CFD modeling for direct liquefaction of biomass in hydrothermal media
The first generation biofuels which is coming from food crops for instance grain and sugar beet are inadequate to achieve desirable oil products because of the scarcity to food supply, therefore the importance of second generation biofuels has increased. Another advantage of second generation biofuel is that the feedstock (non-food-biomass) could be farmed for energy purposes, which enables better production per unit area of the land; and we could utilize the land efficiency. The feedstock of 2nd generation biofuels which are ligno-cellulose in nature includes cereal straw, bagasse, forest residue and vegetable grasses.
This project has theoretically assessed the use of hydrothermal media for direct liquefaction of biomass in a continuous flow tubular reactor using ANSYS Fluent and other relevant software?s. Micro-reactor is considered for better heat and mass transfer, also micro-reactor provides admissible control over unwanted side reactions. The exact reaction path of biomass dissociation is unknown therefore lumped kinetic is considered for model species like cellulose, hemi-cellulose and lignin.
Computationally the velocity, temperature distribution, reaction kinetic, feed percentage and particle modeling are examined. It is being vindicated by results that the effect of fluid velocity over reactor domain is tremendous, and has high influence on temperature profile inside the reactor. The geometry of different dimensions is also investigated, which play integral role in the system. Furthermore, the effect of large or small eddies is examined by weightless particle and discussed in the result section. The optimum biomass particle size is proposed, which is suitable for our system.
For future work, the predicted operating conditions for micro flow tubular reactor by simulation must be validated by experimental work. This computation work will facilitate and provide essential information to start experimental work.
Place, publisher, year, edition, pages
Institutt for energi- og prosessteknikk , 2013. , 78 p.
IdentifiersURN: urn:nbn:no:ntnu:diva-22569Local ID: ntnudaim:10205OAI: oai:DiVA.org:ntnu-22569DiVA: diva2:649814
Tran, Khanh-Quang, FørsteamanuensisTurunen, Ilkka