Relation of energy content variations of straw to the fraction size, humidity, composition and environmental impact

Abstract

Biomass is the major source of renewable energy, the use of which is very important in energy, environment and economical aspects. Biomass enables the replacement of fossil fuels, the importance of biomass usage is related to global warming questions. Biomass moisture content is one of the main factors affecting straw preparation for the usage cost. In this research the main focus is on straw and different biomass composition and how it influences the solid biofuels preparation for usage, paying attention to straw fraction, humidity, composition and finally how it influences the energy and environmental aspects. Tested samples consist of different composition- raw straw, 100% yellow straw pellets, 100% grey straw pellets, 98% straw pellets with 2% additives, 50% straw and 50% hay pellets, 49% straw and 49% hay pellets with 2% additives, 100% hay pellets, 98% hay pellets with 2% additives and additionally two samples of straw briquettes with different chop size - (20 mm) and (30 mm and 10 mm). This research pays attention to the main material characteristics - moisture value, ash content, HHV (higher heating value), pyrolysis coke. Research results will help to find the best biomass pellet and briquette composition for solid biofuel usage. During the research it was found that the lowest moisture value was 98% hay pellets with 2% CaO additive - 5.79%. Highest amount of ash value was found in 50% straw and 50% hay composition pellets - 0.021 g. Highest amount of HHV were tested pellets which consisted of 98% hay with 2% CaO additives. Highest amount of pyrolysis coke in organic and dry matter were in 100% yellow straw tested samples. Achieved results will help to estimate material fraction, humidity and composition on biomass preparation for conversion steps, following biomass usage energy and environment requirementsVytauto Didžiojo universitetasŽemės ūkio akademij