PYROLYSIS OF NAPIER GRASS AND PHRAGMITE REEDS PRETREATED WITH ACIDIC PYROLYTIC WATER

摘要

Napier grass, Pennisetum Purpureum, and the phragmite reed, Phragmites Australis, are high yielding and fast growing perennial plants. The phragmites reed has been classified as Canada's worst invasive plant due to it being almost impossible to eradicate. These plants can be easily grown on marginal land, land that offers poor soil characteristics not suitable for food production, as dedicated energy crops. Inorganic content in grassy feedstocks is typically higher than other woody materials and are known to catalyze unfavorable reactions that affect the pyrolysis yields and bio-oil chemical composition and properties. Acid washing is a pre-treatment step that can be used to lower the inorganic content of these grassy feedstocks. There are two disadvantages associated with this step, firstly, the chemical cost and secondly, the energy intensive drying stage after washing. These disadvantages have been overcome by using acidic water trapped using a novel fractional condensation system, coupled to a bench scale mechanically fluidized bed reactor (MFR), as a source of acid water for pre-treatment and by mechanical dewatering, using two different proprietary technologies. The study aims to address the impact of pre-treatment, optimization of pyrolysis conditions and its fraction condensation system on the chemical composition of the bio-oil and char products. Particular attention is focused towards the characterization of the bio-oil sugar content and possible bio-oil conversion opportunities that may arise, such as the conversion of bio-oil to ethanol or butanol.