scholarly journals Investigation on Smoke Suppression Mechanism of Hydrated Lime in Asphalt Combustion

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Kai Zhu ◽  
Yunhe Wang ◽  
Qi Zhou ◽  
Daquan Tang ◽  
Lingzhu Gu ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Magnesium Hydroxide ◽  
Barrier Layer ◽  
Cone Calorimeter ◽  
Combustion Process ◽  
Hydrated Lime ◽  
Smoke Suppression ◽  
Gaseous Products ◽  
Acidic Gases ◽  
Suppression Mechanism

In this study, cone calorimeter and thermogravimetric analyses were used to simulate the asphalt combustion process under the conditions of fire radiation and programmed temperature increase. The gaseous compositions and release rules were analyzed by infrared spectroscopy to investigate the influence of hydrated lime on the smoke suppression mechanism in the asphalt combustion process. The experimental results show that hydrated lime can promote the asphalt mastic surface to form a barrier layer during the combustion process. This barrier layer can reduce the burning intensity of asphalt. Although the compositions of gaseous products do not change much, the rates of CO production and smoke release are decreased. In addition, hydrated lime is alkaline and can thus neutralize acidic gases such as SO2 and reduce the toxicity of gaseous products. With the addition of 40 wt.% hydrated lime, the total smoke release and the CO release rate both decrease by more than 20% relative to the addition of the same amount of limestone fillers and decrease by more than 10% relative to the addition of the same amount of magnesium hydroxide flame retardant.

scholarly journals Synergistic effect of aluminum diethylphosphinate/sodium stearate modified vermiculite on flame retardant and smoke suppression properties of amino coatings

RSC Advances ◽  
2021 ◽  
Vol 11 (54) ◽  
pp. 34059-34070
Author(s):  
Siwei Li ◽  
Jihu Wang ◽  
Shaoguo Wen ◽  
Yabo Chen ◽  
Jijia Zhang ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Flame Retardant ◽  
Combustion Process ◽  
Sodium Stearate ◽  
Smoke Suppression ◽  
Suppression Mechanism

Schematic illustration of the flame retardant and smoke suppression mechanism of ANE coatings during the combustion process.

scholarly journals The Effect of Ultrafine Magnesium Hydroxide on the Tensile Properties and Flame Retardancy of Wood Plastic Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiping Wu ◽  
Na Hu ◽  
Yiqiang Wu ◽  
Shuyun Wu ◽  
Zu Qin
Keyword(s):  
Thermogravimetric Analysis ◽  
Tensile Properties ◽  
Magnesium Hydroxide ◽  
Flame Retardancy ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Combustion Process ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Cone Calorimeter Test

The effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) on the tensile properties and flame retardancy of wood plastic composites (WPC) were investigated by tensile test, oxygen index tester, cone calorimeter test, and thermogravimetric analysis. The results showed that ultrafine magnesium hydroxide possesses strengthening and toughening effect of WPC. Scanning electron micrograph (SEM) of fracture section of samples provided the positive evidence that the tensile properties of UMH/WPC are superior to that of WPC and OMH/WPC. The limited oxygen index (LOI) and cone calorimeter test illustrated that ultrafine magnesium hydroxide has stronger flame retardancy and smoke suppression effect of WPC compared to that of ordinary magnesium hydroxide. The results of thermogravimetric analysis implied that ultrafine magnesium hydroxide can improve the char structure which plays an important role in reducing the degradation speed of the inner matrix during combustion process and increases the char residue at high temperature.

TG-FTIR Analysis of Wood Based Bio-Oil

2011 ◽  
Vol 347-353 ◽  
pp. 2661-2665
Author(s):  
Jin Xing Peng ◽  
Bei Bei Yan ◽  
Guan Yi Chen ◽  
Xin Li Zhu ◽  
Chao Wang
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fast Pyrolysis ◽  
Combustion Process ◽  
Gaseous Product ◽  
Combustion Mechanism ◽  
Ftir Analysis ◽  
Gaseous Products ◽  
Second Stage ◽  
Bio Oil

The combustion mechanism of bio-oil derived from wood fast pyrolysis was investigated by thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TG–FTIR) in flowing air. The results show that the combustion process of bio-oil consists of two main consecutive stages at a low heating rate. The combustion reaction becomes more and more intense from the first to the second stage. The release of volatiles occurs mainly at 80～200 °C and 350～500°C, and the gaseous products in each stage are different. The main products in the first stage are H2O with a few low molecule weight compounds, such as methanol, formic acid, etc. In the second stage, some new volatiles such as CO2, CO and CH4, etc. are present. Among the above volatiles, CO2 is the dominant gaseous product in the whole combustion process. The concentrations of CO2 and CO keep increasing, and reach the maximum at about 450 °C. Over 570°C, there are few products released at the end of the combustion process.

scholarly journals Lab-scale evaluation of possible mercury speciation in flue gas and mercury emission from combustion of pulverised solid fuels

2019 ◽  
Vol 201 ◽  
pp. 06001
Author(s):  
Maciej Cholewiński ◽  
Wiesław Rybak
Keyword(s):  
Flue Gas ◽  
Combustion Process ◽  
Flue Gases ◽  
Solid Fuels ◽  
Hard Coal ◽  
Scale Evaluation ◽  
Gaseous Products ◽  
Scale Method ◽  
Early Validation ◽  
Solid Biomass

In this work a new lab-scale method dedicated to the evaluation of both concentration and oxidation level of mercury in flue gases from pulverised fuel fired boiler was proposed. To detect the abovementioned parameters, 2 main steps need to be evaluated. Firstly, a calorimeter bomb is utilised - by a proper implementation of mass balance of mercury within substrates and products, the quantity of oxidised mercury in gaseous products can be evaluated. Then, to simulate solid fuel fired power unit and to calculate mercury concentrations in flue gases, one of the stoichiometric mathematical models of combustion process must be applied. Early validation of the method showed considerable differences between solid fuels in mercury oxidation efficiencies and concentrations in flue gasses. Four examined fuels (lignite, hard coal and 2 types of solid biomass) was investigated. Calculated mercury concentrations in raw flue gas (>700°C) varied between 4 and 75 µg/m3ref. The lowest quantity of oxidised forms ofHg in flue gases were identified in the case of investigated lignite (27% of total Hg), while significantly higher – for selected hard coal (72%) and one type of biomass (with high chlorine concentration; up to 98%).

scholarly journals The formation of charcoal reflectance and its potential use in post-fire assessments

2016 ◽  
Vol 25 (7) ◽  
pp. 775 ◽  
Author(s):  
Claire M. Belcher ◽  
Victoria A. Hudspith
Keyword(s):  
Heat Release ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Fire Severity ◽  
Combustion Process ◽  
Peak Heat Release Rate ◽  
Fire Front ◽  
Char Oxidation ◽  
Reflectance Microscopy ◽  
Potential Use

Charcoal has an exceptional ability to reflect light when viewed using reflectance microscopy. The amount of light reflected is variable depending on the differential ordering of graphite-like phases within the charcoal itself. It has been suggested that this relates to the temperature of formation, whereby higher formation temperatures result in high charcoal reflectance. However, this explanation is derived from oven-based chars that do not well represent the natural combustion process. Here, we have experimentally created charcoals using a cone calorimeter, in order to explore the development of charcoal reflectance during pre-ignition heating and peak heat-release rate, through to the end of flaming and the transition to char oxidation. We find that maximum charcoal reflectance is reached at the transition between pyrolysis and char oxidation, before its conversion to mineral ash, and indicates that our existing understanding of reflectance is in error. We suggest that charcoal reflectance warrants additional study as it may provide a useful quantitative addition to ground-based fire severity surveys, because it may allow exploration of surface heating after the main fire front has passed and the fire transitions to smouldering phases.

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