In the last years, interest on alternative energy sources is increasing. In particular, among renewable fuels, the employment of biomass and biofuels (biogas, ethanol, glycerol, organic waste, etc...) as raw feedstock for energy production, through gasification and pyrolysis technologies are often proposed. Pyrolysis is a promising process for to convert biomass into liquid fuels (bio-oil) mainly due to its low capital and operating cost advantages compared to competing technologies, such as: thermal-acidic, organic solvent extraction, transesterification, fermentation or gasification. The pyrolysis bio-oil can be potentially used for direct combustion in energy generation, or can be upgraded further into liquid transport fuels and bio-chemicals. In particular, the catalytic "in situ" cracking pyrolysis is a promise process that produce directly a pyrolysis up-grated bio-oil. This means that the bio-oil is produced with high acidity, oxygen content and grater low heating value. Hence, the use of different catalytic materials (HZSM-5, CeO2, Ni-based catalyst) were proposed in literature to promote the conversion both biomass and biofuels (i.e. biogas) [1]. Further, Ni catalysts combined with Cerium oxides resulted very active into deoxygenation reactions for production of high-quality bio-oil from algae [2]. In this context, many papers are present in literature on catalytic biomass pyrolysis for bio-oil production however, researches on effect of catalysts on pyrolysis process apply to sea plants are really scarce [3]. Thus, the main objective of this work was to investigate about the feasibility to produce high-quality bio-oil from a Mediterranean sea plant (Posidonia Oceanica) by pyrolysis process. First, experiments of pyrolysis at 500 °C in a fixed bed reactor were carried out in order to investigate about yields of the reaction in terms of bioproducts (bio-oil, bio-char and syngas) selectivity. Furthermore, the bio-oil obtained was analysed in terms of oxygen and organic compounds content. Successively, effects of different "home-made" Ni, Ce, HZSM-5 based catalysts on bio-oil yield and bio-oil oxygen content were evaluated. Results highlighted that the bio-oil coming from catalytic pyrolysis of Posidonia Oceanica has a lower content of acids and oxygen and high hydrocarbons and HHV values. In particular, using CeO2 catalyst was recorded the highest bio-oil yield (51.15 wt.%) and the lowest bio-oil oxygen content (6.87 wt.%). Though, the best composition in terms of hydrocarbons content (34.18 %), detected by GC-MS, was obtained by Ni/HZSM-5 catalyst.
Bio-oil deoxygenation from catalytic pyrolysis of Posidonia Oceanica
S Maisano;F Urbani;N Mondello;V Chiodo
2017
Abstract
In the last years, interest on alternative energy sources is increasing. In particular, among renewable fuels, the employment of biomass and biofuels (biogas, ethanol, glycerol, organic waste, etc...) as raw feedstock for energy production, through gasification and pyrolysis technologies are often proposed. Pyrolysis is a promising process for to convert biomass into liquid fuels (bio-oil) mainly due to its low capital and operating cost advantages compared to competing technologies, such as: thermal-acidic, organic solvent extraction, transesterification, fermentation or gasification. The pyrolysis bio-oil can be potentially used for direct combustion in energy generation, or can be upgraded further into liquid transport fuels and bio-chemicals. In particular, the catalytic "in situ" cracking pyrolysis is a promise process that produce directly a pyrolysis up-grated bio-oil. This means that the bio-oil is produced with high acidity, oxygen content and grater low heating value. Hence, the use of different catalytic materials (HZSM-5, CeO2, Ni-based catalyst) were proposed in literature to promote the conversion both biomass and biofuels (i.e. biogas) [1]. Further, Ni catalysts combined with Cerium oxides resulted very active into deoxygenation reactions for production of high-quality bio-oil from algae [2]. In this context, many papers are present in literature on catalytic biomass pyrolysis for bio-oil production however, researches on effect of catalysts on pyrolysis process apply to sea plants are really scarce [3]. Thus, the main objective of this work was to investigate about the feasibility to produce high-quality bio-oil from a Mediterranean sea plant (Posidonia Oceanica) by pyrolysis process. First, experiments of pyrolysis at 500 °C in a fixed bed reactor were carried out in order to investigate about yields of the reaction in terms of bioproducts (bio-oil, bio-char and syngas) selectivity. Furthermore, the bio-oil obtained was analysed in terms of oxygen and organic compounds content. Successively, effects of different "home-made" Ni, Ce, HZSM-5 based catalysts on bio-oil yield and bio-oil oxygen content were evaluated. Results highlighted that the bio-oil coming from catalytic pyrolysis of Posidonia Oceanica has a lower content of acids and oxygen and high hydrocarbons and HHV values. In particular, using CeO2 catalyst was recorded the highest bio-oil yield (51.15 wt.%) and the lowest bio-oil oxygen content (6.87 wt.%). Though, the best composition in terms of hydrocarbons content (34.18 %), detected by GC-MS, was obtained by Ni/HZSM-5 catalyst.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
