Alternative fuel reburning

Maly, Peter M.; Vladimir, Zamansky,; Ho, Loc; Payne, R.

doi:10.1016/s0016-2361(98)00161-6

Cited by 103 publications

(60 citation statements)

References 3 publications

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“…It should be fuels which while decomposing in the reduction zone produce a large amount of CH i radicals. The results of recent investigations have shown that also heavy fuel oil, lignite (Hardy, 2003), some kind of biomass (Adams and Harding, 1998;Cariln et al, 2009) and even some municipal waste (Maly, 1999) may be good reburning fuels. A good example of reburning fuels can be the gas obtained from sewage sludge gasification.…”

Section: Fig 1 Overall Mechanism Of No Formation and Reductionmentioning

confidence: 99%

Estimation of reburning potential of syngas from sewage sludge gasification process

Werle¹

2011

Chemical and Process Engineering

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The motivation of this work was to define the reburning potential of sewage sludge gasification gas (syngas). Numerical simulation of co-combustion process of syngas in hard coal-fired boiler has been done. All the calculations were performed using the Chemkin program. Plug-Flow Reactor model was used. The calculations were modelled using GRI-Mech 2.11 mechanism. The highest NO conversions are obtained at the temperature of about 1000-1200 K. The highest reduction efficiency was achieved for the molar flow ratio of syngas equal to 15%. The combustion of hard coal with sewage sludge -derived syngas reduces NO emissions and the amount of coal needed to produce electricity and heat. Advanced reburning, which is a more complicated process gives efficiency of up to 80%. The calculations show that the analyzed syngas can yield better results.

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Section: Fig 1 Overall Mechanism Of No Formation and Reductionmentioning

confidence: 99%

Estimation of reburning potential of syngas from sewage sludge gasification process

Werle¹

2011

Chemical and Process Engineering

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“…The reburn study carried out by Maly et al [10] was reported as a function of the reburn fuel fraction (R ff %). Extreme care was taken when applying the conversion procedures for the literature data so that the comparison of NOx reduction results could be made with the greatest confidence.…”

Section: Pulverised Tyre As An Alternative Fuel For Nox Reburningmentioning

confidence: 99%

“…The reduction of NO by CH i radicals proceeds via a complex reburn mechanism involving the intermediate HCN [7][8][9] . Maly et al [10] carried out reburn tests with natural gas (CH 4 ), biomass, orimulsion, coal, coal pond fines (CPF), and carbonised refuse derived fuel (CRDF) using CH 4 as a primary fuel. The parameters investigated, as in this present study, were reburn zone stoichiometry and initial NO x concentrations.…”

Section: Introductionmentioning

confidence: 99%

The evaluation of waste tyre pulverised fuel for NOx reduction by reburning

Nimmo¹,

Singh²,

Gibbs³

et al. 2008

Fuel

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The combustion of coal for power generation will continue to play a major role in the future, however, this must be achieved using cleaner technologies than we use at present. Scrap tyre arisings in the UK are 400,000 tonnes per year amounting to 30 million tyres and in the EU as a whole, more than 2.5 million tonnes of tyres per year are scrapped. The recent EC Waste Landfill Directive (1999) sets a deadline for the banning of whole and shredded tyres from landfill sites by 2006. Consequently, there is an urgent need to find a mass disposal route for tyres. We describe, in this paper, a novel use for tyre rubber pulverized fuel in a NOx reburning process which may have an application in power station boilers. This method of disposal could represent a way of combining waste disposal, energy recovery and pollution control within one process. A preliminary study of micronised tyre combustion was undertaken to identify the suitable size ranges for application in NOx reduction by reburning. Tests were performed in a down-fired, pulverised fuel combustor (PFC) operating at about 80kW. Superior combustion characteristics i.e. burnout were achieved with particle sizes less than 250 µm. A South African coal was used as the primary fuel in the reburn tests and the tyre was fed pneumatically via a separate feed system. Parameters studied, were, reburn zone stoichiometry and reburn fuel fraction. Additionally, the carbon content of the ash was carefully monitored for any effect on burnout at the fuel-rich reburn stoichiometries. The NOx reductions achieved with tyres are compared with reburning with coal. NO x reductions up to 80% were achieved with tyres at half of the reburn fuel feed rate required to achieve the same reductions by coal. The results have been evaluated within the context of other studies available in the literature on NOx reburning by bituminous coal, brown coal, gas and biomass.

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“…Fuel reburn is an effective low-NO x combustion technology, and it is different from conventional combustion. Fuel reburn is a three-step combustion: in the first step the main fuel (usually coal) is burnt completely under oxidizing atmosphere, and the combustion zone is called as primary combustion zone; in the second step reburn fuel is injected into the furnace above the primary combustion zone to develop reducing atmosphere for NO x reduction, and the combustion zone is called as reburn zone; the third step over-fire air (OFA) is injected into the furnace above the reburn zone to oxidize carbon monoxide, hydrogen and any remaining unburned char coming from the reburn zone, and the combustion zone is called as burnout zone [1,2]. Reburn fuel can be any of three basic fossil fuel types: coal, natural gas, or oil.…”

Section: Introductionmentioning

confidence: 99%

“…Many researchers have investigated the influences of some variables on NO x emissions during COCR, and these important variables are as following: the reburn fuel fraction (R ff ); the position of reburn nozzle; the air stoichiometric ratio in primary combustion zone (SR 1 ); the air stoichiometry in reburn zone (SR 2 ) [2][3][4][5][6][7]. In practice, the furnace temperature distributions and furnace wall heat flux distributions are indispensable for boiler furnace design [8].…”

Section: Introductionmentioning

confidence: 99%

Effect of coal-over-coal reburn on furnace temperature and heat flux distributions in 1MW tangentially fired furnace

Zhou

et al. 2010

International Journal of Thermal Sciences

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a b s t r a c tThe furnace temperature and heat flux distributions of 1 MW tangentially fired furnace were studied during coal-over-coal reburn, and the influences of the position of reburn nozzle and reburn fuel fraction on furnace temperature and heat flux distributions were investigated. Compared with the baseline, the flue gas temperature is 70-90 C lower in primary combustion and 130-150 C higher at furnace exit, and the variations of the flue gas temperature distributions along furnace height are slower. The temperature distribution along the width of furnace wall decreases with the increase of the relative furnace height. In the primary combustion zone and the reburn zone, the temperature and heat flux distributions of furnace wall are much non-uniform and asymmetric along the width of furnace wall, those of furnace wall in the burnout zone are relatively uniform, and the temperature non-uniformity coefficients of the primary combustion zone, the reburn zone and the burnout zone are 0.290, 0.100 and 0.031, respectively.

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Alternative fuel reburning

Cited by 103 publications

References 3 publications

Estimation of reburning potential of syngas from sewage sludge gasification process

Estimation of reburning potential of syngas from sewage sludge gasification process

The evaluation of waste tyre pulverised fuel for NOx reduction by reburning

Effect of coal-over-coal reburn on furnace temperature and heat flux distributions in 1MW tangentially fired furnace

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