Abstract—We successfully developed and tested a new separation layer solving problems with unmanageable deposits inside the boilers of Zluticka Heating Plant. The deposits are mainly created by glass-forming melts. We plotted straw ash compositions in K 2 O- CaO-SiO 2 phase diagram and illustrated that they are in the area of low-melting eutectic points. To prevent the melting of ash and the formation of deposits, we modified ash compositions by injecting additives into biomass fuel, and thus effectively suppressed deposits in a burner. Keywords—Biomass, straw, combustion, deposit, heat, additives I. INTRODUCTION URRENTLY, biomass is the most often renewable source of energy in the Czech Republic. The potential of wood fuel is at its limit because of steeply increasing number of new biomass heating and power plants that brings a huge demand and a steep increase of wood prices. Hence, crop residues and the agriculture production of energy plants represent a very reasonable alternative. This energy production strategy has several positive effects, like the decentralization of energy production and significant energy independence of a region as well as the creation of new jobs. The crop residues, such as straw, are ideal for a combustion process generating heat in local heating plants. Currently, the building of new heating plants burning straw is obstructed by a significant draw back in this technology caused by the formation of hardly manageable glassy deposits inside boilers reducing its efficiency. This problem can be overcome by applying our new technology of straw combustion. This technology was successfully tested in Zluticka Heating Plant where they burn 1 000 tons of wheat, rye, barley, or rape straw every year. When using the new technology, they have not encountered significant problems. Authors thank for the support of the Ministry of Industry and Trade “New biomass combustion technology with continuous removal of ash with controlled chemical composition” FRTI1/497. P. Volakova is with the company Zluticka Heating Plant, Inc., Velke namesti 131, Zlutice 36452, Czech Republic (phone: +420 353 227 407 e-mail: zlutickateplarenska@ztzlutice.cz). M. Mika is with the Institute of Chemical Technology, Technicka 5, Prague 6, 166 28, Czech Republic (phone: +420 220 444 102; fax: +420 220 350; e-mail: Martin.Mika@vscht.cz). V. Verner is with the company VERNER, Inc., Sokolska 321, Cerveny Kostelec, 54941, Czech Republic (phone: +420 491 465 024; e-mail: sef@verner.cz). II. APPLIED RESEARCH Our goal was to apply a new technology eliminating problems with the melting of ash and the formation of glass deposits, which is closely connected to low melting eutectics of straw ashes. These low melting ashes caused the formation of glass deposits strongly bonded to the walls of refractory ceramics inside the flamer part of boilers. The glassy deposits are formed by melted ash particles carried by flue gasses in a flamer at temperatures around 1100°C. Fig. 1 Glass deposit removed with a layer of refractory ceramics The formation of the glass deposits was a serious problem. Usually, after each three months, the efficiency of the boilers decreased so much, that it was necessary to shut them down for cleaning. Then workers have to perform very laborious and time-consuming removal of the deposits because the glass melt deposits were very strongly stuck to refractory ceramics. The process of removing the deposits with a pneumatic hammer seriously damaged the refractory ceramics and the deposits were very often taken out with the layers of the ceramics (Figure 1). Even though the workers were removing the deposits very carefully, at least 5 mm of the ceramics was removed with each piece of the deposit. Without any technology improvement, the ceramics walls will be dangerously thinner down shortly and the whole ceramic segments would have to be replaced. It would seriously increase the cost of repairs and consequently heat energy prices for costumers. This problem was very serious when certain types of straw were fired, mostly barley. Additionally, the low eutectic temperature of some straw ash caused problems with agglomeration and clogging in a burner. P. Volakova, M. Mika, V. Verner, B. Klapste, O. Jankovsky Successful Straw Combustion Technology in Zluticka Heating Plant C World Academy of Science, Engineering and Technology International Journal of Chemical and Molecular Engineering Vol:6, No:4, 2012 389 International Scholarly and Scientific Research & Innovation 6(4) 2012 scholar.waset.org/1307-6892/9648 International Science Index, Chemical and Molecular Engineering Vol:6, No:4, 2012 waset.org/Publication/9648