A. Oasmaa

Publications (6)0 Total impact

• Article: Characterization of Hydrotreated Fast Pyrolysis Liquids

  A. Oasmaa, E. Kuoppala, A. Ardiyanti, R. H. Venderbosch, H. J. Heeres
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  ABSTRACT: This paper focuses on analytical methods to determine the composition of hydrotreated fast pyrolysis liquids. With this information, it is possible to gain insights in the chemical transformations taking place during catalytic hydrotreatment (hydrogenation and/or hydrodeoxygenation, HDO) of pyrolysis liquids. Three different samples, produced at different hydrotreatment severity levels (defined by temperature and residence time) using Ru/C as the catalyst, were analyzed in detail. The composition of the products was determined by solvent fractionation followed by detailed analysis of the various fractions by gas cheromatography/mass selective detector (GC/MSD), capillary electrophoresis (CE), and NMR (1H NMR, 13C NMR, and 31P NMR). The decrease in the carbohydrate fraction was easily followed by the Brix method after solvent fractionation.
  08/2010;
• Article: Physicochemical Properties of Product Liquid from Pyrolysis of Sewage Sludge

  I. Fonts, E. Kuoppala, A. Oasmaa
  Energy. 01/2009; 23:4121--4128.
• Article: Power generation using fast pyrolysis liquids from biomass

  D Chiaramonti, A Oasmaa, Y Solantausta
  Renewable and Sustainable Energy Reviews. 01/2007; 11:1056--1086.
• Article: Fast Pyrolysis of Forestry Residue. 3. Storage Stability of Liquid Fuel

  A. Oasmaa, E. Kuoppala
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  ABSTRACT: The storage properties of fuels are critical in regard to the introduction of a new fuel into markets. The fuel must be homogeneous, and the properties of the fuel should not change significantly during the storage at the customer's facility. In this research, the storage stability of wood-based pyrolysis liquids was followed by analysis of the changes in the physical properties and chemical composition during storage. The main physicochemical changes took place during the first six months. The high-molecular-mass (HMM) fraction of water-insolubles, which were originally lignin-derived material, increased, because of polymerization and condensation reactions of carbohydrate constituents, aldehydes, and ketones. Therefore, the average molecular mass of pyrolysis liquids increased, which was also observed as an increase in viscosity. There was a clear correlation of the average molecular mass with the viscosity, water-insolubles, and the HMM fraction of water-insolubles. The chemical changes in the aging were similar to those which occurred during the accelerated aging test. The decrease in volatile aldehydes and ketones increased the flash point of the liquids. The increase in viscosity increased the pour point. Water was formed as a byproduct in various condensation reactions. Increases in the amount of water decreased the heating value. The density of the liquid increased, because the increase in HMM lignin fraction was more significant than the increase in water.
  06/2003;
• Article: Fast Pyrolysis of Forestry Residue. 2. Physicochemical Composition of Product Liquid

  A. Oasmaa, E. Kuoppala, Y. Solantausta
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  ABSTRACT: In this second article on fuel oil, use of forestry residue pyrolysis liquids, their physicochemical properties, and the behavior of these liquids are described. Understanding of the chemical composition of forestry residue liquids enables the selection of correct handling and storage conditions. Forestry residue is one of the most viable biomass feedstocks for liquid production in Northern softwood forest zone. A 1025 wt
  Energy. 03/2003; 17:433--443.
• Article: Fast Pyrolysis of Forestry Residue. 1. Effect of Extractives on Phase Separation of Pyrolysis Liquids

  A. Oasmaa, E. Kuoppala, S. Gust, Y. Solantausta
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  ABSTRACT: Although high liquid yields of a single phase product can be obtained from bark free “white” wood feedstocks by fast pyrolysis processes, lower yields and a two phase product are obtained from feedstocks containing bark and needles as is commonly found with forestry residues. The liquid yield is thus reduced from levels of 70−75 wt % to those of 60−65 wt %. This will have a significant impact on the economic viability of pyrolysis projects in Scandanavia as forestry residues are a major source of raw materials. The forestry residue product is composed of an extractive rich upper phase which varies from 10 to 20% of the total product and a bottom phase closely resembling the normal bark free wood product. Phase separation occurs due to the higher extractive content of the residues which due to their much lower oxygen phase separate. Extractives are composed of components such as fatty acids, fatty alcohols, terpenes, resin acids, and terpenoids which have lower oxygen content than pyrolysis liquid compounds in general and which phase separate forming an upper phase that has a higher viscosity and heating value than the bottom phase. The phase separation was found to be enhanced by an increase in temperature and/or in storage time.
  11/2002;