Showing papers on "Pyrolysis published in 2018"
TL;DR: In this article, a large number of experiments on biochar production is presented to give a general overview of the properties that can be achieved by feedstock selection and process design, including torrefaction as well as slow pyrolysis at high temperatures.
681 citations
TL;DR: In this article, a detailed list of production methods of activated carbon from wood biomass is presented systematically, and an attempt has also been made to review the physical properties, such as ultimate and proximate analyses of wood biomass material.
Abstract: Activated carbon has been an ideal material for the separation of a variety of chemical pollutants. Its extensive use is limited due to the cost of production, which has triggered the researches on the viable option for the non-conventional and cost-effective production. The application of biomass waste has been widely explored as an alternative to expensive methods of activated carbon production from coal. In this study, detailed list of production methods of activated carbon from wood biomass is presented systematically. The attempt has also been made to review the physical properties, such as ultimate and proximate analyses of wood biomass material. Further, the chemical compositions of wood, such as hemicelluloses, cellulose, and lignin are also dealt with. Finally, this review incorporates the existing research papers on wood-derived activated carbons to understand the influence of pyrolysis temperature, activation temperature, and effect of various physical and chemical activation conditions on the production, surface characteristics and adsorption behavior of activated carbons. The outcome of this study revealed that the activated carbons from wood biomass exhibit promising characteristics in terms of surface area, pore size and pore volume, surface functional groups, and surface entrapment behavior against various water soluble chemical toxicants.
460 citations
TL;DR: In this paper, the pyrolysis dependent properties of rapeseed stem biochar were investigated under various temperatures (200-700°C, in 50°C intervals), heating rates (1, 5, 10, 15, 20, 20°C/min), and residence times (10,20, 40, 60, 80, 100min).
442 citations
TL;DR: In this paper, a series of nitrogen-doped carbon nanotubes (NCNTFs) with distinguishable nitrogen content and graphitization degree have been successfully prepared through in situ transformation of ZIF-67 under N2/H2 atmosphere at different pyrolysis temperature.
310 citations
TL;DR: In this paper, the effect and potentiality of solid acid catalyst mainly zeolites, biomass particle size and catalyst loading ratio on the yield and quality of bio-oil are then emphasized.
271 citations
TL;DR: In this paper, a review of metal-biochar composites for removing oxyanions from wastewater is presented, and the effects of metal dosing and pyrolysis conditions on the surface chemistry and environmental stability of the composite are discussed.
269 citations
TL;DR: In this paper, biochar, which was synthesized via a facile one-pot pyrolysis of sewage sludge, was proven to be an efficient persulfate activator for pollutant degradation.
Abstract: The persulfate-based advanced oxidation process is a promising technology for water treatment, while its effectiveness depends mainly on the activation efficiency of catalysts and the oxidant yield derived from persulfate. Thus, exploration of efficient and cost-effective activators for persulfate decomposition is highly desired. In this work, biochar, which was synthesized via a facile one-pot pyrolysis of sewage sludge, was proven to be an efficient persulfate activator for pollutant degradation. For a representative endocrine disrupting pollutant, bisphenol A, an average removal rate of 3.21 mol BPA per mol oxidant per h could be achieved by peroxymonosulfate in a wide pH range of 4.0–10.0 at a biochar dosage of 0.2 g L−1. Also, a high mineralization efficiency of ∼80% (total organic carbon removal) was obtained within 30 min. A further catalytic mechanism study demonstrated that singlet oxygen, which was catalytically produced by the ketone structure inside the biochar, was the main reactive species responsible for bisphenol A degradation. More importantly, metals in the sludge precursor were found to play an important role in the active site formation during the pyrolysis of raw sludge. This work not only provides a novel value-added reuse approach for sewage sludge as an efficient persulfate activator but also would be beneficial for further designing and fabricating carbon-based persulfate catalysts.
267 citations
TL;DR: In this article, the authors reviewed the recent progress of the DRM reaction at low temperature and suggested that by investigating the interaction of supports, promoters with nickel, as well as their structural adjustment, the development of low temperature DRM catalysts was feasible.
248 citations
TL;DR: This review found that relative high temperature, long reaction residence time, slow heating rate, high pressure, the presence of some minerals and biomass feedstock of high-lignin content with large particle size are preferable to biochar stability, however, challenges exist to mediate the trade-offs between bio char stability and other potential wins.
238 citations
218 citations
TL;DR: In this article, the potential of pyrolysis for the production of bioenergy was investigated using agricultural waste biomass pea residue for its potential to be used in pyrotechnics.
TL;DR: In this paper, a supported cobalt catalyst with atomically dispersed Co-N x sites (3.5wt% Co) was synthesized by hydrolysis of tetramethyl orthosilicate (TMOS) in a Zn/Co bimetallic zeolitic imidazolate framework (BIMZIF(Co,Zn)), followed by high-temperature pyrolysis and SiO 2 leaching.
TL;DR: It is demonstrated that pyrolysis could be used as an efficient alternative method for stabilizing heavy metals in plant residues obtained after phytoremediation, and their pyrolsis products could be reutilized for dye adsorption.
TL;DR: The results indicate that the microwave-activation approach represents a promising attempt to produce good quality AC for dye adsorption and can be utilized as adsorbent to remove dye.
TL;DR: The transformation of microalgae residue into a highly efficient dye adsorbent is a promising procedure for economic and environmental protection.
TL;DR: In this paper, Ni@NCNTs were employed as both adsorbents and catalysts for activating persulfate to remove an emerging pollutant, antibiotic sulfachloropyridazine.
TL;DR: In this paper, a stable magnetic carbon was synthesized using activated sludge as the carbon precursor, and the ultrasonic pretreatment was used to destroy the cells in the activated ssludge and to release the soluble carbon source, which was responsible for the improved stability of the synthesized magnetic carbon.
Abstract: A stable magnetic carbon was synthesized using activated sludge as the carbon precursor. The ultrasonic pretreatment was used to destroy the cells in the activated sludge and to release the soluble carbon source, which was responsible for the improved stability of the synthesized magnetic carbon. 800 W was demonstrated as the optimized ultrasonication power for the pretreatment of activated sludge. Then, the carbonization parameters, such as pyrolysis temperature, heating rate, and dwell time were optimized as 800 °C, 10 °C/min, and 60 min, respectively. To be more specific, this activated sludge derived magnetic carbon can reduce almost all the hexavalent chromium (Cr(VI)) (2.0 mg/L) in 10 min and has a maximum capacity as high as 203 mg/g. The iron release rate of the synthesized activated sludge derived magnetic carbon was decreased, which improved the electron utilization of zerovalent iron (ZVI). This composite was demonstrated to have a good stability and recyclability as well. Finally, the Cr(VI) r...
TL;DR: In this paper, the authors investigated an effective method of catalytic reforming of tar during biomass high-temperature pyrolysis using rice husk char (RHC) and metal impregnated (Fe, Cu and K) char in a dual-stage reactor.
TL;DR: In this article, the progress in combining fast pyrolysis and catalytic hydrodeoxygenation (HDO) to produce liquid fuel from solid, lignocellulosic biomass is discussed.
TL;DR: In this paper, low-density polyethylene (LDPE), polypropylene (PP) and polyvinyl chloride (PVC) were studied under high heating rate conditions to investigate pyrolysis behaviors and find the most suitable kinetic reaction mechanisms.
TL;DR: In this article, a co-pyrolysis of pinewood and different kinds of plastic wastes in different mass fractions using polypropylene (PP), polyethylene terephthalate (PETE), and polycarbonate (BPC) was investigated.
TL;DR: This research not only obtained a novel method to modify biochar but also furthered research into the lignin of biochar composition, and provided an efficient sorbent for heavy metal.
TL;DR: The results of the investigations into the elucidation of the chemical structure of moieties responsible for the blue and green luminescence of CDs derived from the microwave-assisted pyrolysis of citric acid in the presence of urea are presented.
Abstract: In this report, we present the results of our investigations into the elucidation of the chemical structure of moieties responsible for the blue and green luminescence of CDs derived from the microwave-assisted pyrolysis of citric acid in the presence of urea. The molecular fluorophore that forms during the synthesis of green fluorescing CDs is 4-hydroxy-1H-pyrrolo[3,4-c]pyridine-1,3,6(2H,5H)-trione (HPPT).
TL;DR: This study reports pyrolysis kinetics of biomass blends using isoconversional methods, viz.
TL;DR: In this paper, the plastic derived oil (PDO) samples obtained at low temperature pyrolysis are lighter with low viscosity, high octane number and having high calorific values.
Abstract: Low and high-density polyethylene (LDPE and HDPE) and polypropylene (PP) are three most common polyolefins profusely used as packaging materials and abundantly found in the plastic waste stream. These plastic waste samples were collected from household waste and converted into plastic derived oil (PDO) by low temperature (300 °C to 400 °C) slow pyrolysis (long isothermal holding time) in a semi-batch reactor. The PDO samples obtained had shown variation in their compositions and fuel properties based on the pyrolysis temperature. PDO from the pyrolysis of PP has high octane number (∼92) and low viscosity. Noticeably, the PDO samples obtained at low temperature pyrolysis are lighter with low viscosity, high octane number and having high calorific values. 1H NMR analysis revealed that the oil samples mostly consist of paraffinic and olefinic hydrocarbons. Simulated distillation (SimDist) of PDO indicated that the liquid products resemble the characteristic closer to middle distillate of petroleum fraction having very low pour point and flash point. The temperature with long pyrolysis time also influenced the evolved gas composition and yield. Trace amount of hydrogen, carbon monoxide and carbon dioxide were present in the gaseous product along with various hydrocarbon gases ranging from C1–C5. The degradation mechanism follows end chain scission which produces monomer units whereas random scission results most of the hydrocarbon products. Subsequent reactions like radical recombination and inter or intra molecular hydrogen transfer results in the formation of most of the olefinic components.
TL;DR: Characterization of biochar and hydrochar samples showed that pyrolysis led to chars with more aromatic structures and high thermal stability while HTC process originated char with more aliphatic structures, suggesting that HTC could be an interesting method to obtain soil growing media or green roof materials with adequate hydrophysical properties.
TL;DR: In this article, a review of the use of biochar as an adsorbent material for treating gaseous effluents is presented, which includes common sorbents for removal of contaminants from gas, biochar production methods, and compares biochar with activated carbon.
Abstract: Biochar, a product of pyrolysis of biomass, represents an attractive alternative to non-renewable or unsustainably sourced biomass as an adsorbent material for treating gaseous effluents. Biomass from residues associated with agricultural and forestry operation, otherwise considered waste material or a storage issues, represents a potential sustainable source of adsorbent. There are several adsorbents for removal of contaminants from gases including carbon based, silica based, and metal oxide based adsorbents; however, availability of feedstock, low cost, and potential high adsorption capacity distinguish biochar from other adsorbents. This review includes common sorbents for removal of contaminants from gas, biochar production methods, and compares biochar with activated carbon as one of the most common commercial adsorbents. Adsorption isotherms, mechanisms, and process systems for removal of acid gases such as CO2 and H2S by biochars have been comprehensively reviewed. The application of molecular modeling to describe adsorption by activated carbons and possible extension to biochar were studied. There is still a lack of published information in the molecular modeling of biochars, and using these models to understand the complex adsorbent mechanisms on the very heterogeneous surfaces of biochar (relative to commercial adsorbent materials such as activated carbons). Therefore, further research needs to fill these gaps to identify all potentials of this promising adsorbent.
TL;DR: In this paper, pyrolysis of chicken feather fibers (CFFs) in the temperature range of 400-1400 °C was used to synthesize heteroatom-doped carbon.
Abstract: Doped material is an innovation in developing the lightweight microwave absorbing material. Herein, heteroatom-doped carbon is synthesized by pyrolysis of chicken feather fibers (CFFs) in the temperature range of 400–1400 °C. The synthesis method exhibits that poultry waste is more nature-friendly as no external hazardous dopants are used during pyrolysis, and it has a much lower cost. The morphology and structural characteristics have been studied via SEM, AFM, TEM, XRD, Raman, and XPS. The density of surface chemical states, defects, roughness, and structural property are found to vary significantly with pyrolysis temperature. The electromagnetic properties of CFF/epoxy composites have been studied in the frequency range of 8.2–12.4 GHz (X band). In addition, the correlations between pyrolysis temperature and absorption properties are established. High absorption properties at temperature ≥800 °C are attributed to the large fraction of heteroatoms, defects, surface roughness, and high porosity. In addit...
TL;DR: In this article, two main methods for biochar synthesis, namely conventional pyrolysis and hydrothermal carbonization (HTC), are described, and the influences of biomass nature and reaction conditions, especially temperature, are discussed.
Abstract: Firstly, this paper reviews two main methods for biochar synthesis, namely conventional pyrolysis and hydrothermal carbonization (HTC). The related processes are described, and the influences of biomass nature and reaction conditions, especially temperature, are discussed. Compared to pyrolysis, HTC has advantages for processing high-moisture biomass and producing spherical biochar particles. Secondly, typical features of biochar in comparison with other carbonaceous materials are summarized. They refer to the presence of inorganics, surface functional groups, and local crystalline structures made up of highly conjugated aromatic sheets. Thirdly, various strategies for biochar modification are illustrated. They include activation, surface functionalization, in situ heteroatom doping, and the formation of composites with other materials. An appropriate modification is necessary for biochar used as a catalyst. Fourthly, the applications of biochar-based catalysts in three important processes of biofuel production are reviewed. Sulfonated biochar shows good catalytic performance for biomass hydrolysis and biodiesel production. Biodiesel production can also be catalyzed by biochar-derived or -supported solid-alkali catalysts. Biochar alone and biochar-supported metals are potential catalysts for tar reduction during or after biomass gasification. Lastly, the merits of biochar-based catalysts are summarized. Biochar-based catalysts have great developmental prospects. Future work needs to focus on the study of mechanism and process design.
TL;DR: HTC is a promising pretreatment prior to pyrolysis from the perspective of immobilization of heavy metals in sewage sludge, and the chars derived from hydrochar pyroglysis was more alkaline and had lower risk and less leachable heavy metals.