Temat: biochars - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: The impact of heat treatment on the components of plant biomass as exemplified by Junniperus sabina and Picea abies
Autorzy:: Drygaś, B.
Depciuch, J.
Puchalski, Cz.
Zaguła, G.
Tematy:: torrefaction
biomass
FTIR spectra
changes
biochars; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Oddział w Lublinie PAN
Powiązania:: https://bibliotekanauki.pl/articles/411289.pdf Link otwiera się w nowym oknie
Opis:: Torrefaction is the process of drying biomass at high temperatures in order to transform it into biofuels with properties and composition resembling carbon. The impact of high temperature breaks the chains of hemicellulose, lignin and cellulose and degrades the biomass to simpler organic compounds. The aim of this publication was to specify the impact of the duration of the heat treatment on the stability of biomass structures such as lignocellulose illustrated with examples of selected species of conifers. The research material consisted of shoot tips of Junniperus sabina and Picea abies. The material used in the process was air-dried, dried at 150oC and torrefied at temperatures of 200, 250 and 300oC in a LECO camera – TGA 701 apparatus for 30 minutes. Fresh needles and their torrefied products were measured spectroscopically using FTIR Vertex 70v made by Bruker. Microscopic photographs of samples were taken in the scales 10 μm, 20 μm, and 50 μm using the TESCAN VEGA3 scanning electron microscope. The unprocessed plant material did not differ significantly from one another – the FTIR spectra of both plants exhibited the same functional groups. The biomass heat treatment led to significant changes in its chemical composition and topographic changes in the obtained biochars.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Biochars from wood biomass as effective methylene blue adsorbents
Autorzy:: Charmas, Barbara
Wawrzaszek, Barbara
Jedynak, Katarzyna
Tematy:: activated biochars
pyrolysis
hydrothermal activation
dye adsorption; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/24085657.pdf Link otwiera się w nowym oknie
Opis:: Forest waste is a significant ecological and economic problem, requiring effective solutions that will not only reduce its quantity but also contribute to the protection of the natural environment. This research paper focuses on the use of sawdust from mixed trees, as one of the main forest wastes, for production of biochars characterized by adsorption properties. Sawdust, a by-product of the wood industry, has a porous structure, which makes it an attractive precursor to biochar. Using pyrolysis technology and hydrothermal activation under various conditions, sawdust was transformed into biochars with a developed specific surface area. The studies proved that the parameters of the pyrolysis process have a significant impact on the structural, surface and adsorption properties of biochars. The materials were characterized based on the results of N2 adsorption, scanning electron microscopy SEM/EDS, thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Raman spectroscopy. The surface characterization was made using the Boehm titration and pHpzc determination. The sorption capacity of methylene blue (MB) was studied. It was stated, that the obtained materials were characterized by a large specific surface area (227.5 – 1019 m2/g), the micro/mesoporous structure and the large pores volume (0.106 – 0.784 cm3/g). The surface oxygen functionalities allowed for large adsorption of MB. The adsorption process follows the Langmuir theory (qm,cal from 357.1 to 434.8 mg/g) and can be described using the kinetic pseudo-second-order model (R2 = 0.99). The obtained biochars showed high adsorption capacity of methylene blue impurities which indicates their significant potential for use in water purification.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Exploring the potential of biochars for boosting electrocatalytic oxygen evolution reaction
Autorzy:: Stelmachowski, Paweł
Lofek, Magdalena
Wojtasik, Michał
Markowski, Jaroslaw
Opis:: The world's growing energy demand and the necessity of protecting the environment motivate researchers and industry alike to look for an ecological alternative to fossil fuels as energy sources and carriers, such as hydrogen. On the other hand, biomass waste can be used to obtain bio-oil for energy applications. Fast pyrolysis of biomass results in the highest bio-oil yields, but poor physicochemical properties characterise the produced biochar. This work aimed to develop a procedure to make an electrocatalyst of the oxygen evolution reaction (OER) to produce hydrogen based on biochar from fast pyrolysis of renewable raw materials (carbonised triticale straw, sunflower husk, pine sawdust, walnut shells, and sewage sludge) with a cobalt active phase. No additional chemical and thermal valorisation was applied to increase the graphitisation degree, porosity and specific surface area. However, simple and environmentally friendly air plasma was used as a non-destructive method to improve the surface properties of the biochar materials. The cobalt active phase was introduced by a deposition-precipitation method. The surface modification of carbon materials with plasma improves the electrocatalytic activity by changing the speciation of the biochars' surface oxygen groups. The activity of the obtained materials is very similar, irrespective of the different characteristics of the studied fast pyrolysis by-products, indicating that the developed materials can be obtained from various biochars. The OER overpotentials at $10 mA cm^{−2}$ for all the samples are below 385 mV. The most active material, based on plasma-treated triticale straw biochar $(C_{TS}-pl-Co)$, demonstrated the lowest overpotential of 358 mV, representing a slight improvement compared to its untreated counterpart (η = 363 mV). Furthermore, the $C_{TS}-pl-Co$ catalyst maintained stable operation for 6 h at a current density of $18 mA cm^{−2}$, in contrast to the reference cobalt spinel, which operated for only 3 h at a current density of $15 mA cm^{−2}$. These findings underscore the potential of plasma-functionalised waste-derived biochars as sustainable and effective catalysts for OER applications.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 4.

Tytuł:: Comparative effectiveness of biochar derived from tropical feedstocks on the adsorption for ammonium, nitrate and phosphate
Autorzy:: Zou, Ganghua
Shan, Ying
Dai, Minjie
Xin, Xiaoping
Nawaz, Muhammad
Zhao, Fengljang
Tematy:: nutrients
soil amendment
adsorption model
biochars
tropical feedstock
składniki odżywcze
model adsorpcji
odżywianie gleby
biowęgle
surowce tropikalne; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2203133.pdf Link otwiera się w nowym oknie
Opis:: Biochar has been extensively studied as a soil amendment to reduce nutrients losses. However, the comparative effectiveness of biochar adsorption capacity for ammonium (NH4 -N), nitrate (NO3 -N), and phosphate (PO4-P) remains unknown. In the present study, the effects of feedstock (banana stem and coconut shell) and temperature (300, 500, and 700°C) on biochar adsorption ability for NH4-N, NO3-N, and PO4-P were investigated and fitted by three adsorption models, viz Freundlich, Langmuir, and linear. Freundlich (R2 = 0.95–0.99) and Langmuir (R2 = 0.91–0.95) models were found suitable for adsorption of NH4 -N. The maximum adsorption capacity (Qm) for coconut shell biochar increased with pyrolysis temperature (Qm = 12.8–15.5 mg g-1) and decreased for banana stem biochar (Qm = 12.9–9.7 mg g-1). In the case of NO3 -N adsorption, Freundlich (R2 = 0.82–0.99) and linear model (R2 = 1.00) were found suitable while Langmuir model showed much less contribution, similarly adsorption of PO4-P, was not supported by these three models. The minimum concentrations required for adsorption of phosphate were recorded as 36, 8, and 3 mg L-1 using pyrolyzed biochar at the temperatures of 300, 500, and 700°C, respectively. These results indicate that the feedstock and pyrolysis temperature, as well as aquatic nutrient concentration, were important factors for the adsorption of inorganic nitrogen and phosphorus.
Dostawca treści:: Biblioteka Nauki

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