Search Results (7)

Despite a growing interest in biochar for olive orchard fertility management, little is known about its effects on nitrogen (N) dynamics and greenhouse gas (GHG) emissions in Mediterranean soils, particularly when comparing neutral (pH 6.7) and alkaline (pH 8.2) soils using farmer-accessible flame-curtain pyrolysis biochar. In this 60-day soil mesocosm study, we hypothesized that biochar amendments in fertilized soils would enhance soil N availability and potentially reduce N₂O emissions, with effects modulated by soil pH. Treatments included: control, urea fertilizer, and urea plus biochar (5% w/w). Urea fertilization significantly increased soil ammonium (NH₄⁺) and total oxidized nitrogen (NO₃⁻ + NO₂⁻) in both soils, and co-application of biochar further increased these pools, particularly in the neutral soil (NH₄⁺: + 91% and + 62% in neutral and alkaline soil, respectively). Biochar addition consistently reduced cumulative carbon dioxide (CO₂) emissions in both soils, supporting its role in stabilizing soil organic carbon. However, impacts on nitrous oxide (N₂O) emissions were soil-pH-dependent: biochar slightly reduced N₂O emissions in neutral soil, though nearly doubled N₂O emissions in alkaline soil, highlighting that biochar’s efficacy for GHG mitigation is context-specific. These findings underscore biochar’s potential to improve soil N availability and reduce carbon losses but reveal clear limitations for N₂O mitigation in alkaline soils, necessitating site-specific application strategies that explicitly consider soil pH when targeting climate benefits in Mediterranean olive production. Full article

Simple and low-cost flame curtain (“Kon-Tiki”) kilns are currently the preferred biochar technology for smallholder farmers in the tropics. While gas and aerosol emissions have been documented for woody feedstocks (twigs and leaves) with varying moisture contents, there is a lack of data on emissions from other types of feedstocks. This study aims to document the gas and aerosol emissions for common non-woody feedstocks and to compare emissions from finely grained, high-lignin feedstock (coffee husk) with those from coarser, low-lignin feedstocks (maize cobs, grass, sesame stems). Throughout each pyrolysis cycle, all carbon-containing gases and NO_x were monitored using hand-held sensitive instruments equipped with internal pumps. Carbon balances were used to establish emission factors in grams per kilogram of biochar. The resulting methane emissions were nearly zero (<5.5 g/kg biochar) for the pyrolysis of three dry (~10% moisture) maize cobs, grass, and a 1:1 mixture of grass and woody twigs. For sesame stems, methane was detected in only two distinct spikes during the pyrolysis cycle. Carbon monoxide (CO) and aerosol (Total Suspended Particles, TSP) emissions were recorded at levels similar to earlier data for dry twigs, while nitrogen oxide (NO_x) emissions were negligible. In contrast, the pyrolysis of finely grained coffee husks generated significant methane and aerosol emissions, indicating that technologies other than flame curtain kilns are more suitable for finely grained feedstocks. The emission results from this study suggest that certification of biochar made from dry maize, sesame, and grass biomass using low-tech pyrolysis should be encouraged. Meanwhile, more advanced systems with syngas combustion are needed to sufficiently reduce CO, CH₄, and aerosol emissions for the pyrolysis of finely grained biomasses such as rice, coffee, and nut husks. The reported data should aid overarching life-cycle analyses of the integration of biochar practice in climate-smart agriculture and facilitate carbon credit certification for tropical smallholders. Full article

Jute is an inherent lignocellulosic fiber, consisting of hemicellulose, α-cellulose, and lignin. Industrial ventilation, automotive composites, upholstery, carpets, military uniforms, hospital furnishings, and curtains necessitate the integration of flame-retardance properties into jute fibers. In this investigation, seven weave-structured jute fabrics were treated using an organophosphorus-based flame-retardant (FR) chemical (ITOFLAM CPN) and a crosslinking agent (KNITTEX CHN) by the pad–dry–cure method. The thermal stability, degradation and pyrolysis behavior of jute was measured using a thermogravimetric analyzer (TGA). Surface morphology and element distribution were scrutinized utilizing a scanning electron microscope (SEM) and an energy-dispersive spectrometer (EDS). The ATR-FTIR (Attenuated Total Reflection-Fourier Transform Infrared Spectrometer) technique has been employed for analyzing the composition of chemicals in the jute fabrics. According to the protocols specified in ISO 14184-1, free formaldehyde detection was carried out on the jute fabrics. The flame-retardance property was significantly improved on all of the jute fabrics after FR treatment. FTIR and SEM-EDS studies revealed the presence of FR chemical deposition on the surface of the jute fabrics. TGA analysis indicated that the fabrics treated with FR exhibited premature degradation, leading to the generation of more char compared to untreated samples. The jute fabrics specifically demonstrated a notable enhancement in residual mass, exceeding 50% after FR treatment. However, it is noteworthy that the FR-treated fabrics exhibited an elevated level of free formaldehyde content, surpassing the permissible limit of formaldehyde in textiles intended for direct skin contact. The residual mass loss percentage after ten washes of FR-treated fabrics remained in a range from 32% to 36%. Twill weave designed fabrics (FRD4 and FRD5) clearly showed a lower thermal degradation temperature than the other weaves used in this study. Full article

Pyrolysis is a combustion process of woody biomass conducted under low or no oxygen conditions. It converts any kind of biomass into biochar, bio-oil, or biogas. Hence plants’ woody material can also be converted into bioenergy products. Valorization of woody biomass in the form of energy-rich compound biochar is a more sustainable technique as compared to conventional burning which leads to toxicity to the environment. Innovations and the need to limit open burning have resulted in numerous mobile and fixed plant pyrolysis methods that burn a variety of woody residues. Production technologies that reduce the need for open burning, the main source of potential pollutants, fall under the regulations in the Clean Air Act of 1990. This Act is the legal instrument to regulate air pollution at its source across the United States of America and it is implemented and enforced through the Environmental Protection Agency, in coordination with sister agencies. One newer innovation for reducing wood residues and emissions is an air curtain incinerator. Currently, the Clean Air Act regulates stationary solid waste incinerators, and this is also applied to mobile air curtain incinerators burning woody biomass. However, other woody biochar production methods (e.g., flame cap kilns) are not subjected to these regulations. Discrepancies in the interpretation of definitions related to incineration and pyrolysis and the myriad of differences related to stationary and mobile air curtain incinerators, type of waste wood from construction activities, forest residues, and other types of clean wood make the permit regulations confusing as permits can vary by jurisdiction. This review summarizes the current policies, regulations, and directives related to in-woods biochar production and the required permits. Full article

As thermoplastic materials are widely used in buildings, the fire hazards of thermoplastic materials are increasingly becoming a central issue in fire safety research due to their unique pyrolysis and melting mechanisms. In this paper, the features and common types of thermoplastic materials are introduced first. Then, the combustion behavior of thermoplastic materials is theoretically analyzed based on the empirical formulas and heat balance equations, such as the pyrolysis kinetics, ignition time, melting and dripping, flame, burning rate and mass loss rate, temperature and heat flow, gas products, and influencing factors. The influencing factors basically include the sample properties (width, incline angle, and thickness, etc.), the façade structure (sidewalls, curtain wall, etc.), the ambient conditions (altitude, pressure, and gravity, etc.), and the flame retardant treatment. Similarly, this study also illustrates the vertical and horizontal flame spread behavior of the thermoplastic materials and the influencing factors. The utilized methods include the experimental methods, the analytical methodologies, and the approaches for numerical simulation. Finally, the problems encountered at this stage and worthy of further study in the future are presented. Full article

Pine tree biochar produced by flame-curtain pyrolysis, an inexpensive and simple pyrolysis methodology, was used as the starting material for KOH-activated carbon. Flame-curtain pyrolysis is a simple, low-technology methodology that can be performed by non-specialized personnel. The elemental analysis of the biochars highlighted the high reproducibility of the process. The N₂ adsorption isotherms indicated that KOH activation was effective for the preparation of high-surface-area activated carbons from the biochar. The BET specific surface area increased with the quantity of KOH added in the activation process, achieving a maximum value of 3014 m² g⁻¹ at 85.7 wt.% of KOH addition. The adsorption isotherms of all samples were IUPAC type I, establishing their microporous nature. Results from the Mikhail–Brunauer (MP) method and α_s plot indicated that the pore size distribution became wider and the pore volume increased as the KOH content increased. The measured capacitance values followed the same dependence on KOH content. The maximum capacitance value at 1 mV s⁻¹ was determined as 200.6 F g⁻¹ for the sample prepared at 75 wt.% of KOH addition. Therefore, pine tree biochar prepared by simple pyrolysis equipment is a suitable precursor for the development of an electric double-layer capacitor. Full article

A widely abundant and invasive forest shrub, Eupatorium adenophorum, was pyrolyzed in a cost-efficient flame curtain kiln to produce biochar. The resulting biochar fulfilled all the requirements for premium quality, according to the European Biochar Certificate. The biochar was either applied alone or mixed with fresh cow urine (1:1 volume) to test its capacity to serve as slow release fertilizer in a pumpkin field trial in Nepal. Treatments included cow-manure compost combined with (i) urine-only; (ii) biochar-only or (iii) urine-loaded biochar. All materials were applied directly to the root zone at a biochar dry matter content of 750 kg·ha⁻¹ before seeding. The urine-biochar treatment led to a pumpkin yield of 82.6 t·ha⁻¹, an increase of more than 300% compared with the treatment where only urine was applied, and an 85% increase compared with the biochar-only treatment. This study showed for the first time that a low-dosage root zone application of urine-enhanced biochar led to substantial yield increases in a fertile silt loam soil. This was tentatively explained by the formation of organic coating of inner pore biochar surfaces by the urine impregnation, which improved the capacity of the biochar to capture and exchange plant nutrients. Full article