An open air stockpile of conical shape was formed with 3.5 m base diameter and 5 m height using 500 tons of -200 mm size ROM thermal coal on a concrete floor. Coal sample from the stockpile were collected at 30 days i...An open air stockpile of conical shape was formed with 3.5 m base diameter and 5 m height using 500 tons of -200 mm size ROM thermal coal on a concrete floor. Coal sample from the stockpile were collected at 30 days interval for analysis of various chemical properties like;proximate analysis, ultimate analysis, gross calorific value (GCV) and various combustion related properties such as ignition temperature, peak temperature, burnout temperature, maximum combustion rate, ignition index, burnout index, combustion performance index and combustion rate intensity index. Experimental results show that, due to weathering of coal fixed carbon decreased from 35.6% to 19.9%, elemental carb on (C) decreased from 46.6% to 28.6%, hydrogen (H) decreased from 3.3% to 2.9% and GCV decreased by up to 55% of original value during 330 days of storage of coal in an open atmosphere. Ash con tent of coal increased form 29.2% to 46.6% due to loss of combustibles. Sulfur (S) of coal was found to get increased from 0.33% to 1.08% during storage. The activation energy of coal combustion increased from 22 kJ/mol to 54 kJ/mol. Variation in combustion parameters signifies that weathering has significant negative impact on coal combustion properties as coal become difficult to ignite.展开更多
This work presents the analysis of combustion characteristics of high ash Indian coal(28%-40%)collected from different mines of Singaurali coalfield,India.All the coal samples were characterized by proximate and gross...This work presents the analysis of combustion characteristics of high ash Indian coal(28%-40%)collected from different mines of Singaurali coalfield,India.All the coal samples were characterized by proximate and gross calorific value analysis.Combustion performance of the coals were characterised using thermo-gravimetric analysis to identify the burning profile of individual coals.Various combustion kinetic parameters such as ignition temperature,peak temperature and burnout temperature,ignition index and burnout index,combustion performance index plus rate and intensity index of combustion process,activation energy were determined to analyse the combustion behaviour of coal.Further all these combustion properties were compared with the volatile matter,ash,fixed carbon and fuel ratio of each coal.Theoretical analysis shows that with increase in ash content,combustion performance initially increases and later descends.Further,coal with(25±1.75)%volatile matter,20%-35%ash and fuel ratio 1.4-1.5 were found to be optimum for coal combustion.展开更多
Onsite mine fire generates large volumes of heat-affected coal in Jharia coalfields,India.Direct utilization of such heat-affected coal in thermal utilities is not feasible as such coal does not have the desirable vol...Onsite mine fire generates large volumes of heat-affected coal in Jharia coalfields,India.Direct utilization of such heat-affected coal in thermal utilities is not feasible as such coal does not have the desirable volatile matter required for combustion.In the present work,experimental studies have been carried out to investigate the possible utilization of such heat-affected coal in thermal utilities by blending with other coal.Heat-affected coal(31%ash and 5300 kcal/kg GCV)collected from Jharia coalfield were blended with thermal coal(28%ash and 5650 kcal/kg GCV)in different ratios of 90:10,80:20,70:30 and 60:40 to identify the desirable blend ratio for burning of blended coal in thermal utilities.Burning characteristics of all the coals were carried out using TGA.Various combustion parameters such as ignition temperature,peak temperature,burnout temperature,ignition index,burnout index,combustion performance index,rate and heat intensity index of the combustion process and activation energy were evaluated to analyse the combustion process.Experimental and theoretical analysis shows the blend ratio of 90:10 can be used in place of only thermal coal in utilities to reduce the fuel cost.展开更多
文摘An open air stockpile of conical shape was formed with 3.5 m base diameter and 5 m height using 500 tons of -200 mm size ROM thermal coal on a concrete floor. Coal sample from the stockpile were collected at 30 days interval for analysis of various chemical properties like;proximate analysis, ultimate analysis, gross calorific value (GCV) and various combustion related properties such as ignition temperature, peak temperature, burnout temperature, maximum combustion rate, ignition index, burnout index, combustion performance index and combustion rate intensity index. Experimental results show that, due to weathering of coal fixed carbon decreased from 35.6% to 19.9%, elemental carb on (C) decreased from 46.6% to 28.6%, hydrogen (H) decreased from 3.3% to 2.9% and GCV decreased by up to 55% of original value during 330 days of storage of coal in an open atmosphere. Ash con tent of coal increased form 29.2% to 46.6% due to loss of combustibles. Sulfur (S) of coal was found to get increased from 0.33% to 1.08% during storage. The activation energy of coal combustion increased from 22 kJ/mol to 54 kJ/mol. Variation in combustion parameters signifies that weathering has significant negative impact on coal combustion properties as coal become difficult to ignite.
文摘This work presents the analysis of combustion characteristics of high ash Indian coal(28%-40%)collected from different mines of Singaurali coalfield,India.All the coal samples were characterized by proximate and gross calorific value analysis.Combustion performance of the coals were characterised using thermo-gravimetric analysis to identify the burning profile of individual coals.Various combustion kinetic parameters such as ignition temperature,peak temperature and burnout temperature,ignition index and burnout index,combustion performance index plus rate and intensity index of combustion process,activation energy were determined to analyse the combustion behaviour of coal.Further all these combustion properties were compared with the volatile matter,ash,fixed carbon and fuel ratio of each coal.Theoretical analysis shows that with increase in ash content,combustion performance initially increases and later descends.Further,coal with(25±1.75)%volatile matter,20%-35%ash and fuel ratio 1.4-1.5 were found to be optimum for coal combustion.
文摘Onsite mine fire generates large volumes of heat-affected coal in Jharia coalfields,India.Direct utilization of such heat-affected coal in thermal utilities is not feasible as such coal does not have the desirable volatile matter required for combustion.In the present work,experimental studies have been carried out to investigate the possible utilization of such heat-affected coal in thermal utilities by blending with other coal.Heat-affected coal(31%ash and 5300 kcal/kg GCV)collected from Jharia coalfield were blended with thermal coal(28%ash and 5650 kcal/kg GCV)in different ratios of 90:10,80:20,70:30 and 60:40 to identify the desirable blend ratio for burning of blended coal in thermal utilities.Burning characteristics of all the coals were carried out using TGA.Various combustion parameters such as ignition temperature,peak temperature,burnout temperature,ignition index,burnout index,combustion performance index,rate and heat intensity index of the combustion process and activation energy were evaluated to analyse the combustion process.Experimental and theoretical analysis shows the blend ratio of 90:10 can be used in place of only thermal coal in utilities to reduce the fuel cost.
