Modelni projekt Westerzgebirge na Saškem obsega 27 mest in občin podeželskega območja Aue – Schwarzenberg, Vogtlandkreis, Stollberg und Annaberg. Glavni cilj modelnega projek-ta je poiskati nove poti ...ustvarjalnih rešitev skupaj z lokalnimi dejavniki, z namenom da bi kljub nazadovanju števila prebivalstva, spremenjene sestave potrošnikov in padca kupne moči
The paper presents results of investigations on KCl interaction with halloysite under high temperature conditions. Halloysite is an aluminosilicate that can be used as a fuel additive to prevent ...chlorine corrosion and formation of low melting corrosive deposits during combustion of biomass. It is claimed that an increase of the emission of gaseous chlorine as HCl(g) and decrease of chlorine share in the ash as result of KCl and halloysite interaction should be expected. During presented tests the mixtures of KCl and halloysite with different ratios were thermally decomposed in a muffle furnace at high temperatures of 900°C and 1100°C. Then, the analyses of potassium and chlorine contents in the formed solid residues were determined. Besides, it has been proved that halloysite addition changes the ash deposit structure as well as increases the ash fusion temperatures. This was supported by performing phase equilibrium calculations for the investigated different halloysite/KCl mixtures. The positive effects of halloysite on potassium capture while reducing chlorine content in solid residue to prevent formation of corrosive deposits have been confirmed.
Der Beitrag beschreibt ein Beispiel für die Aktivitäten des Stadtmanagements als Ergebnis des Programms zur Wiederbelebung des Stadtzentrums. Das Problem tritt nach der Entscheidung eines ...Handelsunternehmens auf, ein neues Einkaufszentrum am Rande der Stadt zu errichten. Die Folge dieser Entscheidung könnte der Verlust der Attraktivität des Stadtzentrums sein. Die Einzelhändler und Gastronomen haben gemeinsam mit staatlicher Unterstützung und Experten ein Programm für ein besseres und attraktiveres Angebot im Stadtzentrum erarbeitet.
•Full conversion of 500kW pulverized coal rig to 100% torrefied biomass firing.•Torrefied biomass combustion slower, may lead to higher gas exit temperatures.•Cofiring at 50% thermal share reduces ...SOX and NOX substantially.•Air-staging will reduce NOX during (co)firing of torrefied biomass even further.•Smart biomass–coal blends will ameliorate operational issues such as slagging.
Combustion tests have been performed in a 500kW pulverized coal furnace in order to investigate the cofiring characteristics of torrefied spruce and bituminous coal (El Cerrejon coal from Colombia). Monocombustion test cases for the coal and torrefied spruce were also performed for a comparative evaluation. Measurements performed include burn-out, gas temperature profiles and emissions characteristics (CO, NOX, SO2 and HCl). Combustion behavior was evaluated for all cases via measurement of the spatial distribution of oxygen across the flame and at the active combustion zones within the furnace. The impact of air staging on NOX reduction was investigated at two different primary or burner stoichiometric ratios for all fuels, while operational issues such as deposit formation and characteristics were also evaluated.
The experimental study demonstrates the operational feasibility of cofiring at higher shares while also showing that emissions such as NOX and SOX can be reduced just by cofiring. Air-staging will even further reduce NOX emissions while smart fuel mixing will ameliorate operational issues related to ash characteristics such as slagging.
Summary
Oxy‐combustion of biomass can be a major candidate to achieve negative emission of CO2 from a pulverized fuel (pf)‐firing power generation plants. Understanding combustion behavior of biomass ...fuels in oxy‐firing conditions is a key for design of oxy‐combustion retrofit of pulverized fuel power plant. This study aims to investigate a lab‐scale combustion behavior of torrefied palm kernel shell (PKS) in oxy‐combustion environments in comparison with the reference bituminous coal. A 20 kWth‐scale, down‐firing furnace was used to conduct the experiments using both air (conventional) and O2/CO2 (30 vol% for O2) as an oxidant. A bituminous coal (Sebuku coal) was also combusted in both air‐ and oxy‐firing condition with the same conditions of oxidizers and thermal heat inputs. Distributions of gas temperature, unburned carbon, and NOx concentration were measured through sampling of gases and particles along axial directions. Moreover, the concentrations of SOx and HCl were measured at the exit of the furnace. Experimental results showed that burnout rate was enhanced during oxy‐fuel combustion. The unburnt carbon in the flue gas was reduced considerably (~75%) during combustion of torrefied PKS in oxy‐fuel environment as compared with air‐firing condition. In addition, NO emission was reduced by 16.5% during combustion of PKS in oxy‐fuel environment as compared with air‐firing condition.
This article summarizes scientific knowledge and practical experiences on the release and capture of SO2 and SO3 with a special focus on the implications of oxy-fuel combustion conditions on sulphur ...emission behaviour. Results, obtained at the experimental, 500 kWth atmospheric, pulverized fuel combustion rig (KSVA) of the IFK regarding sulphur oxide (SO2/SO3) emissions and capture behaviour are presented. The experimental plant was operated with pre-dried sulphur rich lignite in air and oxy-fuel combustion mode. The following issues are highlighted in particular:•General and transient behaviour of SO2 emissions under air and oxy-fuel combustion conditions SO3•separation behavior of the ESP under oxy-fuel conditions•Differences of ESP ash qualities from air and oxy-fuel operation
The 1999/31 Elemental Carbon Directive sets strict rules on the disposal of untreated municipal solid waste in the European Union countries and forces a reduction of the biodegradable quantities ...disposed off to landfills up to 35% of the amount produced in 1995 in the coming decade. More environmentally friendly waste management options shall be promoted under the framework of the Community Waste Strategy (96 399 Final). In this context, the production and thermal use of solid recovered fuels (SRFs), derived from nonhazardous bioresidues and mixed- and mono-waste streams, could be a key element in a future waste management system. Within the scope of the European Demonstration Project, RECOFUEL, SRF cocombustion was demonstrated in two large-scale lignite-fired coal boilers at RWE power station in Weisweiler, Germany. As a consequence of the high biogenic share of the cocombusted material, this approach can be considered beneficial following European Directive 2001/77/EC on electricity from renewable energy sources (directive). During the experimental campaign, the share of SRF in the overall thermal input was adjusted to approximately 2%, resulting into a feeding rate of approximately 25 t/hr. The measurement campaign included boiler measurements in different locations, fuel and ash sampling, and its characterization. The corrosion rates were monitored by dedicated corrosion probes. The overall results showed no significant influence of SRF cocombustion on boiler operation, emissions behavior, and residues quality for the thermal shares applied. Also, no effect of the increased chlorine concentration of the recovered fuel was observed in the flue gas path after the desulfurization unit.
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