Thermo-kinetics and product analysis of the catalytic pyrolysis of Pongamia residual cake

Catalytic fast pyrolysis of Pongamia residual cake (PRC) and the kinetics of this were evaluated using thermogravimetry and pyrolysis-gas chromatography/mass spectrometry analyses. The influence of the heating rate on the devolatilization process was studied to obtain corresponding kinetic information. Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) model-free isoconversion methods were used to predict the kinetic parameters. The major thermal degradation of PRC occurred around 150-550 °C with an activation energy of 97.2-394.3 kJ/mol or 114.5-412.2 kJ/mol as determined by the KAS and FWO methods, respectively. Micro-scale pyrolysis trials were performed to determine the effects of the PRC particle size, reaction temperature and PRC: catalyst weight ratio on the pyrolytic product distribution and upgraded pyrolytic vapor properties for the 5 wt% Ni impregnated on activated carbon (AC), aluminium(III) oxide (Al₂O₃), kaolin and zeolite NaA supports. The results indicated that using a 1:5 PRC: Ni/AC catalyst weight ratio with medium-sized PRC particles (125-425 μm) was the most effective condition for the conversion of oxygenated (O)-compounds to hydrocarbons (HCs) through decarbonylation, decarboxylation and dehydration reactions, giving the highest decrease (99%) in O-compounds. Increased HC yields, to more than 58%, were also obtained with this catalyst. Similarly, using the other synthesized Ni catalysts resulted in a reduction in the O-compounds and production of favorable HC species, albeit to a lesser extent. Therefore, the catalytic pyrolysis process of this residue, especially with a Ni/AC catalyst, has the potential to be a viable option for producing upgraded pyrolysis oil, which may be applied as a quality alternative biofuel.

Development of a thermostable microneedle patch for polio vaccination

The aim of this study was to develop a dissolving microneedle (MN) patch for administration of inactivated polio vaccine (IPV) with improved thermal stability when compared with conventional liquid IPV. Excipient screening showed that a combination of maltodextrin and D-sorbitol in histidine buffer best preserved IPV activity during MN patch fabrication and storage. As determined by D-antigen ELISA, all three IPV serotypes maintained > 70% activity after 2 months and > 50% activity after 1-year storage at 5 °C or 25 °C with desiccant. Storage at 40 °C yielded > 40% activity after 2 months and > 20% activity after 1 year. In contrast, commercial liquid IPV types 1 and 2 lost essentially all activity within 1 month at 40 °C and IPV type 3 had < 40% activity. Residual moisture content in MN patches measured by thermogravimetric analysis was 1.2–6.5%, depending on storage conditions. Glass transition temperature measured by differential scanning calorimetry, structural changes measured by X-ray diffraction, and molecular interactions measured by Fourier transform infrared spectroscopy showed changes in MN matrix properties, but they did not correlate with IPV activity changes during storage. We conclude that appropriately formulated MN patches can exhibit thermostability that could enable distribution of IPV with less reliance on cold chain storage.

Thermal pyrolysis characteristics and kinetics of hemicellulose isolated from Camellia Oleifera Shell

Camellia Oleifera Shell (COS) is a kind of renewable lignocellulose resource and contains abundant hemicelluloses. In this work, the hemicelluloses in COS were extracted by alkali treatment and precipitated by ethanol with different concentration. Thermal pyrolysis kinetics of COS hemicelluloses were investigated using a thermogravimetric analyzer at the heating rates of 5, 10, and 20 °C/min based on Coats-Redfern, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) model. The results showed that the best fitting thermal pyrolysis mechanism of COS hemicelluloses was one-dimensional diffusion reaction analyzed by Coats-Redfern model. The activation energies of COS hemicelluloses ranged from 175.07 to 247.87 kJ·mol^-1 and from 174.74 to 252.50 kJ·mol^-1 calculated by FWO and KAS, respectively. The thermal stabilities of COS hemicelluloses were enhanced with the precipitated ethanol concentration increasing, and reflected by thermodynamic parameters ΔH, ΔG and ΔS. This study may provide basic theoretical supports for the thermochemical conversion of COS hemicelluloses.

The influence of temperature on the physicochemical properties of products of pyrolysis of leather-tannery waste

The present paper examines the pyrolysis of waste from leather tanneries at 300-500 °C. These studies are important because of difficulties in the utilisation of this type of waste as well as its energy potential as fuel. The pyrolysis of tannery waste and data from the relevant literature showed that thermal degradation can be explained using tanned collagen as a reference. Moreover, the experimental results indicated that this process is highly non-linear, due to various mechanisms of heat transport which cause temperature differences in a laboratory pyrolysis reactor. Thermogravimetric analysis has shown that the greater part of mass loss is observed between 80 and 500 °C and that the most significant mass release occurs at 325 °C. Moreover, the proportions of CO₂ and CO decrease along with increasing temperatures. The paper presents characteristics of the composition of solid, liquid, and gaseous products of leather-waste pyrolysis at various temperatures. The maximum heating value of gaseous products at 500 °C was 9.54 MJ/Nm³. An increase from 300 to 500 °C results in the dominant position of condensation polymerisation; the maximum value of the liquid phase yield is reached at 400 °C (42%). HHV analysis of the resulting char showed a maximum value of 21.18 MJ/kg at 450 °C. The results of oxidised component analysis showed that the major oxidised component of char was chromium oxide (Cr₂O₃), with a content of approximately 8.5% at all pyrolysis temperatures.

Optical properties and colorimetry of gelatine gels prepared in different saline solutions

Gelatine has been widely used in many multidisciplinary research fields due to its biocompatibility. Using saline solutions in the gelation of gelatine allows for new properties to be incorporated into the prepared gels. This study examined the optical and colour properties of gelatine gels prepared in saline solutions, containing three different metal chlorides (NiCl₂·6H₂O, CoCl₂·6H₂O, and CrCl₃·6H₂O) with concentrations of up to 50%, to prepare three groups of gels. FTIR spectroscopy indicated a loss in the helical structure of the metal-containing gelatine gels, and a shift in the amide bands towards lower wavenumbers. From the thermogravimetric analysis (TGA), the starting degradation temperatures (SDTs) of the prepared gelatine gels were found to be correlated to the concentration of the gelling solutions. All SDTs were above 250 °C, making these gels suitable for standing temperatures beyond the daily range. UV-vis spectroscopy showed that d-d transitions were responsible for the colour properties of the metal-containing gelatine gels. It is concluded that the studied properties and the measured parameters were found to depend on both salt type and concentration. With the current findings, the prepared gels can be used as optical thermometers, colour-selective corner cube retroreflectors, laser components, and coatings for OLEDs.

Effect of oxygen concentration on oxy-fuel combustion characteristic and interactions of coal gangue and pine sawdust

Coal gangue is an inevitable coal waste from coal mine, which results in serious environmental problems. Oxy-fuel firing of coal waste and biomass waste is an alternative technology for efficient and clean utilization and CO₂ reduction of coal waste. In this study, the oxy-fuel combustion characteristics and interactions of coal gangue and pine sawdust were investigated using thermogravimetric analysis, with a focus on the effect of oxygen concentration on interactions between coal gangue and pine sawdust during oxy-fuel combustion. The oxy-fuel combustion of pine sawdust had two obvious stages, including the release of volatile matter and the combustion of the remaining char, which differed from oxy-fuel combustion of coal gangue with one overlapped stage of devolatilization and char oxidation. Moreover, the addition of pine sawdust could improve the oxy-fuel combustion reactivity of coal gangue. The significant deviations between the experimental derivative thermogravimetric curves and theoretical derivative thermogravimetric curves for the blends indicated that interactions between coal gangue and pine sawdust had occurred in the temperature range of 400-600 °C. The interaction mechanism was primarily thermal effect between coal gangue and pine sawdust during oxy-fuel combustion. The oxygen concentration had a significant effect on the interactions between coal gangue and pine sawdust. The increase of oxygen concentration from 20% to 40% could improve interactions between coal gangue and pine sawdust obviously. However, relative small improvement of interactions was detected between coal gangue and pine sawdust when oxygen concentration was further increased from 60% to 80%. This was related to the difference of rate controlling factor for oxy-fuel combustion reaction under various oxygen concentrations.

Non-isothermal thermogravimetric kinetic analysis of the thermochemical conversion of human faeces

The "Reinvent the Toilet Challenge" set by the Bill & Melinda Gates Foundation aims to bring access to adequate sanitary systems to billions of people. In response to this challenge, on-site sanitation systems are proposed and being developed globally. These systems require in-situ thermal treatment, processes that are not well understood for human faeces (HF). Thermogravimetric analysis has been used to investigate the pyrolysis, gasification and combustion of HF. The results are compared to the thermal behaviour of simulant faeces (SF) and woody biomass (WB), along with the blends of HF and WB. Kinetic analysis was conducted using non-isothermal kinetics model-free methods, and the thermogravimetric data obtained for the combustion of HF, SS and WB. The results show that the devolatilisation of HF requires higher temperatures and rates are slower those of WB. Minimum temperatures of 475 K are required for fuel ignition. HF and SF showed similar thermal behaviour under pyrolysis, but not under combustion conditions. The activation energy for HF is 157.4 kJ/mol, relatively higher than SS and WB. Reaction order for HF is lower (n = 0.4) to WB (n = 0.6). In-situ treatment of HF in on-site sanitary systems can be designed for slow progressive burn.

Co-hydrothermal carbonization of corn stalk and swine manure: Combustion behavior of hydrochar by thermogravimetric analysis

The combustion behavior of the hydrochar from co-hydrothermal carbonization (HTC) of corn stalk (CS) and swine manure (SM) was thermogravimetrically investigated. Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) were used for kinetic analysis, and the thermodynamic parameters were determined. Results showed that HTC decreased the combustion property and stability of SM, while co-HTC with CS significantly improved the combustion performance of the hydrochar including the increased ignition temperature and decreased burnout temperature. HTC of SM decreased the average activation energy (E_a) value from 140.40 and 137.31 KJ/mol to 124.40 and 120.17 KJ/mol by FWO and KAS, respectively, and increasing proportion of CS during co-HTC increased the E_a value of the hydrochar to 141.53-171.23 and 138.35-169.66 KJ/mol, respectively. The thermodynamic parameters confirmed the enhanced combustion reactivity of the hydrochar from co-HTC of CS and SM. These findings demonstrated that co-HTC with CS benefited the hydrochar production from SM with improved combustion performance.

Deproteinization of Cortical Bone: Effects of Different Treatments

Bone is a biological composite material having collagen and mineral as its main constituents. In order to better understand the arrangement of the mineral phase in bone, porcine cortical bone was deproteinized using different chemical treatments. This study aims to determine the best method to remove the protein constituent while preserving the mineral component. Chemicals used were H₂O₂, NaOCl, NaOH, and KOH, and the efficacy of deproteinization treatments was determined by thermogravimetric analysis and Raman spectroscopy. The structure of the residual mineral parts was examined using scanning electron microscopy. X-ray diffraction was used to confirm that the mineral component was not altered by the chemical treatments. NaOCl was found to be the most effective method for deproteinization and the mineral phase was self-standing, supporting the hypothesis that bone is an interpenetrating composite. Thermogravimetric analyses and Raman spectroscopy results showed the preservation of mineral crystallinity and presence of residual organic material after all chemical treatments. A defatting step, which has not previously been used in conjunction with deproteinization to isolate the mineral phase, was also used. Finally, Raman spectroscopy demonstrated that the inclusion of a defatting procedure resulted in the removal of some but not all residual protein in the bone.

Matrix degradation in osteoarthritis primes the superficial region of cartilage for mechanical damage

Osteoarthritis (OA) is a degenerative disease that affects 25% of the world's population over fifty years of age. It is a chronic disease of the synovial joints, primarily the hip and knee. The main pathologies are degradation of the articular cartilage and changes to the subchondral bone, as a result of both mechanical wear and a locally elevated inflammatory state. This study compares the viscoelastic properties of cartilage that represents the biochemical changes in OA and age-matched healthy tissue. Further, the mechanical damage induced by this compressive loading cycle was characterised and the mechanism for it was investigated. The storage modulus of OA cartilage was shown to be significantly lower than that of healthy cartilage whilst having a higher capacity to hold water. Following mechanical testing, there was a significant increase in the surface roughness of OA cartilage. This change in surface structure occurred following a reduction in sulphated glycosaminoglycan content of the superficial region in OA, as seen by alcian blue staining and quantified by micro X-ray fluorescence. These findings are important in understanding how the chemical changes to cartilage matrix in OA influence its dynamic mechanical properties and structural integrity.

STATEMENT OF SIGNIFICANCE

Cartilage has a very specialised tissue structure which acts to resist compressive loading. In osteoarthritis (OA), there is both mechanically- and chemically-induced damage to cartilage, resulting in severe degradation of the tissue. In this study we have undertaken a detailed mechanical and chemical analysis of macroscopically undamaged OA and healthy cartilage tissue. We have demonstrated, for the first time in human tissue, that the mechanical degradation of the tissue is attributed to a chemical change across the structure. In macroscopically undamaged OA tissue, there is a reduction in the elastic response of cartilage tissue and an associated destabilisation of the matrix that leaves it susceptible to damage. Understanding this allows us to better understand the progression of OA to design better therapeutic interventions.

Experimental tests of co-combustion of pelletized leather tannery wastes and hardwood pellets

This study examines the possibility of using pelletized leather tannery wastes (LTW) in the co-combustion process with hardwood pellets (HP). The experiments were carried out in a small-scale combustion reactor and were followed by thermogravimetric analysis (TGA) of fuels in the nitrogen and air atmosphere. The experimental investigation has indicated that the leather tannery wastes can be an interesting fuel with a relatively high heating value (HHV), at the level of 16 MJ/kg, and the volatile content of about 68%. Thermal decomposition of the leather tannery sample occurs at temperatures ranging between 220 and 420 °C, with the maximum of intensity at 320 °C. The experimental results indicated that the averaged maximum temperatures obtained during the combustion reached similar values for all samples, which indicates that doping wood pellets with leather waste pellets does not have a significant impact on the temperature characteristics of the combustion process. However, decreasing the amount of hardwood pellets in the mixture reduces the bulk density of the fuel bed and the combustion front velocity. The emission of nitrogen oxides for combusting blends is twice as high as for combustion of pure HP, which is related to higher nitrogen content in leather waste as well as higher ash content.

Thermogravimetric, thermochemical, and infrared spectral characterization of feedstocks and biochar derived at different pyrolysis temperatures

Biochar is a promising biomass product for soil amendment, remediation, and carbon sequestration. In this study, the effect of pyrolysis temperature and feedstock type on biochar physiochemical properties including stability, recalcitrance, and surface functionality were investigated through thermogravimetric, thermochemical, and infrared spectral analyses. It is concluded in this research that pyrolysis temperature was the dominating factor determining the inherent characteristics of the derived biochar. High-temperature pyrolysis (≥600 °C) derived the biochar with a high pH, stability, recalcitrance, and higher heating value (HHV). On the other hand, the biochar produced from low-temperature pyrolysis (≤400 °C) had a larger mass yield, energy recovery, more volatile content, and diverse surface functional groups. The different biochar characteristics will lead to different agricultural and environmental applications. Also in this research, a carbon-based recalcitrance index (R_50,C) based on a novel multi-element scanning thermal analysis (MESTA) was proposed to improve the current recalcitrance index (R₅₀) based on the conventional thermogravimetric analysis (TGA) for the evaluation of biochar's carbon sequestration potential. The direct comparison of the two indexes, as well as the results from the infrared spectral analysis and ultimate analysis, indicated that R_50,C was better at characterizing biochar's recalcitrance, especially when the mineral content of the feedstock was high. In addition, the cost breakdown indicated that the pretreatment of feedstock was the costliest process during biochar production.

Discernment of synergism in pyrolysis of biomass blends using thermogravimetric analysis

This study reports pyrolysis kinetics of biomass blends using isoconversional methods, viz. Friedman, FWO and KAS. Blends of three biomasses, viz. saw dust, bamboo dust and rice husk, were used. Extractives and volatiles in biomass and minerals in ash had marked influence on enhancement of reaction kinetics during co-pyrolysis, as indicated by reduction in activation energy and increase in decomposition intensity. Pyrolysis kinetics of saw dust and rice husk accelerated (positive synergy), while that of bamboo dust decelerated after blending (negative synergy). Predominant reaction mechanism of all biomass blends was 3-D diffusion in lower conversion range (α ≤ 0.5), while for α ≥ 0.5 pyrolysis followed random nucleation (or nucleation and growth mechanism). Higher reaction order for pyrolysis of blends of rice husk with saw dust and bamboo dust was attributed to catalytic effect of minerals in ash. Positive ΔH and ΔG was obtained for pyrolysis of all biomass blends.

Fuel properties and steam reactivity of solid waste streams from contingency bases

The solid waste generated from military contingency bases (CBs) is a potential fuel for appropriately-scaled, waste to energy (WTE) systems. To inform WTE system design, fuel properties of seventeen components of synthetic contingency-base waste recipes from the literature were characterized for ultimate analysis, heating values, proximate analysis and reactivity in a steam atmosphere at three temperature typical of gasification conditions. A simple mathematical approach was applied to predict the properties and reactive behavior of composite mixtures using the weighted sum of the corresponding components, assuming negligible interaction between components. The method was validated using prepared composite mixture samples. In addition, chemical equilibrium calculations for steam gasification of the composite samples were conducted to explore the effects of waste composition variability on syngas production and composition.

Thermogravimetric kinetic modelling of in-situ catalytic pyrolytic conversion of rice husk to bioenergy using rice hull ash catalyst

The thermal degradation behaviour and kinetic parameter of non-catalytic and catalytic pyrolysis of rice husk (RH) using rice hull ash (RHA) as catalyst were investigated using thermogravimetric analysis at four different heating rates of 10, 20, 50 and 100 K/min. Four different iso conversional kinetic models such as Kissinger, Friedman, Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) were applied in this study to calculate the activation energy (E_A) and pre-exponential value (A) of the system. The E_A of non-catalytic and catalytic pyrolysis was found to be in the range of 152-190 kJ/mol and 146-153 kJ/mol, respectively. The results showed that the catalytic pyrolysis of RH had resulted in a lower E_A as compared to non-catalytic pyrolysis of RH and other biomass in literature. Furthermore, the high Gibb's free energy obtained in RH implied that it has the potential to serve as a source of bioenergy production.

Pressurized liquid extraction of flavanols and alkaloids from cocoa bean shell using ethanol as solvent

Cocoa shell (CS) is a co-product of the cocoa industry used mainly as fuel for boilers but with secondary applications as fertilizer and in animal feed. Although it is known that this material is rich in flavanols and alkaloids, to date, a study has not been conducted that has quantitatively identified these compounds in CS. Thus, the aim of this work was to characterize CS in terms of its composition, regarding catechin, epicatechin, procyanidin B2, caffeine and theobromine, and to evaluate the extraction kinetics of the total flavanols using pressurized liquid extraction (PLE) with absolute ethanol. For the determination of the extraction kinetic data, the DMAC method was used, while each compound was quantified using a UPLC-MS/MS analysis. The major compounds found were theobromine and epicatechin (mean values of 9.89 and 3.5 mg/g CS, respectively). PLE proved to be quite effective; the flavanols extraction yield was enhanced by increasing the temperature and extraction time however, high extraction times and temperatures degraded the procyanidins B2. Peleg's model applied to extraction data description provided a reasonable agreement with the experimental results, which allows their application in modeling and optimization of solid-liquid extraction of the total flavanols from cocoa bean shell.

A kinetic study on the catalysis of KCl, K2SO4, and K2CO3 during oxy-biomass combustion

Biomass combustion under the oxy-fuel conditions (Oxy-biomass combustion) is one of the approaches achieving negative CO₂ emissions. KCl, K₂CO₃ and K₂SO₄, as the major potassium species in biomass ash, can catalytically affect biomass combustion. In this paper, the catalysis of the representative potassium salts on oxy-biomass combustion was studied using a thermogravimetric analyzer (TGA). Effects of potassium salt types (KCl, K₂CO₃ and K₂SO₄), loading concentrations (0, 1, 3, 5, 8 wt%), replacing N₂ by CO₂, and O₂ concentrations (5, 20, 30 vol%) on the catalysis degree were discussed. The comparison between TG-DTG curves of biomass combustion before and after water washing in both the 20%O₂/80%N₂ and 20%O₂/80%CO₂ atmospheres indicates that the water-soluble minerals in biomass play a role in promoting the devolatilization and accelerating the char-oxidation; and the replacement of N₂ by CO₂ inhibits the devolatilization and char-oxidation processes during oxy-biomass combustion. In the devolatilization stage, the catalysis degree of potassium monotonously increases with the increase of potassium salt loaded concentration. The catalysis degree order of the studied potassium salts is K₂CO₃ > KCl > K₂SO₄. In the char-oxidation stage, with the increase of loading concentration the three kinds of potassium salts present inconsistent change tendencies of the catalysis degree. In the studied loading concentrations from 0 to 8 wt%, there is an optimal loading concentration for KCl and K₂CO₃, at 3 and 5 wt%, respectively; while for K₂SO₄, the catalysis degree on char-oxidation monotonically increases with the loading potassium concentration. For most studied conditions, regardless of the potassium salt types or the loading concentrations or the combustion stages, the catalysis degree in the O₂/CO₂ atmosphere is stronger than that in the O₂/N₂ atmosphere. The catalysis degree is also affected by the O₂ concentrations, and the lowest catalysis degree is generally around 20 vol% O₂ concentration. The kinetic parameters under the different studied conditions are finally obtained.

Effect of various electrokinetic treatment regimes on solids surface properties and thermal behavior of oil sediments

The electrokinetic process has shown its ability to separate the different material phases. However, not much is known about the effect of the electric fields on the surface properties of solids in the oil sediments and their behavior under different electrical regimes. In this study, the effect of four different types of electrical current on the surface properties of oil sediments was investigated, namely constant direct current (CDC), pulsed direct current (PDC), incremental direct current (IDC) and decremental direct current (DDC). X-ray photoelectron spectroscopy (XPS) analyses showed a decrease in the concentration of carbon from 99% in centrifuged samples to 63% on the surface of the solids in the PDC-treated oil sediment. Wettability alteration and contact angle studies showed an enhance in hydrophilicity of the solids following electrokinetic treatment. A significant change in carbon and oxygen-containing functionalities at the surface solids of the DDC-treated sediment was also observed. Thermogravimetric analyses (TGA) confirmed the ability of electrokinetic treatment in separating the phases by shifting the thermogram profiles towards lower temperatures. The findings showed that the electrokinetic process exerts its effect by altering the surface properties of the sediment solids and destabilizing water-in-oil emulsions to facilitate phase separation of this complex waste.

Thermogravimetric analysis and kinetic modeling of low-transition-temperature mixtures pretreated oil palm empty fruit bunch for possible maximum yield of pyrolysis oil

The impacts of low-transition-temperature mixtures (LTTMs) pretreatment on thermal decomposition and kinetics of empty fruit bunch (EFB) were investigated by thermogravimetric analysis. EFB was pretreated with the LTTMs under different duration of pretreatment which enabled various degrees of alteration to their structure. The TG-DTG curves showed that LTTMs pretreatment on EFB shifted the temperature and rate of decomposition to higher values. The EFB pretreated with sucrose and choline chloride-based LTTMs had attained the highest mass loss of volatile matter (78.69% and 75.71%) after 18 h of pretreatment. For monosodium glutamate-based LTTMs, the 24 h pretreated EFB had achieved the maximum mass loss (76.1%). Based on the Coats-Redfern integral method, the LTTMs pretreatment led to an increase in activation energy of the thermal decomposition of EFB from 80.00 to 82.82-94.80 kJ/mol. The activation energy was mainly affected by the demineralization and alteration in cellulose crystallinity after LTTMs pretreatment.

Combustion behaviors and kinetics of sewage sludge blended with pulverized coal: With and without catalysts

The combustion behaviors of sewage sludge (SS), pulverized coal (PC), and their blends were studied using a thermogravimetric analyzer. The effect of the mass ratio of SS to PC on the co-combustion characteristics was analyzed. The experiments showed that the ignition performance of the blends improved significantly as the mass percentage of SS increased, but its combustion intensity decreased. The burnout temperature (T_b) and comprehensive combustibility index (S) of the blends were almost unchanged when the mass percentage of SS was less than 10%. However, a high mass percentage of SS (>10%) resulted in a great increase in T_b and a notable decrease in S. Subsequently, the effects of different catalysts (CaO, CeO₂, MnO₂, and Fe₂O₃) on the combustion characteristics and activation energy of the SS/PC blend were investigated. The four catalysts promoted the release and combustion of volatile matters in the blended fuels and shifted their combustion profiles to a low temperature. In addition, their peak separating tendencies were obvious at 350-550 C, resulting in high peak widths. All the catalysts improved combustion activity of the blended fuel and accelerated fixed carbon combustion, which decreased the ignition temperature and burnout temperature of the fuels. CeO₂ had the best catalytic effects in terms of the comprehensive combustion performance and activation energy, followed closely by Fe₂O₃. However, the rare-earth compounds are expensive to be applied in the catalytic combustion process of SS/PC blend at present. Based on both catalytic effects and economy, Fe₂O₃ was potentially an optimal option for catalytic combustion among the tested catalysts.

Update on thalassemia diagnosis: New insights and methods

A novel approach based on Thermogravimetric analysis followed by Chemometrics (TGA/Chemometrics) is provided for Thalassemia diagnosis and a comprehensive study consisting of the coupled approach TGA/Chemometrics, the Complete Blood Count (CBC) and Red Blood Cell (RBC) indices is developed and results are compared. A number of 128 subjects were involved in this study included 16 thalassemia intermedia transfusion-dependent (TI-TD) patients, 18 thalassemia intermedia non transfusion-dependent (TI-NTD) patients, and 14 thalassemia major β (TM-TD) patients. Thalassemic patients were found to be clearly distinct from healthy donors as a function of a different thermal behavior. The chemometric analysis identifies the differences in the composition of blood and a model of prediction for β-thalassemia was developed and validated to distinguish all patients. TGA/Chemometrics method also permitted to differentiate thalassemic patients according to the severity of anaemia while the evaluation of the indices and the CBC are not able to identify TI-TD, TI-NTD and TM-TD patients at first level test. TGA/Chemometrics was successfully applied for thalassemia diagnosis with 100% of correct classification rate. Chemometric analysis demonstrated that red cell distribution width (RDW), haemoglobin (Hb) and RBC are the diagnostic features in thalassemia compared to mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH). New insights into the significance of the haematological features were provided for an update of the thalassemia classification.

Co-pyrolysis characteristics and kinetic analysis of organic food waste and plastic

In this work, typical organic food waste (soybean protein (SP)) and typical chlorine enriched plastic waste (polyvinyl chloride (PVC)) were chosen as principal MSW components and their interaction during co-pyrolysis was investigated. Results indicate that the interaction accelerated the reaction during co-pyrolysis. The activation energies needed were 2-13% lower for the decomposition of mixture compared with linear calculation while the maximum reaction rates were 12-16% higher than calculation. In the fixed-bed experiments, interaction was observed to reduce the yield of tar by 2-69% and promote the yield of char by 13-39% compared with linear calculation. In addition, 2-6 times more heavy components and 61-93% less nitrogen-containing components were formed for tar derived from mixtures.

Kinetic analysis of pyrolysis and combustion of the olive tree pruning by chemical fractionation

This paper presents a kinetic analysis of thermal decomposition of olive tree pruning from its basic compounds in pyrolysis and combustion reactions. Experiments were performed by TGA under inert and oxidant conditions and results indicated that the decomposition of the olive tree pruning was related to the material composition. Pseudo-mechanistic models were proposed estimating the yield of pyrolysis on its basic compounds (hemicelluloses, cellulose and lignin). Validity and reliability of the proposed kinetic models were verified by the good fitting between the simulated and experimental curves (with values of R² higher than 0.99 in most cases). Moreover, during the fractionation process, an acid fraction was obtained with great fuel properties, a high calorific value and a low residue after its combustion.

Co-combustion of sewage sludge and coffee grounds under increased O2/CO2 atmospheres: Thermodynamic characteristics, kinetics and artificial neural network modeling

(Co-)combustion characteristics of sewage sludge (SS), coffee grounds (CG) and their blends were quantified under increased O₂/CO₂ atmosphere (21, 30, 40 and 60%) using a thermogravimetric analysis. Observed percentages of CG mass loss and its maximum were higher than those of SS. Under the same atmospheric O₂ concentration, both higher ignition and lower burnout temperatures occurred with the increased CG content. Results showed that ignition temperature and comprehensive combustion index for the blend of 60%SS-40%CG increased, whereas burnout temperature and co-combustion time decreased with the increased O₂ concentration. Artificial neural network was applied to predict mass loss percent as a function of gas mixing ratio, heating rate, and temperature, with a good agreement between the experimental and ANN-predicted values. Activation energy in response to the increased O₂ concentration was found to increase from 218.91 to 347.32 kJ·mol^-1 and from 218.34 to 340.08 kJ·mol^-1 according to the Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa methods, respectively.

Pyrolysis kinetics and thermodynamic parameters of castor (Ricinus communis) residue using thermogravimetric analysis

Castor plant is a fast-growing, perennial shrub from Euphorbiaceae family. More than 50% of the residue is generated from its stems and leaves. The main aim of this work is to study the pyrolytic characteristics, kinetics and thermodynamic properties of castor residue. The TGA experiments were carried out from room temperature to 900 °C under an inert atmosphere at different heating rates of 5, 10, 15, 20, 30 and 40 °C/min. The kinetic analysis was carried using different models namely Kissinger, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS). The average E_ɑ calculated by FWO and KAS methods were 167.10 and 165.86 kJ/mole respectively. Gibbs free energy varied from 150.62-154.33 to 150.59-154.65 kJ/mol for FWO and KAS respectively. The HHV of castor residue was 14.43 MJ/kg, considered as potential feedstock for bio-energy production. Kinetic and thermodynamic results will be useful input for the design of pyrolytic process using castor residue as feedstock.