Combustion Of Woody Biomass Research Articles

Role of Particle Geometry on the Structural Integrity of Sand and Rock Ilmenite Used as Oxygen Carrier in Combustion of Woody Biomass

Role of Particle Geometry on the Structural Integrity of Sand and Rock Ilmenite Used as Oxygen Carrier in Combustion of Woody Biomass

Uticaj individualnih ložišta na biomasu na zagađenost vazduha u urbanim sredinama

The usage of biomass as a regionally available renewable energy source is one of the key steps towards decarbonisation and the achievement of sustainable development. Biomass used in a sustainable way is considered as a carbon-neutral fuel. Due to its properties, it is considered an energy source that can help achieve carbon neutrality. Although, compared with fossil fuels biomass results i lower pollutant emissions during a controlled complete combustion process, problems arising from inadequate use of biomass are becoming more common. In many developing countries, biomass, especially wood, is often used in a traditional and inefficient way for cooking and space heating in stoves with minimal control possibilities over the combustion process. Such an inefficient way of using biomass can cause serious environmental problems. The incomplete combustion of woody biomass can result in the emission of harmful matters, including particulate matter (a mixture of smoke, soot and acid) and carbon monoxide (CO). These substances are dangerous to human health and have negative effects on air quality. In addition, burning biomass at high temperatures can generate nitrogen oxides (NOx), further exacerbating the environmental impact. According to the 2022 census, just 20% of dwellings are connected to district heating systems, while 77% have individual heating systems (31% of individual systems are dwellings with central heating installations) in Serbia. Of the total of occupied dwellings in urban areas that are not connected to the district heating system, 47.60% use wood, 2.07% coal, 17.40% natural gas, and 29.00% electricity for space heating. In the paper, 15 urban areas in Serbia with III category of air quality have been analysed. The district heating systems of th analysed cities are based on natural gas usage (11 cities), while coal is the predominant fuel in three cities and heating oil in one city. Individual heating systems often account for more than 70% of the total share in most of the analysed cities, and they are mostly fuelled by solid biomass. Daily excesses of PM particle emissions, which are several times above the limit, are over 95% during the heating season

Influence of ash species on particle size dependence of water- and citric-acid-soluble potassium concentrations of woody biomass combustion ashes with low potassium content

The dependence of the concentrations of water- and citric-acid-soluble potassium on particle size was investigated for two types of low-potassium-content woody biomass combustion ash discharged from different biomass power plants. For both types of ash, the potassium concentration increased as the median diameter decreased; crystalline potassium, such as KCl and K2SO4, was identified more in fine combustion ash, whereas crystalline SiO2 and CaCO3 were abundant in coarse ash. The potassium components could be present as finer ash particles or as cover over coarser ash particles composed of crystalline SiO2 surfaces. Differences in the existence forms of the potassium components caused differences in the dependence of potassium concentration on the median diameter of the ash. Moreover, the methods used to calculate the particle size distributions of three ash particle components (water-soluble, citric-acid-soluble, and insoluble) in the ash residues can be used to evaluate the particle size dependence of both potassium concentrations to some extent. The potassium enrichment process demonstrated in this study could be successfully performed on a factory scale via the surface grinding of bottom ash. The collected fine grinding debris containing rich potassium, separated from the surface of the silica, was found to be possibly reusable as fertilizer.

Role of surface morphology in bed particle layer formation on quartz bed particles in fluidized bed combustion of woody biomass

The influence of quartz bed particle surface morphology on the bed particle layer and crack layer formation process in fluidized bed combustion of woody biomass was investigated in this work. Bed material samples were collected at different sampling times from the startup with a fresh bed in industrial scale bubbling fluidized bed (BFB) and circulating fluidized bed (CFB) boilers, both utilizing woody biomass. X-ray microtomography (XMT) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) were employed to characterize bed particle layers and crack layers in the samples. Results showed that there is a noticeable difference between the bed layer characteristics over the so-called “concave” and “convex”-shaped morphologies on the bed particle surface with respect to layer formation. The concave areas are mainly covered with a thin inner layer, whilst the convex display a comparably thick inner layer and an outer layer. In addition, 3D images of the particles revealed that the crack layers mainly originate from concave areas where the particle is less protected by an outer bed particle layer in conjunction with cracks in the inner layer.

Socioecological effects of swidden management in traditional Maya agroforests in the Selva Lacandona of Chiapas, Mexico

For millennia, Maya farmers (i.e., milperos) throughout Mesoamerica have managed milpa: sequential agroforests initiated by slashing and burning patches of secondary forest and then cultivating a diverse polyculture of trees and annual crops. To reduce greenhouse gas emissions associated with deforestation, the Mexican government and non-governmental organizations have urged milperos to cease burning. We collaborated with Maya milperos in several communities in the Montes Azules Biosphere Reserve region in Chiapas, Mexico to determine carbon retained as char in traditional milpas, carbon loss associated with burning, and effects of burning on soil quality. We found the carbon retention of char in Maya milpas (24 ± 6.5% of C in vegetation) is 4–1400% higher than other slash-and-burn agroecosystems reported in the literature. Burning resulted in significant carbon loss of 12.6 (±3.6) t C ha−1 yr−1, but this was partially mitigated by char production (3.0 [±0.6] t C ha−1 yr−1) and incomplete combustion of woody biomass. The effects of burning on soil were minimal, with the only significant changes observed being increases in pH, potassium availability, and cation exchange capacity (2, 100, and 7%, respectively). The mean residence times of charred materials were at least double that of uncharred biomass. While there is a risk that shortening fallow periods would undermine the sustainability of Maya swidden agroecology, proper management and secure land tenure can help maintain intensive production without enduring environmental degradation. The char produced in these swiddens and successional management could allow this agroforestry system to be a long-term carbon sink.

A comparative study in 3D of bed particle layer characteristics in quartz and K-feldspar from fluidized bed combustion of woody biomass using X-ray microtomography

Bed particle layer and crack layer characteristics at different ages were studied for quartz and K-feldspar bed particles from a 30 MWth bubbling fluidized bed and a 90 MWth circulating fluidized bed, both using woody biomass as fuel. X-ray microtomography (XMT) was utilized to determine the bed particle layer distribution on the bed particles' surface. For each bed particle type, the average bed particle layer thickness as well as average volume fractions of the bed particle layer and crack layers to the entire bed particle volume were determined at three different bed particle ages by utilizing XMT analysis. Comparison of the two different bed particle types showed that K-feldspar retains a thinner bed particle layer in both conversion processes compared to quartz. Crack layers were observed extensively in quartz bed particles to the extent of 19.3 vol% and 32.1 vol% after 13 days in the BFB and the CFB, respectively, which could cause deposition of the bed particle fragments. On the contrary, K-feldspar has almost no tendency toward forming crack layers.

Modeling and Evaluation of Ash-Forming Element Fate and Occurrence in Woody Biomass Combustion in an Entrained-Flow Burner

Biomass combustion equipment is often susceptible to ash deposition due to the relatively significant quantities of potassium, silicon, and other ash-forming elements in biomass. To evaluate the propensity for ash deposition resulting from biomass combustion, a biomass combustion model was integrated with a chemical equilibrium model to predict the fate and occurrence of ash-forming elements in a pilot-scale entrained-flow burner. The integrated model simulated the combustion of white wood (virgin wood) and recycled wood (treated wood) previously combusted in the burner. The key advantage of this model in comparison to a model with general equilibrium assumed is that it was able to consider the rate of release of trace and minor species with time, the local equilibrium in the particles, and separately, that in the continuum phase (which also included any solid or liquid materials nucleating). The simulation generated the fate and occurrence profiles of each ash-forming element along the burner. The qualitative comparisons between the modeled profiles and the previous experimental findings under similar operating conditions show reasonable agreement. The concentrations of ash-forming elements released from the burner were also compared with the experimental online inductively coupled plasma readings. However, the latter comparison shows overestimation using the modeled results and might suggest that further considerations of other parameters such as ash nucleation and coagulation are required. Nonetheless, based on the ongoing performance of the integrated model, future use of the model might be expanded to a broader range of problematic solid fuels such as herbaceous biomass or municipal solid waste.

Utilization of Biomass to Ash: An Overview of the Potential Resources for Alternative Energy.

Climate change and the potential depletion of fossil fuels have increased international demand for alternative and renewable energy sources. In terms of the energy sector, for example, most of the South-East Asian countries (SACs) have a large number of biomass sources due to their vast forest resources and agriculture-based economies. Thus, the critical review was aimed at highlighting the overview of biomass energy in South-East Asia as a dynamically developing region, in order to obtain economic and environmental benefits from the existing sources of biomass in the world. The current review analyzed the sources of biomass, as well as their energy potential, use, and management, based on reports from different countries, published studies, and scientific articles. In SAC, the main sources of biomass were found to be coconut residues, oil palm residues, sugar cane residues, rice straw, rice husks, wood waste, and firewood. The combined annual biomass potentials in the forestry and agricultural sectors in South-East Asia were approximately over 500 million tons per year and more than 8 gigajoule of total energy potentials. The study identified the challenges and barriers to using biomass in these countries to achieve sustainable use of biomass sources and recommended sustainable approaches to using biomass energy by comparing traditional uses of biomass. Smart grid technologies have ways for solutions for better electric power production and efficient ways for distribution and transmission of electricity. Smart grids require less space and can be more easily installed when compared to traditional grids because of their versatilities. Upcoming challenges include technology optimization for the following uses of biomass energy: direct combustion of woody biomass; pyrolysis and gasification of biomass; anaerobic digestion of organic waste to produce biogas; landfill gas production direct incineration of organic waste. The barriers in this technology are emissions of carbon and nitrogen oxides, unpleasant odors, as well as the uncontrolled harvesting of biomass, which can harm nature.

Utilization of woody biomass combustion fly ash as a filler in the glue used for plywood production

The feasibility of the effective utilization of combustion ash from a woody biomass power plant as a novel filler added to adhesives used in plywood production is investigated. For this, plywood was prepared with glues containing combustion ashes having different properties, and the adhesion performance of the glues was examined in detail and compared with that of a glue containing calcium carbonate powder as the filler. Through optical microscopy observations and analyses of the adhesive layer in the plywood, the relationship between the properties of the glue, the structure of the adhesive layer, and the adhesion performance was unraveled. Results revealed that the glue containing woody biomass combustion ash without the unburned carbon component shows a better and more homogeneous adhesion performance than that containing calcium carbonate powder. The adhesion performance could be enhanced more uniformly by decreasing the particle size of the filler. The study also indicated that the difference in the adhesion performance according to the kind of filler is not due to the difference in the chemical structure of the adhesive layer, but because of the difference in the denseness of the adhesive layer dominated by the viscosity of the glue. Thus, this study confirms that woody biomass combustion ash could be practically utilized as a filler substitute of calcium carbonate powder in glues for manufacturing plywood.

Geochemical characterization of sediments from the archaeological site Vinča – Belo Brdo, Serbia

In this study, a multidisciplinary approach was used for a detailed characterization of sediments from the archaeological site Vinča – Belo Brdo, Serbia, one of the most important Neolithic settlements in Europe. This research aimed to determine the paleoenvironmental conditions during Pleistocene and Early Holocene sedimentation prior to Early Neolithic settlement (~5800 cal BC) and provide novel insight into the interaction between humans and the environment during the Middle and Late Neolithic (5300–4550 cal BC). For the first time, organic geochemical characterization, combined with organic petrography, grain size, mineralogy, and inorganic analysis were done on sediment samples from geological and archaeological sections of the Vinča – Belo Brdo site. In the archaeological section, the layer with remains of the burned house and the overlaying leveling layer were particularly interesting.The samples from the oldest geological layers were characterized by the relatively high content of carbonates, the largest amount of soluble organic matter (OM), predominance of liptinite macerals, along with the prevalence of short and mid-chain n-alkanes indicating a marsh-lake depositional environment. The sedimentation of overlaying geological layers continued in an oxbow lake, followed by a shallow depositional environment with stronger input of vascular plants. This was indicated by an increase of the terrigenous component, a high amount of huminite maceral, especially textinite, the predominance of odd long-chain n-alkanes, as well as the presence of diterpanes, pimarane, and 16α(H)-phyllocladane.Quartz was the most abundant mineral in paleosol, while the OM had a mixed origin with a major input of microorganism in the precursor biomass. Estimated average paleosol temperature around 12–16 °C and mean annual precipitation of 938 mm/yr were favorable for ancient civilization settlement.In archaeological samples, the OM was predominantly formed by microorganisms, with a certain contribution of terrestrial plants. Their occurrence was substantiated by the presence of telohuminite, detrohuminite, resinite, and sporinite. The prevalence of n-alkane C18, along with the occurrence of inertinite macerals, semifusinite and fusinite, in the layer with the burned house remains confirmed the incomplete combustion of woody biomass at temperatures <500 °C. Organic and inorganic geochemical parameters for the leveling layer covering the destroyed buildings showed analogous composition as the lowest geological layers. This proved that Vinča inhabitants excavated material for leveling at a site in their vicinity, and used it for covering the burnt debris, clearing the areas for a new settlement. In this context, the decades long archaeological dilemma of the origin of the leveling material was resolved.

Demonstrating Fuel Design To Reduce Particulate Emissions and Control Slagging in Industrial-Scale Grate Combustion of Woody Biomass

The demand for increased overall efficiency, improved fuel flexibility, and more stringent environmental legislations promotes the development of new fuel- and technology-related concepts for the b ...

Soil biochemical activities after the application of pyroligneous acid to soil

Pyroligneous acid (PA) is produced during the combustion of woody biomass and is a complex aqueous fraction resulting from the thermochemical rupture of the components of vegetable biomass. We evaluated the effect of PA on the soil microbial community and activity in order to assess the applicability of this acid in soil and to gather further information on the mechanisms of its toxicity or stimulation. Five concentrations of PA solution (0, 0.5, 1, 2 and 5%) were selected to monitor the biochemical parameters of the soil. The respirometric test showed that the increase in the evolved carbon dioxide-carbon (C) was not due to a release of the native organic C from the soil, but only from the organic compounds of PA. The highest values of microbial biomass content were found in the soil treated with the lowest PA doses, but decreased with increased doses. At higher application doses (2 and 5%), there was a decrease in most enzymatic activities and a loss of soil quality. When PA was applied in doses of up to 1%, our results indicated no negative effects on soil biology and that there was even an improvement.

An Estimation of the Ash Generated from Woody Biomass Combustion Plants using the Feed-in Tariff Scheme in Japan

木質バイオマス発電の導入が進む昨今，発電に伴って発生する木質バイオマス燃焼灰の量を把握することは廃棄物の適正処理と資源の有効利用の観点で重要である。本研究では固定価格買取制度 (FIT) の認定を受けた木質バイオマス発電施設 191 施設を対象に，6 種類の木質バイオマス燃料の文献調査を通じて得た燃料性状を用いて木質バイオマス燃焼灰の発生量を推計した。2023 年度，対象 191 施設では合計 3,500 万 MWh の電力を生産するために 2,600 万～ 3,000 万 ton の木質バイオマスが燃焼され，17 万～ 81 万 ton の木質バイオマス燃焼灰が発生すると推計された。このうち 63 %はパーム椰子殻 (PKS) 燃焼灰が占めると予想された。推計上限値は，都市ごみ焼却残渣の約 20 %に相当し，有効利用や適正処理法の早期の確立が望まれるとともに，燃料や灰の性状を含めた全国的な実態調査が急務である。

Reduction of Alkali Release by Two Fuel Additives at Different Bed Temperatures during Grate Combustion of Woody Biomass

The use of small- and medium-scale combustion of biomass for energy utilization is expected to grow in the coming decades. To meet standards and legislation regarding particle emissions and to redu ...

Toxic emissions from smouldering combustion of woody biomass and derived char with a case study of CO build-up in an ISO container

ABSTRACT Carbon monoxide (CO) from the use of biomass products causes some deaths in the United Kingdom every year. This study was undertaken to evaluate the amount of CO from five species of wood sawdust, and charcoal with a case study of CO in a confined ISO container. Laboratory experiments were conducted at temperatures between 350°C and 600°C under flowing air. Results showed a strong dependence of CO emissions on temperature and airflow. The CO emissions in the ISO container were above the recommended exposure limits due to poor ventilation.

Environmental assessment of valorisation alternatives for woody biomass ash in construction materials

Ash generated during the combustion of woody biomass for energy production is an industrial waste that should be properly managed in order to minimise the respective environmental impacts. Woody biomass ash valorisation in construction materials to replace conventional materials is an alternative that has proven to be technically feasible. On the other hand, it can present potential environmental impacts that should be evaluated to support the choice of more sustainable alternatives. Thus, the purpose of this work is to assess the potential impacts of woody biomass ash valorisation of through incorporation in construction materials using life cycle assessment. The valorisation alternatives consider the incorporation of woody biomass ash in cement mortars, adhesive mortars, concrete blocks, and bituminous asphalts. In addition, a base scenario consisting of ash landfilling is also assessed. Four types of woody biomass ashes were considered, namely fly and bottom ashes generated in a vibrating grate and fly and bottom ashes generated in a fluidised bed. The impact assessment method used is that suggested in the International Reference Life Cycle Data System for selected impact categories. The results showed that the impacts of ash transport and pre-processing and the impacts of producing the avoided materials are factors that affect the net impact of the valorisation scenarios and should be considered in the end-of-life management of biomass ash. Nevertheless, all valorisation scenarios had a lower impact than landfilling in all the impact categories under study, resulting in a significant decrease of the environmental impacts in some scenarios.

Reactivity improvement of ilmenite by calcium nitrate melt infiltration for Chemical Looping Combustion of biomass

Chemical Looping Combustion is a novel process that generates sequestration-ready CO2 from the combustion of woody biomass without requiring a gas separation step and without diluting the CO2 with N2 from air. This is achieved by oxidizing the fuel with lattice oxygen of a metal oxide oxygen carrier. When using cheap and abundant ilmenite ore (FeTiO3) as the oxygen carrier, the rather low reactivity towards volatiles released from the biomass upon devolatilization, as well as detrimental structural changes due to a segregation of Fe and Ti in the material, are of concern. These issues can be addressed by modifying ilmenite with Ca via melt infiltration. In this work, we demonstrate that this modification results in a good distribution of Ca throughout the ilmenite particles that a) prevents detrimental Fe/Ti segregation, b) improves the mechanical stability of the particle compared to materials prepared by solution impregnation and c) improves the reactivity of this material towards hydrogen and wet methane. Moreover, fixed bed experiments showed that the Ca modification not only resulted in increased methane conversion, but also in an increased degree of oxidation of gaseous intermediates CO and H2. We thus conclude that the performance of ilmenite in Chemical Looping processes can be significantly enhanced by Ca modification of ilmenite either prior to use or in-situ during operation of this bed material with Ca-rich fuels such as woody biomass.

Source Apportionment and Macro Tracer: Integration of Independent Methods for Quantification of Woody Biomass Burning Contribution to PM10

ABSTRACT During the last few years, the rise in woody biomass burning (BB) for household heating has caused an increase in PM mass concentrations, particularly for the fine fraction, in Europe, as reported by the European Environmental Agency. Estimating the contribution from biomass combustion to airborne particulate matter is therefore an important issue in air quality governance, due to its potential health and environmental impacts. Wood burning’s contribution to PM10 was estimated in winter at a rural site in southern Italy by means of two independent methods: source apportionment analysis with Positive Matrix Factorization (BBPMF) and the macro tracer approach, based on levoglucosan concentrations (BBLevo). PM10 and PM2.5 samples were collected every 24 h and every 8 h, respectively, and analyzed to determine the organic and elemental carbon, levoglucosan, inorganic ions and elements. The results obtained via these methods showed good agreement (r = 0.85), with a linear correlation slope of about 1, and provide a reliable assessment of the BB contribution. Woody biomass combustion contributed significantly to the PM10 (on average, slightly less than 30% of the total mass) during winter. The combination of the independent methods proposed here may be used as a methodology for refining the BB contribution to air pollution.

Influence of the Flue Gas Temperature on the Behavior of Metals during Biomass Combustion

The influence of the flue gas temperature on the concentration of metals in fly ash and deposited ash during heavy-metal-contaminated woody biomass combustion was investigated. The biomass gathered...

On the Assessment of the CO2 Mitigation Potential of Woody Biomass

Woody biomass, a renewable energy resource, accumulates solar energy in form of carbon hydrates produced from atmospheric CO2 and H2O. It is therefore a means of CO2 mitigation for society as long as the biogenic carbon released to the atmosphere when delivering its energy content by oxidation can be accumulated again during growth of new woody biomass. Even when considering the complete life cycle, usually, only a small amount of fossil CO2 is emitted. However, woody biomass availability is limited by land requirement and therefore it is important to maximize its CO2 mitigation potential in the energy system. In this study, we consider woody biomass not only as a source of renewable energy but also as a source of carbon for seasonal storage of solar electricity. A first analysis is carried out based on the mitigation effect of woody biomass usage pathways, that is the avoided fossil CO2 emissions obtained by using one unit of woody biomass to provide energy services, as alternative to fossil fuels. Results show that woody biomass usage pathways can achieve up to 9.55 times the mitigation effect obtained through combustion of woody biomass, which is taken as a reference. Applying energy system modelling and multi-objective optimisation techniques, the role of woody biomass technological choices in the energy transition is then analysed at a country scale. The analysis is applied to Switzerland, demonstrating that the use of woody biomass in gasification-methanation systems, coupled with electrolysers and combined with an intensive deployment of PV panels and efficient technologies, could reduce the natural gas imports to zero. Electrolysers are used to boost synthetic natural gas production by hydrogen injection into the methanation reaction. The hydrogen used is produced when there is excess of solar electricity. The efficient technologies, such as heat pumps and battery electric vehicles, allow increasing the overall efficiency of the energy system while generating demand for the solar electricity.