Effect Of Residence Time Research Articles

Study on characteristics of toluene/chlorobenzene nitrification in different microreactors

Aromatic nitrification with mixed acid is an important industrial reaction with fast, strong-exothermic, and high-risk reaction characteristics. To investigate the promotion for the preparation of nitrotoluene (MNT) and nitrochlorobenzene (NCB), three microreactors with different structural features, namely, heart-shaped, diamond-shaped, and zigzag-shaped microreactors, are designed and fabricated. Firstly, the effects of temperature, residence time, and molar ratio on toluene (TOL) and chlorobenzene (CB) nitrification are investigated, and orthogonal experiments are further conducted to determine the optimum reaction conditions. Results showed that channel structures and the residence time τ have negligible effects on the isomers selectivity of the three microreactors, and higher reaction temperatures and mole ratios would lead to the substantial occurrence of side reactions and byproducts in the zigzag microreactor. The heart-shaped microreactor has the highest value of 91.49 % for the MNT's optimal yield, followed by the diamond-shaped and zigzag-shaped microreactors (89.91 % and 89.81 %, respectively). The heart-shaped microreactor provides the maximum amount of NCB preparation (93.95 %), while the yields of the diamond-shaped and zigzag-shaped microreactors are 91.51 % and 88.25 %, respectively. This work provides the experimental basis for the efficient preparation and industrial scale-up of aromatic nitrification in microreactors.

Insights into n-dodecane steam reforming in gliding arc discharge plasma with experiment and kinetic model

n-dodecane steam reforming (SR) process was investigated from both experimental and modelling views in gliding arc plasma. The effects of water-carbon molar ratio, n-dodecane concentration, input power and residence time on the conversion, yield, energy efficiency EE(C12H26) and hydrogen energy yield EY(H2) were revealed. The most dominant spectral lines detected by optical emission spectroscopy (OES) are CN violet and Hα (3d2D-2p2p0). The highest yields of H2 and CO are 50.1% and 49.9%, respectively. A zero-dimension reaction kinetic model containing 105 species and 793 reactions was developed for the SR process. Using CHENKIN-PRO, the presumable reaction pathways of n-dodecane, H2, CO, H2O and CO2 were described in detail. H2 and CO were produced mainly through reaction C2H4+H⇌C2H3+H2 and reaction HCCO+H⇌CH2(S)+CO.

Effect of Residence Time on Desulfurization and Denitration by the Semi-Dry Ozone Injection Reactor

ABSTRACT The semi-dry nonthermal plasma-induced ozone injection process is a promising desulfurization and denitration method for flue gases emitted from glass melting furnaces. To design a reactor for this process in an actual plant, it is necessary to evaluate the effect of the residence time of the flue gases in the reactor on desulfurization and denitration. In this study, the inner volume of the reactor was vertically divided into ten sections corresponding to the temperature measurement points. The residence time of each section was calculated to determine the residence time in the reactor. The effect of residence time on desulfurization and denitrification was then elucidated. In addition, the nitrite ( N O 2 − ) and nitrate ( N O 3 − ) ions in the droplets collected in the wastewater tank connected to the bottom of the reactor and in the condensates in the condensers downstream of the reactor were measured to evaluate the nitrogen balance with respect to the removed NOx.

Batch electrocoagulation system for the treatment of Borneo urban river in relation to the industrial zone

Urbanization activities on Borneo Island have degraded the water quality of some urban rivers due to increased anthropogenic activities which leading to elevated levels of total organic carbon (TOC) and reduced access to clean water sources. As such, this study aims to develop a batch electrocoagulation treatment system to reduce the TOC levels in Borneo urban river for domestic consumption. Correspondingly, this study analyses the effect of electric current and residence time on TOC reduction efficiency. Subsequent, this study has found that the TOC levels in treated urban river water met domestic consumption safety standard by utilizing a batch electrocoagulation treatment system at 5 A of electric current and 25 minutes of residence time. The treatment system achieves 82.83% of maximum TOC reduction efficiency by decreasing the initial TOC levels from 5.65 mg/L to 0.97 mg/L. The energy operating cost analysis done in this study has reported that electrocoagulation treatment system could generate 116.51 g Al(OH)3 per meter cubic of urban river water at a cost of United States Dollars (USD) 0.32 per m3. Additionally, the reduction of TOC levels in urban river by using in-situ aluminium hydroxide coagulants follows Freundlich isotherm model with a regression coefficient of 0.99, thus, exhibiting a multilayer adsorption. The aluminium hydroxide coagulants could reduce TOC from urban river at 1.40 min−1 of adsorption rate and 0.20 mg/g of maximum adsorption capacity. From the energy dispersive X-ray analysis conducted, this study has observed the presence of electrocoagulation flocs that are constituted with aluminium hydroxide coagulants and carbon element which indicated the occurrence of adsorption process. Overall, this study demonstrates that the batch electrocoagulation treatment system could be utilized to reduce the TOC level from Borneo urban river with an adsorption process which is deemed suitable for domestic consumption at a reasonable cost.

Steam explosion technology as a tool to alter the physicochemical properties of intermediate wheatgrass (Thinopyrum intermedium) bran

Products containing the perennial grain intermediate wheatgrass (IWG) have recently entered the market, but little is known about the effect of processing operations on its constituents. This study investigated the effect of steam explosion (SE) conditions, i.e., temperature (130, 150 or 170 °C) and residence time (5 or 10 min), spanning severity factors from 1.6 to 3.1, on physicochemical properties of IWG bran. Even the lowest temperature and shortest time combination (130 °C, 5 min), was sufficient to inactivate peroxidase, generally regarded as the most heat-stable enzyme in grains. Contents of free phenolic acids as well as water-extractable arabinoxylans significantly increased while phytic acid was reduced after SE. However, starch damage, free fatty acids as well as browning (all negatively affecting quality) increased with treatment severity. Thus, SE is a promising technology to reduce enzymatic activity, enhance phenolic and soluble fiber contents in IWG bran, but severity factors >2.5 may negatively affect quality.

Hydrochars derived via wet torrefaction of empty fruit bunches: Effect of temperature and time, comparison to oil palm trunks counterpart, and their pyrolysis behavior

In this study, hydrochars derived from the wet torrefaction of empty fruit bunches (EFB) were characterized and compared to those of oil palm trunks (OPT). Then, the kinetics modelling of EFB-derived hydrochars was evaluated and compared with the Distributed Activation Energy Model (DAEM) under logistics distribution via thermogravimetric analysis (TGA) under pyrolytic conditions at different heating rates. Bench-scale pyrolysis of EFB-derived hydrochars were also performed and characterized. This study elucidates the effect of prolonged residence time (3–72 hours) at different temperatures (180–220 °C) on the wet torrefaction of EFB, and comparison to OPT provides an understanding of wet torrefaction mechanisms. The pyrolysis kinetics of EFB-derived hydrochars provide insights into their pyrolysis behavior and their potential in pyrolytic application. Increased temperature and residence time enhanced the higher heating value (HHV) of the hydrochars at the expense of low mass yield. Hydrochars obtained at 220 °C and 72 hours had the highest HHV at 27.4 ± 0.5 MJ kg−1 with a mass yield of 38.3 ± 2 wt%. EFB-derived hydrochars had a higher mass yield than OPT-derived hydrochars. The van Krevelen diagram revealed that dehydration was the primary reaction pathway for EFB and OPT-derived hydrochars. SEM showed the formation of secondary deposits on both EFB and OPT hydrochars. EFB-derived hydrochars obtained at 220 °C and 72 hours had the highest mean activation energy (E0) with a distribution of activation energy (σ) from 176.7 to 181.7 kJ mol−1 and 43.4–49.9 kJ mol−1, respectively. The increased mean and distribution of activation energies were attributed to the lignin-dense structure of the hydrochars. The kinetic parameters of the hydrochars were also independent of heating rates at low heating rates (< 20 °C min−1). The thermal stability of the pyrochars obtained from EFB-derived hydrochars enabled their applications in fields such as carbon support, activated carbon, water purification process, or carbon sequestration.

The Effect of Residence Time of No-tunneled Hemodialysis Catheters on Infection and Thrombosis Outcome. Identification of CVC’s Time Cut-off

Introduction: Permanent vascular access (arteriovenous fistula (AVF), arteriovenous graft (AVG)) is susceptible to acute events that reduce patency. The temporary central venous catheter (CVC) constitutes bridging therapy for primary vascular access dysfunction. The impact of “residence time” on the rate of dysfunction/thrombosis or infection remains to be explored. AIM: 1) To evaluate the impact of CVC residence time on outcomes (infection or Thrombosis/dysfunction) in consecutive temporary CVCs adjusted for the insertion site (upper site vs. lower site). 2) To establish a cut-off resident time. Patients and methods: Seventeen prevalent hemodialysis patients with three consecutive CVCs are followed up prospectively in an observational study for a period equivalent to the permanence of the CVCs. The data is recorded at the beginning of the CVC time. The diagnosis of catheter-related bloodstream infection and thrombosis/dysfunction is made following the K-Doqi 2019 guidelines. Statistical analysis: Seventeen hemodialysis patients (51 CVCs) were included. The ‘CVC resident time’ of each individual patient ((i.e. βcoefficient (log-transformed)*AUC)) was determined using LMM and then inserted into multivariate Cox models to assess infection and dysfunction/thrombosis outcomes (Joint Models). The AUC was calculated at various baseline levels of CVC time (10th……50th percentile). The cut-off point for thrombosis in CVC time corresponds to the mean of the CVC time at the 30th percentile of all CVCs. Results: The CVC time is different for CVC’s site insertion and sequence. From the analysis of multivariate joint models, CVC resident time appears not to be significant for infection, but heterogenicity for the insertion site (ref3-4=upper site) is significant for the outcome of thrombosis/dysfunction. From the study of survival analysis, the free survival from outcomes by CVC site insertion appears to be significant for thrombosis/dysfunction. The average time of CVCs’ calculation at the 30th percentile is 14 days (cut-off). Conclusion: No tunneled hemodialysis Catheter (NTHC) residence time is considered not to be a risk factor for infection, but it represents a risk factor for lower access thrombosis. After the cut-off time of 14 days, the advantage of the higher NTHCs is lost.

Exploring the impact of partial pressure and typical compounds on the continuous electroconversion of CO2 into formate

Previous research in CO2 electroreduction primarily focused on cathodic electrocatalysts and electrode configurations using pure CO2. Few studies explored the impact of residence time and N2/O2 compounds, crucial for practical industrial implementation. In this study, the effect of residence time and the influence of N2 and O2 compounds on CO2 electroreduction to formate are investigated, employing Bi carbon-supported nanoparticles in the form of Gas Diffusion Electrodes within an electrochemical flow reactor with a single pass of the reactants. The results highlight the critical role of residence time and the impact of N2 and O2 compounds in the CO2 electroconversion process. On the one hand, the evaluation of residence time holds paramount significance for the potential establishment of a large-scale CO2 recycling plant, as it has the potential to significantly impact both the capital and operational costs of the integrated electrolyzer-separator system. Optimal results are obtained in the range of residence times between 1.8 and 2.9 seconds, corresponding to CO2 flow rates of 150 and 250 mL·min−1, respectively. On the other hand, the study resulted in a promising Faradaic Efficiency for formate of 75.0%, with similar values achieved at CO2 concentrations in the range of 75 – 100 vol%. These results are particularly noteworthy as they demonstrate that achieving a CO2 capture efficiency of 100% is not necessary, thereby reducing the costs associated with this process and, consequently, the overall cost of integrating both capture and utilization processes in a CO2 recycling plant.

Optimization of Exergy Efficiency in a Walking Beam Reheating Furnace Based on Numerical Simulation and Entropy Generation Analysis

An analysis of entropy generation and exergy efficiency can effectively explore the energy-saving potential of reheating furnaces. This paper simulated the combustion, flow, and heat transfer in a walking beam reheating furnace by establishing a half-furnace model. The entropy generation rate distribution of different thermal processes was numerically calculated. The effect of slab residence time and fuel distribution in the furnace was studied to optimize exergy efficiency. The results indicated that combustion and radiative heat transfer are the primary sources of entropy generation. Irreversible losses accounted for 26.39% of the total input exergy, in which the combustion process accounted for 16.43%, and radiative heat transfer accounted for 8.47%. Reducing the residence time by 60 min decreased irreversible exergy loss by about 2.5% but increased heat dissipation and exhaust exergy loss by 5.8%. Energy saving can only be achieved when the heat exchanger’s exergy recovery efficiency exceeds 36% under different fuel supplies. Keeping the total fuel supply unchanged, increasing the fuel mass flow rate in heating-I zone while decreasing it in heating-II zone resulted in a 1.5% decrease in exergy efficiency. This study provides new insights into the energy-saving potential of reheating furnaces.

Effect of residence time on trait evolution in invasive plants: review and meta-analysis

The success of invasive species is often attributed to rapid post-introduction evolution, due to novel selection pressures at the introduced range. However, evolutionary shifts in invasion-promoting traits can also take place within the introduced range over time. Here, we first present a review of the proposed hypotheses regarding the selection pressures and trait divergence along gradients of invasion history and the studies that examined them. In addition, we present the results of a meta-analysis aimed to provide a more general overview of current knowledge on trait evolution with time since introduction. Invasion-promoting traits, including growth, competitive ability and dispersal ability, were proposed to decline in more established populations with a long invasion history due to the attenuation of selection pressures, such as enemy release or interspecific competition, while herbivore defence was suggested to increase. Our meta-analysis results reveal a general indication for the evolution of invasive plants with residence time for most of the studied traits. However, this divergence did not have a consistent direction in most traits, except for growth, which, in contrast with our prediction, increased with residence time. The lack of empirical support for the predicted change in most of the studied traits over time suggests trait evolution might be affected by other context-dependent factors such as climatic gradients along invasion routes. Similarly, the increased allocation to size in older and more established populations may be driven by increased conspecific competition pressure experienced in these populations. The general temporal effect found in our meta-analysis stresses the need to consider population age when comparing attributes of invasive plants between native and invasive ranges. Moreover, the increased size of invasive plants in older populations, suggests that the dominance of these plants might not attenuate with time since introduction, thus highlighting the need to further explore the long-term dynamics between invasive plants and their recipient native communities.

Optimization of solvothermal liquefaction of water hyacinth over PTFE-acid mediated kaolin catalyst for enhanced biocrude production

The invasive nature of water hyacinth and the need for renewable energy sources have necessitated this research. Catalyst development through enhanced pore structure and process parameters optimization are requirements for effective mass transport during the biomass valorization and improved biocrude formation during solvothermal liquefaction process. In this present study, the effects of temperature (250–340 °C), residence time (10–20 min) and catalyst loading (10–13 wt%) on biocrude, biochar, gas yield, and biomass conversion were optimized using a Box-Behnken experimental design. The developed catalyst through the application of polytetrafluoroethylene (PTFE) for pore structure enhancement was characterized using SEM, BET and XRD techniques. The process optimization found maximum biocrude yield (32.0 wt%), minimum biochar yield (19.4 wt%) and maximum conversion efficiency (80.6%) at 340 °C, 20 min residence time, and 13 wt% catalyst loading. The GC-MS result of the biocrude produced at the optimum conditions (13 wt% catalyst loading) consists of ketones (32.2%), acids (22.3%) and had 65.2% carbon, 7.3% hydrogen, HHV of 29.4 MJ/kg and H/C ratio of 1.34 while an increment in catalyst loading of 20 wt% enhanced the overall biocrude properties with HHV of 35.50 MJ/kg. This result depicts the suitability of the PTFE modified acid treated kaolin for high quality biocrude production through valorization of water hyacinth into a candidate for renewable energy material.

Effect of heat-treatment temperature and residence time on microstructure and crystallinity of mesophase in coal tar pitch

Effect of heat-treatment temperature and residence time on microstructure and crystallinity of mesophase in coal tar pitch

Plasma-catalytic CO2 methanation over Ni supported on MCM-41 catalysts: Effect of metal dispersion and process optimization

Catalytic carbon dioxide (CO2) conversion technologies can be important components in carbon capture, storage and utilization for CO2 mitigation and possible future economic activity and have gained significant attention globally in past decades. Electrified non-thermal plasma (NTP) catalysis enables CO2 hydrogenation into value-added chemicals under mild conditions. If the hybrid process is coupled with renewable energy and green hydrogen, it can be the promising solution to address the energy and carbon emission challenges. To enhance the energy efficiency of NTP-catalytic systems, bespoke catalyst design and process optimization are necessary. Here, using Ni catalysts supported on mesoporous MCM-41 and NTP-catalytic CO2 methanation as the model systems, the effects of Ni metal dispersion, argon (Ar) addition and residence time on the NTP catalysis were also studied. The findings show that (i) increased metal dispersion alone did not lead to significant enhancement in the performance of NTP catalysis (e.g., CH4 production rate: 31.4 × 10−5 mol/(s·gNi) for 42.6 % Ni dispersion vs. 26.8 × 10−5 mol/(s·gNi) for 25.1 % dispersion), (ii) Ar addition to the system led to the decreased methane production rate (e.g., CH4 selectivity decreased by ∼19 % due to the increase in Ar addition to the system from 5 to 50 mL/min), and (iii) optimization of the residence time could improve the performance of NTP-catalytic CO2 methanation (i.e., an extension of the residence time to 0.69 s resulted in the higher CO2 conversion of 72.7 % and CH4 selectivity of 95.9 % at 9.6 kV than that at 0.49 s and 11 kV).

Ultrasonic aerosol agglomeration: Manipulation of particle deposition and its impact on air filter pressure drop

Acoustic agglomeration is a technique that leverages on sound waves to promote the collision of aerosol particulate matter, thus leading to the formation of larger particle agglomerates. In this study, this acoustics-driven phenomenon is demonstrated for its usefulness as an aerosol pre-conditioning method to significantly enhance the efficiency of filtration systems in particle treatment processes. Specifically, favorable changes in pressure drop across the filters are observed as a result of receiving less particle mass, for which filters are shown to be able to have their operational life extended remarkably by more than 50%. The involved ultrasonic aerosol agglomeration mechanisms are unveiled through numerical simulations, and the effects of residence time, sound pressure level, and initial particle number concentration on agglomeration performances are experimentally investigated. In addition, validations and measurements of filter pressure drop are obtained through a series of experiments. This study provides a comprehensive overview to the design and performance characterization of acoustics-agglomeration-enhanced filtration systems, which could potentially derive energy savings for fan power in ventilation systems and be scaled up for applications in industrial plants for reducing carbon emissions.

Effect of Residence Time and Carrier Gas on the Dehydrogenation of n-Hexane over Alumina-supported Chromium Catalyst

CrOx/γ-Al2O3 catalyst was prepared by incipient wetness impregnation method, and the influence of residence time and carrier gas on the dehydrogenation of n-hexane were studied. It is found that n-hexane dehydrogenation over CrOx/γ-Al2O3 catalyst with H2 as carrier gas exhibits totally different catalytic behaviors with that of diluting n-hexane with N2. When diluting feed with N2, the selectivity to dehydrogenation product is promoted while the cracking reaction is exhibited with reducing residence time. However, the selectivity to dehydrogenation product is significantly decreased while the isomerization of n-hexane is promoted when using H2 as carrier gas. It is proposed that H2 undergoes dissociation on the dehydrogenation active site, and further facilitates the olefinic dehydrogenation products to form carbocation, which performing isomerization reaction on the acid site on the γ-Al2O3 surface. Therefore, the isomerization of n-hexane is promoted in cost of the selectivity to dehydrogenation product when using H2 as carrier gas.

Reducing the phytotoxicity of spent mushroom substrate (SMS) for sustainable growing media by superheated steam torrefaction: effects of temperature and residence time

Reducing the phytotoxicity of spent mushroom substrate (SMS) for sustainable growing media by superheated steam torrefaction: effects of temperature and residence time

Discussion on Torrefaction Parameters for Making the Refuse-Derived Fuels by Response Surface Methodology

The torrefaction process is one of the mild pyrolysisor the low-temperature carbonization, which is a thermochemical conversion in which biomass is heated in an inert or nitrogen atmosphere, and the temperature ranges from 200°C to 300°C. It is considered to be an effective pretreatment method to make solid fuels. This study utilizes low-temperature carbonization technology to improve the combustion efficiency of solid-derived fuel (RDF-5) made from biomass. In this experiment, a tubular furnace was used to feed nitrogen gas for 15 min, and four raw materials of pennisetum, rice straw, wood chips and Camellia seed cakes were fed. The analysis was carried out, and the effects of temperature and residence time on the calorific value, energy yield and energy density of the four raw materials were explored using response surface methodology (RSM). It can be seen from the experimental results that among the four raw materials, the carbon content and calorific value of Camellia seed cakes are the highest. Elemental analysis showed that the proportions of nitrogen and sulfur in these four raw materials are very low. These four substances were understood to be suitable to be refuse-derived fuels (RDF-5). Comparing the calorific value of the four kinds of biomass after torrefaction process, the calorific value of pennisetum, Camellia seed cakes, wood chips and rice straw increased by 42.5%, 38.7%, 52.7%, and 18.6%, respectively. These findings revealed that the higher temperature and the longer residence time, the smaller energy yield and the higher energy density.

Valorization of bio-oil distillation residue through co-pyrolysis with moso bamboo to prepare biochar: Optimization study on effects of blend ratio, pyrolysis temperature, and residence time

In view of the high energy consumption and pollutant emissions in the cement production industry, biomass as the renewable carbon-neutrality energy is promisingly conducive to remitting cement carbon dioxide emissions and simultaneously realizing waste-to-energy initiatives. In this study, bio-oil distillation residue (DR), with high carbon content and heat value, is co-pyrolyzed with moso bamboo (MB) to optimize the bulk and combustion properties of biochar, aiming at yielding bio-fuel as an alternative fuel to replace coals for energy and heat supply in cement industry. The impacts of three primary process parameters on the carbonization reaction were investigated, while the parametric interactions were further estimated by using response surface methodology (RSM) to optimize the ultimate, proximate and fuel characteristics of biochars. The results showed the co-pyrolysis synergies between bio-oil distillation residue and moso bamboo endowed the maximum biochar yield of 44.62% and the maximum difference biochar yield of 7.56%. Meanwhile, the experimental carbon content, fixed carbon content and high heat value (HHV) were regulated through coupling parametric distribution and further increased by 1.96%, 2.59% and 1.23 MJ/kg, respectively. The parametric responses on combustion characteristics of biochar based on thermogravimetric analysis were predicted, and the optimal carbonization conditions for biochar production were also summarized. This study would offer an optimal biochar production scheme to adaptively yield coal-like biochar for reducing anthropogenic carbon dioxide emissions in cement industry.

Tempe Wastewater Treatment Using Effective Microorganisms Made from Kepok Banana Peel Waste

Wastewater produced by the tempeh industry contains a high organic content, so it requires serious handling so as not to cause pollution in water bodies. One method that can accelerate the decomposition of the organic substance process is to use Lactobacillus sp. bacteria as effective microorganisms (EM). The material used to manufacture EM is sourced from kepok banana peel waste, which has a carbohydrate content of 9.8%. This study aims to examine the effect of EM concentration and residence time on reducing pollutants in tempeh wastewater using EM made from kepok banana peel waste. The EM concentrations were 0%, 10%, 20%, and 30% successively, with residence times of 0, 4, 8, 12, and 16 days. The researchers used a batch system in a 5-litre plastic tube reactor with an aeration system. The results demonstrated the effectiveness of adding EM from kepok banana peel waste in reducing Chemical Oxygen Demand (COD) levels. Specifically, a 20% dose of EM resulted in a 78.13% removal, a 30% dose of Biological Oxygen Demand (BOD) led to a 78.01% reduction, and a 10% dose of Total Suspended Solid (TSS) resulted in a 66.81% removal over an optimum residence time of 16 days.

Micropollutants in biochar produced from sewage sludge: A systematic review on the impact of pyrolysis operating conditions

Biochar obtained from sewage sludge serves as a valuable soil amendment in agriculture, enhancing soil properties by increasing the nutrient content, cation exchange capacity, water retention, and oxygen transmission. However, its utilisation is hampered by the presence of micropollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and volatile organic compounds (VOCs). Previous studies indicate that the type and amount of micropollutants can be significantly adjusted by selecting the right process parameters. This literature review provides an overview of how (1) pyrolysis temperature, (2) carrier gas flow and type, (3) heating rate, and (4) residence time affect the concentration of micropollutants in biochar produced from sewage sludge. The micropollutants targeted are those listed by the European Biochar Certificate (EBC) and by the International Biochar Institution (IBI), including PAHs, PCDD/Fs, PCBs and VOCs. In addition, per- and poly-fluoroalkyl substances (PFAS) are also considered due to their presence in sewage sludge.The findings suggest that higher pyrolysis temperatures reduce micropollutant levels. Moreover, the injection of a carrier gas (N2 or CO2) during the pyrolysis and cooling processes effectively lowers PAHs and PCDD/Fs, by reducing the contact of biochar with oxygen, which is crucial in mitigating micropollutants. Nevertheless, limited available data impedes an assessment of the impact of these parameters on PFAS in biochar. In addition, further research is essential to understand the effects of carrier gas type, heating rate, and residence time in order to determine the optimal pyrolysis process parameters for generating clean biochar.