By-product Of Pyrolysis Research Articles

Carbon nitride nano-biochar exhibit dose-dependent effect on rice growth

Biochar, a byproduct of biomass pyrolysis, has gained interest for its wideranging uses in agriculture and environmental remediation. Nano-biochar, in particular, holds promise for enhancing crop productivity and addressing environmental challenges faced by the plants. Its ability to improve soil properties and biological functions underscores its potential in sustainable agriculture. This study investigates the influence of a carbon-based nanobiocharcarbon nitride (C3N4, derived from melamine) on rice (Oryza sativa) growth. Despite the promise of nanostructured biochar materials in bolstering crop yields, their interaction with varying concentrations of C3N4 remains poorly understood. In this study, we studied the impact of five concentrations (0µM, 500µM, 1000µM, 1500µM, and 2000µM) of C3N4 on rice growth. Our results reveal a concentration-dependent response, with 1500µM and 2000µM concentrations exhibiting toxic effects on rice plants, while 500µM and 1000µM concentrations demonstrate positive effects on rice growth parameters (root-shoot length, fresh-dry biomass) with maximum values obtained in case of the latter. This research sheds light on the potential of C3N4 nanobiochars to influence the growth of crop plants, emphasizing the importance of optimizing concentrations for sustainable agricultural practices. Further exploration in this area could lead to finding of solutions for enhancing agricultural productivity in a sustainable manner.

Investigation of pyrolysis byproducts derived from beech wood residues

Investigation of pyrolysis byproducts derived from beech wood residues

Ecofriendly Biochar as a Low-Cost Solid Lubricating Filler for LDPE Sustainable Biocomposites: Thermal, Mechanical, and Tribological Characterization

The potential of ecofriendly biochar, a carbon-rich byproduct of biomass pyrolysis, as a low-cost solid lubricating filler for low-density polyethylene (LDPE) sustainable biocomposites is investigated in this work. Tensile strength, hardness, thermogravimetric analysis (TGA), melting flow index (MFI), tensile test, flexural test, and frictional tests were used to characterize the biocomposites’ mechanical, thermal, and tribological properties. Energy-dispersive X-ray spectroscopy (EDS) was used to assess the chemical composition of the biochar, while field-emission scanning electron microscopy (FESEM) was used to capture the biochar morphology. The results showed that the incorporation of biochar in LDPE matrix increased the mechanical characteristics of the biocomposites and resulted in a significant increase in tensile strength, flexural strength, and hardness. More specifically, the LDPE+10 wt% composite outperformed the pure LDPE matrix by 1.9% in tensile strength and 47% in flexural strength. Furthermore, integrating biochar into LDPE composites enhances thermal stability, lowers the melt flow index (MFI), and boosts the hardness by 24.3% for the composite with 10% biochar content. Furthermore, biochar improves wear resistance and durability, with the LDPE10 composite exhibiting a friction coefficient that is 56.3% lower than pure LDPE. These findings indicate that biochar is a viable, cost-effective, and environmentally friendly filler for improving the performance of LDPE-based biocomposites for many varieties of applications.

Catalytic pyrolysis of harmful plastic waste to alleviate environmental impacts

Wax is a detrimental byproduct of plastic waste pyrolysis causing challenges upon its release into the environment owing to persistence and potential toxicity. In this study, the valorization of wax materials through conversion into BTEX (i.e., benzene, toluene, ethylbenzene, and xylene) was achieved via catalytic pyrolysis using zeolite-based catalysts. The potential of two types of waxes, spent wax (SW), derived from the pyrolysis of plastic waste, and commercial paraffin wax (PW), for BTEX generation, was investigated. Using HZSM-5, higher yields of oil (54.9 wt%) and BTEX (18.2 wt%) were produced from the pyrolysis of SW compared to PW (32.3 and 14.1 wt%, respectively). This is due to the improved accessibility of lighter hydrocarbons in SW to Brønsted and Lewis acid sites in HZSM-5 micropores, promoting cracking, isomerization, cyclization, Diels-Alder, and dehydrogenation reactions. Further, the use of HZSM-5 resulted in significantly larger yields of oil and BTEX from SW pyrolysis compared to Hbeta and HY. This phenomenon is ascribed to the well-balanced distribution of Brønsted and Lewis acid sites and the identical geometric structure of HZSM-5 micropores and BTEX molecules. The addition of Ga to HZSM-5 further led to 2.24% and 28.30% enhancements in oil and BTEX yields, respectively, by adjusting the acidity of the catalyst through the introduction of new Lewis acid sites. The regeneration of the Ga/HZSM-5 catalyst by removing deposited coke on the spent catalyst under air partially recovered catalytic activity. This study not only offers an efficient transformation of undesirable wax into valuable fuels but also provides an environmentally promising solution, mitigating pollution, contributing to carbon capture, and promoting a healthier and more sustainable environment. It also suggests future research directions, including catalyst optimization and deactivation management, feedstock variability exploration, and techno-economic analyses for sustainable wax conversion into BTEX via catalytic pyrolysis.

Energetic and environmental optimizations and byproduct valorization of pyrolysis of textile dyeing sludge with FeCl3

Maximizing the circular economy of hazardous wastes is one of the imperatives not to overshoot the biogeochemical limits of Earth. This study aimed to characterize and valorize the textile dyeing sludge (TDS) pyrolysis in response to the addition of FeCl3 conditioner in the N2 and CO2 atmospheres. The increase fraction of FeCl3 decreased comprehensive pyrolysis index (CPI600) from 1.05 to 0.42 in the N2 atmosphere and from 0.71 to 0.41 in the CO2 atmosphere at 20 °C/min. The addition of FeCl3 diminished the pyrolysis performance, with a more pronounced inhibitory effect occurring in the N2 atmosphere than in the CO2 atmosphere. Regardless of the type of pyrolysis atmosphere, with or without FeCl3, all the TDS pyrolysis released CO, CO2, CH4, aromatics, NH3, and SO2. The main pyrolytic byproducts were nitrides and hydrocarbons, represented by ethanolamine (C2H7NO) and benzene (C6H6). Not only did 4 % FeCl3 addition facilitate the transformation of nitrides into hydrocarbons during the pyrolysis, but it also achieved the optimal energetic performance and emission reduction. Our findings provide novel and actionable insights into the byproduct valorization and pollution control during the TDS pyrolysis and the promotion of carbon capture, utilization, and storage.

Potential of Biochar as a Peat Substitute in Growth Media for Lavandula angustifolia, Salvia rosmarinus and Fragaria × ananassa.

Peat has long been the primary substrate for the production of ornamental and horticultural plants in pots. Today, peat is no longer considered a renewable resource due to its very lengthy regeneration time. Biochar, a solid by-product of biomass pyrolysis, has been proposed as an agricultural soil amendment. We investigated the effects of two types of biochar, namely biochar from pruning wood waste and biochar activated with wood vinegar ("smoked biochar"), on two ornamental plants (Lavandula angustifolia and Salvia rosmarinus) and on strawberries (Fragaria × ananassa). For both types of biochar, we measured the following parameters: the pH, density, electrical conductivity, humidity, calcium carbonate, total carbon, nitrogen, potassium, calcium, magnesium, sodium, and water retention. For peat, we measured the following parameters: the pH, electrical conductivity, total carbon, and total nitrogen. Our results showed an overall increase in plant growth, particularly in L. angustifolia when using 10% and 50% biochar concentrations and a 10% concentration of biochar activated with wood vinegar. In S. rosmarinus, we observed a slight increase in the total plant weight with the application of 10% smoked biochar (biochar activated with wood vinegar). Finally, in F. × ananassa, we observed an increase in the plant weight and fruit production when 10% biochar was applied. On the other hand, when high concentrations of biochar (50% and 100%) and especially smoked biochar were applied, we observed a significant reduction in the growth of all plants. We concluded that biochar and biochar activated with wood vinegar showed remarkable biological activity with marked phytotoxicity at high concentrations. They promoted plant growth when applied diluted and their use as partial peat substitutes could help support more sustainable horticultural practices.

Pyrolysis and Combustion Characteristics of Two Russian Facemasks: Kinetic Analysis, Gaseous Emissions, and Pyrolysis By-Products

Pyrolysis and combustion experiments were performed on two facemasks (hereafter named Tissue and Surgical) commonly used in the Russian Federation, first in a thermobalance and under four low-temperature ramps (5, 10, 15, and 20 °C/min). The pyrolysis mass rate curves present a unique devolatilization peak. The combustion mass rate curves present a unique devolatilization peak followed by a shoulder or a small further peak on its right-hand side. Both processes mainly occur between 200 and 500 °C. Simulations of these pyrolysis and combustion processes are performed with good agreement using the extended independent parallel reaction (EIPR) model. The gas chromatography technique was used to analyze the by-products of pyrolysis experiments performed under isothermal temperatures of 300, 400, and 500 °C. Combustion experiments were finally performed in a horizontal oven under a temperature ramp approximately equal to 5 °C/min to measure the main gaseous emissions: CO2 emissions are the main emissions of the Tissue mask, while total hydrocarbons are the main emissions of the Surgical mask. Significant differences are observed between the results obtained for the two masks because of the fibers they are built with (natural or synthetic).

Evaluation of the content and degradation rates of PAHs in biochars, in terms of assessing the environmental risks of their application for soil remediation

The growing worldwide practice of biochar application as soil ameliorants, as well as adsorbents for remediation of soil contaminated with oil products and heavy metals, can lead to an increase the risk of environmental pollution by pyrolysis by-products. One of the most dangerous components of biochars is polycyclic aromatic hydrocarbons (PAHs), which are inevitably formed during the production of pyrogenic material. In this work, biochars obtained from various plant materials (millet, corn, willow, linden) under different pyrolysis temperatures were tested for the content of polycyclic aromatic hydrocarbons. The total content of PAHs in the studied samples ranged from 8.49 to 221.21 µg/kg, which does not exceed the limit concentrations established by the International Biochar Initiative. At the same time, polynuclear hydrocarbons with high carcinogenic and immunotoxic properties are found in the composition of biochars. A natural question arises about the effect of the final pyrolysis temperature on the total content and composition of PAHs in pyrolysis by-products. To study the degradation of polycyclic aromatic hydrocarbons in soil, linden biochar obtained by pyrolysis at 250 °C was used, from which the contaminants were extracted and applied to the soil so that the concentration of the marker was 20 and 40 µg/kg. The determination of the residual amount of polycyclic aromatic hydrocarbons was carried out after 1, 2, 6, and 11 months of incubation. Complete degradation of some 3–5-membered polycyclic aromatic hydrocarbons was found after 1–2 months of incubation. The most persistent pollutants were benzo(a)pyrene, benzo(b)fluoranthene, and pyrene, the concentration of which decreased to 31–71% on after 11 months of incubation. The slower degradation was found in the variant of the experiment with the high concentration level of polycyclic aromatic hydrocarbons. It was concluded that in soils selective accumulation of polynuclear PAHs, that most resistant to biodegradation, can occur.

Corn biochar influences yield attributes of two varieties of chili (Capsicum annuum) in the coastal region

A solid biomass pyrolysis byproduct is biochar. The most important uses of this carbon-rich, porous substance are soil enhancement, remediation, and pollution management. Biochar improves soil fertility, water retention, and fertilizer efficiency. Biochar stores plant nutrients, reduces salinity and drought, and neutralizes soil acidity. This component is environmentally favorable. It reduces chemical fertilizer and irrigation as well as lowers farmer costs. Green chili benefits greatly from organic fertilizer. Biochar must pay more attention to this economically valued crop despite its importance. Under a randomized complete block design (RCBD) with 3 replications, a field experiment determined the best dose to boost chili plant yield. Thus, to determine how two green chili varieties—Bangladeshi local hybrid 'Anal 1701 DG F1' (V1) and Indian hybrid 'Bijlee Plus F1' (V2)—react to different corn biochar doses. The treatments included T1 (Control), T2 (0.1kg/m2), T3 (0.3kg/m2), T4 (0.5kg/m2), and T5 (0.7kg/m2). Using biochar significantly (*p<0.05) increased yield characteristics. Bijlee plus F1 had the highest yield and yield-related parameters above Anal 1701 DG F1. The combination of treatments and varieties yielded the maximum (2.40 ton/ha) in T5V2, while the lowest (0.3134 ton/ha) was in T1V1. Most yield-related characteristics (fruit number per plant, single fruit weight, mature chili length, diameter, and total yield) were achieved from T5 treatment and T5V2 interaction. Corn biochar performed well on green chili varieties and yield-related parameters. The investigation proposed using Bijlee plus F1 variety and 0.7kg/m2 corn biochar (T5) dose to maximize chili production. This is an excellent recommendation for the farmers of coastal areas.

Evaluating the evolution and impact of wood vinegar research: A bibliometric study

Wood vinegar, a valuable byproduct of biomass pyrolysis, has gained increasing attention due to its potential applications in agriculture, forestry, environmental sectors and other fields. This study presents a comprehensive bibliometric analysis of research conducted in the field of wood vinegar during the period 2002–2022. The aim is to explore research productivity, collaboration patterns, and publication trends in this domain. A systematic search of the Scopus database yielded 460 scientific articles from journal sources. The collected data were analyzed using bibliometric techniques, including co-authorship analysis, citation analysis, and keyword co-occurrence analysis. The results reveal a steady growth in the number of publications on wood vinegar over the years, indicating a growing research interest in the field. The number of papers published each year increased from 7 in 2002–79 in 2022. The growth increase in 2022 versus 2019 was + 170%. Analysis of authorship patterns highlighted key contributors and collaborative networks within the research community. The most productive country was China with 191 papers. Citation analysis provided insights into influential studies and the impact of research in the field. Through keyword co-occurrence analysis, the study identified prominent research themes and emerging topics within wood vinegar research. This bibliometric analysis offers a comprehensive overview of the research landscape in the field of wood vinegar, facilitating a better understanding of its progress, impact, and potential avenues for future research.

Diluted pyroligneous vinegar promoted Rhododendron growth by changing functional genes involved in N cycling in the rhizosphere

Excessive chemical fertilization in protected horticulture has caused nutrient accumulation, reduction of soil biodiversity, and subsequently soil degradation. Pyroligneous vinegar is a byproduct of pyrolysis for biochar production. While there has been an increase in interest in using pyroligneous vinegar as an amendment to improve soil quality, a paucity of data exists of its effect on the growth of acidophilous plants such as azalea (Rhododendron). To address this, we investigated the changes in the growth of azalea and soil microbial abundance, specifically those involved in nitrogen cycling in the rhizosphere with amendment of conventional inorganic NPK fertilizer (NPK) and four dilutions of pyroligneous vinegar each with matched NPK content. The results showed that the treatments of pyroligneous vinegar increased plant biomass (51%-99%), root length (29%-81%) and surface area (63%-151%), and nitrogen use efficiency (83%-299%) compared to NPK alone. The pyroligneous vinegar treatments decreased soil pH and increased the contents of rhizosphere soil dissolved organic carbon and nitrate, and changed potential denitrification activity. Compared with NPK, pyroligneous vinegar increased archaeal and bacterial amoA genes (AOA and AOB) abundances (45% − 79% and 39% − 75%, respectively) in nitrification, but inhibited the denitrification gene abundances (i.e. nirS and nirK abundance up to 21% lower). Pyroligneous vinegar increased the ratio of nosZ/(nirS + nirK), suggesting an increased potential to lower nitrous oxide emissions.Correlation analysis indicated that nitrogen use efficiency correlated positively with AOA and AOB, but negatively with nirS and nirK abundance. Therefore, our study suggests that pyroligneous vinegar could improve the growth of acidophilous plants and increase their nitrogen use efficiency by changing nitrogen cycling related functional genes, and could be a potential soil amendment in protected horticulture.

Study on the biocontrol efficiency and underlying antagonistic mechanism of valsa canker by pyrolysis tar from apple wood

Apple valsa canker, caused by V. mali, often leads to tree bark rot and yields decreasing. Wood tar, a by-product of biomass pyrolysis contains rich antimicrobial active substances. It has good bonding and waterproofing properties, which is ideal for the control of apple canker. In this study, wood tar obtained from pyrolysis of waste fruit wood was used as supplied test fungicides to explore the biocontrol efficiency and underlying antagonistic mechanism of wood tar against V. mali. Based on the bacteriostatic test, the field experiment was carried out to study the comprehensive control effects of smearing once or twice different times dilution wood tar a year after disease spots treated in different ways. The results showed that the concentrations of wood tar were positively correlated with the inhibition rate of hypha and residual duration, in which the inhibition rate of both 2 and 5 times dilution reached 100% and the residual duration lasted for 7 days. And the control effect of twice annual application after striking off diseased tree spots in zones Ⅰ and Ⅱ, after crisscrossing scratches on diseased tree spots in zone Ⅱ gradually reduced with the increase of wood tar dilution times. The control effect of applying wood tar stock solution and 2 times dilution solution after three kinds of disease spot treatments were 100%, which were improved by 274.5%, 49.9% and 66.7% respectively compared with the control fungicides. The present study demonstrated that wood tar showed promising prospects for use as a biological control agent against apple valsa canker under field conditions.

Kinetic analysis and pyrolysis behavior of pine needles by TG-FTIR and Py-GC/MS

The pyrolysis performances and reaction kinetics of pine needles (PN) were investigated by integrating thermogravimetric analysis, Fourier transform infrared spectroscopy, and pyrolysis-gas chromatography/mass spectrometry. The average activation energy of PN was estimated to be 183.2 kJ/mol by Kissinger Akahira Sunose (KAS) and 183.8 kJ/mol by Flynn Wall Ozawa (FWO), respectively at heating rates of 10, 20, and 40 °C/min. The pyrolysis of PN was found to be more efficient at the lower heating rates, while increased heating rates promoted the reaction. Using the King-Kai (K-K) method, the activation energies of hemicellulose, cellulose, and lignin were calculated to be 156, 165, and 172 kJ/mol, respectively. The descending order of evolving gases and functional groups from PN was found to be CO2, C=C, C=O, H2O, CH4, and CO. The main pyrolytic by-products identified were hydrocarbons, phenols, alcohols, ketones, and aldehydes. The determination of kinetic parameters provides fundamental information for predicting the rates at which chemical reactions occur. This study demonstrates the potential of PN as a suitable source for bioenergy.

Effect of surfactants on the properties of rubber composites prepared from pyrolytic carbon black/natural latex via wet blending method

Pyrolytic carbon black (CBp) is the main by-product of waste tire pyrolysis. CBp has high ash content and poor surface activity which leads to the composites reinforced with CBp has lower performance than composites reinforced with commercial carbon black, making it difficult to meet the requirements of tire. In order to realize the application of CBp in tires, the effect of surfactants on the properties of rubber composites prepared by wet mixing of CBp/natural latex was investigated. In the experimental process, sodium stearate (C17H35COONa), sodium dodecylbenzene sulfonate (C18H29NaO3S), and sodium p-styrenesulfonate (C8H7NaO3S) were used to improve the surface activity and uniform dispersion of the CBp in the natural rubber matrix. The experimental results showed that the dispersity of C18H29NaO3S and C8H7NaO3S modified CBp in rubber matrix has [X] and [Y] values of 7.5 and 7.9, and 9.3 and 9.5, respectively, and the dispersion of these rubber composites is significantly better than that of C17H35COONa. The rubber composites prepared by C18H29NaO3S and C8H7NaO3S surfactants has the better physical and mechanical properties. The rubber composite prepared by C18H29NaO3S has the highest tensile strength of 25.63 MPa, which increment in tensile strength is 15.6% compare to the rubber composite prepared by C17H35COONa. Meanwhile the dynamic mechanical properties of rubber composites prepared by modifying CBp with C18H29NaO3S and C8H7NaO3S are better than CBp with C17H35COONa. The C8H7NaO3S modified CBp/rubber composite has the lowest loss factor (tanδ) value at 60°C, and the C18H29NaO3S modified CBp/rubber composite has the highest tanδ value at 0°C.

Characteristics of glyphosate adsorption with biochar from young coconut waste

Biochar is a carbon-rich by-product of biomass pyrolysis that can limit glyphosate mobility in soil using amelioration technology. Study of the basic principles of glyphosate adsorption behaviour in biochar from young coconut waste using the Kon-Tiki method at temperature (682°C), moisture content (81.27%), and yield ratio (20.87%) at the size of ≤2 mm. The absorption of glyphosate in biochar increased as glyphosate content rose, whereas pH declined. The capacity and adsorption coefficient of glyphosate by biochar from young coconut waste was 0.85 mg g-1 and 56.25 L Kg-1 at a pH of 8.03 and a concentration of 100 mg L-1 glyphosate. The adsorption isotherm of glyphosate occurs in the Freundlich and Langmuir models (Freundlich > Langmuir), wherein the Freundlich model (y = 1.8373x - 2.3971; R2 = 0.9771) with a value of n (0.54) and KF [0.004 (L mg-1)1/n], and the Langmuir model (y = - 17.066x + 251.58; R2 = 0.7239) with a value of Qm (0.06 mg g-1) and KL (0.07 L mg-1).

Activated Carbon Derived from Waste Oil Shale Semi-Coke for Supercapacitor Application.

As fossil fuels gradually deplete, oil shale, one of the world's largest energy resources, has attracted much attention. Oil shale semi-coke (OSS) is the main byproduct of oil shale pyrolysis, which is produced in large quantities and causes severe environmental pollution. Therefore, there is an urgent need to explore a method suitable for the sustainable and effective utilization of OSS. In this study, OSS was used to prepare activated carbon by microwave-assisted separation and chemical activation, which was then applied in the field of supercapacitors. Raman, XRD, FT-IR, TEM, and nitrogen adsorption-desorption were adopted to characterize activated carbon. The results showed that ACF activated with FeCl3-ZnCl2/carbon as a precursor has larger specific surface area, suitable pore size, and higher degree of graphitization compared with the materials prepared by other activation methods. The electrochemical properties of several active carbon materials were also evaluated by CV, GCD, and EIS measurements. The specific surface area of ACF is 1478 m2 g-1, when the current density is 1 A g-1, the specific capacitance is 185.0 F g-1. After 5000 cycles of testing, the capacitance retention rate was as high as 99.5%, which is expected to provide a new strategy of converting waste products to low-cost activated carbon materials for high-performance supercapacitors.

Characteristics of briquettes from plastic pyrolysis by-products

Pyrolysis has been proven as a method to reduce plastic waste and produce useful products, especially liquid fuels. However, plastic pyrolysis also produces gases and char as by-products which are being investigated for useful products. Therefore, our present study aims to investigate the char characteristics of plastic pyrolysis for further use as briquettes. Seven samples of char by-products from the pyrolysis process of low-density polyethylene (LDPE) plastic at various reaction temperatures and catalyst types were studied. The proximate test is used to determine the properties of char such as moisture content, ash, volatile matter, and fixed carbon while the bomb calorimeter is used to determine the calorific value. Briquettes are formed by mixing 4 grams of char and 0.5-1 gram of binder (1% starch and 90% water). The briquettes were formed into solid cylinders with a diameter of 1.75 cm and formed with a pressure of 10 kg/cm2. Furthermore, the impact resistance index (IRI) was used to test the performance of the briquettes and showed an IRI value between 100 and 200. However, of the seven char samples tested, three of them were impossible to process into briquettes because they melted during the combustion test.

ОЛІГОМЕРИЗАЦІЯ ФРАКЦІЇ С9 З ВИКОРИСТАННЯМ 2-(ТРЕТ-БУТИЛПЕРОКСИМЕТИЛАМІНО)АЦЕТАТНОЇ КИСЛОТИ

The oligomerization in solution and suspension oligomerization of the fraction C9 of liquid by-products of pyrolysis of diesel fuel is initiated by 2- (third-butylperoxymethylamineo) acetate acid have been studied. The nature of the effect of oligomerization, the concentration of the initiator, the temperature and duration of the reaction to the output and the physicochemical characteristics of the obtained oligomers were clarified. The optimal technological parameters of the process of oligomerization of the fraction C9 were selected. Relatively peculiarities of the course of suspension oligomerization and oligomerization in the solution of the fraction C9.

Pyrolysis of Lignin in the Presence of Cerium Oxide Coupled with Molten Salts

Lignin is a crucial raw material for the synthesis of phenol due to its high oxygen concentration; however, the selectivity of phenol in pyrolysis products is low. This study chose cerium oxide as the coupling agent for molten salts, and the reaction’s process conditions—including temperature and catalyst dosage—were examined. The influence of metal loading on the reaction and byproducts of catalytic pyrolysis was examined. The outcomes demonstrated that the best monophenol production was accomplished at 550 °C and an Fe loading of 15 wt.%, with 93.93 wt.% monophenols in the bio-oil. While methoxy was more easily broken and rearranged, producing more monophenols, the presence of the catalyst enhanced the oxidation of Cα-OH and the breaking of β-O-4 bonds, which is significant for the study of lignin pyrolysis.

Effect of Biochar Dosage and Fineness on the Mechanical Properties and Durability of Concrete

Biochar (BC), a byproduct of agricultural waste pyrolysis, shows potential as a sustainable substitute material for ordinary silicate cement (OPC) in concrete production, providing opportunities for environmental sustainability and resource conservation in the construction industry. However, the optimal biochar dosage and fineness for enhancing concrete performance are still unclear. This study investigated the impact of these two factors on the mechanical and durability properties of biochar concrete. Compressive and flexural strength, carbonation resistance, and chloride ion penetration resistance were evaluated by varying biochar dosages (0%, 1%, 3%, 5%, 10%) and fineness dimensions (44.70, 73.28, 750, 1020 μm), with the 0% dosage serving as the control group (CK). The results showed that the addition of 1-3 wt% of biochar could effectively reduce the rapid carbonation depth and chloride diffusion coefficient of concrete. The compressive and flexural strength of BC concrete initially increased and then decreased with the increase in biocarbon content, BC with a fineness of 73.28 μm having the most significant effect on the mechanical strength of concrete. At the dosage of 3 wt%, BC was found to promote the hydration degree of cement, improving the formation of cement hydration products. These findings provide valuable insights for the development of sustainable and high-performance cement-based materials with the appropriate use of biochar as an additive.