Search results for "Combustion"

Mathematical modelling and experimental study of straw co-firing with gas using electric field control of combustion characteristics

2020

Mobility of Cr and V in Spent Oil Shale: Impact of Thermal Treatment

2013

Abstract Spent oil shale samples were evaluated for potential chromium and vanadium release upon aerobic combustion used in power generation, or anaerobic retorting used in shale oil recovery. Combusted samples released more Cr than retorted or raw samples due to chromate formation. The behavior of vanadium was just opposite in that more V was released from retorted than from aerobically combusted samples, probably due to reduced vanadyl cation formation.

Landowners’ willingness to promote bioenergy production on wasteland − future impact on land use of cutaway peatlands

2017

Landowners are the key players in bioenergy production on wasteland; such as cutaway peatlands. In this study, the landowner's interest to use cutaway peatlands for bioenergy production was investigated using a survey and GIS (Geographic Information Systems) methods in an area in South Ostrobothnia, Finland. The focus was to identify which different bioenergy production chains are preferred by the respondents: combustion, gasification or biogas production from agriculture, energy-willow short-rotation forestry or forestry based energy crops. Also, the influence of personal environmental values on the selection was measured and the future impacts and barriers for the land use were assessed. …

Importance of iron and aluminium in rapid and slow combustion of peat

1990

Abstract The effects of Fe and Al on peat combustion and the formation of nitrogen oxides were studied under conditions of rapid combustion in an entrained flow reactor, and under conditions of slow combustion in a thermobalance and a differential scanning calorimeter. Iron had a strong catalytic effect on both the slow and rapid combustion, and it decreased the ratio of N2O to NO in the combustion gases. A decrease in the content of inorganic compounds decreased reactivity, probably because of the decrease in iron content. Aluminium did not have a detectable catalytic effect on the combustion rate but it depressed the formation of nitrogen oxides slightly. The chemical treatment to increas…

Occurrence and recovery potential of rare earth elements in Finnish peat and biomass combustion fly ash

2019

Rare earth elements (REEs) are highly important in the modern society as a result of their wide use in various fields of industry. Their high supply risk and increase in demand has led to classification as critical materials, and consequently, new resources for REEs are being prospected widely. Coal fly ash has been suggested as a possible secondary resource for REEs, but very little information is available regarding REE occurrence in biomass or peat derived fly ash. In this paper, fly ash samples from commercial power plants using peat and biomass as fuel were studied for REEs. The average concentration of REEs was 530 ppm, with up to 920 ppm in one fly ash. Five out of seven fly ashes we…

Temporal and spatial persistence of combustion fronts in paper

2003

The spatial and temporal persistence, or first-return distributions are measured for slow-combustion fronts in paper. The stationary temporal and (perhaps less convincingly) spatial persistence exponents agree with the predictions based on the front dynamics, which asymptotically belongs to the Kardar-Parisi-Zhang universality class. The stationary short-range and the transient behavior of the fronts are non-Markovian, and the observed persistence properties thus do not agree with the predictions based on Markovian theory. This deviation is a consequence of additional time and length scales, related to the crossovers to the asymptotic coarse-grained behavior. Peer reviewed

Scaling and Noise in Slow Combustion of Paper

2000

We present results of high resolution experiments on kinetic roughening of slow combustion fronts in paper, focusing on short length and time scales. Using three different grades of paper, we find that the combustion fronts show apparent spatial and temporal multiscaling at short scales. The scaling exponents decrease as a function of the order of the corresponding correlation functions. The noise affecting the fronts reveals short range temporal and spatial correlations, and non-Gaussian noise amplitudes. Our results imply that the overall behavior of slow combustion fronts cannot be explained by standard theories of kinetic roughening. Peer reviewed

Kinetic Roughening in Slow Combustion of Paper

2001

Results of experiments on the dynamics and kinetic roughening of one-dimensional slow-combustion fronts in three grades of paper are reported. Extensive averaging of the data allows a detailed analysis of the spatial and temporal development of the interface fluctuations. The asymptotic scaling properties, on long length and time scales, are well described by the Kardar-Parisi-Zhang (KPZ) equation with short-range, uncorrelated noise. To obtain a more detailed picture of the strong-coupling fixed point, characteristic of the KPZ universality class, universal amplitude ratios, and the universal coupling constant are computed from the data and found to be in good agreement with theory. Below …

The spatial dynamics of atmospheric pollution in Latvia and the Baltic Republics, as measured in mosses, topsoil and precipitation

1994

Atmospheric pollution in the Baltic countries of Estonia, Latvia, and Lithuania has been mapped using measurements of pollutant concentrations in mosses, topsoil and precipitation. Air masses from western Europe deposit industrial pollutants in the Baltic region and concentrations depend on meteorological conditions. Superimposed on this background is the pattern of deposits from local sources. Large areas receive neutral to basic precipitation due to cement industries and fly ash emissions from fossil fuel combustion. The burning of oil-shale in NE Estonia results in precipitation with pH values over 7.0, and high concentrations of V, Fe, and Cd. Heavy metal concentrations in the topsoil a…

CO<inf>2</inf> reduction exploiting RES for EV charging

2016

The world is facing an urgent need to reduce emissions, limiting pollution for a better quality of life. This objective has to be reached by all cities and governments worldwide. This paper focuses on the field of transportation, which is greatly responsible for air pollution, mainly in cities and urban areas such as towns, airports and seaports. The diffusion of electric vehicles (EVs) enables a significant reduction of air pollutants emitted by combustion engines; however, their recharge can affect the total pollution by their increasing energy demand. A solution is the use of Renewable Energy Sources (RES) to charge EVs. This paper analyzes the feasibility of integrating EVs and RES, foc…