scholarly journals Isotopic composition of H2from wood burning: Dependency on combustion efficiency, moisture content, andδD of local precipitation

2010 ◽  
Vol 115 (D17) ◽  
Author(s):  
Thomas Röckmann ◽  
Catalina X. Gómez Álvarez ◽  
Sylvia Walter ◽  
Carina van der Veen ◽  
Adam G. Wollny ◽  
...  
Keyword(s):  
Moisture Content ◽  
Isotopic Composition ◽  
Combustion Efficiency ◽  
Wood Burning

An Experimental Investigation of Wood Combustion

1994 ◽  
Vol 116 (3) ◽  
pp. 186-193 ◽  
Author(s):  
A. Dadkhah-Nikoo ◽  
D. J. Bushnell
Keyword(s):  
Experimental Investigation ◽  
Particle Size ◽  
Moisture Content ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Particulate Emissions ◽  
Fuel Particle ◽  
Wood Combustion ◽  
Part Load ◽  
Excess Air

This paper presents the results from an experimental investigation of wood combustion. Variables chosen for investigation are fuel moisture content, fuel particle size, excess air, fraction and temperature of under-fire air. Influence of the off-design (part load) operation of the combustion unit on combustion efficiency and particulate emission is also investigated. Data recorded during the experiments include the composition and temperature of the combustion products, particulate emissions, and combustible fraction of the particulate. Based on the experimental data, a linear regression model was developed to investigate the variables affecting the combustion process. A computer model was used to calculate the temperature and composition of the combustion products under adiabatic conditions. Results of the adiabatic model and the experimental regression analysis are compared and discussed. According to the results presented, it is concluded that the combustion efficiency and particulate emissions are most influenced by the factors that increase the volume of the combustion products in the combustion chamber. These variables include excess air, moisture content of the fuel, and the combustion air temperature. Fuel particle size and the fraction of under-fire air did not significantly affect the combustion efficiency and particulate emissions. It is also concluded that the off-design (part-load) operation of the combustion unit, results in higher particulate emissions and lower combustion efficiency.

scholarly journals Influence of coal properties on the performance of fixed-bed coal-burning braziers

2017 ◽  
Vol 28 (2) ◽  
pp. 40 ◽  
Author(s):  
Tafadzwa Makonese ◽  
Daniel M. Masekameni ◽  
Harold J. Annegarn
Keyword(s):  
Moisture Content ◽  
Low Income ◽  
Co2 Emission ◽  
Fixed Bed ◽  
Combustion Efficiency ◽  
Emission Factors ◽  
Coal Burning ◽  
Air Ventilation ◽  
Carbon Dioxide Co2 ◽  
Ventilation Rates

Informal fixed-bed coal-burning braziers are used extensively in low-income communities of South Africa for space-heating and cooking needs. An investigation was carried out on the effects of coal moisture content and coal quality on the thermal and emissions performance of domestic coal-burning braziers in three field-procured braziers (with three different air ventilation rates), using the bottom-lit updraft (BLUD) and top-lit updraft (TLUD) ignition methods. Results showed that an increase in coal moisture content (from 2.4 wt.% to 8.6 wt.%) led to 18% and 30% decreases in fire-power when using the TLUD and BLUD methods, respectively. The combustion efficiency increased by 25% with an increase in moisture content. Measured carbon monoxide (CO) emission factors increased with an increase in moisture content, while carbon dioxide (CO2) emission factors remained unchanged. The use of A-grade coal resulted in a 49% increase in PM emissions compared with D-grade coal at high ventilation rates, despite no statistically significant differences (p > 0.05) in CO and CO2 emission factors produced between coal grades.

Optimization Process of Biomass Combustion in the Advanced FBC Using Factorial Design and Response Surface Methodology

2005 ◽  
Author(s):  
Shijun Zhu ◽  
Yun Liu ◽  
Seong Lee
Keyword(s):  
Response Surface Methodology ◽  
Moisture Content ◽  
Factorial Design ◽  
Poultry Manure ◽  
Combustion Efficiency ◽  
Air Injection ◽  
Excess Air ◽  
Secondary Air Injection ◽  
Carbon Combustion ◽  
Secondary Air

This paper studied the optimization process of the combustion of poultry waste material (i.e. poultry manure) in an advanced fluidized bed combustor (FBC) with the secondary air tangential injection. In order to test the influences of combustion parameters on the carbon combustion efficiency, factorial design (FD) and response surface methodology (RSM) were applied in the experimental process and data analysis. The parameters studied were moisture content, waste/natural gas ratio, excess air ratio, secondary/total air ratio, and the height levels of the secondary air injection. Using the 25−1 fractional factorial design, moisture content, excess air and secondary air injection height were found to be significant for the carbon combustion efficiency at the critical level of type-I error α = 0.1. The RSM was used to approach the optimal combustion condition. The optimal condition regarding the significant factors was found. Then the data from a validation experiment was compared with the computed combustion efficiency under the optimal condition. The result showed the combustion efficiency for poultry manure can reach up to 83%, which indicated that the poultry manure could be effectively burned in the advanced FBC.

A Theoretical Analysis of Predrying of Solid Fuels With Flue Gas

1988 ◽  
Vol 110 (2) ◽  
pp. 119-123 ◽  
Author(s):  
C. M. Kinoshita
Keyword(s):  
Moisture Content ◽  
Flue Gas ◽  
Air Entrainment ◽  
Combustion Efficiency ◽  
Solid Fuels ◽  
Fuel Moisture ◽  
Gas Temperature ◽  
Ambient Conditions ◽  
Dimensionless Parameters ◽  
Fuel Moisture Content

Combustion efficiency and flue-gas drying of solid fuels are analyzed. A simple, universal arithmetic expression for combustion efficiency is developed. This expression involves four primary dimensionless parameters which relate to (and are fixed for given) fuel and ambient conditions, and three secondary dimensionless parameters which relate to (and vary with) fuel moisture content, excess air, and flue-gas temperature. Additional expressions involving the same primary parameters are developed to calculate the decrease in fuel moisture content due to flue-gas drying with and without entrainment of air into the dryer system and the decrease in flue-gas temperature with air entrainment. Values for the four primary parameters are presented for various fuels; their values do not vary much for most biomass fuels.

The influence of fuel moisture content on the combustion of Eucalyptus foliage

2013 ◽  
Vol 22 (3) ◽  
pp. 343 ◽  
Author(s):  
Malcolm Possell ◽  
Tina L. Bell
Keyword(s):  
Moisture Content ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Emission Factors ◽  
Fuel Moisture ◽  
Time To Ignition ◽  
Fuel Moisture Content ◽  
Co Concentrations

Leaves from three species of Eucalyptus were combusted in a mass-loss calorimeter to characterise the effect of fuel moisture on energy release and combustion products for this genus. Increasing moisture content reduced peak heat release and the effective heat of combustion in a negative exponential pattern while simultaneously increasing time-to-ignition. Estimates of the probability of ignition, based upon time-to-ignition data, indicated that the critical fuel moisture content for a 50% probability of ignition ranged from 81 to 89% on a dry-weight basis. The modified combustion efficiency of leaves (the ratio of CO2 concentration to the sum of the CO2 and CO concentrations) decreased exponentially as fuel moisture increased. This was because CO2 concentrations during combustion declined exponentially while CO concentrations increased exponentially. However, CO2 mixing ratios were always greater by at least one order of magnitude. Emission factors for CO2 declined exponentially with increasing fuel moisture content while CO emission factors increased exponentially to a maximum. The emission factors for volatile organic compounds increased in a pattern similar to that for CO with increasing fuel moisture content. The empirical relationships identified in this study have implications for fire-behaviour modelling and assessing the effect of fire on air quality and climate.

scholarly journals A Review on Suspended Wood Dust Combustion. Efficiency and Fuel Quality

2012 ◽  
Vol 9 (1) ◽  
pp. 28-34
Author(s):  
Kaspars Silins
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Wood Dust ◽  
Fuel Quality ◽  
Particle Combustion ◽  
Air Supply ◽  
Influencing Parameters ◽  
Particle Size And Shape

Abstract The paper is dedicated to review the combustion efficiency in low capacity wood dust suspension burners. Fuel quality is reviewed as the main contributor to the combustion efficiency. Wood dust moisture content, particle size and shape, amount of volatiles are discussed as the main contributors. Some additional aspects like burner ignition, fuel and combustion air feeding are reviewed to increase the efficiency. A brief overview of particle combustion process is provided followed by an identification and discussion of combustion efficiency influencing parameters. The significance of fuel feeding and air supply is discussed at the end of the paper.

Preparation and Standardization of a Stable AHF Plasma

1968 ◽  
Vol 19 (03/04) ◽  
pp. 423-429 ◽  
Author(s):  
G. M Thelin ◽  
Keyword(s):  
Moisture Content ◽  
Primary Standard ◽  
Healthy Male ◽  
Healthy Donors ◽  
Fresh Plasma

SummaryA stable, lyophilized AHF reference plasma has been prepared from pooled plasma from at least 50 normal healthy donors and standardized against a primary standard of fresh plasma from 20 healthy male donors aged 20 to 40. Average AHF potency of a typical lot is 98.8%, and moisture content is less than 0.5%. Under storage at -25° C, this AHF reference plasma is stable for at least 18 months. It has been used in several major coagulation laboratories, and has given consistently satisfactory and reproducible results in AHF assays.

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