목질계 바이오매스 열분해 및 이산화탄소 가스화

Abstract

The energy demand is increasing due to the increase of population and economic development globally. Nowadays, energy supply is mostly comprised by coal, petroleum, and natural gas. However, those fossil energy are limited, in addition it has the severity problem about the environment. In case of Korea highly depends on the other countries for the energy resources and therefore the alternative energy development is urgent. Biomass-derived energy also holds the promise of reducing emissions of carbon dioxide which is significant contributor to global warming. Also, biomass can be converted to various forms of energy through thermochemical conversion processes. In this study, a screw pyrolyzer was designed and manufactured for wood biomass gasification. The wood biomass was used as a waste wood chip, and experiments in the pyrolysis and CO2 gasification were achieved in the products of producer gas, tar, and char. The test was performed for the pyrolysis and CO2 gasification. The pyrolysis was conducted according to the variation of temperature for the comparison in the CO2 gasification. For the CO2 gasification test, parametic studies were conducted for temperature, water content, and amount of CO2. The producer gas increased and tar decreased with increasing the gasification temperature. The producer gas of H2 and CO increased and tar decreased with increasing the moisture content by tar steam gasification and water-gas reaction. H2 decreased and CO increased by the reverse water-gas shift reaction and Boudouard reaction with an increase of CO2 feeding. And gravimetric tar increased due to reducing the thermal cracking while light tar production decreased. A comparison between the pyrolysis and CO2 gasification was achieved. The CO2 gasification is better to get a good quality char having a lot of pores and specific surface. This is because the CO2 gives to make the Boudouard reactions with carbon on the char in the high temperature. And the producer gas had large amount of carbon monoxide.