Assessment of a simplified equilibrium model for waste gasification

The applicability is studied of a simplified equilibrium model for prediction of the composition and quality of producer gas from gasification of different waste. A simplified equilibrium model of stoichiometric type based on system thermodynamic equilibrium has been developed in the form of a stand-alone computer application. Standard numerical methods have been implemented for solving the mathematical problem formulation. The model`s predicted results have been compared with the published results for biomass and some waste types - municipal solid wastes and refuse derived fuels. Results are included for a bubbling fluidized bed and downdraft fixed bed allothermal gasification, also for catalytic supported gasification. Producer gas predictions by calibrated and non-calibrated versions of the simplified equilibrium model have been studied. The accuracy of these predictions has been evaluated. The results obtained by the simplified equilibrium model have confirmed that such model is a very useful tool for studying the gasification process for municipal solid wastes and refuse derived fuels process parameters for two mostly implemented gasifier types

Assessment of a simplified equilibrium model for waste gasification

The applicability is studied of a simplified equilibrium model for prediction of the composition and quality of producer gas from gasification of different waste. A simplified equilibrium model of stoichiometric type based on system thermodynamic equilibrium has been developed in the form of a stand-alone computer application. Standard numerical methods have been implemented for solving the mathematical problem formulation. The model`s predicted results have been compared with the published results for biomass and some waste types - municipal solid wastes and refuse derived fuels. Results are included for a bubbling fluidized bed and downdraft fixed bed allothermal gasification, also for catalytic supported gasification. Producer gas predictions by calibrated and non-calibrated versions of the simplified equilibrium model have been studied. The accuracy of these predictions has been evaluated. The results obtained by the simplified equilibrium model have confirmed that such model is a very useful tool for studying the gasification process for municipal solid wastes and refuse derived fuels process parameters for two mostly implemented gasifier types

Equilibrium model for gasification of waste

Ena izmed možnosti za energijsko izrabo odpadkov je uporaba v procesih uplinjanja, katerih glavni produkt je sintezni plin. Na osnovi napovedane sestave in kvalitete sinteznega plina je mogoče presojati primernosti odpadkov za uporabo v procesu uplinjanja (zadržana kurilnost, potrebno podporno gorivo), pripravljati na osnovi odpadkov alternativno gorivo za proces, ocenjevati primerne procesne pogoje. Zaradi raznovrstnosti in nestalnosti sestave odpadkov se soočimo s pomanjkanjem ustreznih eksperimentalnih rezultatov uplinjanja. Pokaže se potreba po modelu za napoved sestave sinteznega plina v odvisnosti od sestave odpadkov in procesnih pogojev ter v uporabniku prijazni aplikaciji. V delu je predstavljen razvoj modela za določanje kvaltete iz odpadkov pridobljenega sinteznega plina. Predstavljeni so bili objavljeni modeli za uplinjanje podobnih goriv. Predstavljene so bile zakonske omejitve za uporabo tehnologije uplinjanja na odpadkih. Za napoved kvalitete iz odpadkov pridobljenega sinteznega plina je bil izbran stehiometrijski ravnotežni model uplinjanja. Primerjana sta bila dva modela za opis termodinamičnih lastnosti idealnih plinov. Zaradi boljše stabilnosti je bil izbran model s polinomskim opisom. Iskanje rešitev matematično formuliranega modela je temeljilo na numeričnih metodah. Zaradi boljše konvergentnosti je bila za reševanje sistema nelinearnih enačb izbrana Newton-Raphsonova metoda. Razvita je bila samostojna računalniška aplikacija modela. Rezultati modela so bili primerjani z objavljenimi rezultati na primeru trdnih komunlanih odpadkov in odpadnih blat iz čiščenja komunalnih odpadnih vod. Z modelom napovedani rezultati so se izkazali za dovolj uporabne za namen za katerega je bil model razvit.Gasification of waste with syngas as main product is an alternative of waste to energy conversion. Depending on predicted composition and quality of syngas (heating value of produced syngas, supporting process heat/fuel needed) preparation of waste derived fuel or study of process parameters is possible. Because of composition diversity of waste materials there is not enough of experimental reults for gasification avaiable. An waste composition dependend syngas composition prediction model could be welcomme in user friendly form. An gasification of wastes produced syngas quality prediction model developement has been presented. Published syngas prediction models for gasification of similar fuels have been presented. Limits by legislative regulation for implementation of gasification technology for wastes has been presented. As basis for syngas prediction an stoichiometric thermodynamic equilibrium model has been implemented. An polynomial description of thermodynamic properties of ideal gases has been selected. Numerical methods have been implemeted for solving of mathematical problem formulation. An Newton-Rapson method for solving system of nonlinear equastions has been implemented. An stand alone computer application of the model has been developed. Model predicted results has been compared with published results for municipial solid wastes and sewage sludge. Model predicted results has been presented as enough usable for purposes model has been developed for