OP-II-3

PINEWOOD PYROLYSIS UNDER VACUUM CONDITIONSIN A CONICAL SPOUTED BED REACTORAmutio M., Lopez G., Artetxe M., Elordi G., Olazar M., Bilbao J.OP-III-A-4Chemical Engineering Department, University of the Basque Country, PO Box 644E48080 Bilbao, Spain. Phone: +34 94 601 5414, e-mail: maider.amutio@ehu.esBiomass is considered one of the most interesting alternatives to fossil fuels,since adequately used it does not contribute to a net rise in the level of CO 2 in theatmosphere. Flash pyrolysis of biomass is one of the most promising techniques thatmay enable this raw material to become a viable alternative to oil. The interest ofvacuum pyrolysis lies in the advantages associatee with the decresae in the inter gasflowrate and residence time of volatiles in the reactor [1]. Conical spouted bedreactor is a suitable reactor for solids that are difficult to handle, irregular or sticky, asbiomass [2], because of the good contact between the gas and the solid phase.Pine (pinus insignis) sawdust pyrolysis has been carried out in a conical spoutedbed reactor, provided with a system for continuous feeding of biomass (Figure 1).The bed was initially made up of 100 g of sand, allowing the continuous removal ofthe char from the bed by a lateral outlet. The experiments have been carried out at500 °C and two pressure levels: 0.25 and 1 atm. Product stream components havebeen analyzed online using a Varian 3900 chromatograph, injecting the samples tothe GC by means of a thermostated line maintained at 260 °C.The products obtained in the pinewood pyrolysis have been grouped into fourdifferent fractions: gas, bio-oil, water and char. The results of the obtained yields aresummarized in Table 2.Table 2. Effect of pressure on pinewood pyrolysis product yields (% wt, wet basis).Fraction 500 °C, 1 atm 500 °C, 0.25 atmGas 7.3 7.4Bio-oil 50.0 52.3Water 25.4 25.0Char 17.3 15.3As it is observed, high yields of liquid are obtained in both vacuum andatmospheric pyrolysis in the conical spouted bed reactor. However, product yieldsare hardly affected by reaction pressure and the major difference is that a 2 % moreof bio-oil is obtained. Gas fraction is mainly composed of CO and CO 2 . When157