Simulation Model of Pyrolysis Biofuel Yield Based on Algal Components and Pyrolysis Kinetics

Abstract

Yield and composition of pyrolysis oil were tested by fixed bed pyrolysis reactor and GC-MS. Algae pyrolysis kinetics was also calculated by Lorentzian fitting multi-heating rate method with R2 > 0.98. Their activation energy was ranged from 94 to 216 kJ/mol and most of fitting peaks could be described by the random nucleation followed by growth mechanism. Higher bio-oil yield of 35.0 % for Chlorella biomass and 40.6 % for Spirulina biomass at 425 °C have been obtained, while it is 49.4 % at 450 °C for Chrysophyceae biomass. The main compounds of pyrolysis oil included aliphatic and alicyclic hydrocarbons, aromatic hydrocarbons, nitrogenated compounds (nitriles, amines, amines, and N-heterocyclic compounds), carboxylic acids, ketones, alcohols, furans, phenols, ester, and others. Carbon number distribution of bio-oil is similar to that of gasoline and diesel, and fatty acid has an influence on bio-oil carbon distribution. Components biofuel model based on algal biomass component was established and the difference between simulated value and experiment value is less 3.58 %. Kinetics biofuel model based on fitting peak areas in pyrolysis kinetics was established and the difference between simulated value and experiment value is less 3.45 %. Pyrolysis oil yield can be quickly and efficiently achieved with these two models.