Investigation of Fuel Lean Reburning

2009 ◽  
Author(s):  
Hak Young Kim ◽  
Seung Wook Baek
Keyword(s):  
Experimental Study ◽  
Heat Input ◽  
Nox Reduction ◽  
Combustion Process ◽  
Total Heat ◽  
Nox Emission ◽  
Fuel Saving ◽  
Liquefied Petroleum Gas ◽  
Zero Level ◽  
Co Emission

The present work is focused on a fuel-lean reburn system to experimentally control NOx emission from combustion process. Fuel-lean reburn system is found here to be able to replace a conventional reburning technique due to reburn fuel saving. In the conventional reburning process the NOx emission is reduced up to 45% using 20∼25% reburn fuel of total heat input, while CO emission is restricted within acceptable limits by adopting additional air supplying system. However, in the fuel-lean reburn system, by contrast, the amount of injected reburn fuel into the reburning zone is low enough to maintain overall fuel-lean condition in the furnace, so that no additional air system is required, and CO emission can be maintained at almost zero level. In this study, an experimental study has been done to examine the formation characteristics of NOx in a lab scale combustor (15kW) with various oxygen enhanced combustion conditions. LPG (liquefied Petroleum Gas) was used as main fuel and reburn fuel. Finally, the current fuel-lean reburn system, even with only an amount of reburn fuel of 13% of total heat input, was observed to achieve a maximum of 48% in NOx reduction.

NOx Reduction by In Situ Catalytic Reduction in the Combustion Process of Coke

2012 ◽  
Vol 610-613 ◽  
pp. 2104-2108
Author(s):  
Yan Guang Chen ◽  
Hong Jing Han ◽  
Jia Lu ◽  
Jin Lian Li ◽  
Ying Chen ◽  
...  
Keyword(s):  
Catalytic Reduction ◽  
Nox Reduction ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Nox Emission ◽  
Impregnation Method ◽  
Supporting Effect ◽  
Catalytic Effects ◽  
Co Emission

A new method, NOx reduction by in-situ catalytic effects of additives loaded in coke, was proposed. A series of coke samples with different loading amounts of CaCl2, Ce(SO4)2 and La2(SO4)3 were prepared by using the impregnation method, the rules of NOx and CO emissions in the combustion were investigated. The results show that CaCl2, Ce(SO4)2 and La2(SO4)3 play in-situ catalytic effects on the NOx reduction reactions. When the loading of CaCl2 is 4.0%, the amount of NOx emission is reduced by 13.9%. When the loading of Ce(SO4)2is 4.0%, the amount of NOx emission decreases by 17.2%. When the loading of La2(SO4)3 is 4.0%, the amount of NOx emission decreases by 8.7%. Ce(SO4)2 possesses the combustion-supporting effect. As 4.0% Ce(SO4)2 in coke, the CO emission is reduced by 26%, which improves the combustion efficiency of coke.

Effects of Alkali and Alkaline Earth Metals on NOx Reduction in Coke Combustion

2013 ◽  
Vol 634-638 ◽  
pp. 522-525 ◽  
Author(s):  
Yan Guang Chen ◽  
Hong Jing Han ◽  
Jia Lu ◽  
Dan Dan Li ◽  
Jin Lian Li ◽  
...  
Keyword(s):  
Alkaline Earth ◽  
Nox Reduction ◽  
Combustion Process ◽  
Fixed Bed ◽  
Alkaline Earth Metals ◽  
Reduction Ratio ◽  
Nox Emission ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Loading Amount

A series of coke samples with loading alkali and alkaline earth metals were prepared by the impregnation method, the NOx emission were investigated in a silica fixed bed reactor in the combustion process of raw coke and coke modified by Na, K, Ca and Mg. The results show that Na, K, Ca and Mg play in-situ catalytic effects on the NOx reduction reactions. When the loading amount of Na2CO3 is 2.0%, the NOx reduction ratio was around 17.4%, when the loading of K2CO3 is 2.0%, the amount of NOx emission is reduced by 26.5%. When the loading of CaCl2 is 2.0%, the amount of NOx emission is reduced by 22.3%. When the loading of MgCl2 is 2.0%, the NOx reduction ratio is about 10.9%.

NOx Emission of Diesel Fuel Blended with Different Saturation Degrees of Biofuel and with Oxygenator

2014 ◽  
Vol 660 ◽  
pp. 397-401 ◽  
Author(s):  
Mohd Fareez Edzuan bin Abdullah ◽  
Mohd Hisyamuddin bin Sulaiman ◽  
Noor Aliah Binti Abdul Majid
Keyword(s):  
Diesel Fuel ◽  
Flue Gas ◽  
Combustion Process ◽  
Nox Emission ◽  
Dominant Factor ◽  
Compression Ignition ◽  
Nox Formation ◽  
Fuel Blends ◽  
Combustion Tests ◽  
Co Emission

This paper discusses the nitrogen oxides (NOx) emission characteristics of compression ignition diesel engine operating on diesel fuel blends with different saturation degrees of biofuel and with methanol. In order to investigate the dominant factor of increased NOx in biofuels, diesel combustion tests were conducted under idling condition and the tailpipe exhaust emissions were measured by a flue gas analyzer. The general trend where NOx emission increased and reduced carbon monoxide (CO) emission in the biofuel and methanol blend cases were observed. The NOx emission levels increased as the biofuel saturation degree decreased, where it may be suggested that the prompt NOx mechanism is significant in total NOx formation of biofuel combustion process.

scholarly journals Modeling of pulverized coal combustion for in-furnace NOx reduction and flame control

2017 ◽  
Vol 21 (suppl. 3) ◽  
pp. 597-615 ◽  
Author(s):  
Srdjan Belosevic ◽  
Ivan Tomanovic ◽  
Nenad Crnomarkovic ◽  
Aleksandar Milicevic
Keyword(s):  
Coal Combustion ◽  
Numerical Study ◽  
Nox Reduction ◽  
Combustion Process ◽  
Pulverized Coal ◽  
Operating Conditions ◽  
Nox Emission ◽  
Differential Model ◽  
No Formation ◽  
Turbulent Reactive Flows

A cost-effective reduction of NOx emission from utility boilers firing pulverized coal can be achieved by means of combustion modifications in the furnace. It is also essential to provide the pulverized coal diffusion flame control. Mathematical modeling is regularly used for analysis and optimization of complex turbulent reactive flows and mutually dependent processes in coal combustion furnaces. In the numerical study, predictions were performed by an in-house developed comprehensive three-dimensional differential model of flow, combustion and heat/mass transfer with submodel of the fuel- and thermal-NO formation/ destruction reactions. Influence of various operating conditions in the case-study utility boiler tangentially fired furnace, such as distribution of both the fuel and the combustion air over the burners and tiers, fuel-bound nitrogen content and grinding fineness of coal were investigated individually and in combination. Mechanisms of NO formation and depletion were found to be strongly affected by flow, temperature and gas mixture components concentration fields. Proper modifications of combustion process can provide more than 30% of the NOx emission abatement, approaching the corresponding emission limits, with simultaneous control of the flame geometry and position within the furnace. This kind of complex numerical experiments provides conditions for improvements of the power plant furnaces exploitation, with respect to high efficiency, operation flexibility and low emission.

Experimental Study on NOx Reduction and CO Emission by Fuel Lean Reburning Process

2008 ◽  
Vol 32 (3) ◽  
pp. 216-223
Author(s):  
Chang-Yeop Lee ◽  
Hak-Young Kim ◽  
Seung-Wook Baek ◽  
Se-Won Kim
Keyword(s):  
Experimental Study ◽  
Nox Reduction ◽  
Co Emission

Experimental Study of Coal Liquefaction Diesel Combustion and Emissions

2013 ◽  
Vol 291-294 ◽  
pp. 1914-1919
Author(s):  
Yu Li Dai ◽  
Yi Qiang Pei ◽  
Jing Qin ◽  
Jian Ye Zhang ◽  
Yun Long Li
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Ignition Delay ◽  
Cetane Number ◽  
Combustion Process ◽  
Load Condition ◽  
Coal Liquefaction ◽  
Soot Emissions ◽  
Co Emission ◽  
Load Conditions

An experimental study was conducted on the combustion processes and emissions of direct coal liquefaction (DDCL) and Fischer-Tropsch (FT) fuels in a single-cylinder research diesel engine. Under low load conditions (5 bar IMEP), the results show that the ignition delay is shorter for the FT fuel compared with the reference fuel (Euro IV diesel), while it is longer for the DDCL fuel compared with the reference fuel. However, under high load conditions (10-15 bar IMEP), the Cetane number (CN) shows insignificant effects on the combustion process. The premixed heat release peaks of the fuels are correlated with the ignition delays, i.e. shorter ignition delay led to lower premixed heat release peak. For the emissions, both the FT fuel and the DDCL fuel show similar NOx level to the reference fuel under the conditions tested. The two liquefaction fuels show significantly lower soot emissions than the reference fuel, specifically for the higher load conditions (>=10bar IMEP), and the FT fuel produced the lowest level of soot emissions among the three fuels. For the FT and DDCL fuels, the HC emissions are generally lower than those of the reference fuel, except for the lowest load condition, which DDCL produces slightly higher HC emission. However, the CO emission of FT is lower than the reference fuel while the CO emission of DDCL is higher. In terms of unregulated emissions, the two liquefaction fuels show insignificant difference compared with the reference fuel at very low levels.

Reduction of NOx in a Regenerative Industrial Furnace With the Addition of Methanol in the Fuel

2004 ◽  
Vol 126 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Q. Jiang ◽  
C. Zhang ◽  
J. Jiang
Keyword(s):  
Mixture Fraction ◽  
Nox Reduction ◽  
Combustion Process ◽  
Nox Emission ◽  
Moment Closure ◽  
Combustion Model ◽  
Industrial Furnace ◽  
Reduction Of Nox ◽  
Closure Method ◽  
Probability Density Function Pdf

The analysis of the combustion process and NOx emission in a gas-fired regenerative industrial furnace has been carried out numerically. The effect of the additive, methanol CH3OH, to the fuel on the NOx emission is studied. A moment closure method with the assumed β Probability Density Function (PDF) for the mixture fraction is used to model the turbulent non-premixed combustion process in the furnace. The combustion model is based on the assumption of instantaneous full chemical equilibrium. The P-1 model is chosen as the radiation model, and the Weighted-Sum-of-Gray-Gases Model is used to calculate the absorption coefficient. The numerical results showed that the use of CH3OH is effective in the reduction of NOx in a regenerative industrial furnace. The mechanism of NOx reduction by the use of CH3OH is also discussed.

An Experimental Study on the Effects of Intake Charge and Pilot Injection on Premixed Burn Fraction and NOx Emission Characteristics of a CRDI Turbocharged Diesel Engine

2019 ◽  
Author(s):  
Nivin Chacko ◽  
Thangaraja Jeyaseelan ◽  
Vijay Anirudh Premnath
Keyword(s):  
Experimental Study ◽  
Diesel Engine ◽  
Combustion Process ◽  
Premixed Combustion ◽  
Nox Emission ◽  
Pilot Injection ◽  
Turbocharged Diesel Engine ◽  
Combustion Phase ◽  
Pilot Fuel ◽  
Gas Recirculation

Abstract The engine-out NOx emission from the combustion process depends on the fraction of premixed fuel burned. Hence, the study of the premixed combustion phase provides the flexibility to understand the NOx and other emissions. Here we performed an experimental study by modifying the intake charge along with pilot fueling on a twin-cylinder turbocharged CRDi diesel engine. The operating parameters, exhaust gas recirculation (EGR) and pilot injection were controlled to study about the premixed combustion phase, which gives minimum NOx emission without compromising other emissions particularly smoke. The results indicate that the premixed burn fraction decreased with an increase in pilot fuel quantity, dwell period and increased with higher EGR percentage. The optimum pilot sequences yielded a 41% reduction in NOx and 60% with smoke emissions. Also, the combination of pilot injection and EGR resulted in a drastic reduction of HC and CO emissions ∼54%.

NOx Reduction of a Medium Speed Diesel Engine Using a Charge Air Moisturizer System

2006 ◽  
Author(s):  
Hyoung-Keun Park ◽  
Sang-Hak Ghal ◽  
Byong-Seok Kim ◽  
Ki-Doo Kim ◽  
Jong-Suk Kim
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Nox Reduction ◽  
Water Injection ◽  
Combustion Process ◽  
Hot Water ◽  
Nox Emission ◽  
Injection System ◽  
Medium Speed ◽  
A Charge

It is well known that water can be used to prevent NOx formation during a combustion process. It is based on the principle by decreasing flame temperature with increasing the specific heat capacity of combustion air by adding water to a combustion chamber. Introducing water into a charge air enables much more water addition into a combustion chamber than other methods, which can reduce NOx emission to lower level than the others. The method has also the advantage of low installation cost. In a general water injection system for a charge air only hot water is sprayed into the charge air and vaporized, but more effective means to introduce water into the charge air is needed because only small amount of water is evaporated in hot water injection system. In this study, steam and hot moisturizing water are injected simultaneously. The steam supplies steady additional energy for evaporation of the water and can be vapor by itself. The new method was evaluated for NOx reduction performance on a medium speed diesel engine. NOx emission was reduced to 10∼38% on the 27∼59gram water per kilogram dry air.

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