Effect of Excess Air Levels on PAHs Content in Smoke During Charcoal Combustion in Grilling Process

2020 ◽  
Vol 9 (2) ◽  
pp. 83-88
Author(s):  
Athiti Phakut ◽  
Thiranan Kunanopparat ◽  
Suwit Siriwattanayotin
Keyword(s):  
Emission Factor ◽  
Complete Combustion ◽  
Incomplete Combustion ◽  
Excess Air ◽  
Carcinogenic Pahs ◽  
Co2 Concentrations

Charcoal grilling may lead to carcinogenic PAHs contamination of grilled food from incomplete combustion of charcoal. The objective of this study was to determine the effect of complete combustion of charcoal on PAHs content in smoke during the grilling process. Firstly, proximate and ultimate compositions of the charcoal were determined to identify the amount of air required for combustion according to stoichiometry. Different excess air levels consisting of stoichiometric air, 60, 100 and 150% excess air during combustion of charcoal on 16 PAHs released in smoke were studied. Moreover, CO and CO2 concentrations were measured. The use of excess air decreased the emission factor of CO and increased the emission factor of CO2. The 16 PAHs contents in smoke produced from charcoal combusted with stoichiometric air, 60, 100 and 150% excess air were 73.62, 51.78, 27.68 and 19.23 μg/kg dry charcoal, respectively. The use of excess air during charcoal combustion resulted in significantly lower PAHs contents in the smoke. Therefore, the use of excess air during charcoal grilling is one way to reduce the risk of PAHs contamination in grilled food.

Research and Improvement on Calculation Method of Optimal Excess Air Ratio

2014 ◽  
Vol 536-537 ◽  
pp. 1583-1586
Author(s):  
Jun Xiong Qi
Keyword(s):  
Heat Loss ◽  
Correction Factor ◽  
Calculation Method ◽  
Traditional Method ◽  
Combustion Efficiency ◽  
Exhaust Gas ◽  
Incomplete Combustion ◽  
Excess Air

By analyzing the relations of the excess air ratio to heat loss due to exhaust gas, chemical incomplete combustion and combustibles in refuse, the traditional method for solving the optimal excess air ratio is improved. A correction factor is proposed for heat loss due to combustibles in refuse, making the solving method more accurate, which is of great importance for improving the combustion efficiency of the boiler.

scholarly journals Black Carbon - A Silent Contributor to Climate Change

2021 ◽  
pp. 242-246
Author(s):  
Shikha Uniyal Gairola ◽  
Siddharth Shankar Bhatt
Keyword(s):  
Particulate Matter ◽  
Black Carbon ◽  
Organic Compounds ◽  
Fossil Fuels ◽  
Complex Mixture ◽  
Cloud Formation ◽  
Complete Combustion ◽  
Incomplete Combustion ◽  
Carbon Particles ◽  
Work Done

Black carbon is a potent climate-warming component of particulate matter formed by the incomplete combustion of fossil-fuels, wood and other fuels. Complete combustion would turn all the carbon in the fuel into carbon dioxide, but combustion is never complete, and CO2, CO, volatile organic compounds, organic compounds, and black carbon particles are formed in the process. It contributes to warming by converting incoming solar radiation to heat. When deposited on ice and snow, BC and co-emitted particles reduce surface albedo thereby melting the glaciers. The complex mixture of particulate matter resulting from incomplete combustion is referred as soot. When suspended in the atmosphere, black carbon contributes to warming by converting incoming solar radiations to heat. It also influences cloud formation and impacts regional circulation and rainfall pattern. The Artic and the glaciated regions such as Himalayas are particularly vulnerable to melting as a result. The present paper aims to review the work done on black carbon and its mitigation measure.

DILUTE CAUSTIC AND WATER COMPARISONS AS SOLVENTS IN THE REMOVAL OF ACIDIC GASES FROM COMBUSTION EXHAUST STREAM OF A BOILER.

2020 ◽  
Vol 1 (2) ◽  
Keyword(s):  
Complete Removal ◽  
Simulation Software ◽  
Complete Combustion ◽  
Incomplete Combustion ◽  
Acidic Gases ◽  
Aspen Hysys ◽  
Data Prediction ◽  
Water As Solvent ◽  
Exhaust Stream ◽  
Incomplete Reaction

This work focused on the comparative analyses between the use of dilute caustic with a composition of 1.84% and using water alone (pH=7) that have the potential to remove SO2 completely from the exhaust flue gas of a combustion system and H2S in the incomplete reaction scenario. Two reaction pathways were utilized for the study, the complete combustion pathway as well as the incomplete combustion pathway. ASPEN HYSYS 8.6, a process simulation software, was used to simulate conditions with PENG-ROBINSON utilized as the vapour-liquid equilibrium (VLE) data prediction tool of the software. For the complete combustion pathway, a complete removal of SO2 was achieved using caustic while with the same conditions, utilizing water as solvent achieved a reduction of 90%. For the incomplete combustion pathway, using caustic gave about 53% removal efficiency for H2S while the water only showed a poor 16% increase of H2S. The study recommended the use of the dilute caustic for the following reasons; it gave a better removal percentage than using water alone, the use of the caustic will not contribute to caustic corrosion because of the low composition of the dilute caustic that will be used in the absorber, the choice of the caustic was also observed to be economical. Keywords: Caustic, Absorption, Emission, Simulation, Combustion, Solvents.

Simulating the homogeneous charge compression ignition process using a detailed kinetic model for n-heptane mixtures

2000 ◽  
Vol 1 (3) ◽  
pp. 281-289 ◽  
Author(s):  
J Kusaka ◽  
T Yamamoto ◽  
Y Daisho
Keyword(s):  
Compression Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Combustion Model ◽  
Ignition Process ◽  
Compression Ignition ◽  
Complete Combustion ◽  
Hcci Combustion ◽  
Excess Air ◽  
Auto Ignition ◽  
Homogeneous Charge

The homogeneous charge compression ignition (HCCI) combustion has been attracting growing attention in recent years due to its potential for simultaneous improvement of exhaust gas emissions and fuel consumption in diesel engines. For practical application of HCCI to internal combustion (IC) engines, precise control of auto-ignition of pre-mixtures during the compression stroke is inevitable. This paper discusses the auto-ignition processes in an HCCI engine operated with n-heptane/air mixtures using a zero-dimensional combustion model including a detailed kinetics. The model proposed is validated first by a comparison between calculated and experimental pressure diagrams, and then the effects of initial charge conditions, compression ratio and excess air ratio on ignition and combustion are investigated. It was found from the parametric study that HCCI combustion of n-heptane/air mixtures is classified into three types of combustion: complete combustion, only low-temperature reaction and misfire, depending on the compression ratio and excess air ratio at which the engine is operated. Finally, the major paths of the HCCI reaction occurring in the engine cylinder were clarified by a sensitivity analysis of chemical reactions involved in the HCCI reaction scheme.

scholarly journals Emission Rate Estimation of Fuel Oil in A Combustion System Using Empirical Method

2019 ◽  
Vol 4 (12) ◽  
pp. 6-8
Author(s):  
N. Harry-Ngei ◽  
I. Ubong ◽  
E. Ojong
Keyword(s):  
Emission Rate ◽  
Reaction Pathway ◽  
Empirical Method ◽  
Fuel Oil ◽  
Reaction Pathways ◽  
Emission Rates ◽  
Combustion System ◽  
Complete Combustion ◽  
Incomplete Combustion ◽  
Oil Flow

This work highlighted the prediction of the emission rates of the products of combustion using a fuel oil of specific gravity of 0.9. The two reaction pathways of complete combustion and incomplete combustion were used differently to ascertain the emission rates. Ultimate analysis were conducted on the fuel oil to show the percentage composition of elements using ASTM 3178 method for carbon and hydrogen, Kjedahl method for nitrogen, ASTM D1552 for sulphur and the differences used to compute that of oxygen. The estimated percentages of the various elements were the stoichiometrically used to compute the emissions rates at standard conditions. The basis of the computation was a fuel oil flow rate of 10Tonnes/h and the following emission rates were predicted for the complete combustion reaction pathway: 31,246Kg/h for CO2, 65Kg/h for H2O, 158Kg/h for NO2 and 20Kg/h for SO2 while 9,940Kg/h for CO2, 15,623Kg/h for CO, 11,700Kg/h for H2O, 11Kg/h for H2S and 158Kg/h for NO2 were predicted for the incomplete combustion pathway. The study noted that this predictive path should be taken where effective devices or logistics are not in place to measure emissions from combustion systems.

scholarly journals Research on the Carbon Dioxide Emission Factor as a Result of Fuel Combustion

2019 ◽  
Vol 70 (2) ◽  
pp. 585-590 ◽  
Author(s):  
Tudora Cristescu ◽  
Monica Emanuela Stoica ◽  
Silvian Suditu
Keyword(s):  
Carbon Dioxide ◽  
Comparative Analysis ◽  
Emission Factor ◽  
Carbon Dioxide Emission ◽  
Calculation Model ◽  
Fuel Combustion ◽  
Minimum Amount ◽  
Mass Composition ◽  
Complete Combustion ◽  
Evaluation Models

The present paper first discusses a calculation model for the complete combustion of fuels � with the minimum amount of air needed � whose volumetric and mass composition is known. It then describes evaluation models for the heat resulting from fuel combustion, i.e., superior and inferior caloric power value. In this context, the carbon dioxide emission factors for fuel and biofuel combustion, respectively, are evaluated. The results obtained have allowed a comparative analysis regarding carbon dioxide emission.

Adiabatic Flame Temperature and Product Composition for Lean Combustion of Hydrogen-Methane Combination

1994 ◽  
Author(s):  
Zafer Dülger
Keyword(s):  
Equivalence Ratio ◽  
Flame Temperature ◽  
Adiabatic Flame Temperature ◽  
Lean Combustion ◽  
Excess Air ◽  
Co2 Concentrations ◽  
Hydrogen Mixtures ◽  
Lean Limit ◽  
Hydrogen Enrichment ◽  
Combustion Of Hydrogen

Abstract Adiabatic combustion of methane (natural gas)-hydrogen mixtures is analyzed The adiabatic flame temperature and products composition (especially NOx and CO2 concentrations) variation with excess air (fuel-air equivalence ratio), hydrogen enrichment of methane, and reactant temperature is determined It is shown that reductions in NOx and CO2 emissions are possible with the extended lean limit of combustion of methane associated with hydrogen enrichment CO2 concentrations are also reduced with hydrogen enrichment, reductions being dependent upon the degree of enrichment.

scholarly journals THE EFFECT OF THE THERMODYNAMIC MODELS ON THE THERMOECONOMIC RESULTS FOR COST ALLOCATION IN A GAS TURBINE COGENERATION SYSTEM

2015 ◽  
Vol 14 (2) ◽  
pp. 47 ◽  
Author(s):  
R. G. Dos Santos ◽  
P. R. De Faria ◽  
J. J. C. S. Santos ◽  
J. A. M. Da Silva ◽  
J. L. M. Donatelli
Keyword(s):  
Gas Turbine ◽  
Cost Allocation ◽  
Combustion Process ◽  
Complex Model ◽  
Point Of View ◽  
Working Fluid ◽  
Thermodynamic Models ◽  
Complete Combustion ◽  
Excess Air ◽  
Cogeneration System

The thermoeconomics combines economics and thermodynamics to provide information not available from conventional energy and economic analysis. For thermoeconomics modeling one of the keys points is the thermodynamic model that should be adopted. Different thermodynamic models can be used in the modeling of a gas turbine system depending on the accuracy required. A detailed study of the performance of gas turbine would take into account many features. These would include the combustion process, the change of composition of working fluid during combustion, the effects of irreversibilities associated with friction and with pressure and temperature gradients and heat transfer between the gases and walls. Owing to these and others complexities, the accurate modeling of gas turbine normally involves computer simulation. To conduct elementary thermodynamic analyses, considerable simplifications are required. Thus, there are simplified models that lead to different results in thermoeconomics. At this point, three questions arise: How different can the results be? Are these simplifications reasonable? Is it worth using such a complex model? In order to answer these questions, this paper compares three thermodynamic models in a gas turbine cogeneration system from thermoeconomic point of view: cold air-standard model, CGAM model and complete combustion with excess air.

Combustion properties of Bromus tectorum L.: influence of ecotype and growth under four CO2 concentrations

2006 ◽  
Vol 15 (2) ◽  
pp. 227 ◽  
Author(s):  
Robert R. Blank ◽  
Robert H. White ◽  
Lewis H. Ziska
Keyword(s):  
Bromus Tectorum ◽  
Combustion Process ◽  
Co2 Concentration ◽  
High Elevation ◽  
Total Heat ◽  
Tissue Concentrations ◽  
Complete Combustion ◽  
Co2 Concentrations ◽  
Combustion Properties ◽  
Heat Released

We grew from seed the exotic invasive annual grass Bromus tectorum L., collected from three elevation ecotypes in northern Nevada, USA. Plants were exposed to four CO2 atmosphere concentrations: 270, 320, 370, and 420 μmol mol–1. After harvest on day 87, above-ground tissue was milled, conditioned to 30% relative humidity, and combustion properties were measured using a cone calorimeter. Plants exposed to 270 μmol mol–1 CO2 had significantly less total heat released than plants exposed to higher CO2 concentrations. Total heat released was least for the low-elevation ecotype, statistically similar for the mid-elevation ecotype, and significantly increased for the high-elevation ecotype. Plant attributes that significantly correlated with heat release included tissue concentrations of lignin, glucan, xylan, potassium, calcium, and manganese. The data suggest that a decline in tissue concentrations of lignin, xylan, and mineral constituents, as CO2 concentration increases from 270 μmol mol–1 to higher levels, affects the combustion process. We suspect that as tissue concentrations of lignin and inorganics decline, char formation decreases, thereby allowing more complete combustion. Changes in combustion parameters of B. tectorum induced by different CO2 concentrations and elevation ecotype may be a strong consideration to understanding fire behaviors of the past, present, and future.

The Optimal Operation Problem of Boilers

2014 ◽  
Vol 953-954 ◽  
pp. 1454-1458
Author(s):  
Cong Sun
Keyword(s):  
Heat Loss ◽  
Optimal Operation ◽  
Combustion Heat ◽  
Incomplete Combustion ◽  
Excess Air ◽  
Exhaust Heat ◽  
Excess Air Coefficient ◽  
Main Factors ◽  
The Relationship

Boiler optimum efficiency problem can be solved by optimum excess air coefficient model. It is the key to find the relationship between main factors and the excess air coefficient. These main factors are smoke exhaust heat losschemistry incomplete combustion heat loss and mechanical incomplete combustion heat loss.In this paper, we projected the relationship between the factors and the excess air coefficient by using the computational formulas of principles of boiler. Then we synthesized the three formulas to establish the excess air coefficient model. Finally, this paper geted the optimum excess air coefficient using extremum method.That is αp=1.152596.

Sign in / Sign up

Export Citation Format

Share Document