Combustion characteristics of coal, petroleum coke, biomass and their ternary blends

2021 ◽  
pp. 1-27 ◽  
Author(s):  
Pritam Kumar ◽  
Barun Nandi
Keyword(s):  
Power Generation ◽  
Energy Density ◽  
Petroleum Coke ◽  
Thermal Power ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Ternary Blends ◽  
Alkali Oxides ◽  
Blended Fuel ◽  
Catalytic Effects

Abstract This work presents the combustion characteristics of coal, petroleum coke (PC), rice straw (RS), mustard cake (MC) and their blends to assess the applicability of blended fuel for thermal power generation. Characterization results show that PC has the highest GCV (35990 kJ/kg) to improve the overall energy density of the blend significantly. Higher VM present in RS and MC improved the ignition behavior and combustion efficiency of the blend. For 10 OC/min heating rate at 350 OC, with the increase in RS in blends from 10% to 30%, combustion efficiency increased from 12.85% to 32.66%. Synergistic analysis signifies that higher biomass content enhances blends' combustion characteristics through catalytic effects of alkali oxides present in RS/MC. Thermodynamic analysis (ΔH, ΔG and ΔS) inferred that RS and MC combustion is easier than coal and PC. With the increase in MC in blends from 10% to 30%, ΔH decreased from 114.81 to 82.31 kJ/mol, ΔG declined from 159.33 to 122.86 kJ/mol and ΔS improved from −63.59 to −58.14 J/mol.K, indicating blending of biomass improved the combustion.

Modeling and Experiment on Combustion Characteristics for Biomass Rotary Burner

2020 ◽  
Vol 04 ◽  
Author(s):  
Guohai Jia ◽  
Lijun Li ◽  
Li Dai ◽  
Zicheng Gao ◽  
Jiping Li
Keyword(s):  
Combustion Chamber ◽  
Combustion Temperature ◽  
Combustion Efficiency ◽  
Middle Part ◽  
Combustion Characteristics ◽  
Maximum Temperature ◽  
Excess Air ◽  
Element Simulation ◽  
Excess Air Coefficient ◽  
Secondary Air

Background: A biomass pellet rotary burner was chosen as the research object in order to study the influence of excess air coefficient on the combustion efficiency. The finite element simulation model of biomass rotary burner was established. Methods: The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in steady condition and the effects of excess air ratio on pressure field, velocity field and temperature field was analyzed. Results: The results show that the flow velocity inside the burner gradually increases with the increase of inlet velocity and the maximum combustion temperature is also appeared in the middle part of the combustion chamber. Conclusion: When the excess air coefficient is 1.0 with the secondary air outlet velocity of 4.16 m/s, the maximum temperature of the rotary combustion chamber is 2730K with the secondary air outlet velocity of 6.66 m/s. When the excess air ratio is 1.6, the maximum temperature of the rotary combustion chamber is 2410K. When the air ratio is 2.4, the maximum temperature of the rotary combustion chamber is 2340K with the secondary air outlet velocity of 9.99 m/s. The best excess air coefficient is 1.0. The experimental value of combustion temperature of biomass rotary burner is in good agreement with the simulation results.

Possibility of solar thermal power generation technologies in Nigeria: Challenges and policy directions

2019 ◽  
Vol 29 ◽  
pp. 24-41 ◽  
Author(s):  
Daniel Akinyele ◽  
Olubayo Babatunde ◽  
Chukwuka Monyei ◽  
Lanre Olatomiwa ◽  
Adebunmi Okediji ◽  
...  
Keyword(s):  
Power Generation ◽  
Thermal Power ◽  
Solar Thermal ◽  
Solar Thermal Power ◽  
Thermal Power Generation ◽  
Solar Thermal Power Generation

Performance evaluation of a supercritical circulating fluidized bed boiler for power generation under flexible operation

2021 ◽  
pp. 095765092199396
Author(s):  
Matteo Bruzzone ◽  
Silvia Ravelli
Keyword(s):  
Power Generation ◽  
Fluidized Bed ◽  
High Performance ◽  
Circulating Fluidized Bed ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Hard Coal ◽  
Cfb Boiler ◽  
Power Cycles ◽  
Commercial Code

It is well known that the Łagisza power plant in Poland is the world’s first supercritical circulating fluidized bed (CFB) boiler, whose commercial operation started on June 2009. It has attracted a great deal of interest and operational data are publicly available, therefore it has been chosen as the object of the present study aimed at assessing load and fuel flexibility of supercritical CFB plants. First, the thermal cycle was modelled, by means of the commercial code Thermoflex®, at nominal and part load conditions for validation purposes. After having verified the validity of the applied modelling and simulation tool, the advantage of having supercritical steam combined with CFB boiler over subcritical steam and pulverized coal (PC) boiler, respectively, was quantified in terms of electric efficiency. As a next step, the designed fuel, i.e. locally mined hard coal, was replaced with biomass: 100% biomass firing was taken into account in the case of subcritical CFB boiler whereas the maximum share of biomass with coal was set at 50% with supercritical CFB boiler, consistently with the guidelines provided by the world leading manufacturers of CFB units. A broad range of biomass types was tested to conceive mixtures of fuel capable of preserving quite high performance, despite the energy consumption in pretreatment. However, the overall efficiency penalty, due to biomass co-firing, was found to potentially undermine the benefit of supercritical steam conditions compared to conventional subcritical power cycles. Indeed, the use of low-quality biomass in thermal power generation based on steam Rankine cycle may frustrate efforts to push the steam cycle boundaries.

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