Feedstock choice, pyrolysis temperature and type influence biochar characteristics: a comprehensive meta-data analysis review

AbstractVarious studies have established that feedstock choice, pyrolysis temperature, and pyrolysis type influence final biochar physicochemical characteristics. However, overarching analyses of pre-biochar creation choices and correlations to biochar characteristics are severely lacking. Thus, the objective of this work was to help researchers, biochar-stakeholders, and practitioners make more well-informed choices in terms of how these three major parameters influence the final biochar product. Utilizing approximately 5400 peer-reviewed journal articles and over 50,800 individual data points, herein we elucidate the selections that influence final biochar physical and chemical properties, total nutrient content, and perhaps more importantly tools one can use to predict biochar’s nutrient availability. Based on the large dataset collected, it appears that pyrolysis type (fast or slow) plays a minor role in biochar physico- (inorganic) chemical characteristics; few differences were evident between production styles. Pyrolysis temperature, however, affects biochar’s longevity, with pyrolysis temperatures > 500 °C generally leading to longer-term (i.e., > 1000 years) half-lives. Greater pyrolysis temperatures also led to biochars containing greater overall C and specific surface area (SSA), which could promote soil physico-chemical improvements. However, based on the collected data, it appears that feedstock selection has the largest influence on biochar properties. Specific surface area is greatest in wood-based biochars, which in combination with pyrolysis temperature could likely promote greater changes in soil physical characteristics over other feedstock-based biochars. Crop- and other grass-based biochars appear to have cation exchange capacities greater than other biochars, which in combination with pyrolysis temperature could potentially lead to longer-term changes in soil nutrient retention. The collected data also suggest that one can reasonably predict the availability of various biochar nutrients (e.g., N, P, K, Ca, Mg, Fe, and Cu) based on feedstock choice and total nutrient content. Results can be used to create designer biochars to help solve environmental issues and supply a variety of plant-available nutrients for crop growth.

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Changes in the physicochemical characteristics of peanut straw biochar after freeze-thaw and dry-wet aging treatments of the biomass

BioResources ◽

10.15376/biores.14.2.4329-4343 ◽

2019 ◽

Vol 14 (2) ◽

pp. 4329-4343

Author(s):

Yongqiang Cao ◽

Yande Jing ◽

Hao Hao ◽

Xuan Wang

Keyword(s):

Specific Surface ◽

Surface Area ◽

Functional Groups ◽

Specific Surface Area ◽

Pyrolysis Temperature ◽

Ph Value ◽

Aging Treatment ◽

Physicochemical Characteristics ◽

Freeze Thaw ◽

Peanut Straw

Effects of aging after pyrolysis were tested relative to the physicochemical characteristics of peanut straw biochar. Biochar was prepared at pyrolysis temperatures of 350 °C, 500 °C, and 650 °C; then, it was freeze-thawed and dry-wet aged. The physicochemical characteristics of the fresh and aged biochar were analyzed. The results showed that the pyrolysis temperature, ambient temperature, and humidity affected the physicochemical characteristics of the biochar. With the increase of pyrolysis temperature, the yield and surface acidic functional groups of the fresh biochar decreased, whereas the ash content, C content, pH, specific surface area, and mesoporous volume of the fresh biochar increased. The aging treatment increased the acidic functional groups content in the biochar and reduced the aromatic functional groups content, which decreased the pH value of the biochar. The aging treatment increased the specific surface area and pore volume of the biochar, and the effect of freeze-thaw aging was greater than that of dry-wet aging. The aging treatment also destroyed the complete shape of the fresh biochar, and reduced its stability. After the aging treatment, the C content of the biochar decreased, whereas the O content increased, due to oxidation of the biochar.

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Examinations of Cross-Linked Polyvinylpyridine in Open Reactor

Materials Science Forum ◽

10.4028/www.scientific.net/msf.494.369 ◽

2005 ◽

Vol 494 ◽

pp. 369-374 ◽

Cited By ~ 14

Author(s):

M. Milošević ◽

N. Pejić ◽

Ž. Čupić ◽

S. Anić ◽

Lj. Kolar-Anić

Keyword(s):

Specific Surface ◽

Bifurcation Diagram ◽

Surface Area ◽

Specific Surface Area ◽

Bifurcation Point ◽

Particle Density ◽

Physicochemical Characteristics ◽

Stirred Tank ◽

Stirred Tank Reactor ◽

Tank Reactor

Macroporous cross-linked copolymer of 4-vinylpyridine and 25% (4:1) divinylbenzene is analyzed under open conditions, that is in a continuous well-stirred tank reactor (CSTR). With this aim the appropriate bifurcation diagram is found and the behavior of the system with and without polymer in the vicinity of the bifurcation point is used for the polymer examinations. Two different granulations of polymer are considered. Moreover, some physicochemical characteristics of the polymer, such as specific surface area, skeletal and particle density, are determined.

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Optimization of compositions and technology of production of small-clinker floured cements using the most effective fillers

Bulletin of L N Gumilyov Eurasian National University Technical Science and Technology Series ◽

10.32523/2616-7263-2021-136-3-46-55 ◽

2021 ◽

Vol 136 (3) ◽

pp. 46-55

Author(s):

N.B. Sarsenbayev ◽

◽

B.K. Sarsenbayev ◽

Zh.T. Aimenov ◽

A.Zh. Aimenov ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Crystalline Structure ◽

Specific Surface Area ◽

Chemical Properties ◽

Surface Layers ◽

Fine Powders ◽

Energy Demands ◽

Actual Evaluation ◽

Technology Of Production

Considering the physical chemistry of grinding it is worth quoting the grinding of mineral building material as “the change of physical-chemical properties of finely ground materials can not only be due to the reducing the particle sizes, at mechanical grinding significant changes of the crystalline structure of their surface layers (thickness 15-20 microns) take place, in many cases the technological properties of fine powders are not so much due to dispersability but are namely due to the structure rupture”, at that the energy costs for this are “significantly greater than for the exposal of surfaces with a clean cleavage”. The speed of heterogeneous chemical processes involving fine powders is determined primarily not by the magnitude of their specific surface area, as commonly is believed, but by the decrease of energy of activation as the result of crystalline structure rupture and amorphization. However, both specific surface area and energy demands to achieve are actual evaluation of the effectiveness of any material grinding at a particular unit. The main factor of the production process of cements of low water demand is the grinding, characterized by grindability.

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Influence of the Calcination Temperature on the properties of The Alumina as Catalyst Support for Catalysis

Paliva ◽

10.35933/paliva.2020.04.03 ◽

2020 ◽

pp. 155-161

Author(s):

Tomáš Hlinčík ◽

Veronika Šnajdrová ◽

Veronika Kyselová

Keyword(s):

Specific Surface ◽

Surface Area ◽

Calcination Temperature ◽

Specific Surface Area ◽

Catalyst Support ◽

Chemical Properties ◽

Total Pore Volume ◽

Temperature Range ◽

Calcination Temperatures ◽

Physical And Chemical

Alumina is commonly used in industrial practice as a catalyst support and it is made from boehmite. Depending on the calcination temperature, this mineral is transformed into various crystalline modifications which have different physical and chemical properties. For this reason, the following parameters were determined at different calcination temperatures: length, width, material hardness, specific surface area and total pore volume. The results show that with increasing calcination temperature there have been significant changes which may be important when using the material as a catalyst support, e.g. in the preparation of catalysts or in the design of cat-alytic reactors. The specific surface area, which decreases in the temperature range 450–800 °C, is an important parameter for the preparation of catalysts, so it is appropriate to choose a temperature of 600 °C, when the specific surface area is above 200 m2·g-1. The effect of calcination temperature on the structural transitions of boehmite was also monitored. The results showed that γ-Al2O3 has the most suitable properties as a catalyst sup-port in the temperature range 450–800 °C.

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Investigations of Latvian Illite/Kaolinite Clays Irradiated Under Action of Accelerated Electrons

Materials Science ◽

10.5755/j01.ms.26.1.21446 ◽

2019 ◽

Vol 26 (1) ◽

pp. 99-102

Author(s):

Dāvis CONKA ◽

Līga AVOTINA ◽

Ruta SVINKA ◽

Visvaldis SVINKA ◽

Laris BAUMANE ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Chemical Properties ◽

Absorbed Dose ◽

Free Fraction ◽

Natural Clay ◽

Ir Spectrometry ◽

Accelerated Electrons ◽

Ft Ir

Natural clay is a perspective material for application as sorbents for wastewater treatment as well as for sorption of radionuclides, where the properties of the clays can be changed under influence of ionizing radiation. For application of Latvian illite/kaolinite clays for isotope sorption it is important to characterize the physic-chemical properties of pre-prepared air dried clays. Two fractions of the illite clays were selected. A fraction with grain size 100 μm (SiO2 content 60.9 ± 1.5 wt.%, specific surface area 35 m2/g) and a sand free fraction – 2 μm (SiO2 47.7 ± 1.9 wt.%, specific surface area 38 m2/g). Selected fractions were irradiated with accelerated electrons (5 MeV, ELU-4, Salaspils, absorbed dose up to 500 kGy). Non-irradiated and irradiated clays were analysed with means of Fourier transform infrared (FT-IR) spectrometry.

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Some Physical, Chemical and Mineralogical Properties of Some Canadian Fly Ashes

MRS Proceedings ◽

10.1557/proc-86-113 ◽

1986 ◽

Vol 86 ◽

Cited By ~ 4

Author(s):

R. C. Joshi ◽

B. K. Marsh

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Chemical Properties ◽

Water Soluble ◽

Pozzolanic Activity ◽

Unburned Carbon ◽

Magnetic Fraction ◽

Fly Ashes ◽

Physical And Chemical

ABSTRACTThis paper gives physical and chemical properties of some Canadian fly ashes. Specific surface area, magnetic fraction, water soluble fraction and fraction finer than 45 μm were determined as part of the physical tests. Thermo-gravimetric analyses (TGA) in oxygen and nitrogen were conducted on raw ash samples. The change of pH with time in suspensions of the different ashes in water was also determined. Pozzolanic activity of the ashes with lime for all the ashes was evaluated to measure ash reactivity.The ash activity seems to be related to fineness of the ash measured by the Blaine air permeability method, but not to the fineness measured by nitrogen sorption. Generally the greater the specific surface area, the higher the reactivity of the ash. The correlation was, however, not strong and no other physical or chemical parameter measured in this investigation seems to be related to pozzolanic activity.The results of pH and TGA tests indicated that the ashes differ in many respects from each other. The TGA data suggest that loss on-ignition in many of the ashes is not entirely due to the presence of unburned carbon. Specific surface area determined by various methods seems to provide different values. No characterization parameter was found that was uniquely related to coal type.

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Characterization of Samarium Doped Ceria Powders Having High Specific Surface Area Synthesized by Carbon-Assisted Spray Pyrolysis

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.485.137 ◽

2011 ◽

Vol 485 ◽

pp. 137-140 ◽

Cited By ~ 2

Author(s):

Kenichi Myoujin ◽

Hiroki Ichiboshi ◽

Takayuki Kodera ◽

Takashi Ogihara

Keyword(s):

Specific Surface ◽

Relative Density ◽

Spray Pyrolysis ◽

Surface Area ◽

Specific Surface Area ◽

Carbon Sources ◽

Chemical Properties ◽

High Specific Surface Area ◽

Doped Ceria ◽

Physical And Chemical

Spherical samarium doped ceria (Ce0.8Sm0.2O1.9, SDC) powders having high specific surface area (SSA) were successfully synthesized by carbon-assisted spray pyrolysis (CASP). Saccharides, such as monosaccharides and disaccharides, or organic acids were used as carbon sources. The physical and chemical properties of these powders were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Thermo gravimetry-Differential Thermal Analysis (TG-DTA), and BET. Decarbonized powders obtained by this method exhibit spherical morphologies and nano- and submicron-sizes. The SSA of SDC obtained from CASP was more than seven times higher than that obtained from conventional spray pyrolysis (CSP). The SSA of the decarbonized SDC powders obtained by calcination at 900 °C was estimated to be approximately 70 m2/g by using the BET method. The relative density of SDC obtained from CASP was higher than that obtained from CSP. The relative density of the SDC pellet was highest (96 %) when it was sintered at 1400 °C.

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Effects of the Pyrolysis Temperature on Adsorption of Carbamazepine and Ibuprofen by NaOH Pre-treated Pine Sawdust Biochars

Journal of Korean Society of Environmental Engineers ◽

10.4491/ksee.2020.42.2.29 ◽

2020 ◽

Vol 42 (2) ◽

pp. 29-39

Author(s):

Jinwoo Kwak ◽

Sangwoo Park ◽

Jaegwan Shin ◽

Kangmin Chon

Keyword(s):

Ionic Strength ◽

Specific Surface ◽

Pore Size ◽

Surface Area ◽

Specific Surface Area ◽

Pore Volume ◽

Pyrolysis Temperature ◽

Repulsive Interaction ◽

Pine Sawdust ◽

Adsorption Mechanisms

Objective: The main purpose of this study was to examine the impacts of the pyrolysis temperature on the removal of pharmaceuticals (i.e., ibuprofen (IBF) and carbamazepine (CBZ)) using NaOH pre-treated biochars produced from pine sawdusts.Methods:Two different types of kinetic and isotherm models were applied to investigate the adsorption mechanisms of IBF and CBZ by the NaOH pre-treated biochars produced at 600℃ (PB-600) and 800℃ (PB-800). In addition, the removal efficiencies of IBF and CBZ by PB-600 and PB-800 were compared under various conditions (adsorbent doses: 5-40 mg/L; 20-160 mg/L; temperature: 15-45℃; ionic strength: 0-0.5 M) to assess their feasibility as an alternative adsorbent for the removal of pharmaceuticals. Results and Discussion:PB-800 could more effectively remove CBZ and IBF than PB-600 because of its larger specific surface area (PB-600 = 408.70 m2/g; PB-800 = 472.92 m2/g), pore volume (PB-600 = 0.336 cm3/g; PB-800 = 0.658 cm3/g), and pore size (PB-600 = 4.63 nm; PB-800 = 6.25 nm). The Langmuir isotherm was more suitable for adsorption of IBF by PB-600 and the Freundlich isotherm was well fitted to the adsorption of CBZ by PB-600 and adsorption of CBZ and IBF by PB-800. The adsorption of CBZ by PB-600 and PB-800 was not affected by temperature while the removal efficiency of IBF was decreased with increasing the temperature due to the increased repulsive interaction between IBF and the biochars. Furthermore, the effects of the ionic strength on the adsorption of IBF were more pronounced than that of CBZ due to the differences in the surface charge properties.Conclusions:The higher pyrolysis temperature can improve the physicochemical properties of the NaOH pre-treated pine sawdust biochars associated with the removal of the pharmaceuticals (i.e., CBZ and IBF). Moreover, the adsorption mechanisms of CBZ and IBF by the biochars were strongly influenced by their specific surface area, pore volume and pore size.

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Effective cesium removal from Cs-containing water using chemically activated opaline mudstone mainly composed of opal-cristobalite/tridymite (opal-CT)

Scientific Reports ◽

10.1038/s41598-021-94832-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sunki Kwon ◽

Yumi Kim ◽

Yul Roh

Keyword(s):

Specific Surface ◽

Adsorption Capacity ◽

Surface Area ◽

Specific Surface Area ◽

Chemical Properties ◽

High Specific Surface Area ◽

Acid Activation ◽

Simple Modification ◽

Physico Chemical ◽

Acid And Base

AbstractOpaline mudstone (OM) composed of opal-CT (SiO2·nH2O) has high potential use as a cesium (Cs) adsorbent, due to its high specific surface area (SSA). The objective of this study was to investigate the Cs adsorption capacity of chemically activated OM and the adsorption mechanism based on its physico-chemical properties. We used acid- and base-activation methods for the surface modification of OM. Both acid- and base- activations highly increased the specific surface area (SSA) of OM, however, the base-activation decreased the zeta potential value more (− 16.67 mV), compared to the effects of acid-activation (− 6.60 mV) or non-activation method (− 6.66 mV). Base-activated OM showed higher Cs adsorption capacity (32.14 mg/g) than the others (acid: 12.22 mg/g, non: 15.47 mg/g). These results indicate that base-activation generates pH-dependent negative charge, which facilitates Cs adsorption via electrostatic attraction. In terms of the dynamic atomic behavior, Cs cation adsorbed on the OM mainly exist in the form of inner-sphere complexes (IS) containing minor amounts of water molecules. Consequently, the OM can be used as an effective Cs adsorbent via base-activation as an economical and simple modification method.

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