(79b) Challenges in Guard Bed Design for a Biofuel Hydrotreater

Bio-oils derived from fragmentation of biomass building blocks (cellulose, hemicellulose, and lignin) are unstable. Hydrotreatment of the oxygenated bio-oils to drop-in hydrocarbon fuels is necessary. Traditional hydrotreating catalysts, such as sulfided CoMo or NiMo supported on alumina have been reported in hydrodeoxygenation of biofuels and the process conditions are similar to those used in the refining of petroleum cuts. Besides the high oxygen content in bio-oils, bio-oils also differ from petroleum feedstock in sulfur, phosphorus and metal content. To prevent the hydrotreating catalyst fast deactivation and prolong the catalyst lifetime, a guard bed is necessary, and the guard bed design is very important. This presentation will address some challenging issues in the guard bed design for bio-oils hydrotreating.