Xu Xiwei

Influence of Pyrolysis Parameters and CaCl2 Catalyzer on Pyrolysis of Elephant Grass (Pennisetum purpureum Schum.)

Elephant grass is a fast growing and low nutrient demand plant with significant potential as a renewable energy source. In this work, the influence of heating temperatures, N2sweeping gas flow rates and CaCl2 catalyzer weights on the yields of products and chemical composition of bio-gas was investigated by pyrolysis and catalytic pyrolysis of elephant grass in a fixed bed reactor. The results showed that as the heating temperature increased, the yield of charcoal decreased, while bio-gas and bio-oil increased. The concentration of CO2decreased 20 vol.% at the heating temperature of 600 ¡æ than that at 350 ¡æ and the concentration of CO reached 25 vol.% in600 ¡æ. With the flow rate of N2 sweeping gas risen, high yield of bio-oil, low yield of bio-gas and high concentration of CO2were gained. CaCl2 had an obvious catalytic effect on elephant grass pyrolysis, and the low level of CaCl2 (less than 15.4 wt.%of grass weight) evolved high yield of charcoal. The high level of CaCl2 doping was helpful to evolve the degree of decomposition and improve the yield of bio-oil, but had a slight effect on the chemical composition of bio-gas.

A Preliminary Study on the Components of Cotton Stalk Wood Vinegar by TG-FTIR

Wood vinegar is a product of agriculture and forestry residues pyrolysis with insecticidal, antibacterial effect, and is even found to have health care. In recent years, wood vinegar is being taken seriously more and more by people. Cotton stalk wood vinegar is derived from cotton stalk pyrolysis. It is the gases generated from the pyrolysis of cottons talk, changing into liquid products through condensation£¬itscompositions are complex, mainly are acid, phenol, ketone, alcohol and other substances. This paper studied initially the way of the compositions formation about cotton wood vinegar, drawing the following conclusions: The initial phrase of cottons talk pyrolysis mainly occurred the precipitation of free water and a small amount of organic acid, In the pre-carbonization phrase, a small amount of volatile gases composed by small molecules were released, The main pyrolysis phrase, corresponding to the maximum infrared absorption spectrum, was the main phrase during which the composition of wood vinegar were produced, At last, some phenols we reproduced in charring phrase. During the prolysis of cottons talk, some organics generated continued to the charring stage like phenols.