The effects of an additive on the release of potassium in biomass combustion

Clery, Diarmaid S.; Mason, Patrick E.; Rayner, Christopher M.; Jones, Jenny M.

doi:10.1016/j.fuel.2017.11.040

Cited by 90 publications

(45 citation statements)

References 21 publications

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“…To reduce harmful potassium emissions, inhibition technologies can be used and classified into the following two categories: (1) pretreatment by water washing to remove potassium before combustion [28] and (2) addition of potassium sorbent additives to inhibit potassium release during combustion [29]. While both approaches have shown their potential to alleviate ash deposition and corrosion in biomass-fired furnaces, the additive approach appears more advantageous in that it saves water and the additives can be directly injected into boilers without any major reconfiguration.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of potassium release during biomass-pellet combustion and its interaction with inhibitive additives

Liu

Wan

et al. 2020

Fuel

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In the present study, two types of biomass were investigated as typical agricultural and woody biomass fuel, i.e., corn straw and poplar. Firstly, laser induced breakdown spectroscopy (LIBS) was employed to investigate the release characteristics of potassium (K) from a burning biomass pellet. In order to further investigate the correlation between K release and the combustion process, combustion parameters including pellet surface temperature and pellet diameter were simultaneously measured with LIBS. A dual-peak trend is observed in the K release history of poplar, but only a single peak is found in that of corn straw. Both biomass samples show the strongest K release during the devolatilization stage in comparison with the subsequent char burnout and ash cooking stages. Similar tendencies are observed between K release and pellet temperature, which suggests that K release is closely related to the combustion process. The K release mechanism can be attributed to temperature rise and therefore breakdown of chemical bonds during combustion. Then the release of different chemical forms of K was investigated by chemical fractionation treatment of the biomass samples. 2 The released amount of H2O-soluble, NH4Ac-soluble and HCl-soluble potassium compounds were obtained. The H2O-soluble potassium is found to be the major released potassium compound. Finally, four kinds of additives (two pure additives, i.e., silica and alumina, and two typical natural mineral additives, i.e., kaolin and mica) were added to the biomass samples to investigate their inhibition effects on K release. The natural sorbent additives show better inhibition effects than the pure ones.

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Section: Introductionmentioning

confidence: 99%

Experimental study of potassium release during biomass-pellet combustion and its interaction with inhibitive additives

Liu

Wan

et al. 2020

Fuel

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“…Coal fly-ash has the advantage of being abundant and low-cost. Diarmaid et al [11] have very recently studied the efficacy of coal-fly ash in reducing the release of potassium from various biomass (white wood pellets, straw, and olive cake) pellets suspended in a methane flame. Additive loadings of 5, 15, and 25 wt.% were used.…”

Section: Potassium Removal By Adsorptionmentioning

confidence: 99%

“…Even though renewable energy sources like solar and wind power are more and more cost competitive [8] and make up an increasing share of power generation in most regions [9], some thermal power plant capacity is still needed due to the renewables' fluctuating nature and the current lack of sufficient storage capacity [10]. Firing and co-firing of biomass can cause several problems in the power plant like slagging and fouling problems in boilers [11], ash deposition on heat exchangers, and increased catalyst deactivation in the NO x removing unit [12][13][14][15][16][17][18]. This review deals with the last-mentioned problem.…”

Section: Introductionmentioning

confidence: 99%

“…The increased rate of catalyst deactivation experienced in biomass-fired plants is mostly caused by the relatively high alkali-and alkali-earth metal contents in most biomasses [11,17,[20][21][22][23][24]. Alkaline metals cause deactivation by neutralizing the catalyst's acid sites, hence reducing the adsorption of NH 3 [13,[25][26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

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Strategies of Coping with Deactivation of NH3-SCR Catalysts Due to Biomass Firing

Schill¹,

Fehrmann²

2018

Catalysts

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Firing of biomass can lead to rapid deactivation of the vanadia-based NH3-SCR catalyst, which reduces NOx to harmless N2. The deactivation is mostly due to the high potassium content in biomasses, which results in submicron aerosols containing mostly KCl and K2SO4. The main mode of deactivation is neutralization of the catalyst’s acid sites. Four ways of dealing with high potassium contents were identified: (1) potassium removal by adsorption, (2) tail-end placement of the SCR unit, (3) coating SCR monoliths with a protective layer, and (4) intrinsically potassium tolerant catalysts. Addition of alumino silicates, often in the form of coal fly ash, is an industrially proven method of removing K aerosols from flue gases. Tail-end placement of the SCR unit was also reported to result in acceptable catalyst stability; however, flue-gas reheating after the flue gas desulfurization is, at present, unavoidable due to the lack of sulfur and water tolerant low temperature catalysts. Coating the shaped catalysts with thin layers of, e.g., MgO or sepiolite reduces the K uptake by hindering the diffusion of K+ into the catalyst pore system. Intrinsically potassium tolerant catalysts typically contain a high number of acid sites. This can be achieved by, e.g., using zeolites as support, replacing WO3 with heteropoly acids, and by preparing highly loaded, high surface area, very active V2O5/TiO2 catalyst using a special sol-gel method.

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“…The use of biomass pellets in boilers for process heat and power generation applications can be made in two somewhat different ways—(i) boiler can be fired exclusively with biomass pellets or (ii) biomass pellets are co-fired with coal. While the slagging and fouling risks of several biomass feedstocks, given their high alkali, silica, or chlorine contents (Werther et al 2000 ; Teixeira et al 2012 ; Du et al 2014 ) currently limit their application in combustion processes, additives based on different chemical compositions and possible counteracting effects can be used to abate ash-related problems during biomass combustion (Wang et al 2012 ; Clery et al 2018 ). Ahn and Lee ( 2014 ) investigated the potential of non-used forest biomass residues as raw materials for making wood pellets with additives such as wood tar and starch and to evaluate fuel characteristics of the pellets.…”

Section: Introductionmentioning

confidence: 99%

Biomass pellets for power generation in India: a techno-economic evaluation

Purohit

Chaturvedi

2018

Environ Sci Pollut Res

104

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Modern bioenergy is being recognized as an increasingly important low-carbon resource by policy-makers around the world to meet climate policy targets. In India also, there is a clear recognition of the significant role of bioenergy in electricity generation as well as in other applications. In this study, a preliminary attempt has been made to assess the techno-economic feasibility of biomass pellets-based power (BPBP) generation in India. Surplus availability of biomass feedstock from agriculture and forestry/wasteland sector is estimated at 242 million tonnes (Mt) for 2010–11 and is expected to rise to 281 Mt in 2030–31 due to increased crop production and associated waste/residue availability. In terms of related capacity, the potential of BPBP projects is estimated at 35 GW for 2030–31. The associated carbon dioxide mitigation potential resulting from the substitution of coal is estimated at 205 Mt in 2030–31 if the entire biomass surplus is to be diverted for power generation. The levelized cost of electricity is estimated at €0.12 per kWh for BPBP projects as compared to €0.10 per kWh for imported coal based power plants. For states with the lower tariff for biomass power, the break-even price of carbon for BPBP projects is estimated at €18 per tonne. Additionally, BPBP projects will generate employment of more than 5 million person-months in the construction of biomass power plants and over 200,000 full-time employments in the operation of BPBP plants and in the production of biomass pellets.Electronic supplementary materialThe online version of this article (10.1007/s11356-018-2960-8) contains supplementary material, which is available to authorized users.

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The effects of an additive on the release of potassium in biomass combustion

Cited by 90 publications

References 21 publications

Experimental study of potassium release during biomass-pellet combustion and its interaction with inhibitive additives

Experimental study of potassium release during biomass-pellet combustion and its interaction with inhibitive additives

Strategies of Coping with Deactivation of NH3-SCR Catalysts Due to Biomass Firing

Biomass pellets for power generation in India: a techno-economic evaluation

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