862 research outputs found
A cost-benefit analysis of a pellet boiler with electrostatic precipitator versus conventional biomass technology: A case study of an institutional boiler in Syracuse, New York
BACKGROUND: Biomass facilities have received increasing attention as a strategy to increase the use of renewable fuels and decrease greenhouse gas emissions from the electric generation and heating sectors, but these facilities can potentially increase local air pollution and associated health effects. Comparing the economic costs and public health benefits of alternative biomass fuel, heating technology, and pollution control technology options provides decision-makers with the necessary information to make optimal choices in a given location.
METHODS: For a case study of a combined heat and power biomass facility in Syracuse, New York, we used stack testing to estimate emissions of fine particulate matter (PM2.5) for both the deployed technology (staged combustion pellet boiler with an electrostatic precipitator) and a conventional alternative (wood chip stoker boiler with a multicyclone). We used the atmospheric dispersion model AERMOD to calculate the contribution of either fuel-technology configuration to ambient primary PM2.5 in a 10 km x 10 km region surrounding the facility, and we quantified the incremental contribution to population mortality and morbidity. We assigned economic values to health outcomes and compared the health benefits of the lower-emitting technology with the incremental costs.
RESULTS: In total, the incremental annualized cost of the lower-emitting pellet boiler was 1.7 million annually, greatly exceeding the differential costs even when accounting for uncertainties. Our analyses also showed complex spatial patterns of health benefits given non-uniform age distributions and air pollution levels.
CONCLUSIONS: The incremental investment in a lower-emitting staged combustion pellet boiler with an electrostatic precipitator was well justified by the population health improvements over the conventional wood chip technology with a multicyclone, even given the focus on only primary PM2.5 within a small spatial domain. Our analytical framework could be generalized to other settings to inform optimal strategies for proposed new facilities or populations.This research was supported by the New York State Energy Research and Development Authority (NYSERDA), via an award to the Northeast States for Coordinated Air Use Management (Agreement #92229). The SCICHEM work of KMZ was supported by the Electric Power Research Institute (EPRI)
Características químicas e toxicológicas de partículas de queima doméstica de biomassa
Biomass combustion for residential heating is recognised as an important source
of particulate matter, not only in the ambient air, but also inside the dwellings.
Exposure to biomass burning particles has been linked to a vast array of adverse
health effects. The physical and chemical properties of inhaled particles are
thought to greatly affect the biological responses. Over the years, many studies
have focused on emission source profiles of residential biomass combustion.
However, with the advent and growing market share of new small-scale
appliances automatically fed with compressed biofuels, research efforts need to
be devoted to the characterisation of emissions from these appliances either
from new commercially available pellets or from pellets made from potentially
relevant raw materials. Despite the wealth of publications on emissions and
composition of particles from residential biomass combustion, the impact of this
source on the indoor air quality has been scarcely studied, especially with regard
to the chemical and toxicological characteristics of the particles. The two main
objectives of this thesis were: i) to obtain chemical and toxicological profiles for
pellet-fuelled heating systems, and ii) to evaluate the impact of traditional
appliances on indoor air quality, properties of particulate matter, deposited dose
in the respiratory tract and biological responses. For the fulfilment of the first
objective, four types of pellets were selected (two brands of ENplus A1 certified
pellets, one brand of non-certified pellets, and laboratory-produced acacia
pellets) to carry out experiments in a laboratory combustion facility to determine
emission factors of gaseous compounds and particulate matter (PM10). To
achieve the second objective, particulate samples were collected in two
households equipped with distinct combustion appliances (open fireplace and
woodstove) in the absence of other indoor sources. The dose of inhaled indoor
particles deposited in the human respiratory tract was estimated using an
exposure dose model (ExDoM2). The chemical composition of PM10 from both
laboratory experiments and residential microenvironments was analysed for
water soluble inorganic ions, organic and elemental carbon and detailed organic
speciation. Additionally, in samples collected indoors, major and trace elements
were also determined. A battery of in vitro assays was used to assess the
ecotoxicity, cytotoxicity and mutagenicity of the PM10 samples. The results
obtained from the laboratory measurements indicated that the alternative woody
raw material selected for pelletising contributed to a dramatic increase in
particulate emissions, with distinctive chemical properties and increased
toxicological potential. It was observed that even certified material does not
always meet emission requirements set by the Ecodesign directive. Particles
from pellet combustion were mainly composed of water soluble inorganic
constituents. The carbonaceous fraction of particulate samples from commercial pellets was
dominated by elemental carbon, while organic carbon was the most abundant
constituent in samples from the combustion of acacia pellets. The results showed
that particles from acacia pellets were the most ecotoxic and cytotoxic, while
mutagenicity was not detected for any biofuel. In the sampling campaign carried
out in residential microenvironments while using different combustion devices,
higher exposures, higher doses in the human respiratory tract and higher toxicity
of the particles collected during the operation of the open fireplace were
observed, as a result of the lower combustion efficiency. When using this
combustion equipment, a higher increase in particulate matter levels (over 12
times compared to background concentrations) was registered compared to that
measured with the woodstove (2-fold increase). The carbonaceous material
accounted for a PM10 mass fraction of about 44% in samples from the room
equipped with fireplace, while the woodstove operation almost halved the total
particulate carbon content. Water soluble ions and trace elements showed
variable contributions to the mass of the indoor particles and were generally
higher during the operation of the woodstove. Several chemical markers of
biomass combustion were detected in both residential microenvironments,
highlighting the input of this source to indoor particles. The bioreactivity
assessment showed that particles emitted by the fireplace were the most
ecotoxic and cytotoxic, while mutagenicity was not detected in any of the tested
samples. Combustion-related organic compounds in indoor particles, such as
polycyclic aromatic hydrocarbons, displayed significant correlations with the
increase in toxicity. In view of the results obtained, homeowners should be
encouraged to upgrade the wood burning technology in order to reduce the
products of incomplete combustion inside their dwellings.A combustão de biomassa para aquecimento residencial é reconhecida como
uma fonte importante de material particulado não apenas no ar ambiente, mas
também no interior das habitações. A exposição a partículas resultantes da
queima de biomassa tem sido associada a um vasto leque de efeitos adversos
na saúde. Sabe-se que as propriedades físicas e químicas das partículas
inaladas afetam acentuadamente as respostas biológicas. Ao longo dos anos,
muitos estudos tiveram como foco os perfis de emissão da combustão
residencial de biomassa. No entanto, com o aparecimento e a crescente quota
de mercado de novos equipamentos de pequena escala alimentados
automaticamente com biocombustíveis prensados, a investigação deve ser
direcionada para a caracterização das emissões desses sistemas de combustão
alimentados quer com novos pellets disponíveis no mercado, quer com pellets
produzidos a partir de novas matérias primas potencialmente relevantes. Apesar
da abundância de publicações dedicadas às emissões e composição das
partículas da queima residencial de biomassa, o impacto desta fonte na
qualidade do ar interior tem sido pouco estudado, sobretudo no que diz respeito
às características químicas e toxicológicas do material particulado. Os dois
objetivos principais desta tese foram: i) obter os perfis químicos e toxicológicos
para sistemas alimentados a pellets, e ii) avaliar o impacto de equipamentos
tradicionais na qualidade do ar interior, propriedades do material particulado,
dose depositada no trato respiratório e respostas biológicas. Para atingir o
primeiro objetivo, foram selecionados quatro tipos de pellets (duas marcas de
pellets com certificação ENplus A1, uma marca de pellets sem certificação e
pellets de acácia produzidos em laboratório) para realizar experiências numa
instalação laboratorial de combustão e determinar fatores de emissão de gases
e material particulado (PM10). Para atingir o segundo objetivo, realizaram-se
amostragens de partículas em duas habitações com equipamentos de
combustão distintos (lareira aberta e recuperador de calor), na ausência de
outras fontes interiores. A dose de partículas inaladas no interior das habitações
e depositadas no trato respiratório humano foi estimada utilizando um modelo
de exposição/dose (ExDoM2). A composição química das PM10 resultantes quer
dos ensaios laboratoriais, quer dos microambientes residenciais, foi analisada
em termos de iões inorgânicos solúveis em água, carbono orgânico e elementar
e especiação orgânica detalhada. Adicionalmente, nas amostras de partículas
colhidas no interior das habitações, foram também determinados elementos
maioritários e traço. Foi utilizada uma bateria de ensaios in vitro para avaliar a
ecotoxicidade, citotoxicidade e mutagenicidade das amostras de PM10. Os resultados obtidos nos ensaios laboratoriais indicaram que o material
lenhoso alternativo selecionado para a peletização contribuiu para um aumento
dramático das emissões de partículas, as quais apresentaram propriedades
químicas distintas e um potencial toxicológico elevado. Observou-se que mesmo
o material certificado nem sempre cumpre os requisitos de emissão
estabelecidos pela diretiva Ecodesign. As partículas emitidas pela combustão
de pellets apresentaram na sua composição maioritariamente iões inorgânicos
solúveis em água. O carbono elementar dominou a fração de material
carbonáceo nas partículas dos pellets comerciais, ao passo que o carbono
orgânico constitui a componente mais abundante nas amostras resultantes da
queima de pellets de acácia. Os resultados mostraram que as partículas dos
pellets de acácia foram as mais ecotóxicas e citotóxicas, enquanto não foi
detetada mutagenicidade para nenhum biocombustível. Na campanha de
amostragem realizada em microambientes residenciais durante a utilização de
diferentes equipamentos de combustão, observou-se uma exposição mais
elevada, dose depositada no trato respiratório humano mais alta e uma toxidade
superior para as partículas colhidas durante a operação da lareira aberta,
refletindo a menor eficiência de combustão deste equipamento. Durante a sua
utilização, foi registado um aumento superior nos níveis de material particulado
(mais de 12 vezes relativamente às concentrações de fundo) em comparação
com o observado para o recuperador de calor (aumento de 2 vezes). O material
carbonáceo representou cerca de 44% da massa de PM10 nas amostras colhidas
durante a operação da lareira, enquanto a operação do recuperador de calor
reduziu quase pela metade o conteúdo total de carbono nas partículas. Os iões
solúveis em água e os elementos apresentaram contribuições variáveis para a
massa das partículas no interior das habitações, sendo geralmente superiores
durante a operação do recuperador de calor. Em ambos os microambientes
residenciais foram detetados vários traçadores químicos de combustão de
biomassa, assinalando a contribuição desta fonte para as partículas interiores.
A avaliação da biorreatividade revelou que as partículas emitidas pela lareira
foram as mais ecotóxicas e citotóxicas, enquanto que não foi detetada
mutagenicidade em quaisquer das amostras testadas. Vários constituintes
detetados nas partículas internas, como os hidrocarbonetos aromáticos
policíclicos, apresentaram correlações significativas com o aumento da
toxicidade. Considerando os resultados obtidos, os proprietários devem ser
encorajados a atualizar a tecnologia de combustão, a fim de reduzir os produtos
de combustão incompleta dentro das suas habitações.Programa Doutoral em Ciências e Engenharia do Ambient
Emissions from residential pellet combustion of an invasive acacia species
Currently, different types of raw materials are under investigation to fulfil the demand for pellet-based renewable energy. The aim of this study was to experimentally quantify and characterise the gaseous and particulate matter (PM10) emissions from the combustion of a pelletised invasive species growing in the Portuguese coastal areas. The combustion of acacia pellets in a stove used for domestic heating led to a noticeable production of environmentally relevant contaminants, such as carbon monoxide (CO, 2468 ± 485 mg MJ−1), sulphur dioxide (SO2, 222 ± 115 mg MJ−1) and nitrogen oxides (NOx, 478 ± 87 mg MJ−1). Besides gaseous pollutant emissions, substantial particle emissions (118 ± 14 mg MJ−1) were also generated. Particles consisted mostly of inorganic matter, mainly alkaline metals, sulphur and chlorine. About 25%wt. of the PM10 emitted had carbonaceous nature. The chromatographically resolved organic compounds were dominated by anhydrosugars, especially levoglucosan (284 μg g−1 PM10), and several types of phenolic compounds. Retene (8.77 μg g−1 PM10) was the chief compound among polyaromatic hydrocarbons.publishe
Investigation of the olive mill solid wastes pellets combustion in a counter-current fixed bed reactor
Combustion tests and gaseous emissions of olive mill solid wastes pellets (olive pomace (OP), and olive pits (OPi)) were carried out in an updraft counter-current fixed bed reactor. Along the combustion chamber axis and under a constant primary air flow rate, the bed temperatures and the mass loss rate were measured as functions of time. Moreover, the gas mixture components such as O2, organic carbon (Corg), CO, CO2, H2O, H2, SO2, and NOx (NO + NO2) were analyzed and measured. The reaction front positions were determined as well as the ignition rate and the reaction front velocity. We have found that the exhaust gases are emitted in acceptable concentrations compared to the combustion of standard wood pellets reported in the literature (EN 303-5). It is shown that the bed temperature increased from the ambient value to a maximum value ranging from 750 to 1000 °C as previously reported in the literature. The results demonstrate the promise of using olive mill solid waste pellets as an alternative biofuel for heat and/or electricity production
D1.4 Mapping, characterization and critical evaluation of the state-of-the-art
EU/H2020; 818349publishedVersio
Power Form Agripellets
Currently, the production of thermal energy by biomass has shown a clear trend toward densified biofuels (pellets). This is due to their consistent size and shape that can be more easily delivered to homes, businesses, and power plants and can be automatically fed into advanced pellet boilers in a controlled and calibrated way. The use of densified biofuels also reduces the costs associated with handling and transportation, due to the increase in density involved by densification process. Demand for wood pellets is currently growing at a faster rate than supply in Europe. It is estimated that pellet market is growing to 50 Mt year−1 by 2025; however, most wood waste is already committed for pressed wood products and pellets, therefore more supply of raw materials are needed. With the possible shortage of woody raw materials for pellet production and considering the low forestry residues potential in several countries, agricultural residues could be largely used in the future for fuel pellets manufacturing. Agricultural pellets, as well known as “agripellets”, are emerging and promising. However, they have certain differences compared to conventional wood pellets
Impact of fuel quality and burner capacity on the performance of wood pellet stove
Pellet stoves may play an important role in Serbia in the future when fossil fuel fired conventional heating appliances are replaced by more efficient and environmentally friendly devices. Experimental investigation was conducted in order to examine the influence of wood pellet quality, as well as burner capacity (6, 8, and 10 kW), used in the same stove configuration, on the performance of pellet stove with declared nameplate capacity of 8 kW. The results obtained showed that in case of nominal load and combustion of pellets recommended by the stove manufacturer, stove efficiency of 80.03% was achieved The use of lower quality pellet caused additional 1.13 kW reduction in heat output in case of nominal load and 0.63 kW in case of reduced load This was attributed to less favourable properties and lower bulk and particle density of lower quality pellet. The use of different burner capacity has shown to have little effect on heat output and efficiency of the stove when pre-set values in the control system of the stove were not altered It is concluded that replacement of the burner only is not sufficient to increase/decrease the declared capacity of the same stove configuration, meaning that additional measures are necessaly. These measures include a new set-up of the stove control system, which needy to be properly adjusted for each alteration in stove configuration. Without the adjustment mentioned, declared capacity of the stove cannot be altered, while its CO emission shall be considerably increase
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