Thermochemical Characterization Research Articles

A comparative thermo-chemical characterization of oilseed, millet and pulse stem biomass for bioethanol production

Various thermochemical and biochemical processes are resorted to transform agri-wastes into diverse green fuels. Current investigation encompassed three different types of biomass viz., gingelly, kodo millet and horse grams, whose desirability as biofuel feedstock have been largely unexplored till date. The existence of significant amount of cellulose (38.07 %), volatiles (75.19 %), calorific value (avg. 16.98 MJ/kg) in the gingelly biomass, demonstrates the effectiveness of the concerned biomass for utilization as feedstock in diverse industrial applications. The mean estimates of Eα were lower for kodo millet (approx. 150 kJ/mole), followed by gingelly (approx. 178 kJ/mole) and horse gram (approx. 180 kJ/mole). The mean estimates of ΔHα were 174.81 (FWO), 170.22 (KAS), 169.17 (S) and 170.40 (T) kJ/mol for the gingelly biomass. The mean estimates of ΔHα were 147.83 (FWO), 148.81 (KAS), 147.93 (S) and 149.04 (T) kJ/mol for kodo millet biomass, while for horse gram biomass, mean estimates of ΔHα were 178.91 (FWO), 169.61 (KAS), 168.56 (S) and 168.81 (T) kJ/mol. The minor difference of 3–4 kJ/mole between Aα and Hα, signifies the viability of the thermal disintegration process. From master plot, it's evident that the experimental curve intersects multiple theoretical curves, highlighting the intricate characteristics of the thermal disintegration process. The overall ethanol recovery was highest in gingelly as compared to both the biomasses. Gingelly biomass yielded an ethanol titer of 24.8 g/L after 24 h, resulting in a volumetric ethanol productivity of 1.03 g/L/h and an ethanol yield of 0.36 g/g.

Thermo-Chemical Characterization of Organic Phase Change Materials (PCMs) Obtained from Lost Wax Casting Industry

The high global energy demand drives the search for sustainable alternatives for energy production and storage. Among the most effective solutions are phase change materials (PCMs). In particular, organic PCMs offer a high capacity to store and release thermal energy in response to external thermal variations, even over a wide temperature range. They find profitable applications in various sectors, from construction to electronics, offering flexibility and considerable energy storage according to need. In the search for new and effective PCMs, reusing by-products from different industries would offer both economic and environmental benefits. With this goal in mind, several organic PCMs with different characteristics and origins were analyzed in the present study. Two of them were by-products of the lost wax casting industry. In fact, we wanted to verify whether this waste could be employed as an effective, low-cost PCM. For comparison purposes, two commercial PCMs were selected, namely a paraffin and a microencapsulated PCM. Finally, a PCM blend was produced by mixing a commercial PCM and a waxy by-product. The five selected or developed PCMs were subjected to different tests to investigate their chemical composition, thermal characteristics, and thermal stability before and after repeated (i.e., 100) cycles of melting and crystallization processes. The results demonstrated that the durability of the non-commercial PCMs with regard to thermal loads was not inferior, and was in some cases even superior, to commercial PCMs. This study therefore proposes an innovative path to reuse the by-products of different production processes to support the environment.

Assessment of pyrolysis potential of Indian municipal solid waste and legacy waste via physicochemical and thermochemical characterization

This study explores the viability of utilizing municipal solid waste (MSW) and legacy waste as a renewable energy source through pyrolysis, akin to solid fuels. The heating value of MSW and legacy waste were found to be 37737.89 and 40432.84 kJ/kg, respectively. Proximate analysis shows that MSW fits within Tanner diagram parameters, eliminating the need for auxiliary fuel in pyrolysis. With 47.6 % and 44.16 % lignin content in MSW and legacy waste were deemed suitable for char production. Thermal degradation resulted in mass losses of 68 % for MSW and 82 % for legacy waste. The kinetic and thermodynamic assessment indicates lower activation energy (Ea) and Gibbs free energy (ΔG) for MSW (5.72 kJ/mol and 170.37 kJ/mol, respectively) compared to fossil fuels, suggesting faster reactions without additional energy requirement. MSW emerges as a promising alternative to fossil fuels, aligning with the United Nations’ 2030 Sustainable Development Goals.

Modeling initiation and propagation of thermal runaway in pouch Li-ion battery cells: Effects of heating rate and state-of-charge

The implementation of lithium-ion batteries (LIB) in battery energy storage systems (BESS) for utility-scale renewable energy generation has led to increased fire and explosion hazards. These hazards are attributable to the heat and flammable gases released during LIB thermal runaway (TR). TR can be triggered within an individual LIB cell and cause intra-cell TR propagation (TRP), the energy release from which causes TR in adjacent cells, leading to inter-cell TRP. Safety assessments are critical to preventing such incidents, and numerical modeling is a key tool in developing such assessments. This work presents an inverse modeling approach utilizing measurements of cell-level experiments of large-format 63Ah pouch cells used in BESS. Such an approach is a practical alternative to existing approaches that rely on a detailed thermochemical characterization of LIB internal components which are seldom available when dealing with commercial batteries encountered in BESS. Owing to the critical role played by gas and solid venting for external flaming and inter-cell TRP, we develop an approach to capture these quantities in the model. Two key parameters affecting TRP are the state-of-charge (SOC) and heating rate. The former provides some control of the system hazard, the latter affects TR behavior of LIB cells subject to different levels of preheating often encountered in BESS fires. We develop the capability to capture the effects of these parameters in the model. To determine model parameters, we rely on existing single-cell experimental data at different heating rates, and augment this with new experiments for the same type of cells at different SOCs. The modeling results recover the experimental TR and intra-cell TRP behavior quantitatively. Analysis reveals that, at lower heating rates, the temperature is greater at the time of the onset of TR, but the location is farther away from the heated cell surface; its location and the greater internal temperature then facilitate faster intra-cell TRP. When SOC is lower, the reduced internal heat release delays the onset of TR, and we find that its location moves away from the heated surface and intra-cell TRP is slower. Our findings provide physical insights to TR initiation and intra-cell propagation in support of large-scale TRP model development.

Thermochemical characterization of different mulberry species (Morus spp.) for bioenergy production

Thermochemical characterization of different mulberry species (Morus spp.) for bioenergy production

Thermochemical Characterization and Kinetics of Biomass, Municipal Plastic Waste, and Coal Blends and Their Potential for Energy Generation via Gasification

Thermochemical Characterization and Kinetics of Biomass, Municipal Plastic Waste, and Coal Blends and Their Potential for Energy Generation via Gasification

Camellia japonica Flowers as a Source of Nutritional and Bioactive Compounds.

In recent decades, plants have strengthened their relevance as sources of molecules potentially beneficial for health. This underpinning effect also arises from the extensive research that has been conducted on plants that are typically undervalued, besides being scarcely used. This is the case with Camellia japonica in Galicia (NW Spain), where, despite its abundance, it is exclusively used for ornamental purposes and has been studied only for its proximate composition. Thus, the present study was conducted on several additional parameters in the flowers of eight C. japonica varieties. Our results show that camellia has a high nutritional value, with carbohydrates as the most abundant macronutrients followed by a moderate protein content (4.4-6.3 g/100 g dry weight) and high levels of polyunsaturated fatty acids (especially ω-3 fatty acids, which represent 12.9-22.7% of the total fatty acids), raising its potential for use for nutritional purposes. According to the thermochemical characterization and elemental composition of camellia, the raw material has poor mineralization and low nitrogen content, but high percentages of volatile matter and high carbon-fixation rates, making it a promising alternative for biofuel production. Furthermore, preliminary analysis reveals a high concentration of different bioactive compounds. As a result of these findings, camellias can be used as food or functional ingredients to improve the nutritional quality of food formulations.

Thermochemical Characterization of Rice-Derived Residues for Fuel Use and Its Potential for Slagging Tendency

Rice is the most important cereal in Asia. However, it also results in the generation of large quantities of rice-derived residues (i.e., rice straw and rice husk). Due to the residues richness in lignocellulosic components, they potentially have considerable value in material and/or energy production without illegal burning in open fields. This work focused on investigating the thermochemical properties and inorganic/metal element contents of rice straw and rice husk. The former included proximate analysis, calorific value, thermogravimetric analysis (TGA) and energy dispersive X-ray spectroscopy (EDS). The latter covered the ten elements most relevant to their slagging/fouling indices. The results showed that they are suitable for energy use as biomass fuels, but rice husk was superior to rice straw because of the high silica content in the rice husk and the significant contents of potassium, sulfur and phosphorus in the rice straw. Using several slagging and fouling indices, the evaluation results were also consistent with their contents of inorganic elements or oxides. To increase the fuel properties of rice-derived residues, they could be pretreated with alkaline leaching, thus causing lower emissions of particulates and reduced slagging tendency when co-firing them with coal in industrial boilers.

Pressurized oxy-fuel combustion of pulverized coal blended with wheat straw: Thermochemical characterization and synergetic effect

Pressurized oxy-fuel combustion is recognized as the second generation of oxy-fuel combustion technology that can facilitate carbon capture and reduce energy consumption, while coal and biomass combustion is also an effective way to decrease carbon emissions. This study innovatively integrates these two clean combustion technologies and investigates the effects of pressure and blending ratio on the combustion characteristics (ignition, combustion rate, volatile combustion, semi-coke combustion, burnout) of coal, biomass and their blends using an advanced magnetic levitation HPTGA. The results show that pressurization can improve the combustion rate of coal and biomass, but it will cause ignition delay when system pressure exceeds 0.5 MPa. The effect of pressure on combustion characteristics is both facilitative and inhibitive, in terms of reaction kinetics, pressurization can significantly promote combustion but it also plays a role in inhibiting oxygen diffusion, the competition between the two effect leads to an optimum value of pressure in the combustion performance of the blends, which is about 1 MPa. Biomass is more sensitive to pressure than coal, and pressurization changes the ignition mode of biomass. In addition, a new synergy index is defined to quantify the synergistic effect of the whole co-combustion process. Pressurization could suppress both catalytic and non-catalytic mechanisms in the co-combustion process, and different sensitivities of biomass and coal to pressurization lead to more significant differences in combustion time and temperature interval compared with normal pressure, all these factors contribute to negative synergistic effect under pressurization.

Investigation of Thermochemical Properties and Pyrolysis of Barley Waste as a Source for Renewable Energy

Energy consumption is rising dramatically at the price of depleting fossil fuel supplies and rising greenhouse gas emissions. To resolve this crisis, barley waste, which is hazardous for the environment and landfill, was studied through thermochemical characterization and pyrolysis to use it as a feedstock as a source of renewable energy. According to proximate analysis, the concentrations of ash, volatile matter, fixed carbon, and moisture were 5.43%, 73.41%, 18.15%, and 3.01%, consecutively. The ultimate analysis revealed that the composition included an acceptable H/C, O/C, and (N+O)/C atomic ratio, with the carbon, hydrogen, nitrogen, sulfur, and oxygen amounts being 46.04%, 6.84%, 3.895%, and 0.91%, respectively. The higher and lower heating values of 20.06 MJ/kg and 18.44 MJ/kg correspondingly demonstrate the appropriateness and promise for the generation of biofuel effectively. The results of the morphological study of biomass are promising for renewable energy sources. Using Fourier transform infrared spectroscopy, the main link between carbon, hydrogen, and oxygen was discovered, which is also important for bioenergy production. The maximum degradation rate was found by thermogravimetric analysis and derivative thermogravimetry to be 4.27% per minute for pyrolysis conditions at a temperature of 366 °C and 5.41% per minute for combustion conditions at a temperature of 298 °C. The maximum yields of biochar (38.57%), bio-oil (36.79%), and syngas (40.14%) in the pyrolysis procedure were obtained at 400, 500, and 600 °C, respectively. With the basic characterization and pyrolysis yields of the raw materials, it can be concluded that barley waste can be a valuable source of renewable energy. Further analysis of the pyrolyzed products is recommended to apply in the specific energy fields.

Thermochemical characterization of post-phytoremediated vetiver (Vetiveria zizanioides (L.) Nash) root and shoot for their prospective bioenergy potential

Critical information as regards the thermochemical characterization of biomass is imperative for the design of efficient biomass thermochemical systems. Present study deals with comprehensive characterization of vetiver root (VR) and vetiver shoot (VS) after being employed for phytoremediation of heavy metal-contaminated alluvial soil. Physico-chemical properties, thermal degradation behavior, functional groups, and surface morphology were determined and compared through proximate, ultimate, HHV, TGA, XRD, FTIR, and FESEM analyses. The cellulose and hemicellulose content put together was found to be significantly high in VR (87.73 wt%) and VS (87.65 wt%). VR was found to contain about twofold inorganic matter than VS. Amorphous nature of VS suggested its potential to produce more pyro-gas and biochar vis-a-vis VR. Volatile matter content of VR (80.25 wt%) and VS (79.42 wt%) was significantly higher as compared to other grass biomasses. Porous structures of VR and VS examined via FESEM micrographs, revealed a large surface area for the reactions to occur. The weight loss for VR and VS in the active zone was found to be 56.06% and 45.74%, respectively as per the thermogravimetric experiments. The average activation energy for pyrolysis of VS was found to be 129.76 and 131.93 kJ/mol and that for VR was found to be 162.15 and 162.19 kJ/mol from KAS and FWO methods, respectively. The thermal decomposition of VR and VS was found to follow reaction-order mechanism (specifically R1, R2, and R3 models) and diffusion mechanism (specifically D4 model proposed by Ginstling-Brounshtein) at lower and higher conversions, respectively. • Volatile matter content of VR (80.25%) and VS (79.42%) was significantly higher than some other biomasses. • TG curves revealed that VR released more volatiles (56.06%) vis-a-vis VS (45.74%) in stage-II. • E a for pyrolysis of VS was found to be lower than VR by both KAS and FWO methods. • Average pore size of VS and VR was found to be 51.53 µm and 19.97 µm, respectively. • Amorphous nature of VS suggested its potential to produce engineered biochar.

Sulfonated-Recycled-PEEK as Matrix of Water Vapor Adsorbent SAPO-34 Based Composite Coatings for Adsorption Heat Pumps: Mechanical and Thermochemical Characterization

In this work, a composite adsorbent coating constituted by high SAPO 34 content and a sulfonated recycled poly (ether ether ketone) was investigated for adsorption heat pump technology. Specifically, the effect of polymer recycling on mechanical and thermal properties, as well as on water vapor adsorption and desorption performance, has been investigated. The degree of sulfonation obtained after 48 h of reaction remained approximately unaltered. The degradation of the polymer due to recycling anticipates the degradation of the C-C bonds of the polymer by about 20 °C without affecting the temperature at which the sulfonic groups degrade. From the mechanical point of view, the coating containing 90% zeolite, due to the use of recycled PEEK, evidenced a worsening of only 11.8% in scratch resistance compared to the virgin one, whereas the adhesive strength exhibited an increase of about 23.2% due to better miscibility of the sulfonated recycled polymer. Adsorption/desorption isobars show an almost similar adsorption capacity of the coating produced with recycled polymer compared to the virgin one, confirming that the water vapor diffusion is not hindered by the polymer matrix during the adsorption/desorption process.

An interesting case of symmetry breaking in the absence of symmetry: the bicarbonate radical (HCO3)

As part of a computational study of the thermochemical properties of systems related to carbonic acid (HCO), an interesting phenomenon was observed in the bicarbonate radical (HCO). This species belongs to the class of formoxyl radicals, but lacks the geometric symmetry of the more heavily-studied and prototypical HCO and FCO molecules. However, it is not immune from the problems that those molecules present to electronic structure calculations. Specifically, at geometries in the vicinity of the equilibrium structure, three solutions to the unrestricted Hartree-Fock equations can be found: two in which the unpaired spin is largely localized onto one of the (inequivalent) carbonyl oxygen atoms, and one in which the spin is delocalized. While all three of these reference functions comprise orbitals that transform as pure irreducible representations of the point group, the two localized choices qualitatively correspond to the symmetry-broken solution of the formoxyl species and the delocalized solution qualitatively corresponds to the symmetry-preserving (but orbitally unstable) solution. The three solutions are described in this work, as well as the corresponding ambiguities that result in the thermochemical characterization of this species.

Thermochemical characterization of husk biomass resources with relevance to energy use

Thermochemical characterization of husk biomass resources with relevance to energy use

Thermochemical characterization and assessment of residual biomass energy in Paraguay

Thermochemical characterization and assessment of residual biomass energy in Paraguay

Thermochemical Characterization of African Oil Bean Husk for Potential Biofuel Production

Thermochemical Characterization of African Oil Bean Husk for Potential Biofuel Production

Thermochemical Characterization of Cycas Circinalis Seed Shell to Evaluate their Potential as Biofuel Source

Increased environmental pollution anxieties and quest for high energy demand from renewable energy sources forced to use lignocellulosic biomass to produce Bio-fuels. Cycas circinalis seed shell is a plant-derived bio-waste readily available in the southern coastal part of India. This research aims to explore the thermochemical characteristic of Cycas circinalis seed shells. Substantial volume reduction of feedstock and low processing time makes the thermal conversion route more attractive than any other method of waste to energy conversion. Biomass degradation behavior is studied by Thermogravimetric and derivative thermogravimetric analysis (TGA and DTG); this depicts biomass degradation in three primary stages, each corresponding to the decomposition of hemicellulose, cellulose, and lignin components. Functional groups were determined by Fourier transform infrared (FTIR) spectroscopy. The obtained calorific value of biomass was found to be 16.17 MJ/Kg. Proximity analysis results showed the percentage of moisture content, volatile matter, ash content, and fixed carbon as7.95%,77.35%,2.05%,12.65%respectively. The ultimate analysis determines the composition of significant elements present in Cycas ciricinails. Carbon, Hydrogen, and Oxygen are found to be 45.54%, 6.5 %, and 47.16 %, respectively. Sulfur and nitrogen component values were observed to be lower, which is also a promising result in view of environmental concerns.

Thermochemical Characterization of Eight Seaweed Species and Evaluation of Their Potential Use as an Alternative for Biofuel Production and Source of Bioactive Compounds.

Algae are underexplored resources in Western countries and novel approaches are needed to boost their industrial exploitation. In this work, eight edible seaweeds were subjected to their valorization in terms of nutritional characterization, thermochemical properties, and bioactive profile. Our results suggest that seaweeds present a rich nutritional profile, in which carbohydrates are present in high proportions, followed by a moderate protein composition and a valuable content of ω-3 polyunsaturated fatty acids. The thermochemical characterization of seaweeds showed that some macroalgae present a low ash content and high volatile matter and carbon fixation rates, being promising sources for alternative biofuel production. The bioactive profile of seaweeds was obtained from their phenolic and carotenoid content, together with the evaluation of their associated bioactivities. Among all the species analyzed, Porphyra purpurea presented a balanced composition in terms of carbohydrates and proteins and the best thermochemical profile. This species also showed moderate anti-inflammatory activity. Additionally, Himanthalia elongata extracts showed the highest contents of total phenolics and a moderate carotenoid content, which led to the highest rates of antioxidant activity. Overall, these results suggest that seaweeds can be used as food or functional ingredient to increase the nutritional quality of food formulations.

Theoretical structural and thermochemical characterization of partially fluorinated alcohols

Molecular conformations, harmonic vibrational frequencies and standard enthalpies of formation for CH3-nFnCF2CH2OH, CH3-nFnCH2OH and CH3-nFnOH (n = 1,2,3) partially fluorinated alcohols were computed at different levels of theory using isodesmic and isogiric work reactions. The lack of data and large uncertainties in the reported thermodynamic properties motivated the present study. As average at the G4 and CBSQB3 levels of theory, standard enthalpies of formation at 298 K of −313.9±1.8, −258.2±1.8 and −208.4±1.8 kcal mol−1 were computed for CF3CF2CH2OH, CHF2CF2CH2OH and CH2FCF2CH2OH, respectively; values of −213.0±1.7, −154.5±1.7 and −100.4±1.7 kcal mol−1 were obtained for CF3CH2OH, CHF2CH2OH and CH2FCH2OH; while −216.9±1.2, −159.8±1.2 and −100.9±1.7 kcal mol−1 were derived for CF3OH, CHF2OH and CH2FOH. The corresponding enthalpies of formation presented here for CF3CF2CH2OH and CH2FCF2CH2OH were predicted for the first time. Hydrogen abstraction reactions enthalpies by OH radicals were also estimated and comparisons with previously reported results were performed.

Development and thermochemical characterization of an antioxidant material based on polyhydroxybutyrate electrospun microfibers

The use of antioxidants such as curcumin (Cur) or quercetin (Que) in biomedical and biotechnological applications has been studied owing to their capability to prevent oxidative stress and inhibit free radicals. Using polyhydroxybutyrate (PHB) electrospun fibers is presented as a proper option to encapsulate curcumin and quercetin due to its biocompatibility and biodegradability characteristics. Electrospun fibers were obtained dissolving commercial PHB in chloroform:N,N-dimethylformamide (DMF) (4:1) at 7% m/V, and adding two different concentrations of antioxidant (Cur, and Que) 1%m/m, and 7% m/m. These polymeric solutions were electrospun at different conditions and the obtained fibers were characterized by scanning electron microscopy (SEM), thermogravimetric (TGA) analysis, and Fourier transform infrared spectroscopy (FT-IR). The curcumin and quercetin releases into phosphate buffer saline (PBS) at pH 7.4 were obtained in vitro and measured by spectrophotometry. Antioxidant activities were measured by spectrophotometry in a microplate reader using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Fibers obtained with different formulations presented a chemical composition in accordance with PHB according to FTIR spectra, the diameters fluctuate between 0.761 ± 0.123 and 1.803 ± 0.557 μm, with qualities over 0.95 according to their morphology, and the melting temperature resulted near 178 °C according to the bibliography. The crystallinity of fibers decreases while curcumin or quercetin concentration increases for the studied interval, indeed, quercetin showed a higher impact on the relative crystallinity of fibers. Antioxidant activity of active compounds is maintained after encapsulation in PHB electrospun fibers, and quercetin resulted in near four times antioxidant activity compared to curcumin according to DPPH analysis.