Biomass Carbonization

Carbonization is the art of reinventing the waste biomass into a carbon−/energy-rich charcoal. It redefines the principles of renewable energy and power generation. Char is produced by a pyrolysis process in which the biomass is heated in an inert atmosphere to high temperatures until absorbed volatiles are expelled thus enriching its heating value and energy content. Carbonization itself is an old process that is being used till now, but the renewed interest in it especially with biomass is because it opens new doors for commercial and scientific applications. The carbon can be extracted from the produced char to form the precious graphite and graphene. This chapter provides a general overview about slow pyrolysis processes including carbonization and the torrefaction process which is a mild carbonization process. The characterization of different biomass species and their effect on the carbonization process and the final product will be also discussed. Different carbonization processes and methodologies which vary in the process parameters will be addressed, and the most promising ones will be highlighted. An important addition to this chapter is the general design parameters, methodologies, and factors that must be taken into consideration when designing carbonization reactors for lab and industrial designs

A model for mono- and multi-component droplet heating and evaporation and its implementation into ANSYS Fluent

[EN] A model for heating and evaporation of mono- and multi-component droplets, based on analytical solutions to the heat transfer and species diffusion equations in the liquid phase, is summarised. The implementation of the model into ANSYS Fluent via User-Defined Functions (UDF) is described. The model is applied to the analysis of pure acetone, ethanol, and mixtures of acetone/ethanol droplet heating/cooling and evaporation. The predictions of the customised version of ANSYS Fluent with the newly implemented UDF model are verified against the results predicted by the previously developed in house, one-dimensional code.The authors would like to recognise that this work was supported by the UK’s Engineering and Physical Science Research Council, a studentship to support one of the authors (LP) [EPSRC grant EP/N509607/1; EP/K005758/1; EP/K020528/1; EP/M002608/1]Poulton, L.; Rybdylova, O.; Sazhin, SS.; Crua, C.; Qubeissi, M.; Elwardany, AE. (2017). A model for mono- and multi-component droplet heating and evaporation and its implementation into ANSYS Fluent. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 67-74. https://doi.org/10.4995/ILASS2017.2017.4759OCS677

A new approach to formulation of complex fuel surrogates

This paper presents a new approach to the formulation of fuel surrogates in application to gasoline, diesel, and their biofuel blends (including blends of biodiesel/diesel and ethanol/gasoline). This new approach, described as a ‘Complex Fuel Surrogates Model (CFSM)’, is based on a modified version of the Multi-Dimensional Quasi-Discrete Model (MDQDM). The new approach is aimed to reduce the full composition of fuel to a much smaller number of components based on their mass fractions to formulate fuel surrogates. The formulated surrogates for gasoline and blended ethanol/gasoline fuels matched the data of the full compositions of the same fuels for droplet lifetime, surface temperature, density, vapour pressure, H/C ratio, molar weight and research octane number, using the CFSM. Also, the cetane number and viscosity of diesel and biodiesel/diesel blends were mimicked by their suggested surrogates. The results were verified, with up to 7.2% errors between the two sets of predicted droplet lifetimes: surrogates and full compositions of fuels

Experimental Investigation on Performance of a Compression Ignition Engine Fueled with Waste Cooking Oil Biodiesel–Diesel Blend Enhanced with Iron-Doped Cerium Oxide Nanoparticles

The effect of iron-doped cerium oxide (FeCeO2) nanoparticles as a fuel additive was experimentally investigated with waste cooking oil methyl ester (WCOME) in a four-stroke, single cylinder, direct injection diesel engine. The study aimed at the reduction of harmful emissions of diesel engines including oxides of nitrogen (NOx) and soot. Two types of nanoparticles were used: cerium oxide doped with 10% iron and cerium oxide doped with 20% iron, to further investigate the influence of the doping level on the nanoparticle activity. The nanoparticles were dispersed in the tested fuels at a dosage of 90 ppm with the aid of an ultrasonic homogenizer. Tests were conducted at a constant engine speed of 2000 rpm and varying loads (from 0 to 12 N.m) with neat diesel (D100) and biodiesel⁻diesel blends of 30% WCOME and 70% diesel by volume (B30). The engine combustion, performance, and emission characteristics for the fuel blends with nanoparticles were compared with neat diesel as the base fuel. The test results showed improvement in the peak cylinder pressure by approximately 3.5% with addition of nanoparticles to the fuel. A reduction in NOx emissions by up to 15.7% were recorded, while there was no noticeable change in unburned hydrocarbon (HC) emissions. Carbon monoxide (CO) emission was reduced by up to 24.6% for B30 and 15.4% for B30 with nano-additives. Better engine performance was recorded for B30 with 20% FeCeO2 as compared to 10% FeCeO2, in regard to cylinder pressure and emissions. The brake specific fuel consumption was lower for the fuel blend of B30 with 10% FeCeO2 nanoparticles, in low-to-medium loads and comparable to D100 at high loads. Hence, a higher brake thermal efficiency was recorded for the blend in low-to-medium loads compared to D100

New alternative techniques for strengthening deep beams with circular and rectangular openings

Numerous deep beam design models have been proposed; however, even the most recent design manuals provide limited guidance for deep beam design, especially when the beams have complicated features such as web openings. The openings cause a geometric discontinuity, which makes the distribution of nonlinear stress along the depth of the beam more complicated. In this paper, the structural behavior of the deep beams with openings was investigated experimentally via a total of twenty concrete beam specimens and analytically in four themes. In the first theme, eleven concrete beam specimens with circular and rectangular openings, including the reference solid specimen, were tested to examine how the shape, size, and position of the openings affected the structural behavior of the deep beams. According to earlier studies, the crack patterns and modes of failure for the specimens were discussed in the first theme, and various techniques for strengthening the openings, whether circular or rectangular, were suggested in the second theme. Six concrete beam specimens with rectangular openings were strengthened; three of them were internally strengthened using various thickness plates around the openings, and the other three were strengthened using external fasteners subjected to torque moments. As for the concrete beam specimens with circular openings, these openings were strengthened with three different reinforcement techniques in the three tested beams. The load capacity, deflection, and crack patterns for the strengthened and unstrengthened specimens were recorded and discussed. The experimental results indicated that the load capacity and stiffness of the tested beams were significantly reduced by the presence of openings. Additionally, there was a distinct variety in how the size, position, and shape of the openings affected the beams performance. The results also demonstrated that concrete beam specimens with rectangular openings that were strengthened externally by the fasteners were the best, whereas the efficiency of the remaining strengthening was lower than expected. In the third theme, a numerical study using the nonlinear finite element model (NLFE), the program ANSYS V-19.2, 2018 was conducted on some of the tested strengthened and unstrengthened specimens. The analytical study's findings demonstrated the effectiveness of the NLFE model by comparing with load carrying capacity and load-deflection curve of the tested specimens. In the fourth theme, based on Bi-directional Evolutionary Structural Optimization (BESO), an algorithm developed in MATLAB and integrated with the FEA solver SAP software was used to build the optimal strut and tie model (OSTM) for two concrete beam specimens with rectangular and circular openings. This was undertaken with the objective of seeking and finding a strengthening technique that is more effective and is dependent on a clear methodology, not on trial and expectation. In agreement with the final obtained OSTM, new alternative strengthening techniques were proposed and evaluated using NLFE. In comparison to the other techniques that were described in this research, the proposed strengthening techniques based on BESO was the best and most effective, they increased the ultimate load in some cases by 72.7 %. BESO can be used efficiency for strengthening the deep beams with openings

Shock Tube Measurements Of The Reaction Rates Of Oh With Ketones At High Temperatures

Ketones are potential biofuel candidates and are also formed as intermediate products during the oxidation of large hydrocarbons or oxygenated fuels, such as alcohols and esters. This paper presents a shock tube study of the reaction rates of hydroxyl radicals (OH) with 2-butanone and 3-buten-2-one. The measurements were performed over the temperature range of 950 -1400 K near 1.5 atm. The OH profiles were monitored by the narrow-line-width ring-dye laser absorption of the well-characterized R1(5) line in the OH A-X (0, 0) band near 306.69 nm. The measured reaction rate of 2-butanone with OH agreed well with the literature data, while we present the first high-temperature measurements for the reaction of OH with 3-buten-2-one. The following Arrhenius expressions are suggested over the temperature range of 950 -1450 K: Kc2H5COCH3+OH = 6.78× 1013exp(-2534/T)cm3mol-1s-1/Kc2H3COCH3+OH = 4.178× 1013exp(-2534/T)cm3mol-1s-1 The presence of the double bond in 3-buten-2-one causes the reaction rate constant with OH to show non-Arrhenius behavior and the rate increase as temperature decreases at lower temperatures

Does Metakaoline Replacement Adversely Affect the Cyclic Behavior of Non-Strengthened and Strengthened RC Beams: An Experimental Investigation

The need to reduce carbon emissions has recently become prevalent in light of concerns related to climate change. Since the cement industry causes approximately 8% of global CO2 emissions, it might be an urgent necessity to include cement replacement materials within the concrete industry. An important question arises about if such replacement negatively affects the cyclic or seismic behavior of reinforced concrete (RC) elements. This research presents an experimental investigation of the effect of using different percentages of metakaolin replacement on the monotonic and cyclic behavior of RC beams. The investigated parameters include the flexural strength, ductility and energy dissipation capacity of the tested beams. The current paper also aims to study the effect of using the CFRP-strengthening technique with 15% metakaolin replacement on the behavior of RC beams under the same loading protocols. The experimental results reveal that metakaolin can be used as a partial substitute for cement up to 20% without negative effect on the concrete behavior under both loading protocols. For cyclic loading, the percentage of replacement did not negatively affect the ductility; rather, it provided some improvement

A Shock Tube And Laser Absorption Study Of Ignition Delay Times And Oh Reaction Rates Of Ketones: 2-Butanone And 3-Buten-2-One

Ketones are potential biofuel candidates and are also formed as intermediate products during the oxidation of large hydrocarbons or oxygenated fuels, such as alcohols and esters. This paper presents shock tube ignition delay times and OH reaction rates of 2-butanone (C2H5COCH3) and 3-buten-2-one (C2H3COCH3). Ignition delay measurements were carried out over temperatures of 1100-1400K, pressures of 3-6.5atm, and at equivalence ratios (F{cyrillic}) of 0.5 and 1. Ignition delay times were monitored using two different techniques: pressure time history and OH absorption near 306nm. The reaction rates of hydroxyl radicals (OH) with these two ketones were measured over the temperature range of 950-1400K near 1.5atm. The OH profiles were monitored by the narrow-line-width ring-dye laser absorption of the well-characterized R1(5) line in the OH A-X (0, 0) band near 306.69nm. We found that the ignition delay times of 2-butanone and 3-buten-2-one mixtures scale with pressure as P-0.42 and P-0.52, respectively. The ignition delay times of 3-buten-2-one were longer than that of 2-butanone for stoichiometric mixtures, however, for lean mixtures (F{cyrillic}=0.5), 2-butanone had longer ignition delay times. The chemical kinetic mechanism of Serinyel et al. [1] over-predicted the ignition delay times of 2-butanone at all tested conditions, however, the discrepancies were smaller at higher pressures. The mechanism was updated with recent rate measurements to decrease discrepancy with the experimental data. A detailed chemistry for the oxidation of 3-buten-2-one was developed using rate estimation method and reasonable agreements were obtained with the measured ignition delay data. The measured reaction rate of 2-butanone with OH agreed well with the literature data, while we present the first high-temperature measurements for the reaction of OH with 3-buten-2-one. The following Arrhenius expressions are suggested over the temperature range of 950-1450K: kC2H5COCH3+OH=6.78×1013exp(-2534/T)cm3mol-1s-1kC2H3COCH3+OH=4.17×1013exp(-2350/T)cm3mol-1s-1. © 2013 The Combustion Institute

Pyrolysis, kinetics, and structural analyses of agricultural residues in Egypt: For future assessment of their energy potential

Agricultural residues receive significant attention worldwide as a sustainable and green energy source. The accurate assessment of agricultural residues’ energy potential depends on physicochemical properties that change with location and climate. Several studies provide an imprecise estimation of agricultural residues’ energy potential in Egypt based on characteristics in literature from other sites. This study investigates the physicochemical properties, pyrolysis, and kinetics of seven types of agricultural residues, namely corn stalks, switchgrass, okra stems along with ficus, camphor, desert olive, and blueberry tree woodchips sampled from several locations in Egypt. The thermogravimetric, differential thermal, proximate, ultimate, lignocellulosic constituents, kinetics, crystallinity, and microstructure analyses are used to characterize the biomass. Kinetic parameters were determined by applying Coats-Redfern and Direct-Arrhenius approaches. The results revealed that woody residues have higher volatile matters, energy contents, hemicellulose, and lignin with lower ash, moisture, and cellulose than herbaceous residues. The activation energies of woody residues are lower than that of switchgrass and okra stems but higher than Cornstalks. The tested residues are bulk with nonuniform crystal structures, and their usages require further processing. The woody residues have promising properties. This study facilitates the accurate assessment of the agricultural residues’ energy potential in Egypt