Weight Loss Ratio Research Articles

Pulverization of municipal solid waste and utilization of pulverized product as alternative fuel for blast furnace injection

In order to utilize municipal solid waste (MSW) in blast furnace ironmaking to realize synergistic reduction of pollution and carbon emissions, a novel method for pulverization of MSW by low temperature heat treatment and crushing, and evaluation of the properties of pulverized product for blast furnace injection were performed. In the present research work, residual waste obtained from MSW classification under the conditions of most Chinese cities was used as the representative raw material. The crushing performance of MSW can be improved by heat treatment. Considering the weight loss ratio, pulverization effect and density of heated MSW at different temperatures and durations, the optimal heat treatment parameters can be set as 300 °C and 20 min. The volatile content, fixed carbon content, ash content, S content, lower heating value of the pulverized product were 61.56 wt%, 19.02 wt%, 19.42 wt%, 0.39 wt% and 25.47 kJ/g, respectively. The pulverized product had worse fluidity and similar jet flow compared to industrial injection coal. Its decomposition heat for injection was 1732 kJ/kg. The initial combustion temperature and burnout temperature of the mixed fuel gradually decreased with the increasing of added pulverized product due to its much better combustion property. About 0.163 kg CO2 can be reduced if 1 kg of raw MSW was injected into blast furnace. The experimental results demonstrates that the obtained pulverized MSW could be used for blast furnace ironmaking to some extent as an environmentally friendly, low-carbon, and economically substitute of fossil fuel.

Comparative analysis of anaerobic degumming effects on different bast fibers from the angle of enzyme activity and microbial community structure

Bast fiber textiles are becoming more and more popular, and degumming is a key process to obtain fiber. However, the more widely used degumming methods currently have a high level of pollution, which has become a primary problem restricting the development of the textile industry. Therefore, this study developed a continuous-flow anaerobic biological degumming system for bast fibers (Ramie and Hemp), with a self-developed spiral symmetry stream anaerobic bioreactor (SSSAB) as the core. The basic indicators of the degumming systems’ operation were analyzed, including pH, COD (Chemical Oxygen Demand), weight loss ratio, fineness, and breaking strength. pH and COD results indicated that the systems are operated continuously and steadily. The breaking strength of Ramie fiber and Hemp fiber were found about 4–6.5 cN/dtex and 2–4 cN/dtex, respectively, which meet subsequent spinning needs. The weight loss ratio of Ramie fiber (maximum value 27.27%) obtained by this anaerobic degumming method was generally higher than that produced by the traditional degumming method. SEM (Scanning Electron Microscopy) found the bast fibers current degumming time was too long and a lot of microorganisms adhered to the surface of the fibers. Enzyme activities testing in different fiber degumming systems found that the Ramie fiber degumming system has a higher cellulase activity than the Hemp fiber degumming system. From the perspective of community structure, it was believed that there were significant differences in microbial flora between Ramie and Hemp degumming systems, but there was no significant difference in archaea between them. This not only explored the adaptability of anaerobic continuous flow biological degumming system varieties but also provided theoretical guidance for enterprises to degum different bast fibers.

Biodegradable packaging paper derived from chitosan-based composite barrier coating for agricultural products preservation

Development of green packaging materials is essential to replace traditional plastics in fresh agricultural products preservation. Herein, a coated paper was designed by applying chitosan-based composite coating on paper substrate through a facile automatic coating method. The hydroxypropyl trimethyl ammonium chloride chitosan (HACC) was obtained by direct quaternization via the introduction of hydroxypropyl trimethyl ammonium chloride into the amino group of chitosan, then mixed with polyvinyl alcohol (PVA) to prepare the HACC/PVA coating. Accordingly, the key performance of coated paper were improved ascribed to the synergy effect of HACC/PVA coating and paper substrate. In particular, the minimum oxygen permeability of the coated paper could reach to 0.87 × 10−13 cm3·cm/cm2·s·Pa, and the optimum water vapor permeability and tensile strength of HACC/PVA coated paper was 0.75 × 10−12 g·cm/cm2·s·Pa and 6.88 kN/m, respectively. The coated paper used as packaging material not only reduced weight loss ratio of strawberry and greengrocery, but also exhibited lower chromatic aberration and better sensory evaluation, indicating a favorable effect on fruit and vegetable storage. Taken together, the designed eco-friendly coated paper has shown tremendous potential for green and biodegradable packaging material in agricultural products preservation.

Bioefficacy of Mucana pruriens extracts against Rice weevil, Sitophilus oryzae (Coleoptera: Curculionidae)

In the agricultural sector, the rice weevil, Sitophilous oryzae L. is one of the most damaging pests, causing significant economic losses worldwide. It is an internal feeder of grains. The female rice weevil causes damage to the grain by creating a hole in it and laying her eggs inside. The main purpose of our study was to investigate the biological effect of an aqueous extract of Mucana prurienson rice weevil under laboratory conditions. To assess the biological activities, data like number of the days to adult emergence, total adult emergence, percent infestation, weight loss, adult longevity, and adult sex ratio were recorded. The findings showed that, in the case of a 100 mg/ml plant extract, the maximum number of days needed for the adult emergence of rice was 66 and 72 days for wheat weevil, and the minimum number of days required was 20 and 25 in case control of both rice and wheat grains. When rice grains were treated with 0 mg/ml aqueous extracts, the maximum number of adult emergences observed was 72 on rice grains, while 66.00 occurred on wheat grains. The highest percentage of infestation (40.00%) was found in rice grains, while the highest percentage (39.78%) was found in wheat grains treated with 0 mg/ml aqueous extracts. The lowest weight loss (7.99%) was observed in rice grains and the highest weight loss (16.66%) in wheat grains treated with 100 mg/ml extracts; on the other hand, the lowest weight loss (13.33%) was observed in rice grains and the highest in wheat grains treated with 0 mg/ml aqueous extracts. When weevils were raised on untreated rice and wheat grains, the longest recorded adult lifespan was achieved overall. For rice weevil control that is safer, plant aqueous extracts with concentrations of 100 mg/ml and 75 mg/ml ought to be utilized. The present studies were carried out to examine the environmentally friendly aqueous extracts of Mucana pruriens and their pesticidal efficacy in controlling rice weevil. The study anticipates that Mucana pruriens extracts will exhibit significant insecticidal properties, potentially providing a natural alternative to synthetic insecticides. This study contributes to sustainable pest management strategies for stored grains.

High-temperature oxidation and gas thermal shock studies of IC10 simulated specimens with thermal barrier coatings

PurposeThe purpose of this study is to investigate the effects of high-temperature oxidation tests and gas thermal shock tests on IC10 simulated components with thermal barrier coatings under different temperatures and oxidation times.Design/methodology/approachIn the high-temperature oxidation test, specimens were oxidized at three different temperatures of 850, 980, and 1,100 °C for durations of 10, 20, 50, 100, 200, and 300 h, respectively. In the gas thermal shock test, specimens were pre-oxidized for 10, 20, 50, and 100 h, followed by a high-temperature gas thermal shock test at 1,100 °C.FindingsIn the high-temperature oxidation tests, with increasing oxidation time, the oxidation layer thickened, and the air-film holes diameter decreased. The microstructure of the bond coat transitioned from strip-like to block-like, and internal cracks transformed from numerous and short to larger and deeper. Below the bond coat, a noticeable disappearance layer of strengthening phase appeared, with increasing thickness. The strengthening phase in the substrate transitioned from regular square shapes to circles as temperature increased. In gas thermal shock tests at 1,100 °C, the oxidation weight gain ratio increased with longer pre-oxidation times, whereas the erosion weight loss ratio gradually decreased.Originality/valueThe originality and significance of this study lie in its departure from the typical subjects of high-temperature oxidation and thermal shock tests. Unlike common research targets, this study focuses on IC10 simulative specimens with thermal barrier coatings and air-film holes. Furthermore, it investigates the effects of varying temperatures and oxidation durations.

Effect of different pre-treatments on the physical properties, frying kinetics and organoleptic physiognomies of fried sweet potato (Ipomoea batatas) chips

The study explored the effects of different pre-treatments: freezing pre-treatment (FP), osmotic dehydration (OSD) and air-drying pre-treatments (ADP) on the physical and quality properties of fried sweet potato. The physical and quality properties of pre-treated fried sweet potato slices were assessed for percentage weight loss after frying, shrinkage ratio, the kinetics of moisture loss (frying kinetics), organoleptic properties and mathematical modeling of fried sweet potato slices. The results showed that OSD of pre-treated fried sweet potato slices recorded the highest percentage weight loss (46 %) and lowest shrinkage ratio (19 %) after frying compared to the ADP (41.5 %, 36 %) and FP (36.5 %, 46 %) fried sweet potato samples, respectively. OSD pre-treated fried sweet potato preserved the sensory properties of the ADP and FP fried sweet potato compared to the untreated sample. Among the three pre-treatments, OSD was found to enhance the frying kinetics compared to the ADP and FP samples. First order model best fitted well to the experimental results of frying kinetics (R2 > 0.99) compared to Page model.

Vacuum sintering of the self-developed Chang’E-5 lunar regolith simulant

The utilization of in-situ lunar resources through the additive manufacturing of lunar regolith (LR) has attracted considerable interest. Sintering of LR is considered a promising method for lunar construction due to its high utilization rate and excellent service stability. However, numerous studies have been carried out on Apollo series LRs with similar chemical compositions in air or inert gas atmospheres. The effects of the lunar ultra-high vacuum conditions and the complex chemical composition of LRs on the sintering process require extensive investigation. In this study, a self-developed Chang’E-5 lunar regolith simulant (LRS) with a high-Fe content was used as the only raw material to investigate its potential applicability for future lunar construction in vacuum environment. The effects of sintering temperature on the microstructure, linear shrinkage, bulk density, weight loss ratio, and mechanical and thermal expansion properties were investigated. The results show that the linear shrinkage and weight loss ratio increase with increasing sintering temperature. However, the bulk density and unconfined compressive strength (USC) initially increase and then decrease, with the sample sintered at 1075℃ giving the highest bulk density of 2.10 ± 0.03 g/cm3 and a USC of 31.19 ± 1.96 MPa. This is attributed to the transformation of the sample sintered at 1090℃ into a semi-porous material with many cracks. Furthermore, the mechanism of pore and crack formation was revealed. The coefficient of thermal expansion (CET) of the sintered samples is approximately 7×10–6°C−1, which maintains a good service stability after cyclic temperature stress from room temperature up to 200°C. Both the USC and CET of the sample sintered at 1075℃ are superior to those of common terrestrial concrete materials. This indicates that the vacuum sintering process appears feasible for the production of building materials with sufficient mechanical strength and thermal durability for lunar base construction.

Chemical activation and magnetization of carbonaceous materials fabricated from waste plastics and their evaluation for methylene blue adsorption.

In this study, novel adsorbents were synthesized via the activation and magnetization of carbon spheres, graphene, and carbon nanotubes fabricated from plastics to improve their surface area and porosity and facilitate their separation from aqueous solutions. Fourier transform infrared spectroscopy "FTIR", X-ray diffraction "XRD", energy-dispersive X-ray spectroscopy "EDX", transmission electron microscope "TEM", and X-ray photoelectron spectroscopy "XPS" affirmed the successful activation and magnetization of the fabricated materials. Further, surface area analysis showed that the activation and magnetization enhanced the surface area. The weight loss ratio decreased from nearly 60% in the case of activated graphene to around 25% after magnetization, and the same trend was observed in the other materials confirming that magnetization improved the thermal stability of the fabricated materials. The prepared carbonaceous materials showed superparamagnetic properties according to the magnetic saturation values obtained from vibrating sample magnetometry analysis, where the magnetic saturation values were 33.77, 38.75, and 27.18 emu/g in the presence of magnetic activated carbon spheres, graphene, and carbon nanotubes, respectively. The adsorption efficiencies of methylene blue (MB) were 76.9%, 96.3%, and 74.8% in the presence of magnetic activated carbon spheres, graphene, and carbon nanotubes, respectively. This study proposes efficient adsorbents with low cost and high adsorption efficiency that can be applied on an industrial scale to remove emerging pollutants.

Optimizing a mouse model of exertional heat stroke to simulate multiorgan and brain injuries.

Exertional heat stroke (EHS) is a clinical entity characterized by abnormalities of the central nervous system (CNS) and is associated with multiple organ injury, some of which may be irreversible. It is valuable to establish an optimized model of EHS that is able to induce and assess damage to the CNS and multiple organs. We induced EHS by using an environmental chamber with adjustable temperature and humidity and a mice forced running wheel. The endpoint for the EHS was defined as either exhaustion or a core temperature of 42.5°C being reached. Injury to the liver, kidney, and CNS of mice in the EHS group was revealed through pathological studies using hematoxylin and eosin staining of harvested organs at different time points and detection of biomarkers. The depressive-like behavior of EHS mice was assessed through open field tests, forced swimming tests, and tail suspension tests. The favorable environmental conditions for induction of EHS based on this presented model are 38°C, 70% RH. The EHS mice developed thermoregulatory dysfunction and experienced a significantly higher weight loss ratio compared to the SHE (sham heat exercise) group. The liver, kidney, and brain tissues of EHS mice were significantly damaged, and the pathological damage scores for each organ were significantly higher than those of the SHE group. In the open field test (OFT), compared to the SHE group, there was a significant reduction in the number and time of EHS mice entering the center of the open field. Additionally, there was a significant increase in immobile time during forced swimming test (FST) and tail suspension test (TST). This study presents an improved animal model that has the potential to assess for neurological and multiple organ injury caused by EHS and simultaneously, while accurately reflecting the clinical characteristics observed in EHS patients.

New approaches in pear preservation: Putrescine and modified atmosphere packaging applications to maintain fruit quality during cold storage.

Pear (P. communis L.), which is a climacteric fruit species, has a very short storage and shelf life, and significant losses occur due to high metabolic activity and the fruit's respiration rate after harvest. Therefore, preventing or reducing post-harvest quality losses in pear is one of the most basic problems awaiting solution. In this study, we planned for this purpose; the fruits of the Ankara pear cultivar treated with modified atmosphere packaging (MAP), putrescine (1 mM), and MAP + putrescine were stored for 120 days at 1°C and 90 ± 5% relative humidity. The quality analyses and measurements, such as weight loss, decay rate, fruit firmness, soluble solids content (SSC), titratable acidity (TA), total phenolic compounds, antioxidant capacity, organic acids, and specific phenolic compounds, were performed on the 30th, 60th, 90th, and 120th days. Weight loss and decay ratios were lower for putrescine and putrescine + MAP-applied fruit. With these applications, the softening of the fruit was slowed down, and the increasing SSC in the fruit and the decreasing TA rates were lower, and thus the ripening of the fruit was delayed. Changes in individual phenolic content and organic acids were lower in MAP and putrescine-applied fruit. The study revealed that MAP and putrescine applications in pear can be used effectively to maintain fruit quality after harvest.

Impact of different condition on population density and weight loss ratio of Callosobruchus Spp beetles, and its control

Impact of different condition on population density and weight loss ratio of Callosobruchus Spp beetles, and its control

Reaction mechanism between carbon and CaO–SiO2–Al2O3–Na2O slag system during continuous casting process

The reaction behavior between the carbon and mold fluxes during the heating process is vital for a successful continuous casting process and the high billet quality. A detailed investigation combined with thermogravimetry-mass spectrometry (TG-MS), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and transmission electron microscopy (TEM) techniques was carried out to systematically investigate the transformation mechanistic of the macro physicochemical properties, melting behavior, viscosity, crystallization, and heat transfer performance caused by the reaction behavior. The results showed that the mold flux underwent carbonate decomposition (973–1223 K), solid reaction (1273–1573 K), and melting process (1473–1673 K) during the continuous casting process. The carbon-bearing mold flux exhibited an endothermic peak at approximately 1673 K, corresponding to a weight loss ratio of approximately 14.5% on the TG curve, confirming that carbon could react with the middle mineral phases Ca2SiO4, Ca2Al2SiO7, and Na6Ca3Si6O18 to form SiC, increasing the breaking temperature by approximately 293 K. SEM and TEM results indicated that the melting behavior was restrained by the carbon itself and the newly formed components. Besides, the addition of carbon increased the degree of polymerization of molten slag, the thickness of slag film and the proportion of small crystals in slag film, further leading to an increase in crystallization and heat transfer performances. The reaction mechanism between carbon and slag and the subsequent effects on melting point, viscosity, crystallization ratio and heat flux density were clearly understood, which is meaningful for the carbon blending process of the mold flux.

Optimization of banana fibers degumming by high temperature alkaline method and spinning

Banana fibers are a promising textile resource. However, due to their high gum and lignin content, the development of an efficient degumming method is crucial for their successful utilization. This article researches an improved traditional fiber degumming method using the high temperature alkali method, and the effects of sodium hydroxide concentration, time and temperature on the physical properties of banana fibers were investigated through a single factor experiment. The banana fibers were characterized with FTIR, XRD, SEM and chemical composition. The optimized process parameters of degumming can be achieved. The processing temperature was 140 °C and sodium hydroxide concentration was 10% for 1h. The weight loss and residual gum ratio of the fibers reached 51.84 and 4.13% respectively, the breaking strength was 5.57 cN/dtex, and the crystallinity was increased to 61.33%. These results demonstrate the effectiveness of this new degumming method. Additionally, the optimized banana fibers employed a softening process and were subsequently blended with cotton fibers at a 60/40 ratio for 60tex blended yarn. The breaking strength of the blended yarn was 6.22cN/tex, and the bacterial inhibition ratio was above 70%. This improved method is more suitable for mass production with a high degumming efficiency, and has great potential in the industry. Meanwhile, the excellent antimicrobial properties of banana fibers provide new ideas for development in bedding and clothing applications.

Fabrication of a straw-based degradable mulch film with magnetically controlled-release glyphosate

To solve three main problems in agriculture (plastic mulch pollution, difficult straw recycling, and low utilization efficiency of pesticides), a multifunctional mulch film (MF) was fabricated. In this study, corn straw was mixed with xanthan gum, glyphosate (Gly), Fe3O4, and MIL-100(Fe) to obtain a MF named as SMFG with magnetically controlled-release Gly. To improve the hydrophobicity and stability of SMFG, the surface was coated by amino silicone oil (ASO) to get SMFG@ASO. SMFG@ASO had well insulation and moisture retention properties close to polyethylene MF. Meanwhile, the weight loss ratio of SMFG@ASO increased with time and could reach 59% underground in 120 d, indicating the good biodegradation behavior of SMFG@ASO. Importantly, pot experiment showed that SMFG@ASO could significantly promote growth of crop and inhibit grass. Besides, earthworm experiment illustrated that SMFG@ASO possessed a high biosafety and could increase the relative abundance of beneficial bacteria (Flavobacterium) from 0.08 to 0.21 and soil quality. Thus, this study provides a new method to prepare a straw-based degradable MF for resolving the problems of plastic pollution and waste of straw resources simultaneously to realize the integration of herbicide and MF.

Photoaged Tire Wear Particles Leading to the Oxidative Damage on Earthworms (Eisenia fetida) by Disrupting the Antioxidant Defense System: The Definitive Role of Environmental Free Radicals.

Tire wear particles (TWPs) have caused increasing concerns due to their detrimental effects on the soil ecosystem. However, the role of weathering in altering the toxicity of TWP to soil organisms is poorly understood. In this study, the toxicity of original and photoaged TWP was compared using earthworms (Eisenia fetida) as soil model organisms. The obtained results indicated that photoaging of TWP resulted in an increase of environmentally persistent free radicals (EPFRs) from 3.69 × 1017 to 5.20 × 1017 spin/g. Meanwhile, photoaged TWP induced the changes of toxic endpoint in E. fetide, i.e., the increase of the weight loss and death ratio from 0.0425 to 0.0756 g/worm and 23.3 to 50% compared to original TWP under a 10% concentration, respectively. Analyses of transcriptomics, antioxidant enzyme activity, and histopathology demonstrated that the enhanced toxicity was mainly due to oxidative damage, which was induced by disruption in the antioxidant defense system. Free-radical quenching and correlation analysis further suggested that the excessive production of ex vivo reactive oxygen species, induced by EPFRs, led to the exhaustion of the antioxidant defense system. Overall, this work provides new insights into the potential hazard of the weathered TWP in a soil environment and has significant implications for the recycling and proper disposal of spent tire particles.

Effects of wind speed on performance of a novel forced-air ice slurry wet precooling system

Aiming at the problems of low humidity and high dry consumption in the present forced-air precooling room, the combination of the ice slurry wet cooling system with the forced-air precooling was proposed, and a novel forced-air ice slurry wet precooling test platform was designed and built. The purpose of this paper is to experimentally study the effects of wind speeds on the performance of ice slurry wet precooling system by taking tomatoes as precooling objects, including precooling rate, precooling uniformity, precooling energy consumption and weight loss ratio of tomatoes. Also, the results are compared with those of other similar studies such as traditional forced-air precooling system. The results show that with the increase of wind speed, the precooling rate increases, the required precooling time is shortened, and the temperature variation coefficient of tomatoes decreases first and then increased, that is, the precooling uniformity becomes better and then worse. When the wind speed is 2.5 m/s, the overall precooling uniformity is the best. The precooling energy consumption decreases first and then increases, and is relatively low when the wind speed is between 1.5 m/s and 2.5 m/s (lowest at 2.5 m/s), which is lower than that of traditional forced-air system. With the increase of wind speed, the weight loss of tomatoes decreases first and then fluctuates slightly, and the weight loss ratio is about 0.1 %, which is much lower than that of tomatoes in the traditional forced-air precooling system. Overall, the maximum wind speed is not recommended to exceed 2.5 m/s for the precooling system studied in this work. The results can provide references for the further research and development of forced-air precooling technology.

Study on the Performance of SBS/Polyphosphoric Acid Composite Modified Asphalt

To address the issue of bad compatibility between a single polymer modifier and asphalt and high preparation cost, the composite modified asphalt with polyphosphoric acid (PPA) and SBS as a modifier was prepared. Basic properties, viscosity characteristics, high-temperature and low-temperature rheological performance, and aging-resistant performance of SBS/PPA composite modified asphalt were comprehensively evaluated, and the best content of PPA was obtained through the experimental results below. By performing an infrared spectrum test and a scanning electron microscope test, structural changes and modifying mechanisms of composite modified asphalt were analyzed. The results indicate the optimal PPA content is 0.75%. After adding PPA, the penetration and ductility of composite modified asphalt were reduced, while the softening point increased. At 135 °C, the viscosity was 1.2 times that of SBS modified asphalt. The average weight loss ratio was 0.163%. When the content of PPA was 0.75% and 1%, the rutting factor increased significantly. Therefore, PPA can not only improve the thermal oxidation aging resistance of asphalt, it can also improve the shear resistance, high-temperature performance, and temperature sensitivity of asphalt. Between 1027 and 1150 cm−1, the composite modified asphalt forms a new absorption peak, and from 1610 cm−1, the absorption peak presents an upward trend, suggesting that PPA reacts chemically with asphalt, produces the new substance, and also increases a large number of hydrocarbon components with chain structure. The surface appearance of the compound modified asphalt gradually presents a smooth wrinkle state due to the increase of PPA, so the issue of easy segregation of SBS in asphalt is improved.

Model for estimating the weight-loss ratio of damaged Korla fragrant pears

Model for estimating the weight-loss ratio of damaged Korla fragrant pears

N-doped carbon quantum dots as corrosion inhibitor for ultra-high voltage etched Al foil

In this work, the N-doped carbon quantum dots (N-CQDs) were synthesized by hydrothermal method, and introduced into the preparation process of ultra-high voltage etched Al foil as corrosion inhibitor, in order to alleviate its over-etching (tunnels clustering and overall thinning), thus to increase its specific capacitance. N-CQDs were characterized by ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometer (EDS). The effects of N-CQDs on etched tunnels, cross section of tunnel tunnels and electrochemical behavior of etched Al foil were investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), open circuit potential (OCP), cyclic voltammetry curve (CV), potentiodynamic polarization curves (PDP) and electrochemical impedance spectroscopy (EIS). As a result, when 100 mg·L−1 N-CQDs is added, the over-etching on etched Al foil surface is obviously modified, together with the extended depth, the relieved tunnels clustering, and the lowed Al foil weight loss ratio. Meanwhile, compared with the sample without N-CQDs, the specific capacitance of the ultra-high voltage formed foils prepared by anodizing at 600 V increased by 30 % from 0.49 μF·cm−2 to 0.64 μF·cm−2.

Homogenizing microwave pyrolysis of oily sludge using nano-Fe3O4: volatile gas product analysis

ABSTRACT To improve the homogeneity of heating, the magnetic absorbing material Fe3O4 is considered to use in microwave pyrolysis of oily sludge. Therefore, the effect of Fe3O4 on the microwave pyrolysis of oily sludge is investigated based on gas volatile products. Thermogravimetric mass spectrometry result certifies that Fe3O4 will increase the weight-loss ratio from 13.0% to 14.1%. Also, the characteristic peak intensity of CO in gas products decreases from 5.41 × 10−10 A/g to 1.95 × 10−10 A/g, while H2O increases from 3.57 × 10−10 A/g to 7.32 × 10−10 A/g and CO2 increases from 6.87 × 10−10 A/g to 8.92 × 10−10 A/g. This is caused by the esterification of alcohols and esters and the reduction of Fe3O4 by CO. Based on the decrease in activation energy and enthalpy values of Stage II and IV, it infers that Fe3O4 catalyzes the pyrolysis process of oily sludge to some extent. Similarly, gas chromatography-mass spectrometry results show that Fe3O4 can make the types of gas products increase. Especially, the number of molecular species increases from 5 to 46 under 200–300 °C. Finally, a simple molecular dynamics simulation model is conducted, and the results are in agreement with the experimental results. This study shows that Fe3O4 improves the pyrolysis homogeneity and the pyrolysis efficiency also improves.