Biomass gasification
Thermochemical processes
Different thermochemical processes can be applied to biomass in order to get useful energy. These conversion routes depend on the amount of oxygen needed by the process: pyrolysis (no oxidizing conditions), gasification (substoichiometric oxidizing conditions) and combustion (oxidizing conditions).
The ISE research group is currently focused on the gasification process, a promising technology to reduce the greenhouse emissions and the dependence on fossil fuels, in addition to social benefits. During gasification, the biomass is mainly transformed in a mixture of gases, and small amounts of liquid and solid by a partial oxidation at high temperature. The combustible gas is mainly formed by H2, CO, CH4, CO2, N2 and light hydrocarbons. This product gas can finally used in gas engines, boilers or as raw material to get different chemicals and biofuels. The better temperature control, good gas-solid mixing and heat and mass transfer rates or the wide variety of feedstock quality make fluidized beds a good option for these types of processes among other technologies. However, the production of a raw gas with small quantities of tars and the reduction of the agglomeration problems is a key issue in the commercialization of this technology.
Experimental facilities
In our laboratory, a lab-scale bubbling fluidized bed of 52.8 mm of inner diameter is employed for biomass gasification. The facility has different sections for gas cleaning and tar sampling.
Biomass
The biomass used by the ISE research group for gasification is an energy crop, Cynara cardunculus L., native from Mediterranean regions. The hot and dry weather from these areas are suitable cardoon growth. The cultivation of C. cardunculus L. reduces the agro-chemicals, improves soil characteristics, needs low amounts of water and is cheaper than other energy crops.
The use of this plant for energy purposes is motivated by the CARDENER-CM program (S2009/ENE1660) for the C. cardunculus L. implementation and use as an energy crop in the Madrid region due to its high potential and valorisation for solid and liquid biofuels. Different research groups works together for this purpose.
Research lines
- Fluidized bed dynamics: agglomeration
The high potassium and sodium content in biomass and especially in C. cardunculus L. is a major issue in the biomass gasification. These elements react with the silica from the bed material to form compounds with a low melting point. Bed particles start to agglomerate and form big clinkers that lead to the defluidization of the reactor. Different catalysts and additives are used to reduce this problem.
In the ISE research group, sepiolite has been used as bed material during cardoon gasification in a lab-scale fluidized bed reactor in order to test its performance at different fluidization velocities in terms of defluidization time. Results have been compared with silica sand, the most used bed material employed for these purposes. The study reveals that sepiolite improves considerably the defluidization time with respect to silica sand due to the lower density of sepiolite and the better mixing obtained in this case.
- Fluidized bed applications: gasification
The ISE research group investigates the use of different biomass feedstocks (C. cardunculus L. and olive tree pruning) and different bed materials (silica sand, sepiolite, magnesite, olivine…) for the gasification process in an experimental lab-scale facility located at the Carlos III University of Madrid and in a pilot-scale plant in collaboration with The Carbolea research group at the University of Limerick. Different operational conditions are tested in order to analyze the gas composition, gasification performance, tar generation and composition, and ash characterization.
PhD thesis related
A PhD thesis has been specifically developed in the ISE research group with the aim to study the C. cardunculus L. gasification in fluidized bed.
D. Serrano García 2016. Experimental study of C. Cardunculus L. gasification in bubbling fluidised bed. Carlos III University of Madrid.
Related publications
Journal publications
SERRANO, D., KWAPINSKA, M., SÁNCHEZ-DELGADO, S., LEAHY, J.J.
Fly ash characteristics and recovery from Cynara cardunculus L. gasification.
Fuel (under review)
SERRANO, D., SÁNCHEZ-DELGADO, S., HORVAT, A.
Effect of sepiolite bed material on gas composition and tar mitigation during C. cardunculus L. gasification.
Chemical Engineering Journal (under review)
SERRANO, D., KWAPINSKA, M., HORVAT, A., SÁNCHEZ-DELGADO, S., LEAHY, J.J.
Cynara cardunculus L. gasification in a bubbling fluidized bed: The effect of magnesite and olivine on product gas, tar and gasification performance.
Fuel, 173 (2016) 247-259
GÓMEZ-HERNÁNDEZ, J., SERRANO, D., SORIA-VERDUGO, A., SÁNCHEZ-DELGADO, S.
Agglomeration detection by pressure fluctuation analysis during Cynara cardunculus L. gasification in a fluidized bed
Chemical Engineering Journal, 284 (2016) 640-649
SERRANO, D., SÁNCHEZ-DELGADO, S., SOBRINO, C., MARUGÁN-CRUZ, C.
Defluidization and agglomeration of a fluidized bed reactor during Cynara cardunculus L. gasification using sepiolite as a bed material
Fuel Processing Technology 131 338-347. 2015
Conference proceedings
Sepiolite performance as bed material towards gas and tar compositions during C. cardunculus L. gasification.
25th European Biomass Conference and Exhibition (25th EUBCE). Stockholm (Sweeden). June 12-15, 2017
SERRANO, D., SÁNCHEZ-DELGADO, S., HORVAT, A.
Ash properties from Cynara cardunculus L. gasification.
24th European Biomass Conference and Exhibition (24th EUBCE). Amsterdam (The Netherlands). June 6-9, 2016
SERRANO, D., KWAPINSKA, M., SÁNCHEZ-DELGADO, S., LEAHY, J.J.
Magnesite and olivine performance during Cynara cardunculus L. gasification: gas and tar analysis.
24th European Biomass Conference and Exhibition (24th EUBCE). Amsterdam (The Netherlands). June 6-9, 2016
SERRANO, D., KWAPINSKA, M., HORVAT, A., SÁNCHEZ-DELGADO, S., LEAHY, J.J.
Dynamics and agglomeration of a fluidized bed reactor under Cynara cardunculus L. gasification with a new catalyst (sepiolite)
4th International Symposium on Gasification and it’s Applications (iSGA4), 2014.
SERRANO, D., SÁNCHEZ-DELGADO, S., SOBRINO, C., MARUGÁN-CRUZ, C.