Utilisation of biomass gasification by-products for onsite energy production.
Small scale biomass gasification is a sector with growth and increasing applications owing to the environmental goals of the European Union and the incentivised policies of most European countries. This study addresses two aspects, which are at the centre of attention concerning the operation and development of small scale gasifiers; reuse of waste and increase of energy efficiency. Several authors have denoted that the low electrical efficiency of these systems is the main barrier for further commercial development. In addition, gasification has several by-products that have no further use and are discarded as waste. In the framework of this manuscript, a secondary reactor is introduced and modelled. The main operating principle is the utilisation of char and flue gases for further energy production. These by-products are reformed into secondary producer gas by means of a secondary reactor. In addition, a set of heat exchangers capture the waste heat and optimise the process. This case study is modelled in a MATLAB-Cantera environment. The model is non-stoichiometric and applies the Gibbs minimisation principle. The simulations show that some of the thermal energy is depleted during the process owing to the preheating of flue gases. Nonetheless, the addition of a secondary reactor results in an increase of the electrical power production efficiency and the combined heat and power (CHP) efficiency.
Faculty of Science and Technology, Free University of Bolzano, Bolzano, Italy stergios.vakalis@outlook.com.
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S
Vakalis
School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
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Sotiropoulos
School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
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K
Moustakas
School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
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D
Malamis
Faculty of Science and Technology, Free University of Bolzano, Bolzano, Italy.
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Baratieri
D056804:Biofuels; D018533:Biomass; D002245:Carbon Dioxide / Q000032:analysis; D002248:Carbon Monoxide / Q000032:analysis; D002606:Charcoal; D004867:Equipment Design; D005740:Gases / Q000737:chemistry; D006859:Hydrogen / Q000032:analysis; D008697:Methane / Q000032:analysis; D008962:Models, Theoretical; D013696:Temperature; D018505:Waste Management / Q000295:instrumentation* / Q000379:methods*; D014866:Waste Products
D056804:Biofuels; D005740:Gases; D014866:Waste Products; C540010:biochar; D002245:Carbon Dioxide; D002606:Charcoal; D002248:Carbon Monoxide; D006859:Hydrogen; D008697:Methane
Char; biomass; co-generation; gasification; resource efficiency; small scale