Pre-treatment of Malaysian agricultural wastes toward biofuel production

Various renewable energy technologies are under considerable interest due to the projected depletion of our primary sources of energy and global warming associated with their utilizations. One of the alternatives under focus is renewable fuels produced from agricultural wastes. Malaysia, being one of the largest producers of palm oil, generates abundant agricultural wastes such as fibers, shells, fronds, and trunks with the potential to be converted to biofuels. However, prior to conversion of these materials to useful products, pre-treatment of biomass is essential as it influences the energy utilization in the conversion process and feedstock quality. This chapter focuses on pre-treatment technology of palm-based agriculture waste prior to conversion to solid, liquid, and gas fuel. Pre-treatment methods can be classified into physical, thermal, biological, and chemicals or any combination of these methods. Selecting the most suitable pre-treatment method could be very challenging due to complexities of biomass properties. Physical treatment involves grinding and sieving of biomass into various particle sizes whereas thermal treatment consists of pyrolysis and torrefaction processes. Additionally biological and chemical treatment using enzymes and chemicals to derive lignin from biomass are also discussed

Nutzung fester Biomasse in Verbrennungsanlagen : unter besonderer Berücksichtigung des Verhaltens aschebildender Elemente

Band 1 der Schriftenreihe Thermische Biomassenutzung Nutzung fester Biomasse in Verbrennungsanlagen unter besonderer Berücksichtigung des Verhaltens aschebildender Elemente Wesentliche Themen dieses Buches - Die Bedeutung der thermischen Biomassenutzung in Europa im Vergleich zu Österreich - Stoff- und Energieströme von fester Biomasse (Holz, Stroh, Energiepflanzen) - Ist-Analyse, Potentiale und zukünftige Entwicklung in Österreich - Erforderliche Eigenschaften von Biomasse-Brennstoffen und deren Einfluss auf den Verbrennungsprozess - Biomassefeuerungen - Stand der Technik, Möglichkeiten der Optimierung, zukünftige Entwicklungen - Effiziente Leitungssysteme für Fernwärme - Zusammensetzung, Verwendungsmöglichkeiten und Umweltverträglichkeit von Aschen aus Biomassefeuerungen - Fraktionierte Schwermetallabscheidung in Biomassefeuerungen - Das Schwermetallverhalten im System Kondensatschlamm in Rauchgaskondensationsanlagen von Biomassefeuerunge

Decentralized biomass combustion: State of the art and future development

The present amount of biomass used for heat, and to a smaller extent electricity production, is already considerable in several European countries but the potential unused in Europe is even higher. Combustion is the most mature conversion technology utilized for biomass. The systems addressed in this paper are plants with a nominal boiler capacity greater 0.5 MWth. The main combustion technologies used for these systems are underfeed stoker furnaces, moving grate firings (over-bed stoker fired units), bubbling and circulating fluidized beds. The most important biomass fuels are sawdust, wood chips, bark, straw, cereals and grass. The essential differences between them are their different combustion behaviour as well as the different concentrations of combustion relevant elements (such as N, S, Cl, K) they contain, influencing the necessary combustion, process control and hue gas cleaning technology. Important points that are now under development focus on possibilities of NOx reduction by primary measures, as well as on higher plant efficiencies by efficient biomass drying by well adjusting the excess oxygen level in the flue gas to the requirements for a complete combustion and by recovering energy from the flue gas. Furthermore, possibilities of influencing the material fluxes of ash forming elements by primary measures aiming at a sustainable ash utilization and an efficient dust precipitation are in progress. Problems still unsolved that need comprehensive R&D in the near future are reactions taking place in the hot flue gas, causing depositions and corrosion in furnaces and boilers (especially when K-, S- and Cl-rich biomass fuels such as straw, cereals and grass are used). Research on possibilities to prevent or control them (by material selection or appropriate technologies) are of great importance. Furthermore, the ash melting behaviour and its influencing variables have to be treated as urgent. Staged combustion systems, hot fly ash precipitation as well as specially designed boilers could represent solutions for these ash and aerosol related problems. Combined heat and power (CHP) production, already realized in plants with a nominal boiler capacity greater 10 MWth based on steam turbines, is also of growing importance for small-scale applications. Moreover, the lower limit for CHP plants is a nominal boiler capacity of about 5 MWth at the moment, due to the lower electric efficiencies achievable and to the economy of scale. Interesting technologies which are right now under development are sterling engines, a newly developed steam engine (screw-type motor) and organic rankine cycles (ORC) with hydrocarbons as working fluids operating at low temperature and pressure levels tin comparison with conventional steam processes). The basic requirements for the selection of an appropriate CHP process are a high electric efficiency to investment costs ratio and a well tested technology to ensure a continuous and undisturbed operation of the plant

Decentralized biomass combustion: State of the art and future development

The present amount of biomass used for heat, and to a smaller extent electricity production, is already considerable in several European countries but the potential unused in Europe is even higher. Combustion is the most mature conversion technology utilized for biomass. The systems addressed in this paper are plants with a nominal boiler capacity greater 0.5 MWth. The main combustion technologies used for these systems are underfeed stoker furnaces, moving grate firings (over-bed stoker fired units), bubbling and circulating fluidized beds. The most important biomass fuels are sawdust, wood chips, bark, straw, cereals and grass. The essential differences between them are their different combustion behaviour as well as the different concentrations of combustion relevant elements (such as N, S, Cl, K) they contain, influencing the necessary combustion, process control and hue gas cleaning technology. Important points that are now under development focus on possibilities of NOx reduction by primary measures, as well as on higher plant efficiencies by efficient biomass drying by well adjusting the excess oxygen level in the flue gas to the requirements for a complete combustion and by recovering energy from the flue gas. Furthermore, possibilities of influencing the material fluxes of ash forming elements by primary measures aiming at a sustainable ash utilization and an efficient dust precipitation are in progress. Problems still unsolved that need comprehensive R&D in the near future are reactions taking place in the hot flue gas, causing depositions and corrosion in furnaces and boilers (especially when K-, S- and Cl-rich biomass fuels such as straw, cereals and grass are used). Research on possibilities to prevent or control them (by material selection or appropriate technologies) are of great importance. Furthermore, the ash melting behaviour and its influencing variables have to be treated as urgent. Staged combustion systems, hot fly ash precipitation as well as specially designed boilers could represent solutions for these ash and aerosol related problems. Combined heat and power (CHP) production, already realized in plants with a nominal boiler capacity greater 10 MWth based on steam turbines, is also of growing importance for small-scale applications. Moreover, the lower limit for CHP plants is a nominal boiler capacity of about 5 MWth at the moment, due to the lower electric efficiencies achievable and to the economy of scale. Interesting technologies which are right now under development are sterling engines, a newly developed steam engine (screw-type motor) and organic rankine cycles (ORC) with hydrocarbons as working fluids operating at low temperature and pressure levels tin comparison with conventional steam processes). The basic requirements for the selection of an appropriate CHP process are a high electric efficiency to investment costs ratio and a well tested technology to ensure a continuous and undisturbed operation of the plant