Assesment of the feasibility plant biomass cultivation and utilization fuel

Abstract

The present paper provides the results of the tests plant biomass suitability for use as fuel, as well as the findings on energy potential of swards and energy efficiency of biofuel production from herbaceous plants. Reed canary grass, awnless bromegrass and its mixtures with sweet clover, perennial lupine and goat's rue, and topinambour were grown for fuel. The swards were analysed for dry matter (DM) yield, fibre content in DM, bulk density, calorific value andcombustion temperature of biomass, and NOx content in flue gasses whenm burning the biomass in the hearth-type furnace. Energy potential of swards and energy input for biofuel production was calculated according to the DM data.The productivity of swards under congenial weather conditions ranged between 6,3-8,8 t/ha DM, while under adverse conditions between 2,8-6,5 t/ha. The productivity of topinambour steams ranged between 5,7-7,3 t/ha DM. Fibre content in SDM was highly dependent on the cutting data of swards, i. e. on the maturity of swards at harwesting andfluctuated from 32 to 51%. Conditional bulk density of the grass chops ranged from 39.4 to 56.3 kg/m³, topinambour - 65-78 kg/m³. The net calorific value of dry biomass ranged from 17.1 to 18.7 MJ/kg and depended on sward composition, growing conditions and cutting time. Copmbustions temperature ranged from 770 to 955°C. Ther combustion temperature of the biomass of sward cut in the late summer or early spring was the highest and had the lowest NOx content in flue gases. In Lithuanian climatic conditions the energy potential of herbaceous plant was 115-153 GJ/ha. Total energy input for biofuel production - cultivation and harwesting of grass/legume mixtures amounted to 7.98 GL/ha, and of topinambours - 14.4 GJ/ha respectively.