Tars, biomass

The surface analyses of the Co/MgO catalyst for the steam reforming of naphthalene as a model compound of biomass tar were performed by TEM-EDS and XPS measurements. From TEM-EDS analysis, it was found that Co was supported on MgO not as particles but covering its surface in the case of 12 wt.% Co/MgO calcined at 873 K followed by reduction. XPS analysis results showed the existence of cobalt oxide on reduced catalyst, indicating that the reduction of Co/MgO by H2 was incomplete. In the steam reforming of naphthalene, film-like carbon and pyrolytic carbon were found to be deposited on the surface of catalyst by means of TPO and TEM-EDS analyses. 

Bragc, C. Yu, Q., Chen, G., SjostrOm, K. Use of Amino phase Adsorbent for Biomass Tar Sampling and Separation , Department of Chemical Engineering and Technology, Chemical Technology, Royal Institute of Technology. Stockholm, Sweden. Fuel. Vol. 76, No. 2, pp. 137-142, Jan. 1997... 

Development of chemometric methods for full quantification of the biomass tar compounds... 

C.Bragc, Qizhuang Yu, Guanxing Chen and K.SJ6str6m Use of amino phase adsorbent for biomass tar sampling and separation. Fuel 76 (2) 137-142 (1997),... 

Himmelblau D.A. (1996) Phenol-Formaldehyde Resin Substitutes from Biomass Tars. In Wood Adhesives 1995, Forest Products Society, Madison, WI. 

ABSTRACT The volatility of tars from pyrolysis of biomass and biomass-derived materials is of special interest. This interest is related to the question whether or not biomass tar evaporation has a significant effect on the total rate escape of tar from pyrolyzing substance and therefore on pyrolysis kinetics. In fact, in many practical applications (especially in fossil fuel thermal conversion processes), tar vaporization is known to be an important step during pyrolysis that influences both yield and composition of pyrolysis products. 

As part of the answer lies in ability to describe the volatility of biomass tars, the work was primarly undertaken to get some insights into this area. Due to the very complex nature of pyrolysis tars, there are not suitable estimation methods available -experimental data are needed for further development of these techniques. The experimental data are needed to increase our understanding of this phenomenon. In this paper, we present results from tobacco, hemicellulose and lignin tars. 

Biomass tars are known to be very complex mixtures which contain significant amounts of polar compounds that can potentially form hydroxyl bonds. This means that current vapor pressure estimation techniques are not only difficult to apply, but are inaccurate for mixtures with significant oxygen functionalities. Therefore we have chosen to approach this problem from an experimental standpoint. 

The situation regarding the biomass tar vaporization is more complex, and the work above was an attempt to bring some insights into biomass tar volatility. We believe that the question of biomass tar volatility should be given more attention in the discussion of yields of biomass pyrolysis products and even pyrolysis kinetics. 

T.Wang, and J. Chang, Novel catalyst for cracking of biomass tar. Energy Fuels, 19, 22-27., (2005). 

Soltes, E.J. Lin, S-C.K "Hydroprocessin of biomass tars for liquid engine fuels." In Progress in Biomass Conversion, Tillman, D.A. Jahn,E.C , Eds., Academic Press New York, 1984, 5, 1. 

Dayton, D. (2002) A review of the literature on catalytic biomass tar destruction, NREL/TP-510-32815. 

Phuphuakrat, T., Namioka, T. and Yoshikawa, K. (2011) Absorptive removal of biomass tar using water and oily material. Bioresource Technology, 102, 543-549. 

Naphthalene is a key component of tars present in biomass gas. Its absorption efficiency in oily liquids can be ranked as follows diesel fuel > vegetable oil > biodiesel fuel > engine oil (Table 11.3). Diesel fuel however is expensive from an economic viewpoint, vegetable oil becomes the best option for biomass tar removal. 

Devi, L., Ptasinski, K.J. and Janssen, F.J. (2005a) Pretreated olivine as tar removal catalyst for biomass gasifiers investigation using naphthalene as model biomass tar. Fuel Process Technology, 86,707-730. 

Azhar Uddin, M., et al., 2008. Catalytic decomposition of biomass tars with iron oxide catalysts. Fuel 87 (4-5), 451-459. 

Laosiripojana, N., et al., 2014. Conversion of biomass tar containing sulphur to syngas by GdCe02 coated NiFe bimetaUic-based catalysts. Applied Catalysis A General 478, 9-14. 

Okuma et al. (2013) described a simple, rapid and efficient green synthesis of aryl methoxylated benzamides and 2-oxazolines from renewable Eucalyptus biomass-tar derivatives. One pot synthesis was realized using microwave irradiation as an alternative energy source, through a direct condensation reaction of amino alcohol with carboxylic acids as starting materials. 

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