Biomass Combustion Research Articles

Seasonal occurrence and ecological risk assessment of polycyclic aromatic hydrocarbons in the sediments and water in the left-bank canals of Indus River, Pakistan.

This study investigated a pressing environmental concern: the presence, distribution, sources, and ecological implications of sixteen polycyclic aromatic hydrocarbons (PAHs) in the left-bank canals of Kotri barrage-Akram, Pinyari, and Phuleli of the Indus River in Pakistan. These vital waterways, crucial for industrial, domestic, and agricultural activities, are experiencing contamination threats from anthropogenic sources, particularly PAHs. The study collected three water and two sediment samples from each canal in pre-monsoon and post-monsoon seasons. Then the EPA's liquid-liquid extraction method and gas chromatography determined the concentrations of PAHs. The findings of this study reveal alarming contamination levels, with pre-monsoon concentrations ranging from 22.256 to 836.455ng/L in water and 1,459.941 to 43,179.243ng/g in sediments. The post-monsoon concentrations ranged from 60.352 to 5663.058ng/L in water and 2976.770 to 15,238.335ng/g in sediments. The diagnostic ratios and principal component analysis (PCA) identified multiple sources of contamination, including industrial and domestic wastewater discharge, solid waste burning, vehicular emissions, biomass combustion, and petroleum residues. Furthermore, the assessment of the toxic equivalency factor (TEF) underscored the heightened carcinogenic potential of certain PAHs, notably benzo(a)pyrene and benzo(a)anthracene. Thus, the high levels of PAH contamination pose severe health risks to both human populations and aquatic ecosystems, emphasizing the urgency of addressing this issue. Stricter regulations governing industrial and domestic waste discharge, advocacy for cleaner fuel technologies, and the implementation of effective waste management practices must be initiated as crucial strategies in safeguarding the environmental integrity of the left-bank canals and the health of the surrounding communities.

Naturally Deposited Charcoal Enhances Water Retention Capacity of Subtropical Forest Soils

Charcoal, a byproduct resulting from incomplete combustion of biomass in fire events, can modify the physical properties of soil due to its high porosity and large surface area. To evaluate the impact of fire-deposited charcoal on soil hydraulic characteristics, soil–charcoal mixtures were analyzed to investigate the effects of different application doses (wt%: 0, 1%, 3%, 5%, 10% and 20%) of charcoal on soil bulk density (BD), porosity (total, capillary, and non-capillary), residual moisture after free drainage (RM), saturated water content (SC), and saturated hydraulic conductivity (Ks) of loamy and sandy soils collected from subtropical forests in south China. The results showed that the impact of charcoal on soil’s physical and hydraulic properties depends on the soil type and the application dose. The incorporation of charcoal significantly decreased the BD of sandy soil (p < 0.001), while a significant decrease in BD in loamy soil was only observed as a result of the higher application doses (10% and 20%) (p < 0.001). Charcoal application doses of 5% or higher led to a significant increase in the total porosity (TP) of sandy soil (p < 0.001) and doses of 3% and 20% resulted in a significant increase in the TP of loamy soil (p < 0.001). The capillary porosity (CP) of both sand and loamy soils significantly increased when charcoal was applied at doses of 3% or higher (p < 0.001). The minimum charcoal application dose that significantly increased the RM in sandy soil was 5%, while for loamy soil, the minimum effective dose was 10%. Charcoal applied at a dose of 3% significantly increased the Ks of sandy soil (p < 0.001), while no significant effect on Ks was observed for loamy soil (p > 0.05). Collectively, our findings suggest that fire-derived charcoal enhances the soil water-retention capacity in subtropical forests, with the effects becoming more pronounced at higher application doses and being particularly notable in sandy soil compared to loamy soil.

3-D full-field reconstruction of chemically reacting flow towards high-dimension conditions through machine learning

Monitoring chemically reacting flow is crucial for optimizing and controlling the conversion processes in various chemical engineering scenarios. These processes are often influenced by multiple factors, creating a high-dimensional condition space that imposes intensive computational cost to computational fluid dynamics (CFD) methods. We present a machine learning (ML) framework to reconstruct the 3-D scalar field preserving the accuracy and resolution of CFD modeling. We demonstrate the framework’s effectiveness through a case study on biomass combustion in an industrial-scale grate furnace, which exemplifies the challenges of modeling chemically reacting flow in complex geometric domains influenced non-linearly by multiple parameters. The framework implements three core principles: (1) a Reactor-Structure-Resembled Network (RSRNet) reflecting the operational logics of the reactor, (2) an incremental learning strategy based on random Latin Hypercube Sampling, and (3) the incorporation of self-extracted high-level features from data as soft constraints in the loss function. Ground truth data were calculated through a CFD model, with all cases sampled from a 11-variable condition space. Using only 240 randomly sampled cases (around 1 % total cases in the discretized condition space), RSRNet precisely replicated 1-D and 2-D scalar distributions through incremental training. Further reconstruction of 3-D temperature field only used 40 3-D CFD cases, resulting in the training and testing errors decreased to 7.94 × 10-4 and 1.55 × 10-3, respectively, approaching the level of the 2-D reconstruction, with the average error in temperature field predictions not exceeding 50 K. The generalization ability was validated using a separate test dataset with continuously changing excess air ratio and capacity ratio in wide ranges, including some extreme values, and the model successfully captured complex phenomena under unseen conditions.

Biomass-Based Gas Turbine Systems for Power Generation: Sustainable Feedstocks and Environmental Benefits

This paper explores the significance and operational mechanisms of biomass-based gas turbine systems, which present a renewable and sustainable substitute for conventional fossil fuel-based electricity production methods. These systems utilize biomass as a source of fuel to produce heat, which is then converted into power through a gas turbine. The process involves the combustion of biomass fuel to heat a working fluid, such as air, which subsequently drives the turbine to produce electricity. Biomass can be derived from various organic materials, encompassing urban solid trash, forest residues, and agricultural residues, making it a versatile and sustainable fuel option. The paper also includes a practical case study, highlighting the system's advantages and disadvantages. Additionally, it identifies future trends, emphasizing the importance of efficiency enhancement. To achieve this, scientists are increasingly proposing hybrid systems that combine biomass-based gas turbines with other technologies. This approach aims to optimize performance, reduce emissions, and contribute to guaranteeing a future with more sustainable energy. The study underscores the potential of biomass-based gas turbine systems to play a crucial part in the shift to renewable energy sources.

Acidity and Salinization of Soil Following the Application of Ashes from Biomass Combustion Under Different Crop Plant Species Cultivation

Ashes from biomass combustion (BAs) are a valuable source of plant nutrients, making them suitable for fertilizing crops. BAs also contain components that directly affect soil environmental conditions, leading to improved growth and development of plants. Their deacidifying properties allow BAs to serve as a substitute for calcium fertilizers. However, they contain substantial amounts of components that can increase soil salinity, which can have negative effects. The aim of this study was to assess the impact of BAs on changes in pH and salinity of haplicluvisol soil under the cultivation of various plant species. The study also analyzed the effects of BAs on the content of total forms of calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) in the soil. The BAs used in the experiment were sourced from a combined heat and power plant that combusts forest and agricultural biomass. These BAs are distributed as a product for fertilizing agricultural land. However, their application is not subjected to further monitoring. The results indicated that the application of different doses of BAs significantly affected the pH of the analyzed soil. Compared to control objects, a significant increase in pH was observed, with these changes dependent on the species of the cultivated plant. Additionally, even the smallest doses of BAs caused an increase in the electrolytic conductivity (EC) of soil solutions, which serves as a measure of soil salinity. Despite the increase in the average EC value, the application of BAs did not alter the salinity class. The use of BAs also significantly influenced other analyzed parameters. An increase in the average content of total forms of Ca, Mg, K, and Na in the soil was observed, along with a higher degree of soil saturation with alkaline cations, compared to the control and the soil condition before the experiment. The changes in the analyzed soil parameters were significantly influenced not only by the different doses of BAs but also by the species of the cultivated plant. The greatest fluctuations in the obtained values were observed in soil under winter rape cultivation, while the smallest fluctuations were noted in soil under spring barley and potato cultivation.

Hybridization of Concentrated Solar Thermal, Geothermal, and Biomass: Case Study on Kizildere-2 Geothermal Power Plant

The usage of fossil fuel in the energy sector is the primary factor for global GHG emissions, so it is crucial to better utilize RE sources. One way to do that is to hybridize RE technologies to make up for their deficiencies while enabling a more synergistic power production. This study utilizes such an approach to hybridize the KZD-2 Geothermal Power Plant (GPP) with CST and biomass in the southwest region of Turkiye. The main motivation is to address the two main issues of GPPs—excess turbine capacities happening over the operating years and decreasing performance during hot summer months—while also increasing the flexibility of KZD-2. A topping cycle of CST–biomass is added utilizing a PTC field as the CST technology and olive residual biomass combustion as the biomass technology. The hybrid plant is simulated on TRNSYS, and the energetic data show that it is possible to generate more than 20 MWe of additional power during sunny and clear sky conditions while also increasing the Capacity Factor (CF) from 69% to 74–76%. Moreover, the financial results show that the resulting LCOAE is 81.19 USD/MWh, and the payback period is five or nine years for using the YEKDEM incentive or the spot market prices, respectively.

Investigating the sustainable energy generation potential of an invasive weed: Lantana camara.

Lantana camara, one of the world's top ten most invasive species, was initially cultivated for ornamental use. However, it spread uncontrollably across the fallow areas and agricultural lands, threatening approximately 44% of Indian forests. Its invasion disrupts ecosystems by suppressing nearby plant growth through allelopathy and poses toxicity risks to grazing ruminants. It significantly increases forest fire risk by adding large amounts of combustible biomass, particularly dried L. camara. Despite efforts to control it using mechanical, chemical, and biocontrol methods, the results have been largely unsatisfactory, with associated costs estimated at $18,000 per square kilometre. Considering these challenges, recent research explored the potential of L. camara as a bioenergy resource. TheL. camarabriquettes exhibit a heating value of approximately 20MJ/kg with a low sulphur (0.5%), nitrogen (1%), and ash content (2%), making them suitable for decentralised energy production. Furthermore, bioethanol production fromL. camarahydrolysate has shown promising results, yielding 0.33g/g withPichia stipitisand0.47g/g with Saccharomyces cerevisiae, which is comparable to other lignocellulosic feedstocks. Additionally, the gasification of L. camara using a downdraft gasifier produced syngas with a lower heating value (LHV) of 6.4MJ/Nm3. These findings demonstrate that using L. camara for bioenergy production presents a dual solution, addressing the growing demand for renewable energy and managing invasive species. This review aims to critically evaluate the potential and challenges associated with the different energy production pathways for L. camara, highlighting its role in sustainable energy generation.

Solid-to-gas phase transition kinetics of diverse potassium occurrence forms during biomass pellet combustion: Time-resolved detection and multi-step modeling

The solid-to-gas phase transition of potassium during biomass combustion significantly impacts ash-related issues in bioenergy systems, affecting operational efficiency and equipment longevity. However, the specific mechanisms and kinetics of this transition process remain inadequately understood. This work investigates the time-resolved transition of solid-phase potassium to the gas phase during the combustion of rice husk and wheat straw pellets, combining experimental measurements with theoretical modeling. Tunable diode laser absorption spectroscopy (TDLAS) was employed to measure atomic potassium concentrations 15 mm above burning pellets tray, where gas-phase equilibrium is approached. Key combustion characteristics including thermogravimetric profiles, spectral radiation, and temperature were simultaneously monitored. A novel multi-step model was developed to describe the transition of different forms of solid-phase potassium (organic, exchangeable, and inorganic) to the gas phase. This model integrates TDLAS measurements, observed combustion characteristics, and biomass physicochemical properties. Thermodynamic equilibrium calculations were used to estimate the atomic potassium fraction from total gaseous potassium. The results showed that the solid-to-gas phase transition of organic potassium synchronizes with volatiles release. In contrast, the maximum emission rates of inorganic and exchangeable potassium occurred at the onset of char combustion. The developed model agrees well with the online detection experiments and were further validated by offline ICP analysis of residual ash. While not directly simulating gas-solid interface reactions near the particle surface, this work lays groundwork for future multi-scale modeling of particle-laden flows and reactor-scale phenomena in biomass combustion systems.

Chemical Characterization of Organic Aerosol Tracers Derived from Burning Biomass Indigenous to Sub-Saharan Africa: Fresh Emissions versus Photochemical Aging

Chemical Characterization of Organic Aerosol Tracers Derived from Burning Biomass Indigenous to Sub-Saharan Africa: Fresh Emissions versus Photochemical Aging

Utilization of incense stick ash as a supplementary cementitious material: Effects on strength, cement chemistry, and sustainability

Incense stick ash (ISA), a by-product generated from the combustion of biomass during religious rituals, presents challenges regarding its high-volume disposal despite some emerging technologies offering avenues for its reuse. This study aims to investigate the feasibility of utilizing ISA as a supplementary cementitious material and its impact on fresh and hardened properties, hydration kinetics, microstructure, and environmental and economic aspects of Portland cement (PC) pastes. Results reveal that incorporating 5–20 % ISA increases the cumulative heat release per gram of PC. Specifically, replacing 5 % of PC with ISA enhances the 28-day compressive strength, with an increase of 19.78 % compared to plain cement paste. However, further elevation in ISA substitution leads to a decline in compressive strength. The utilization of 5 % ISA refines the pore structure of samples and elevates the content of calcium silicate hydrate (C-S-H), particularly the proportion of high-density C-S-H. Additionally, carbonates present in ISA react with AFm to form monocarbon calcium aluminate, which stabilizes AFt and enhances the microstructural compactness of cement paste. Compared to plain cement paste, the paste with 5 % ISA exhibits lower coefficients for the cost of pastes per cubic meter, CO2 emission of pastes per cubic meter, and non-renewable energy consumption, underscoring the effective utilization of ISA and its role in promoting sustainability. This study will facilitate the application of ISA in cement-based materials and provide technical guidance for subsequent research.

Methods, Progress and Challenges in Global Monitoring of Carbon Emissions from Biomass Combustion

Global biomass burning represents a significant source of carbon emissions, exerting a substantial influence on the global carbon cycle and climate change. As global carbon emissions become increasingly concerning, accurately quantifying the carbon emissions from biomass burning has emerged as a pivotal and challenging area of scientific research. This paper presents a comprehensive review of the primary monitoring techniques for carbon emissions from biomass burning, encompassing both bottom-up and top-down approaches. It examines the current status and limitations of these techniques in practice. The bottom-up method primarily employs terrestrial ecosystem models, emission inventory methods, and fire radiation power (FRP) techniques, which rely on the integration of fire activity data and emission factors to estimate carbon emissions. The top-down method employs atmospheric observation data and atmospheric chemical transport models to invert carbon emission fluxes. Both methods continue to face significant challenges, such as limited satellite resolution affecting data accuracy, uncertainties in emission factors in regions lacking ground validation, and difficulties in model optimization due to the complexity of atmospheric processes. In light of these considerations, this paper explores the prospective evolution of carbon emission monitoring technology for biomass burning, with a particular emphasis on the significance of high-precision estimation methodologies, technological advancements in satellite remote sensing, and the optimization of global emission inventories. This study aims to provide a forward-looking perspective on the evolution of carbon emission monitoring from biomass burning, offering a valuable reference point for related scientific research and policy formulation.

Effect of Potassium on the Co-Combustion Process of Coal Slime and Corn Stover

In this study, the combined combustion characteristics and gaseous product emissions of coal slime and corn stover were compared at different blending ratios. The TG-DTG curves indicate that the optimal performance is achieved when the corn straw blending ratio is 20%. Furthermore, the TG-FTIR coupling results demonstrated an increase in gas species as the blending ratio increased. The composition analysis of ash samples formed at various combustion temperatures using XRD and XRF indicated that a portion of KCl in the fuel was released as volatile matter, while another part reacted with Al2O3 and SiO2 components in the slime to form silica–aluminate compounds and other substances. Notably, interactions between the components of slime and potassium elements in corn stover primarily occurred within the temperature range of 800–1000 °C. These findings contribute to a comprehensive understanding of biomass and coal co-firing combustion chemistry, offering potential applications for enhancing energy efficiency and reducing emissions in industrial processes.

Photocatalysis of Adsorbed Catechol on Degussa P25 TiO2 at the Air-Solid Interface.

Semiconductor photocatalysis with commercial TiO2 (Degussa P25) has shown significant potential in water treatment of organic pollutants. However, the photoinduced reactions of adsorbed catechol, a phenolic air pollutant from biomass burning and combustion emissions, at the air-solid interface of TiO2 remain unexplored. Herein we examine the photocatalytic decay of catechol in the presence of water vapor, which acts as an electron acceptor. Experiments under variable cut-off wavelengths of irradiation (λcut-off ≥ 320, 400, and 515 nm) distinguish the mechanistic contribution of a ligand-to-metal charge-transfer (LMCT) complex of surface chemisorbed catechol on TiO2. The LMCT complex injects electrons into the conduction band of TiO2 from the highest occupied molecular orbital of catechol by visible light (≥2.11 eV) excitation. The deconvolution of diffuse reflectance UV-visible spectral bands from LMCT complexes of TiO2 with catechol, o-semiquinone radical, and quinone and the quantification of the evolving gaseous products follow a consecutive kinetic model. CO2(g) and CO(g) final oxidation products are monitored by gas chromatography and Fourier-transform infrared spectroscopy. The apparent quantum efficiency at variable λcut-off are determined for reactant loss (Φ- TiO2/catechol = 0.79 ± 0.19) and product growth ΦCO2 = 0.76 ± 0.08). Spectroscopic and electrochemical measurements reveal the energy band diagram for the LMCT of TiO2/catechol. Two photocatalytic mechanisms are analyzed based on chemical transformations and environmental relevance.

Peat smoke exposure as a risk factor for deterioration of postnatal development

Introduction. In connection with the growing number and scale of wildfires, the problem of the toxic effect of biomass combustion products is relevant both in Russia and abroad. Data on the consequences of wildfire smoke exposure at various stages of ontogenesis are extremely scarce. The presence in smoke substances that, in addition to general toxic effects, have reprotoxic, gonadotoxic, and genotoxic effects, determines the need to study its effect on the reproductive potential and health of offspring. The purpose of the study was to assess the postnatal development of the offspring, the parent generation of which was exposed to peat smoke during puberty. Materials and methods. Exposure to peat smoke was carried out once for four hours on the 35th day of life for female and on the 45th day for male rats. The average concentrations of carbon monoxide in the exposure chambers were 29.3±11.1 mg/m3, and ultrafine PM2.5 particles – 0.39±0.61 mg/m3. At puberty, peat smoke exposed rats were mated with intact partners. In rat pups from the offspring there was studied the trend in body weight gain, physical development, and sensory-motor reflexes were assessed. Results. Acute exposure to peat smoke during puberty in white rats adversely affects the development of their offspring. A significant lag in the physical and sensory-motor development of rat pups from the offspring of animals exposed to smoke was revealed in comparison with rat pups from the control group. Limitations. The study was limited to the study of postnatal development of offspring obtained from rats exposed to peat smoke during puberty. Conclusion. Exposure to peat smoke during puberty leads to a delay in the physical and somatosensory development of the offspring during early postnatal ontogenesis.

Dominant influence of biomass combustion and cross-border transport on nitrogen-containing organic compound levels in the southeastern Tibetan Plateau

Abstract. The Tibetan Plateau (TP) is highly susceptible to climate change, and nitrogen-containing organic compounds (NOCs) in fine particulate matter (PM2.5) represent one of the largest uncertainties with respect to their impact on the climate in high-altitude areas. Previous studies have shown that NOCs play a vital role in the nitrogen budget of PM2.5. However, our understanding of the composition and sources of NOCs in PM2.5, particularly in the TP, is limited. Here, we aim to enhance our understanding of NOCs in the TP region by examining their identification, concentration levels, sources, and origins. We conducted field sampling at a regional background sampling site in Gaomeigu, in the southeastern margin of the TP from 11 March to 13 May 2017, followed by laboratory analysis of the NOCs collected on the filters. The daily mass concentrations of NOCs ranged from 714.4 to 3887.1 ng m−3, with an average of 2119.4 ± 875.0 ng m−3 during the campaign. This average concentration was approximately 40 % higher than that reported at a typical regional site in the North China Plain (NCP), highlighting a more significant presence of NOCs in the Tibetan area. Biomass burning and secondary sources were identified as the major contributors to total NOCs. This was further substantiated by a regional air quality model, which indicated that over 80 % of the aerosol in the southeast of the TP originated from neighboring countries. This study improves our understanding of NOCs' contribution to PM2.5 in the TP and their potential impacts on climate stability in high-altitude areas.

Chemical Fingerprinting, PAHs Characterization and Ecological Risks of Carcinogenic PAHs in Surficial Sediments of Egi Crude Oil Producing Communities, Niger-Delta, Nigeria

In order to do PAHs rings analysis, its source identification, extent to which cPAHs present and what kind of ecological risk they pose, the surface sediments from various freshwaters in the Egi crude oil producing cities in the Niger Delta, Nigeria were analyzed. Sediments collected from the research areas for PAHs loadings (in mg/kg dry weight) ranged from 0.020 to 1.790, 0.050 to 1.880, and 0.020 to 1.640, respectively for Obite, Obagi, and Ibewa cluster areas, as measured by gas chromatography-mass spectrometer. In these clusters, the respective average concentration of the three dominant carcinogenic PAHs were Indeno(1,2,3-cd)pyrene (1.170.0mg/kg), Dibenz[a,h]anthrancene (0.870.0 mg/kg), and Dibenz[a,h]anthrancene (1.3670 mg/kg) for Ibewa, Obagi and Obite cluster areas. The findings showed that dominant PAHs rings are of high molecular weight (HMW) PAHs in these sediments are, 5 member rings, which are benzo(b)fluoranthene, Benzo(k)fluoranthene, and Benzo(a)pyrène, and 6-member ring which are, Indeno(1,2,3-cd)pyrene, Dibenz[a,h]anthrancene, and Benzo[ghi] perylene, respectively. Their fingerprints points majorly to pyrogenic sources, combustion of coal, biomass, petroleum, and other related anthropogenic petroleum activities as the primary source of PAHs in the environment. Notably, the RQNCs and RQMPCs for single PAHs molecule are both less than 1, it means the contamination it generates is considered of low ecological risk. Again, the research area experiences frequent flooding, it is believed that this contributes to the low ecological risk of PAHs chemical pollution. Consequently, the area is deemed to be quite safe.

Corrosivity of KOH(g) towards superheater materials in a simulated air reactor environment for chemical looping combustion of biomass

Chemical looping combustion (CLC) of biomass has the potential to improve the electrical efficiency in power plants that utilize carbon capture and storage (CCS). This is attributed to the mild corrosive environment anticipated in the air reactor (AR). However, previous studies have measured alkali emissions in the AR, likely in the form of KOH(g), suggesting that alkali may transfer from the fuel reactor (FR) to the AR. To investigate the corrosive effect of KOH(g) release in the AR, a novel experimental set-up was developed to simulate two scenarios for the AR 1) Clean scenario: no release of KOH(g) in the AR (5 % O2 + 3 % H2O + N2 bal.) and 2) Alkali slip scenario: continuous release of KOH(g) in the AR (5 % O2 + 3 % H2O + N2 bal. + 16 ppm KOH(g)). The exposure was carried out at 700 °C and six alloys, relevant as superheater material, ranging from stainless steels to nickel-base (Ni-base) alloys as well as a FeCrAl alloy were investigated. The samples were exposed for a total of 168 h and the morphology of the corrosion products was investigated using SEM-EDX and XRD. The presented results suggest that KOH(g) significantly accelerates the corrosion of the stainless steels and Ni-base alloys investigated, by rapidly destroying the protective Cr-rich oxide scale, resulting in the formation of a multilayer oxide scale with inferior protective properties. On the contrary, the FeCrAl alloy retained a protective Al-rich oxide scale irrespective of the presence of KOH(g). The findings in this study highlight that the release of KOH(g) in the AR during combustion of biomass in CLC could introduce corrosion challenges for installed superheaters that can be significantly mitigated by utilizing FeCrAl alloys.

Ash Interaction with Two Cu-Based Magnetic Oxygen Carriers during Biomass Combustion by the Chemical Looping with Oxygen Uncoupling Process.

Chemical-looping combustion (CLC) stands out as a promising method for carbon capture and storage for the purpose of mitigating climate change. The process involves the conversion of fuel facilitated by an oxygen carrier, with the resulting CO2 inherently separated from other air components. Notably, when applied to biomass combustion this process offers a pathway to achieving negative CO2 emissions. However, a significant challenge for CLC, particularly in its application to biomass, is the management of interactions between ash and oxygen carriers. Biomass-derived ashes typically contain substantial quantities of reactive ash-forming substances, such as alkaline and alkali earth elements. These interactions can impact the performance and longevity of the oxygen carrier, necessitating careful consideration and mitigation strategies in CLC systems utilizing biomass feedstocks. This study examined the interaction between biomass ash components and two recently developed oxygen carriers, Cu30MnFekao7.5 and Cu30MnFe, during combustion in a 1.5 kWth continuous unit. Both oxygen carriers achieved 100% combustion efficiency and a CO2 capture efficiency of 95% at 900 °C. Although the copper in both oxygen carriers did not exhibit any noticeable interaction with ash components, the accumulative presence of potassium and magnesium in Cu30MnFekao7.5 was identified by inductively coupled plasma and scanning electron microscopy with energy dispersive X-ray analysis, indicating an increase in the amount of both elements in the particles after combustion operation. No problems of agglomeration or fluidization were observed in any of the experiments.

Operational and Design Factors in Air Staging and Their Effects on Fouling from Biomass Combustion

Operational and Design Factors in Air Staging and Their Effects on Fouling from Biomass Combustion

Characteristics and health risks assessment of PM2.5-bound heavy metals during winter in urban areas of northern China: A case study in Kaifeng

The health impact of heavy metals in atmospheric PM2.5 has garnered increasingly widespread attention. We have collected PM2.5 samples in a typical city (Kaifeng) within the Central Plains Urban Agglomeration in China during winter and measured the mass concentration of PM2.5-bound heavy metals. The pollution of As and Cr in the urban atmosphere requires significant attention. As PM2.5 concentrations increased, the enrichment factors (EFs) of Mn, Cu, Zn, As, and Pb also rose, suggesting a growing contribution from anthropogenic emissions. The analysis showed that the hazard quotient (HQ) for the non-heating and heating periods (HQ < 1) did not result in a cumulative non-carcinogenic health risk to humans. Regarding carcinogenic effects, As and Cr exhibit significant carcinogenic impacts on both children and adults (ELCR>1 × 10−6), indicating that the carcinogenic risks posed by As and Cr under PM2.5 exposure in Kaifeng could not be overlooked. It was found that industrial and biomass combustion are the primary sources of carcinogenic risk in Kaifeng city. From the non-heating to the heating period, the industrial carcinogenic risk increased from 37.12 % to 43.39 %, while the contribution of biomass burning remained at 25 %. This result was strongly correlated with the high proportions of heavy metal elements such as As, Mn, Pb, and Ni from the metal refinery industry. The results of this study revealed the equally important source of heavy metals, compared to coal combustion in North China Plain. In addition to residential coal combustion, industrial emissions are a major source of PM2.5-bound heavy metals in Kaifeng, contributing significantly to overall air pollution and providing a useful reference to mitigating human health risks in the area.