Fixed Bed Gasification of Biomass Fuels: Experimental Results

Size: px

Start display at page:

Download "Fixed Bed Gasification of Biomass Fuels: Experimental Results"

Julie Walton
5 years ago
Views:

of Biomass Fuels: Experimental Results N. Koukouzas, C. Flueraru, A. Katsiadakis, E.

1 Early-Stage Energy Technologies for Sustainable Future: Assessment, Development, Application EMINENT 2 Workshop, 5-6 May 2008, Veszprem, Hungary Fixed Bed Gasification of Biomass Fuels: Experimental Results N. Koukouzas, C. Flueraru, A. Katsiadakis, E. Karlopoulos CERTH/ISFTA, Ptolemaida, Greece SC OVM-ICCPET SA, Bucharest, Romania Veszprem, 2008

2 Presentation Overview Introduction Biomass Feedstock Experimental set up Results Conclusions

3 Introduction Motivation: To develop a gasification test-rig for providing more experimental results in the research field of biomass gasification, thus providing another basis for the production of combined heat and power and synthetic biofuels, based on biomass gasification. Why fixed bed gasifier?: Simple and reliable design, capacity for wet biomass gasification, favorable economics on the small scale. Scope of the work: To establish the technical operating characteristics of the installation and to examine the effect of pure oxygen addition in the gasification agent (air enriched in oxygen) on the quality of the produced fuel gas.

Widely found in the mountainous regions of Mediterranean countries.

4 Biomass Feedstock Oak wood pellets: Fast growing deciduous tree widely used in the wood industry for the production of commercial lumber and furniture. Widely found in the mountainous regions of Mediterranean countries. Sorghum pellets: Energy crop that represents one of the most promising solid biofuels in southern Mediterranean regions. Can be used in the production of liquid biofuels.

5 Biomass Feedstock Elemental Composition and Heating Value of the Biomass Feedstock (40 50 diameter mm pellets) Component Units (as received) Oak wood saw dust pellets Sorghum pellets Moisture % w/w Ash % w/w Carbon % w/w Hydrogen % w/w Nitrogen % w/w Oxygen % w/w Sulphur % w/w traces traces High Heating Value kcal/kg kj/kg Apparatus: Perkin-Elmer 2400 Series II CHNS/O analyzer, Parr 6300 bomb calorimeter, ASTM standards.

6 Experimental Set Up The installation includes: Biomass bunker Biomass feeding system Fixed bed gasification reactor Cyclone Ash discharge system Air/O 2 feeding system Steam feeding system Oil burning ignition system Thermocouples (Ti) Differential pressure diaphragms (Dpi) Pressure and flow meters (Pi, Qi) Measurement transducers Tree gas analyzers (Ai) Data acquisition system

7 Experimental Set Up Technical data of the installation Dimensions Thermal capacity Biomass flow H = 130 cm, D = 20 cm 100 kw 25 kg/h Air/O 2 flow 33 Nm 3 /h Steam flow 3 kg/h Gasification temperature C Fuel gas flow Preheated air temperature Fuel gas exit temperature Biomass bunker capacity Electricity demand Ignition system thermal output 1,8-2 Nm 3 /kg biomass 350 o C 500 o C 250 kg 15,5 kw 10 kw

8 Experimental Set Up Experimental Procedure The initial runs were performed with atmospheric air in order to monitor the whole process regarding pressure and temperature profiles along the reactor vessel and pipelines. After the initial ignition of the feedstock the installation was operated for 4- hour intervals for each O 2 N 2 proportion applied (air enriched in O 2 ). The fuel gas was drawn and analyzed every 30 minutes during each trial. The major fuel gas compounds were detected using 3 gas analyzers. The N 2 content of fuel gas was determined by difference, upon determining the concentration of the major fuel gas compounds. The fuel gas heating value was calculated by determining the volumetric composition of the fuel gas compounds. Apparatus:TESTO 350 XL gas analyser (CO, CO 2 and O 2 ), H2Scan HY- ALERTA Model 500 hydrogen analyser, GI GA 2000 biogas analyser (CH 4 )

9 Results % Increase of main fuel gas compounds concentration and LHV when the oxygen content of the gasification agent was almost tripled (from atmospheric air to 60% O 2 content in the mixture) Oak wood pellets Sorghum pellets CO 41.4 % 40.5 % H % 47.4 % CH % 57.1 % CO % 72.6 % LHV 42.7 % 45.9 %

10 Results

11 Conclusions The two different kinds of biomass used in the gasification experiments demonstrated similar elemental composition and heating value, although different in nature. The produced fuel gas from oak wood and sorghum pellets demonstrated similar quality characteristics and both kinds of feedstock did not cause any problem in the feeding and ash discharge system of the installation, therefore; they can be used interchangeably in the same gasification system providing higher operational flexibility and minimizing the effect of seasonal supply variation. Oxygen addition in the gasification agent increases the combustible content of fuel gas but increases the cost of the installation, even in the small-scale. The initial trial tests established the functional characteristics of the gasification test unit, providing the basis for further experimental work.

12 Thank you for your attention! Contact:

PRODUCTION OF SYNGAS BY METHANE AND COAL CO-CONVERSION IN FLUIDIZED BED REACTOR

PRODUCTION OF SYNGAS BY METHANE AND COAL CO-CONVERSION IN FLUIDIZED BED REACTOR Jinhu Wu, Yitain Fang, Yang Wang Institute of Coal Chemistry, Chinese Academy of Sciences P. O. Box 165, Taiyuan, 030001,