| Popis: |
In this chapter there is described a tentative of obtain and characterize pyrolysis liquids from cashew nut shell, using a suggested classification of tars. The large amount of tar definitions and measurement methods, as well as the wide spectrum of organic compounds, makes it almost impossible to capture “tars” with a clear definition. And so, in order to facilitate the study of the evolution of liquid fraction composition, the compounds have been grouped according to their chemical nature, but differently from other works, it was extended the range of compounds in order to evaluate the influence of the reactor parameters in liquid fraction compositions. It is described, as well, the pyrolysis and gasification of cashew nut shell, that has been studied in a laboratory scale reactor. It was quantified and classified the production of liquids (tar) and evaluated the final temperature influence (800, 900 and 1000 °C) and the use of N2 in pyrolysis case, and a mixture of N2 and steam or air in the gasification case. Finally, it is described the identification and quantification of tar compositions, by CG-MS and CG-FID analyzes. Around 50 different compounds have been detected in the liquid fraction obtained, most of them being present at very low concentrations and it is observed that in the pyrolysis and gasification processes, phenol and benzene were the major chemical groups, and this fact agree with others works, presented here in a bibliographic revision. |
