A Microreactor System for the Analysis of the Fast Pyrolysis of Biomass

2010 ◽  
Vol 2 (3) ◽  
Author(s):  
Alexander Williams ◽  
J. Rhett Mayor
Keyword(s):  
Fast Pyrolysis ◽  
Heating Rates ◽  
Experimental Heat ◽  
Experimental Heat Transfer ◽  
Study Results ◽  
Design Requirements ◽  
Layer Heating ◽  
The Individual ◽  
Pyrolysis Of Biomass ◽  
Good Agreement

A novel fast pyrolysis microreactor was developed to facilitate control over feedstock dwell time, pyrolysis temperature, and the individual collection of pyrolysis liquid and solid products. The design process followed is presented including design requirements, functional decomposition, commissioning tests, and the final microreactor design. A vibratory assisted spreading study was performed as particle agglomeration was a key challenge within the reactor design. The study results and analysis of variance are presented identifying the most significant factor and a best operating point. Analytical and experimental heat transfer analyses are also presented to validate the reactor’s thermal performance. Through the pairing of the analyses, projections for thin biomass layer heating rates are made resulting in estimates on the order of 400°C/s. Finally, experimental pyrolysis results are given showing fast pyrolysis conversion as a function of time and the process by which kinetic descriptors could be derived using this system’s results. Yield results are compared with literature and are found to be in good agreement with published fast pyrolysis results.

scholarly journals Heat and Mass Transfer to a Cryosurface in Free Convection

1965 ◽  
Vol 87 (4) ◽  
pp. 499-506 ◽  
Author(s):  
R. F. Barron ◽  
L. S. Han
Keyword(s):  
Mass Transfer ◽  
Free Convection ◽  
Heat And Mass Transfer ◽  
Cryogenic Temperatures ◽  
Transfer Rates ◽  
Experimental Heat ◽  
Experimental Heat Transfer ◽  
Laminar And Turbulent Flow ◽  
And Diffusion ◽  
Good Agreement

Heat and mass transfer rates were measured experimentally and compared with analytically developed correlations for frost formation on a vertical flat plate in free convection. The plate was cooled internally to cryogenic temperatures (−310 F or liquid nitrogen temperatures), and both the laminar and turbulent flow regimes were investigated. In the laminar flow correlation, the effects of thermal diffusion and diffusion thermoeffect were included. The analytical and experimental heat transfer rates were in good agreement; however, the mass transfer results were affected by the presence of macromolecules of frost within the boundary layer.

Stabilization of the Mechanical Dynamics of a Road Load Simulator Using Classical Control Techniques

1992 ◽  
Vol 206 (2) ◽  
pp. 85-98
Author(s):  
I A Stringer ◽  
K J Bullock
Keyword(s):  
Control Strategies ◽  
Open Loop ◽  
Loop Transfer Function ◽  
Design Requirements ◽  
Load Simulator ◽  
Motor Dynamometer ◽  
The Individual ◽  
Classical Control ◽  
Mechanical Dynamics ◽  
Good Agreement

The open-loop transfer function of a complex hydrostatic pump-motor dynamometer system was derived from an analysis of the dynamics of the individual components. Many system components exhibit non-linearities; however, internal feedback mechanisms contribute to linearization of sub-systems. The resulting model, which was in good agreement with the system's open-loop performance, was used to predict the behaviour of the closed-loop system, this indicated that the system would be unstable. Classical control theory was used to analyse the performance of a number of stabilizing control strategies, with root locus plots, Bode diagrams and Nichols charts being used to assess the resultant performance. A lead compensation, designed as a differential controller, combined with a bi-linear gain was predicted to provide acceptable speed control. The performance of the system with this controller installed was found to satisfy the design requirements of speed of response, limited overshoot and zero steady-state error.

Design, Development and Characterization of a Micro-Reactor for Fast Pyrolysis of Biomass Feedstocks

2008 ◽  
Author(s):  
J. Rhett Mayor ◽  
Alex Williams
Keyword(s):  
Particle Size ◽  
Heat Loss ◽  
Fast Pyrolysis ◽  
Reactor System ◽  
Design Development ◽  
Heating Rates ◽  
Reaction Surface ◽  
Pyrolysis Of Biomass ◽  
Micro Reactor

This paper presents the latest results in the design, development and performance characterization of a novel prototype micro-reactor system that is uniquely capable of capturing the transient product evolution history of the fast pyrolysis of biomass products. With strong demand driving the technological development of sustainable energy solutions, the consideration of optimal conversion methodologies for biomass energy feedstocks has received a great deal of attention recent years. [1, 2] The pyrolysis of soft woods, in particular spruce and pine, has emerged as a credible alternative to bio-digestive strategies that are reliant on fermentation processes, typically of corn feedstocks. The design objectives for the micro-reactor system are reviewed, highlighting the multi-physics and multi-disciplinary complexity in designing for transient characterization of the pyrolized products by the micro-reactor system. One of the dominant challenges in the design of the micro-reactor for fast pyrolysis reactions is the requirement of very high heating rates for the feedstock, on the order of 100°C/s. A 1D transient thermal model of the reactor is developed that considers the average particle size and morphology, the initial surface temperature of the reaction surface within the micro-reactor, the heat loss to the ambient atmosphere in the reactor, the heat loss through the contact resistance between the sample and the reaction surface and the thermal capacitance of the reaction surface. A parametric evaluation of the design space was performed using the 1D model in order to identify a preferred range of particle size, reactor surface area and thermal input power. Based on the results for the domain reduction study, multi-physics thermo-mechanical 3D FEA was used to undertake a brute-force optimization process of the final design. The key metric considered in the FEA study was the maximum thermal gradient in the reaction surface and was driven to a minimum value. The thermal response of the prototype micro-reactor has been evaluated using infra-red thermography measurement techniques. Thermographical analysis of the results has demonstrated negligible thermal gradients in the reaction plane up to the maximum reaction setpoint of 450°C. Based on the results of the thermal testing of the micro-reactor, the achieved peak heating rates of the sample have been estimated to be on the order of 400°C/s, meeting and exceeding the design requirement.

Investigation Into the Effects of Reaction Duration on the Isothermal Fast Pyrolysis of Biomass

2009 ◽  
Author(s):  
J. Rhett Mayor ◽  
Alexander Williams
Keyword(s):  
Loblolly Pine ◽  
Energy Content ◽  
Biomass Conversion ◽  
Fast Pyrolysis ◽  
Residence Times ◽  
Heating Rates ◽  
Reaction Duration ◽  
Bio Oil ◽  
Pyrolysis Of Biomass ◽  
Conversion Efficiencies

Bio-oils were produced within a fast-pyrolysis micro-reactor at 400°C from Loblolly Pine (Pinus Taeda) with varying residence times. This preliminary study has considered two boundary values for the residence time, evaluating the products of the reaction at 20 seconds and 120 seconds. The collected bio-oils were analyzed for their calorific values (LHV) and biomass conversion efficiencies. Heating rates greater than 100°C/s were achieved for the biomass, allowing for isothermal conditions to exist throughout the majority of the reaction despite short residence times. This study shows the effect that reaction duration has on the mass of the bio-oil yield and energy content present for the isothermal fast pyrolysis of Loblolly Pine and evaluates the predictive capabilities of TGA derived Arrhenius coefficients.

scholarly journals Symptom Cluster-Matching Antidepressant Treatment: A Case Series Pilot Study

2021 ◽  
Vol 14 (6) ◽  
pp. 526
Author(s):  
Sławomir Murawiec ◽  
Marek Krzystanek
Keyword(s):  
Depressive Symptoms ◽  
Pilot Study ◽  
Antidepressant Treatment ◽  
Case Series ◽  
Symptom Cluster ◽  
Study Results ◽  
Cluster Matching ◽  
The Individual ◽  
Meta Analyses ◽  
Effectiveness Studies

Despite treating depression with antidepressants, their effectiveness is often insufficient. Comparative effectiveness studies and meta-analyses show the effectiveness of antidepressants; however, they do not provide clear indications as to the choice of a specific antidepressant. The rational choice of antidepressants may be based on matching their mechanisms of action to the symptomatic profiles of depression, reflecting the heterogeneity of symptoms in different patients. The authors presented a series of cases of patients diagnosed with depression in whom at least one previous antidepressant treatment was shown to be ineffective before drug targeted symptom cluster-matching treatment (SCMT). The presented pilot study shows for the first time the effectiveness of SCMT in the different clusters of depressive symptoms. All the described patients obtained recovery from depressive symptoms after introducing drug-targeted SCMT. Once validated in clinical trials, SCMT might become an effective and rational method of selecting an antidepressant according to the individual profile of depressive symptoms, the mechanism of their formation, and the mechanism of drug action. Although the study results are preliminary, SCMT can be a way to personalize treatment, increasing the likelihood of improvement even in patients who meet criteria for treatment-resistant depression.

scholarly journals Experimental heat transfer evaluation in a porous media

2021 ◽  
Vol 1868 (1) ◽  
pp. 012016
Author(s):  
S Pedrazzi ◽  
G Allesina ◽  
M Puglia ◽  
N Morselli ◽  
F Ottani ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Experimental Heat ◽  
Experimental Heat Transfer
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