SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Pettersson Erik) ;lar1:(hb)"

Sökning: WFRF:(Pettersson Erik) > Högskolan i Borås

  • Resultat 1-7 av 7
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Nordin, Andreas, et al. (författare)
  • Co-Combustion of Municipal Sewage Sludge and Biomass in a Grate Fired Boiler for Phosphorus Recovery in Bottom Ash
  • 2020
  • Ingår i: Energies. - : MDPI. - 1996-1073. ; 13:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Phosphorus has been identified as a critical element by the European Union and recycling efforts are increasingly common. An important phosphorus-containing waste stream for recycling is municipal sewage sludge (MSS), which is used directly as fertilizer to farmland. However, it contains pollutants such as heavy metals, pharmaceutical residues, polychlorinated bi-phenyls (PCBs) and nano-plastics. The interest in combustion of MSS is continuously growing, as it both reduces the volume as well as destroys the organic materials and could separate certain heavy metals from the produced ashes. This results in ashes with a potential for either direct use as fertilizer or as a suitable feedstock for upgrading processes. The aim of this study was to investigate co-combustion of MSS and biomass to create a phosphorus-rich bottom ash with a low heavy metal content. A laboratory-scale fixed-bed reactor in addition to an 8 MWth grate-boiler was used for the experimental work. The concentration of phosphorus and selected heavy metals in the bottom ashes were compared to European Union regulation on fertilizers, ash application to Swedish forests and Swedish regulations on sewage sludge application to farmland. Element concentrations were determined by ICP-AES complemented by analysis of spatial distribution with SEM-EDS and XRD analysis to determine crystalline compounds. The results show that most of the phosphorus was retained in the bottom ash, corresponding to 9-16 wt.% P2O5, while the concentration of cadmium, mercury, lead and zinc was below the limits of the regulations. However, copper, chromium and nickel concentrations exceeded these standards.
  •  
2.
  • Pettersson, Anita, et al. (författare)
  • Application of chemical fractionation methods for characterisation of biofuels, waste derived fuels and CFB co-combustion fly ashes
  • 2008
  • Ingår i: Fuel. - : Elsevier Ltd. - 0016-2361 .- 1873-7153. ; 87:15-16, s. 3183-3193
  • Tidskriftsartikel (refereegranskat)abstract
    • In the important efforts to decrease the net CO2 emissions to the atmosphere, new, alternative fuels are being included in the fuel mixes used in utility boilers. However, these fuels have ash properties that are different from those of the traditionally used fuels and in some cases technical problems, such as ash fouling and corrosion occur due to this. Therefore, diagnostic and predictive methods are developed and used to avoid such problems. Determination of the chemical association forms of important elements, such as potassium and sodium, in the fuel by chemical fractionation is a method well defined for coal and biofuels, such as wood pellets, bark and forest residues. Chemical fractionation is a step by step leaching method extracting water soluble salts in the first step, ion exchangeable elements, such as organically associated sodium, calcium and magnesium in the second step and acid soluble compounds such as carbonates and sulfates in the third step. The solid residue fraction consists of silicates, oxides, sulfides and other minerals. The compound extracted in the two first steps is considered reactive in the combustion with a few exceptions. In this work, it has been applied to some waste fuels, i.e. sewage sludge, straw and refuse derived fuel (RDF), as well as to coal and wood. The present work also includes results from combustion tests in a fluidised bed boiler where three blends of the investigated fuels were used. The fractionation results for the fuel blends are weighted results of the fractionations of the pure fuels discussed above which are compared with fractionations of their corresponding fly ashes. The co-combustion strategy gave very good results in reducing ash problems. Possible chemical mechanisms involved are discussed in the article.
  •  
3.
  • Pettersson, Anita, et al. (författare)
  • Chemical fractionation for the characterisation of fly ashes from co-combustion of biofuels using different methods for alkali reduction
  • 2009
  • Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 88:9, s. 1758-1772
  • Tidskriftsartikel (refereegranskat)abstract
    • a b s t r a c tChemical fractionation, SEM–EDX and XRD was used for characterisation of fly ashes from different cocombustiontests in a 12MW circulating fluidized bed boiler. The fuels combusted were wood pellets asbase fuel and straw pellets as co-fuel in order to reach a fuel blend with high alkali and chlorine concentrations.This fuel blend causes severe problems with both agglomeration of bed material if silica sand isused and with deposits in the convection section of the boiler. Counter measures to handle this situationand avoiding expensive shut downs, tests with alternative bed materials and additives were performed.Three different bed materials were used; silica sand, Olivine sand and blast furnace slag (BFS) and differentadditives were introduced to the furnace of the boiler; Kaolin, Zeolites and Sulphur with silica sand asbed material. The results of the study are that BFS gives the lowest alkali load in the convection pass comparedwith Silica and Olivine sand. In addition less alkali and chlorine was found in the fly ashes in theBFS case. The Olivine sand however gave a higher alkali load in the convection section and the chemicalfractionation showed that the main part of the alkali in the fly ashes was soluble, thus found as KCl whichwas confirmed by the SEM–EDX and XRD.The comparison of the different additives gave that addition of Kaolin and Zeolites containing aluminium-silicates captured 80% of the alkali in the fly ash as insoluble alkali–aluminium-silikates and reducedthe KCl load on the convection section. Addition of sulphur reduced the KCl load in the flue gas even morebut the K2SO4 concentration was increased and KCl was found in the fly ashes anyhow. The chemical fractionationshowed that 65% of the alkali in the fly ashes of the Sulphur case was soluble.
  •  
4.
  •  
5.
  •  
6.
  • Pettersson, Anita, 1965, et al. (författare)
  • The impact of zeolites during co-combustion of municipal sewage sludge with alkali and chlorine rich fuels
  • 2009
  • Ingår i: Proceedings of the 20th International Conference on Fluidized Bed Combustion in Xi:an, China May 18-20, 2009. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9787302201465 ; 2, s. 903-909, s. 902-909
  • Konferensbidrag (refereegranskat)abstract
    • Municipal sewage sludge has proven to eliminate alkali metals and chlorine related problems during combustion of straw and refuse derived fuels (RDF). However, the mechanisms involved have not been clarified. The aim of this work was to gain more knowledge about the behaviour of sewage sludge and detergent zeolites in combustion and about their effects on alkali metal chemistry. Co-combustion tests with combinations of municipal sewage sludge, wood and straw were carried out in a 12 MW fluidised bed (FB) boiler. In addition, a detergent zeolite, Doucil A24, was used as additive during co-combustion of wood and straw. The chemical characteristics of fuels and fly ashes were studied using several methods, such as chemical fractionation and scanning electron microscopy with element analysis by energy dispersive fluorescence detection (SEM-EDX) and X-ray diffraction (XRD). In the co-combustion tests involving sewage sludge no KCl was found in the flue gas prior to the convection pass. The zeolite addition was less effective but the KCl concentration was reduced to some degree in favour of HCl compared to the reference case. Both SEM-EDX and XRD confirmed the presence of potassium-aluminium-silicates in the fly ash fraction in all cases. In addition, the laboratory study showed that Doucil A24 had the ability to capture potassium and KCl at temperatures in the range of 700-900°C.
  •  
7.
  • Vali, Naeimeh, et al. (författare)
  • Pyrolysis of municipal sewage sludge to investigate char and phosphorous yield together with heavy-metal removal—experimental and by thermodynamic calculations
  • 2021
  • Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 14:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Sewage sludge is regarded as a potential source for soil fertilizer However, the direct utilization of sewage sludge in agricultural land is restricted since it also contains heavy metals, pathogens, and toxic compounds. Pyrolysis of the sewage sludge destroys the organic pollutants and partly volatilizes the heavy metals. In this study, pyrolysis of sewage sludge was carried out in order to determine the optimum residence time and temperature to recover the phosphorous and remove heavy metals from the resultant sewage sludge char (SSC). Pyrolysis was conducted on dried sewage sludge (DSS) by means of thermogravimetric analysis (TGA) and high-temperature oven with an N2-atmosphere. Microwave Plasma-Atomic Emission Spectroscopy (MP-AES) was used to determine the concentration of P and trace elements in the resulting solid char fraction. A combination of chemical fractionation (step-by-step leaching) of the DSS and thermodynamic equilibrium calculations were utilized to estimate the availability of phosphorous and removal of heavy metals in the SSC fraction at different temperatures. The results from the thermodynamics calculation were in line with the measured chemical composition of the SSC. Furthermore, the energy contents of the SSC obtained at different temperatures were measured. The pyrolysis evaluation results indicate that phosphorous was enriched in the char, while lead, zinc, and cadmium were significantly removed.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-7 av 7

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy