constitutive relationships for mass loss and mechanical properties based on much-needed experimental data. Furthermore, we formulate a mathematical model to provide a physics-based framework for understanding graft erosion. A novel finding is that despite their porous nature, grafts lost mass exponentially via surface erosion demonstrating a 20% reduction in outer diameter and no significant change in apparent density. A diffusion based, concentration gradient-driven mechanistic model of mass loss through surface erosion was introduced which can be extended to an in vivo setting through the use of two degradation parameters. Furthermore, notably, mechanical properties of degrading grafts did not scale with mass loss. Thus, we introduced a damage function scaling a neo-Hookean model to describe mechanical properties of the degrading graft; a refinement to existing mass-dependent growth and remodelling (G&R) models. This framework can be used to improve accuracy of well-established G&R theories in biomechanics; tools that predict evolving structure–function relationships of neotissues and guide graft design.

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Unstirred Water Layer Effects on Biodegradable Microspheres

Advances in Pharmaceutics ◽

10.1155/2015/823476 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Susan D’Souza ◽

Jabar A. Faraj ◽

Patrick P. DeLuca

Keyword(s):

Drug Release ◽

Mass Loss ◽

Polymer Degradation ◽

Water Layer ◽

Biodegradable Microspheres ◽

Release Process ◽

Unstirred Water Layer ◽

Fourfold Increase ◽

Static Conditions

This study explores the mechanistic aspects of in vitro release from biodegradable microspheres with the objective of understanding the effect of the unstirred water layer on polymer degradation and drug release. In vitro drug release experiments on Leuprolide PLGA microspheres were performed under “static” and “continuous” agitation conditions using the “sample and separate” method. At specified time intervals, polymer degradation, mass loss, and drug release were assessed. While molecular weight and molecular number profiles for “static” and “continuous” samples were indistinct, mass loss occurred at a faster rate in “continuous” samples than under “static” conditions. In vitro results describe a fourfold difference in drug release rates between the “continuous” and “static” samples, ascribed to the acceleration of various processes governing release, including elimination of the boundary layer. The findings were confirmed by the fourfold increase in drug release rate when “static” samples were subjected to “continuous” agitation after 11 days. A schema was proposed to describe the complex in vitro release process from biodegradable polymer-drug dosage forms. These experiments highlight the manner in which the unstirred water layer influences drug release from biodegradable microspheres and stress the importance of selecting appropriate conditions for agitation during an in vitro release study.

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Mr Relaxation Times and Fiber Type Predominance of the Psoas and Multifidus Muscle

Acta Radiologica ◽

10.1177/028418519303400104 ◽

1993 ◽

Vol 34 (1) ◽

pp. 16-19 ◽

Cited By ~ 14

Author(s):

R. Parkkola ◽

A. Alanen ◽

H. Kalimo ◽

I. Lillsunde ◽

M. Komu ◽

...

Keyword(s):

Fiber Type ◽

Relaxation Times ◽

Psoas Muscle ◽

Relative Mass ◽

T2 Relaxation ◽

Multifidus Muscle ◽

Cross Sectional ◽

Mr Relaxation

MR relaxation times, fiber composition, nonmyofiber space, water content, and fat content of human psoas and multifidus muscle samples of 10 male cadavers were studied in vitro. The T1 and T2 relaxation times of multifidus muscle were significantly longer than those of the psoas muscle. On average, type 1 fibers (slow fibers with a small cross-sectional diameter) predominated in both muscles. There was no correlation between the relative mass of type 1 or 2 fibers (fast fibers with a large cross-sectional diameter) or nonmyofiber space and the relaxation times. The quantity of fat in the muscle did not correlate with the relaxation times either.

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