in Wiley Online Library (wileyonlinelibrary.com).To maximize oil yields in the fast pyrolysis of biomass it is generally accepted that vapors need to be rapidly quenched. The influence of the heterogeneous and homogeneous vapor-phase reactions on yields and oil composition were studied using a fluidized-bed reactor. Even high concentrations of mineral low char (till 55 vol %) appeared not to be catalytically active. However, the presence of minerals, either in biomass or added, does influence the yields, especially by the occurrence of vapor-phase charring/polymerization reactions. Contradictory, in the absence of minerals, homogeneous vapor-phase cracking reactions were dominant over polymerization/charring reactions (400-550 C, 1-15 s). With increasing vapor residence time, the oil yield reached an asymptotic value, which decreased with temperature. At a vapor temperature of 400 C no decrease in oil yield was observed, but dedicated analysis showed that homogeneous vapor to vapor reactions had occurred. a Sigma-Aldrich, P9333, purity [ 99.0%, b Sigma-Aldrich S7795, purity [ 99.0%, c Sigma-Aldrich 23653-412 K 2 CO 3 , purity ¼ 99.0%

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The transformation of lignocellulosic biomass into bio‐based commodity chemicals is technically possible. Among thermochemical processes, fast pyrolysis, a relatively mature technology that has now reached a commercial level, produces a high yield of an organic‐rich liquid stream. Despite recent efforts to elucidate the degradation paths of biomass during pyrolysis, the selectivity and recovery rates of bio‐compounds remain low. In an attempt to clarify the general degradation scheme of biomass fast pyrolysis and provide a quantitative insight, the use of fast pyrolysis microreactors is combined with spectroscopic techniques (i.e., mass spectrometry and NMR spectroscopy) and mixtures of unlabeled and 13C‐enriched materials. The first stage of the work aimed to select the type of reactor to use to ensure control of the pyrolysis regime. A comparison of the chemical fragmentation patterns of “primary” fast pyrolysis volatiles detected by using GC‐MS between two small‐scale microreactors showed the inevitable occurrence of secondary reactions. In the second stage, liquid fractions that are also made of primary fast pyrolysis condensates were analyzed by using quantitative liquid‐state 13C NMR spectroscopy to provide a quantitative distribution of functional groups. The compilation of these results into a map that displays the distribution of functional groups according to the individual and main constituents of biomass (i.e., hemicelluloses, cellulose and lignin) confirmed the origin of individual chemicals within the fast pyrolysis liquids.

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The common use of wood together with traditional chemical polymers opens new possibilities in the field of sustainable product development. Wood plastic composites (WPCs) are an ideal combination of these raw materials, which can be produced with standard plastic technology such as extrusion or injection moulding. Wood to plastic ratio in a WPC influences quality and price, thus adaptation of analytical tools for material testing and quality assurance is required. In this study, the suitability of analytical pyrolysis (Py) and differential scanning calorimetry (DSC) was investigated to quantify the amount of polypropylene (PP) in WPCs. The reliability of these methods was tested by analysing WPCs with different ratios of wood and PP. The amount of PP can be determined with DSC based on its melting point as the influence of wood is negligible in this context. The increment of typical PP markers and decrement of wood markers was observed and quantified in the pyrograms if the PP content in WPCs was elevated. Thus, the ratio of PP and wood can be reliably quantified by means of online and offline analytical pyrolysis.

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The vTI‐mini fast pyrolyzer was applied for screening fast pyrolysis reactions of different Organosolv lignins, such as Alcell (Repap Technologies) and lignin from a German biorefinery project. To investigate the catalytic effects on the pyrolysis of the technical lignins, three catalysts such as zeolite HZSM‐5, FCC, and Olivine were used. The catalytic pyrolysis characteristics and decomposition products of the Organosolv lignins were scrutinized by varying pyrolysis temperature and catalyst type. From the pyrolysis experiments, obtained pyrolyzed products were generally categorized into three parts such as coke, noncondensable gas, and biocrude oil. To evaluate the yield of biocrude oil, mass balances of products and reactants were established and the collected biocrude oil was analyzed by GC/MS. From the results, the increase or decrease patterns of certain chemical compounds were found according to the different pyrolysis temperatures as well as various catalysts. In particular, size exclusion chromatography (SEC) was performed for extracts of the solid residue to get information on the catalytic effect and severity of lignin degradation. © 2012 American Institute of Chemical Engineers Environ Prog, 2012