In situ catalytic upgrading of biooil with novel catalysts, from bench scale to pilot plant

Biomass flash pyrolysis is a very promising thermochemical process for the production of bio-liquids and/or chemicals. However, early works have shown that the use of catalysts usually leads to additional water and coke production and to a decrease in the yield of organic products. Additionally, due to the fast catalyst deactivation during the biomass catalytic pyrolysis a catalyst regeneration step is necessary. Consequently, the fully circulating fluid bed (CFB) technology is the best technology for this process. In this paper we present the work performed in CPERI for biomass catalytic pyrolysis based on a circulating fluid bed pilot plant unit and a small scale pyrolyzer. These two units form a strong research tool that allows firstly for the fast screening of different catalysts and secondly for the extensive testing of the most promising ones in a larger scale In our work the effect of several catalysts, such as E-cat, ZSM-5, Zirconium, Magnesium, Titanium and Nickel oxides, on the quality and yield of biooil is investigated in a bench scale pyrolysis unit. Different biooils are produced each with a different oxygen content that is comprised from several chemical groups in different percentages depending on the catalyst used. In addition, several commercial catalysts such as E-cat and different formulations of ZSM-5 catalysts are tested in a pilot plant unit and different biooils are received in quantities of up to several kgs. The CPERI biomass pyrolysis pilot plant unit is working in a fully circulating pilot plant with continuous regenerations. The construction of this unit was based on an existing once through transported fluid bed unit. Data from the bench scale unit are compared to those received from a fully circulating pilot plant unit so that a correlation between the two units is achieved. A detailed characterization of the produced biooils (from both units) is given in the paper. The target was to estimate the achieved deoxygenation of the biooil from various catalysts tested. Several analytical techniques are presented that allow the determination of the elemental analysis of the produced biooil, its water yield and the qualitative and quantitative evaluation of the distribution of the different chemical groups. This distribution was based on GCMS analysis and reveals the different groups of biooil such as aromatic and aliphatic hydrocarbons, phenols, carbonylic compounds, furans, acids etc. The chemical analysis of biooil is very important for both the understanding of the catalytic pyrolysis mechanisms and the evaluation of the effect of different catalytic materials on the end products.