Pyrolysis Of Powder Research Articles

Enhancement of coal tar pitch carbonization with biochar: A metallurgical formed biocoke product produced by waste coke breeze and bamboo powder

The combustion of pulverized fuels in industrial production is inefficient and aggravates haze formation. A novel and green approach via synergetic using two solid waste resources (waste bamboo powder and waste coke breeze) for producing formed biocoke products as a metallurgical coke substitute was proposed in this study. A biochar with high fixed carbon (87.32 %) and low volatiles (2.49 %) was obtained by bamboo powder pyrolysis at 1000 °C for 30 min. Adding this biochar can enhance the strength of the formed coke product prepared using coke breeze with coal tar pitch as the binder. The cracks and pores between coke breeze particles inside the product can be filled by biochar, increasing the product's density. Furthermore, the carbonization of coal tar pitch as the binder can be improved by adding biochar, further enhancing the product strength. A formed biocoke product, with 34.5 MPa compressive strength, 41.29 % CSR and 30.59 % CRI, was obtained at a 2:8 mass ratio (biochar to coke breeze) by carbonization at 1100 °C under a nitrogen atmosphere for 30 min. The experiments of simulating blast furnace production using mixtures of the formed biocoke product with the metallurgical coke (with 21.12 % CRI and 64.58 % CSR) in different mass ratios were carried out. 4 % of the metallurgical coke for blast furnace ironmaking can be replaced by obtained formed biocoke product. This study achieved sustainable high-value-added recycling of coke solid waste resources. It can be an essential reference for recycling other pulverized solid fuels.

Correction to: Preparation of high-performance high temperature superconducting Bi-2212 wires by the spray pyrolysis powder

Correction to: Preparation of high-performance high temperature superconducting Bi-2212 wires by the spray pyrolysis powder

Preparation of high-performance high temperature superconducting Bi-2212 wires by the spray pyrolysis powder

Preparation of high-performance high temperature superconducting Bi-2212 wires by the spray pyrolysis powder

Reduction mechanism of bamboo powder pyrolysis in selective lithium extraction from spent lithium-ion batteries

In light of the increase in demand for lithium resources, selective recovery of lithium from spent lithium-ion batteries (LIBs) is becoming increasingly important. In the preferential lithium extraction process, the choice of reducing agent is crucial, which affects the efficiency of Li+ release. Here, a novel biomass reducing agent waste bamboo powder (BP) is proposed. The thermal reduction mechanism of BP on spent cathode powder (SCP) is explored in detail, and the effect of BP before and after carbonization on the lithium extraction effect is investigated. Based on the regulation of roasting parameters, the SCP can be reduced to Li2CO3, Ni, Co and MnO under the optimal conditions of 650 ℃ for 1.5 h with 1:1 mass ratio of BP/SCP. Furthermore, through thermodynamic calculations and physicochemical characterizations, it is found that the addition of gas-solid reaction in the BP reduction process is superior to the carbonized non-activated carbon (NC) and activated carbon (AC). Moreover, the large specific surface area of 1145.725 m2 g−1 for AC will lead to partial adsorption of lithium during the water leaching process. Finally, more than 99% of lithium is preferentially recovered from the reducing residue through a two-stage leaching process of water leaching and low concentration acid leaching. Water leaching process can recover 82.6% of lithium and the model of physical dissolution kinetics are constructed and systematically studied. This research achieves low-cost, green and selective recovery of lithium from spent LIBs, which has broad industrial application prospects.

Preparation of High-Performance High Temperature Superconducting Bi-2212 Wires by the Spray Pyrolysis Powder

Preparation of High-Performance High Temperature Superconducting Bi-2212 Wires by the Spray Pyrolysis Powder

Suppression effects of ABC powder on explosion characteristics of hybrid C2H4/polyethylene dust

In order to analyze the suppression effects and mechanisms of ABC powder on ethylene gas (C2H4)/polyethylene (PE) hybrid explosion, to explore the suppression characteristics of gas-solid two-phase explosion, the 20-L apparatus are used for the test of the explosion overpressure. The results show that when the volume fraction of C2H4 is 3%, the concentration of ABC powder required to completely inhibit the explosion of 300 g/m3 PE dust increases from 200 g/m3 to 1200 g/m3. When increasing the volume fraction of ethylene to 5% and 7%, the explosion overpressure reduction in the mixture is 40.68% and 28.59%. The results of thermal analysis show that the addition of ABC powder improves the thermal stability of PE particle. Through the physical effects of heat absorption, oxygen insulation, and thermal transmission weakened and the chemical effect of eliminating explosive radicals, ABC powder reduces the rate of explosive chain reaction and heat release rate, thus producing an effective inhibition effect. But C2H4 will induce the explosion process of the mixture from two-phase combustion to homogeneous combustion to promote the explosion, and its effect is opposite to that of ABC powder pyrolysis in the system, which makes the explosion of mixed system more difficult to be suppressed.

One step calcination of bamboo powder enhances the adsorption and photocatalytic performance of red mud

Magnetic photocatalyst (MRM) with high adsorption was prepared by one-step calcination method using industrial solid waste bamboo powder and red mud (RM). The results showed that MRM has a significant removal effect on methylene blue (MB) in wastewater compared with RM. The excellent performance of MRM may be attributed to the following factors: 1. The reducing gas of bamboo powder pyrolysis transforms hematite into maghemite in MRM, which makes the photocatalyst magnetic and easy to recover. 2. The solid product of bamboo powder pyrolysis (biochar) not only inhibits the aggregation of MRM particles, but also broadens the light absorption range of MRM. Further, biochar was used as the transport channel of photogenerated electrons to inhibit the recombination of photogenerated electrons and holes.

Compounds Produced by the Pyrolysis of Powders and Dusts Present in the Alimentary Industry

ABSTRACT Under certain conditions dust explosions occur in the alimentary industry. Following ATEX and other guidelines have not eliminated accidents. Therefore, more knowledge is needed. The current work delivers experimental results describing phase transitions and decomposition of dusts. Dusts from wheat flour, chili powder, corn starch, milk powder, cocoa powder, and by-product of grain are investigated. The temperature of pyrolisation has been identified using TGA to be in the range [250°C, 600°C] in air and [300°C, 450°C] in nitrogen. It was found that the compositions of the pyrolysis gases depend on temperature. Carbon monoxide, carbon dioxide, methane, and hydrogen were the main contributors to the pyrolysis gases. The distributions are described with a polynomial or Gaussian fit. The current paper proposes coefficients for Gaussian polynomials expressing the concentration for the four primary pyrolysis gases.

High-quality syngas production: The green and efficient utilization of waste tire and waste heat from the steelmaking converter process.

This study proposes a new technology in which waste tire powders are injected into a converter vaporization cooling flue for gas recovery via pyrolysis using high-temperature waste heat. The higher temperature pyrolysis behavior of waste tire powder under different heating rates was investigated using a TG-MS technique. A drop tube furnace was used to simulate the converter vaporization cooling flue to investigate the effect of high temperatures on waste tire powder pyrolysis. The results indicated that secondary pyrolysis occurred above 900°C with low weight and weight loss rates, which were considerably lower than those observed in the thermal degradation stage. The main gaseous products formed were CO, CO2, H2, CH4, and H2O. The drop tube furnace experimental results indicated that high temperatures can facilitate the degradation of waste tire powder to generate more H2 and CO and improve the low heating values. At 1200°C, the H2 and CO contents were approximately 19.60% and 4.90%, respectively. The low heating value was 29.64MJ/Nm3. The char yield was in the range of 32.67%-37.33%; the fixed carbon content increased from 79.63% to 84.75%. The results provide preliminary verification of the feasibility of injecting waste tire powders into a converter vaporization cooling flue for gas recovery.

Multiple-distribution DAEM modelling of spruce pyrolysis: An investigation of the best trade-off regarding the number and shape of distributions

The distributed activation energy model (DAEM) is a widely used, accurate and robust method to model biomass pyrolysis. However, the appropriate numerical strategy in terms of distribution number and shape has not been systematically determined. This study analysed spruce powder pyrolysis under different scenarios of multiple-distribution DAEMs with symmetric/asymmetric distributions (Gaussian, logistic and exponential) and different distribution numbers. Dynamic tests at four heating rates (1, 2, 5 and 10 °C/min up to 800 °C) provided solid numerical learning database, and the optimization of residues between numerical calculation and database enabled identification of model parameters. Subsequently, validation was performed with static tests (250 to 500 °C with an interval of 50 °C and 2 h-isothermal stages), and their corresponding residue analysis provided a fundamental basis to assess the model’s true prediction ability. The trade-off between the model’s prediction ability and degrees of freedom was robustly investigated with regard to the number and shape of the distribution. As stated by the quality of validations, a series of Gaussian-DAEMs (distribution number ranged from one to five) allowed for the determination of the best trade-off when the distribution number was three. Finally, the two-Gaussian plus one exponential distribution exhibited the best overall prediction capacity among different multiple-distribution DAEMs, and was confirmed as the best strategy with regard to both distribution shape and number. A DTG simulation investigated each model’s simulation effects with three assigned variation sections and justified the correspondence between pseudo-components and biomass constituents. Finally, the DAEM’s capability to distinguish the effects of heating rate was demonstrated.

Methyl methacrylate (MMA) and alumina recovery from waste artificial marble powder pyrolysis

Owing to various advantages of artificial marble compared to natural marble, its application has been rising exponentially, which has resulted in the generation of a significant amount of waste artificial marble through various processes. This study focuses on the recovery of methyl methacrylate from the waste artificial marble powder through pyrolysis reaction. The pyrolysis experiment was conducted in a horizontal tubular furnace at various pyrolysis temperatures (300–500 °C) at an interval of 50 °C. The liquid product was obtained through condensation. Liquid and solid product characteristics were studied. Significant cracking of the liquid product was obtained for 450 and 500 °C. From the solid phase analysis, it was observed that aluminum oxide (Al2O3) was obtained through the calcination of waste artificial marble powder at 800 °C.

One-step coating of commercial Ni nanoparticles with a Ni, N-co-doped carbon shell towards efficient electrocatalysts for CO2 reduction.

Commercial nickel nanoparticles (Ni NPs) were directly converted to efficient electrocatalysts for CO2 reduction by urea-Ni solid powder pyrolysis, in which a Ni, N-co-doped graphite carbon shell wraps the Ni NPs in situ. 98.3% CO selectivity was realized with a current density of -20.2 mA cm-2 and an overpotential of 0.69 V.

Effect of Temperature and Transport on the Yield and Composition of Pyrolysis-Derived Bio-Oil from Glucose

The fast pyrolysis of biomass forms bio-oil, char, and light noncondensable gases. Bio-oil is the desired product in context of converting biomass to biofuel. The effect of temperature on bio-oil yield and composition is anticipated to be different under reaction-limited and transport-limited operating conditions. Attaining fundamental understanding of the effect of temperature and transport on bio-oil yield and composition is challenging, because of limited knowledge of pyrolysis chemistry and the inter-relationship between chemistry and transport. In this work, we performed thin-film and powder pyrolysis experiments to investigate the thermal decomposition of glucose (biomass model compound) under both reaction-controlled and transport-limited operating conditions. In thin-film (size ≤10 μm) experiments, the effect of temperature on pyrolysis product distribution, especially on bio-oil yield and composition, was studied. In addition, using the thin-film data, mechanistic insights into glucose decomposit...

Isotherm studies of methylene blue adsorption onto waste tyre pyrolysis powder-based activated carbons

This study was aimed to investigate the adsorptive ability of activated carbons derived from waste tyre pyrolysis powder by CO2 activation and ZnCl2 activation. The derived activated carbons and char were characterized for yield and specific surface area. Methylene Blue dye was used as a model pollutant to probe the performance of activated carbons. Result shows that the CO2-activated waste tyre pyrolysis powder exhibits a higher surface area of 97.0 m2/g, hence a greater methylene blue removal capacity of 47.2 mg/g. The methylene blue adsorption data by activated carbons and char obeyed the Langmuir isotherm with R2 of more than 0.99, describing the monolayer adsorption onto homogeneous surface. Physical activation of waste tyre pyrolysis powder using CO2 yields activated carbon with a promising performance for dyes removal from water.

Adjustment of biomass product gas to raise H2/CO ratio and remove tar over sodium titanate catalysts

To raise H2/CO and remove tar for biomass product gas, sodium titanates 4Na2O·5TiO2 and Na2O·3TiO2 were evaluated at 850 °C using wood powder pyrolysis gas produced from a 0.3 kg/h screw pyrolyzer with no extra steam, silica sand was selected as an inert material for comparison. The GHSV of the runs were around 2000 h−1 with tar content of about 200 g/Nm3. The results suggest that 4Na2O·5TiO2 presents the highest activity, Na2O·3TiO2 ranks slightly lower, and silica sand shows no activity of enhancing hydrogen yield. The hydrogen formation is promoted through tar cracking, water gas shift and/or methane reforming. The H2/CO increases to 1.8–2.0, which is higher than that of silica sand (about 0.35) and raw gas (about 0.25). Tar conversion in the 4Na2O·5TiO2 reforming was about 99% and nearly no coke was formed within the test duration of about 8 h, whereas the silica sand was coked obviously in 1 h. Most tar components can be effectively reformed, except for parts of xylene, naphthalene, biphenylene, and anthracene. The activity of 4Na2O·5TiO2 decreases gradually in the long-term test because of the release of sodium and has a tendency to transform to Na2O·3TiO2, the latter exhibits satisfactory stability and activity.

Phase stability and thermal conductivity of nanostructured tetragonal yttria–stabilized zirconia thermal barrier coatings deposited by air–plasma spraying

High performance thermal barrier coatings (TBCs) produced from nanocrystalline 4 mol.% Y2O3–stabilized ZrO2 (4YSZ) powder show significant thermal and mechanical property advantages compared with current benchmark products. The objective of the present study was to investigate the phase stability and thermal conductivity of the nanostructured 4YSZ coatings plasma–sprayed from the sol–spray pyrolysis powder. Characterization results indicated that the as–sprayed 4YSZ coatings were chemically very homogeneous and had a completely tetragonal–prime (t′) structure. Such a uniform composition was almost entirely consistent with that of the feedstock powder. The grain size of as–sprayed 4YSZ coatings was in the range of 35 ~ 75 nm, which resulted in an extremely low thermal conductivity of 0.8–1.2 W m–1 K–1 in the coatings. The high–temperature aging test showed that no monoclinic ZrO2 (m–ZrO2) phase present at all of the 4YSZ coatings after a heat treatment at 1473 K for 1–650 h. Furthermore, the phase composition of the 4YSZ coating kept t′–ZrO2 structure after 1500 thermal cycles at a peak surface temperature of 1373 K. The relative phase stability was attributed to the highly pure t′ phase composition and uniform constituents in the 4YSZ coatings. These results suggested that the development of high performance 4YSZ ceramic powders was benefit to improve the coating properties for TBC application.

Nitrogen and sulfur doped mesoporous carbon as metal-free electrocatalysts for the in situ production of hydrogen peroxide

Mesoporous carbons (MCs) are highly porous materials, which offer high surface area and higher electrochemical performance than traditional carbon materials. Doped carbons are particularly interesting materials due to their possible use as metal-free ORR catalysts. In this paper, nitrogen and sulfur doped or co-doped MCs were prepared according to a hard template approach consisting in pyrolysis of powders obtained by liquid impregnation of mesoporous silica with different heterocyclic condensed aromatic precursors. The synthetized MCs show round shaped particles with mesoporosity of 3–4 nm diameter, a BET surface area higher than 850 m2/g and nitrogen and sulfur contents ranging between 3–8% and 4–14%, respectively. Final doping has been demonstrated by core level photoemission spectra. The effect of the pyrolysis temperature on the physico-chemical properties of the resulting MCs has been investigated as well as the role of the dopant heteroatoms on their catalytic performances towards oxygen reduction reaction (ORR). Electrochemical tests show that both the oxygen-, sulfur- and nitrogen-containing groups can induce an electrocatalytic activity of MCs for ORR. The catalytic activity shows a linear dependence from the nitrogen content and a prevalent 2 electron reduction process leading to the formation of hydrogen peroxide, both in acid and alkaline solution.

Pengaruh Temperatur Terhadap Entalpi dan Kinetic Rate Gas Pirolisis Kayu Mahoni

This study was conducted to determine the effect of temperature on gas enthalpy and kinetic rate of mahogany wood powder pyrolysis results. Research process carried out experimentally with the temperature 673 K, 773 K, 873K, 973 K and 1073 K. Pyrolysis process is carried out for 2 hours with a particle size of sawdust from 0.5 to 1 mm. The results showed that the enthalpy value increase as the temperature increase. Highest enthalpy value achieved at 1073 K, with enthalpy value is 35015.97J.Kinetic rate for temperature 873 K, 973 K and 1073 K is 𝑘 = 1,484𝑒 −2759/𝑇 , kinetic rate for temperature 673 K and 773 K is 𝑘 = 16,5306𝑒 −5368/𝑇 and 𝑘 = 3,0373𝑒 −2980/𝑇 respectively. As the temperature increase, activation energy (Ea) to decompose biomass into gases is decrease.

Pyrolytic conversion of cellulose to fuels: levoglucosan deoxygenation via elimination and cyclization within molten biomass

Fast pyrolysis of biomass thermally cracks solid biopolymers to generate a transportable liquid (bio-oil) which can be upgraded and integrated with the existing petroleum infrastructure. Understanding how the components of biomass, such as cellulose, break down to form bio-oil constituents is critical to developing successful biofuels technologies. In this work, we use a novel co-pyrolysis technique and isotopically labeled starting materials to show that levoglucosan, the most abundant product of cellulose pyrolysis (60% of total), is deoxygenated within molten biomass to form products with higher energy content (pyrans and light oxygenates). The yield of these products can be increased by a factor of six under certain reaction conditions, e.g., using long condensed-phase residence times encountered in powder pyrolysis. Finally, co-pyrolysis experiments with deuterated glucose reveal that hydrogen exchange is a critical component of levoglucosan deoxygenation.

Multiple synthesis routes to transparent ceramic lutetium aluminum garnet

Transparent ceramics may be fabricated using various material sources and processing routes. In an effort to identify key processing parameters, we explored two different particle processing methods for production of ceramic lutetium aluminum garnet doped with cerium (LuAG:Ce): flame spray pyrolysis powder and high-energy-milled commercial powders. Powders were cold-pressed and vacuum sintered prior to hot isostatic pressing. The flame spray pyrolysis route led to phase-pure transparent ceramics, while the high-energy milling route led to multi-phase, translucent ceramics.