Combustion characteristics of high ash Indian coal, wheat straw, wheat husk and their blends

The study is aimed at cleaner and more efficient heat energy production through investigation and analysis of the thermal decomposition of lignocellulosic biomass pellets with different elemental composition, the heating values and contents of hemicellulose, cellulose and lignin. The estimation is provided for the influence of biomass composition on the combustion characteristics for softwood, wheat straw and wheat straw lignin pellets. The kinetics of thermal decomposition was studied experimentally, using a pilot device for two-stage processes of thermochemical conversion including gasification and combustion of biomass pellets under varying conditions. The experimental study includes time-dependent measurements of the biomass pellet weight loss during gasification and the correlating variations of the flame temperature, heat production rates, combustion efficiency and composition of the products at different stages of thermochemical conversion. Estimation is also given for the influence of the biomass composition on the combustion characteristics and heat energy production.

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MATHEMATICAL MODELLING AND EXPERIMENTAL STUDY OF STRAW CO-FIRING WITH GAS

Mathematical Modelling and Analysis ◽

10.3846/mma.2019.031 ◽

2019 ◽

Vol 24 (4) ◽

pp. 507-529

Author(s):

Inesa Barmina ◽

Harijs Kalis ◽

Antons Kolmickovs ◽

Maksims Marinaki ◽

Liiva Ozola ◽

...

Keyword(s):

Experimental Study ◽

Thermal Decomposition ◽

Mathematical Modelling ◽

Wheat Straw ◽

Energy Production ◽

Heat Energy ◽

Combustion Characteristics ◽

Combustion Dynamics ◽

Additional Heat ◽

Ignition And Combustion

The main goal of the present study is to promote a more eﬀective use of agriculture residues (straw) as an alternative renewable fuel for cleaner energy production with reduced greenhouse gas emissions. With the aim to improve the main combustion characteristics at thermo-chemical conversion of wheat straw, complex experimental study and mathematical modelling of the processes developing when co-ﬁring wheat straw pellets with a gaseous fuel were carried out. The eﬀect of co-ﬁring on the main gasiﬁcation and combustion characteristics was studied experimentally by varying the propane supply and additional heat input into the pilot device, along with the estimation of the eﬀect of co-ﬁring on the thermal decomposition of wheat straw pellets, on the formation, ignition and combustion of volatiles (CO, H2). A mathematical model has been developed using the environment of the Matlab (2D modelling) and MATLAB package ”pdepe”(1D modelling) considering the variations in supplying heat energy and combustible volatiles (CO, H2) into the bottom of the combustor. Dominant exothermal chemical reactions were used to evaluate the eﬀect of co-ﬁring on the main combustion characteristics and composition of the products CO2 and H2O. The results prove that the additional heat from the propane ﬂame makes it possible to control the thermal decomposition of straw pellets, the formation, ignition and combustion of volatiles and the development of combustion dynamics, thus completing the combustion of biomass and leading to cleaner heat energy production.

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Effect of rice husk blending on combustion characteristics of high ash Indian coal analyzed in TGA

International Journal of Coal Preparation and Utilization ◽

10.1080/19392699.2021.1990894 ◽

2021 ◽

pp. 1-14

Author(s):

Pritam Kumar ◽

Barun Kumar Nandi

Keyword(s):

Rice Husk ◽

Combustion Characteristics ◽

Indian Coal

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Comparison of combustion characteristics of Petcoke and Indian sub bituminous coal in a CFB Test facility

International Journal of Thermal Technologies ◽

10.14741/ijtt.v7i.8274 ◽

2017 ◽

Vol 7 ◽

Cited By ~ 1

Author(s):

J Jaygopal ◽

K. Ganesh Palappan ◽

M. Rajavel ◽

P. S. Guruchandran ◽

S. Suresh

Keyword(s):

Fluidized Bed ◽

Bituminous Coal ◽

Circulating Fluidized Bed ◽

Combustion Efficiency ◽

Combustion Characteristics ◽

Sulphur Content ◽

Test Facility ◽

Fluidized Bed Combustion ◽

Indian Coal ◽

Indian Coals

Fluidized Bed Combustion (FBC) is one of the best suited combustion technologies for petcoke combustion owing to its capability of handling fuels with low volatile and high sulphur content. In this study, petcoke and Indian sub bituminous coal (coal from Singareni mines, Telengana, India) are fired separately in Circulating Fluidized Bed (CFB) test facility and its combustion characteristics are studied and compared. Even though petcoke is a low reactive fuel compared to Indian coal, temperature profile shows petcoke has a stable combustion. Significant post combustion in cyclone is noticed while combusting petcoke. Around 40-60o C rise in the cyclone temperature is noted during combustion of petcoke compared to 20-30o C while burning sub bituminous coal. Compared to Indian sub bituminous coal petcoke has high sulphur content (4-9 %) and low ash content, therefore it requires limestone addition for in situ sulphur capture and for maintaining bed inventory. Owing to the limestone addition, petcoke firing shows a better material distribution among the splash zone. Although CFB boilers are fuel flexible, and petcoke can be fired in CFB boilers designed for Indian coals, test results show that combustion efficiency of petcoke is lower than that of Indian coal. Combustion efficiency can be improved by certain design modifications such as higher furnace height, higher cyclone efficiency and higher refractory zone. The present study explore the opportunities of using 100% petcoke in CFB boiler.

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Evaluation of combustion characteristics in thermogravimetric analyzer and drop tube furnace for Indian coal blends

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2013.06.054 ◽

2013 ◽

Vol 60 (1-2) ◽

pp. 145-151 ◽

Cited By ~ 22

Author(s):

P. Sarkar ◽

A. Mukherjee ◽

S.G. Sahu ◽

A. Choudhury ◽

A.K. Adak ◽

...

Keyword(s):

Combustion Characteristics ◽

Tube Furnace ◽

Drop Tube ◽

Indian Coal ◽

Thermogravimetric Analyzer ◽

Drop Tube Furnace

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Effects of mustard husk, wheat straw and flaxseed residue blending on combustion behavior of high ash coal and petroleum coke blends

Journal of Energy Resources Technology ◽

10.1115/1.4053438 ◽

2022 ◽

pp. 1-22

Author(s):

Pritam Kumar ◽

Barun Kumar Nandi

Keyword(s):

Wheat Straw ◽

Thermodynamic Parameters ◽

Petroleum Coke ◽

Coal Combustion ◽

Combustion Process ◽

Combustion Characteristics ◽

Maximum Temperature ◽

Combustion Behavior ◽

Combustion Properties ◽

The Impact

Abstract This present work reports the combustion studies of coal, petroleum coke (PC) and biomass blends to assess the effects of the mustard husk (MH), wheat straw (WS) and flaxseed residue (FR) blending towards improvement of coal combustion characteristics. Ignition temperature (TS), maximum temperature (TP), burnout temperature (TC), activation energy (AE) and thermodynamic parameters (ΔH, ΔG and ΔS) were analyzed to evaluate the impact of biomass and PC blending on coal combustion. Experimental results indicate that coal and PC have inferior combustion characteristics compared to MH, WS and FR. With the increase in WS content in blends from 10 to 30%, TS reduced from 371 to 258OC, TP decreased from 487 to 481OC, inferring substantial enhancements in combustion properties. Kinetic analysis inferred that blended fuel combustion could be explained mostly using reaction models, followed by diffusion-controlled and contracting sphere models. Overall, with the increase in FR mass in blends from 10 to 30%, AE decreased from 108.97 kJ/mol to 70.15 kJ/mol signifying ease of combustion. Analysis of synergistic effects infers that higher biomass addition improves coal and PC blends' combustion behavior through catalytic effects of alkali mineral matters present in biomass. Calculation of thermodynamic parameters signified that combustion of coal and PC is challenging than biomasses, however, blending of biomass makes the combustion process easier.

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