tailieunhanh - Progress in Biomass and Bioenergy Production Part 12

Tham khảo tài liệu 'progress in biomass and bioenergy production part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Characterization of Biomass as Non Conventional Fuels by Thermal Techniques 319 residue of oil residue already mentioned before. In particular the effect of inert vs mild oxidizing conditions and the effect of slow vs fast heating are presented. Pyrolysis and oxidative pyrolysis experiments have been carried out in the tubular reactor described in Fig. 4. The reaction products were quickly cooled down as they flowed through 250ml bubblers held at 0 C and -12 C respectively. Tar captured by the bubblers has been characterized off line by means of simulated distillation. The gas which passed through the bubblers was sent directly to a micro-GC Agilent 3000 equipped with four columns Molesieve MS5A Poraplot U Poraplot allumina and OV1 in order to analyse the gaseous products on line. 150 C 350 C 600 C 900 C 900 C Fig. 14. MS curves from experiments TG-IP of a residue of the oil industry. The overall char yield was between 19-22 in all the tests. The tar yield was around 10 but turned out to be rather scattered. The analysis of the tars collected by the bubblers is reported in Tab. 6. The weight fractions corresponding to different boiling points are reported. It can be observed that tar produced from slow pyrolysis under inert conditions has a minor fraction of components with boiling point between 170-300 C a 60 weight fraction has boiling point in the range 350-500 C and 30 above 500 C. These figures are consistent with the weight loss measured by TGA. Tar obtained by fast pyrolysis under inert conditions and by slow pyrolysis with a mild oxidizing atmosphere both contain a larger fraction with boiling point below 350 C. The composition of the gas leaving the bubblers during an experiment of slow pyrolysis in He are reported in Fig. 15. It can be observed that hydrocarbons with more than two carbon atoms are released in two stages. The first more pronounced one occurs between 150400 C the second between 400 and 600 C. Methane is instead released over the entire .