Progress of Cryogenics and Isotopes Separation

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The National Conference with international participation on New Cryogenic and Isotope Technologies for Energy and Environment - EnergEn 2018 is organized by the National Research-Development Institute for Cryogenic and Isotopic Technologies - ICSI Rm. Valcea with the scientific participation of the University of Pitesti and the University of Craiova and will be held at Baile Govora, in 2018.

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FUEL GAS FROM BIOMASS WASTES GASIFICATION IN A 

FREE-FALL REACTOR

 

 

E. David*, S. Preda1, C. Ducu2

 

*National  Research and Development Institute for Cryogenics and Isotope Technologies - ICIT Rm. Valcea, Uzinei Street no.4, O.P Râureni, P.O.Box 7, Code 240050, Rm.Vâlcea, Romania, phone: 0250/732744, fax: 0250/732746,

 

 

ABSTRACT

 

Renewable biomass and biomass-derived fuels could be readily gasified to produce a fuel gas rich in hydrogen. Among the biomass energy conversion schemes gasification produces a product gas, which based on its properties could be used either to co-produce value-added byproducts or hydrogen. As a readily renewable fuel, biomass may become a significant component in the global sustainable energy mix as fossil fuel resources begin to deplete. In addition, biomass utilization can expedite mitigation of greenhouse gas emissions and carbon sequestration cycles and promote "green" industries. Hydrogen or fuel gas produced from biomass could be readily used in most of the present natural gas or petroleum derived hydrogen energy conversion devices and also in advanced systems such as fuel cells.

The main objective pursued in this work is to investigate the fuel gas(rich in hydrogen) production  from biomass wastes  by applying the steam gasification technique. Characteristics of steam gasification of two kinds of biomass (rapeseed oil cakes and walnut shells) at different heating rate (in the order of 10-20°C s−1) and different metal oxide catalysts (CaO, MgO  and a mixture 50% CaO and 50% MgO) in a gas–solid concurrent down flow free-fall reactor were investigated. The effects of steam/biomass (S/B) mass ratio (0.0–1.0 g/g) and reactor temperature (750–850°C) on the product yields and the compositions of product gas were determined. The experimental results show that the gas yields and the content of H2 in the gas increase with reactor temperature, while the yields of tar, char and the content of CO and CH4 in the product gas decrease. The presence of steam increases the gas yield and reduces the tar and char yields. It is inferred that an in situ steam reforming reaction of tar takes place even in a short gas residence time in the free-fall reactor. Water-gas shift reaction determines greatly the gas compositions and H2 production at higher temperature. The effects of different  occurring catalysts, CaO, MgO  and a mixture 50% CaO and 50% MgO, were also investigated in the same unit. The mixt catalyst  reveals a comparably good performance in terms of catalytic activity of tar destruction and the consequential increase in the production of gases in thus a short vapor-catalyst contact time.  The results verify that the presence of steam and catalyst favors the tar decomposition and lead to increasing of hydrogen content in  gas yieldThe present gasification process could  be generally used  to produce fuel gas for heat and power.

 

KEYWORDS: fuel gas, biomass wastes, gasification, catalyst.



*Corresponding author: e-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

1Research Station for Fruit Growing Valcea, Calea lui Traian, no. 464, 240263, Rm.Valcea, Romania, This e-mail address is being protected from spambots. You need JavaScript enabled to view it