Reduction in Difficulties of Phytomass Combustion by Co-Combustion of Wood Biomass

Michal Holubcik,Jozef Jandacka,Jozef Micieta

doi:10.15598/aeee.v14i1.1386

Abstract

Nowadays, the most used biofuel in Slovak republic is log wood. Alternatively, there are also biofuels based on vegetal biomass (phytomass) like wheat straw or grass. The advantage of these biofuels is lower cost price because they are usually considered as waste product. The major disadvantage of these vegetal biofuels is their problematic combustion. It is mainly due to the low ash melting temperature because of chemical composition of ash from phytomass. The low ash melting temperature causes slagging and sintering, which reduce the efficiency of the combustion process. This disadvantage causes very difficult and problematic combustion of phytomass. The article deals the way of trouble reduction during combustion of pellets made from phytomass (specific hay) through the wood pellet co-combustion in a standard automatic boiler for combustion of wood pellets. During the experiments, the mixing ratio of hay pellets and wood pellets is varied and subsequently, there is determined its impact on the combustion process, namely on heat output of the boiler, and there is also evaluated the effect of the mixing ratio on the production of carbon monoxide (CO), nitrogen oxides (NOx), sulphur dioxide (SO2), organic hydrocarbons (OGC) and particulate matters (PM10, PM2.5).

Highlights

Biomass is nowadays becoming more and more popular energy source
The article describes the impact of low-quality pellets made of hay with lowquality wood pellets on the combustion process in ordinary automatic boiler for heating with wood pellets
Co-combustion of alternative pellets, namely pellets made from grass mixes with low-quality wood pellets is implemented on an experimental device for testing boilers

Summary

Introduction

Biomass is nowadays becoming more and more popular energy source. This is due to decreasing reserves of fossil fuels and their rise in prices [1]. From sawdust are made high-quality fuels like wood pellets and briquettes These forms of biofuel satisfy besides energetic, ecologic and environmental requirements, comfort and safety attributes of combustion [7]. Many owners of pellet boilers, which are designed only for wood pellet try to use various alternative biofuels, including pellets made from plants, waste materials or various plant seeds like cereal corn, sunflower, maize and others. A typical combustion trouble of alternative fuels are slagging and creating agglomerates and sintered figures from ash into the combustion chamber and the burner, due to the low ash melting temperature of certain phytomass like wheat straw These agglomerates of ash can reduce the effectiveness of the boiler, because they accumulate on the surfaces of heat exchanger, can create local overheating of the material, support corrosion and contribute to other troubles. During the experiments are determined the heat output of the boiler, and production of gaseous emissions, carbon monoxide (CO), nitrogen oxides (NOx), organic hydrocarbons (OGC), sulfur dioxide (SOx) and particulate matters (PM10, PM2.5)

Used Biofuels

Method of Experiment

Measurement of Thermal-Technic Parameters of Boiler

Findings

Conclusion