https://courses.washington.edu/cfr523/documents/Alonso2010CatalyticConversion.pdf

Catalytic conversion of biomass to biofuels

As the oil reserves are depleting the need of an alternative fuel source is becoming increasingly apparent. One prospective method for producing fuels in the future is conversion of biomass into bio-oil and then upgrading the bio-oil over a catalyst, this method is the focus of this review article. Bio-oil production can be facilitated through flash pyrolysis, which has been identified as one of the most feasible routes. The bio-oil has a high oxygen content and therefore low stability over time and a low heating value. Upgrading is desirable to remove the oxygen and in this way make it resemble crude oil. Two general routes for bio-oil upgrading have been considered: hydrodeoxygenation (HDO) and zeolite cracking. HDO is a high pressure operation where hydrogen is used to exclude oxygen from the bio-oil, giving a high grade oil product equivalent to crude oil. Catalysts for the reaction are traditional hydrodesulphurization (HDS) catalysts, such as Co–MoS2/Al2O3, or metal catalysts, as for example Pd/C. However, catalyst lifetimes of much more than 200 h have not been achieved with any current catalyst due to carbon deposition. Zeolite cracking is an alternative path, where zeolites, e.g. HZSM-5, are used as catalysts for the deoxygenation reaction. In these systems hydrogen is not a requirement, so operation is performed at atmospheric pressure. However, extensive carbon deposition results in very short catalyst lifetimes. Furthermore a general restriction in the hydrogen content of the bio-oil results in a low H/C ratio of the oil product as no additional hydrogen is supplied. Overall, oil from zeolite cracking is of a low grade, with heating values approximately 25% lower than that of crude oil. Of the two mentioned routes, HDO appears to have the best potential, as zeolite cracking cannot produce fuels of acceptable grade for the current infrastructure. HDO is evaluated as being a path to fuels in a grade and at a price equivalent to present fossil fuels, but several tasks still have to be addressed within this process. Catalyst development, understanding of the carbon forming mechanisms, understanding of the kinetics, elucidation of sulphur as a source of deactivation, evaluation of the requirement for high pressure, and sustainable sources for hydrogen are all areas which have to be elucidated before commercialisation of the process.

A review of catalytic upgrading of bio-oil to engine fuels

As petroleum prices continue to increase, it is likely that biofuels will play an ever-increasing role in our energy future. The processing of biomass-derived feedstocks (including cellulosic, starch- and sugar-derived biomass, and vegetable fats) by catalytic cracking and hydrotreating is a promising alternative for the future to produce biofuels, and the existing infrastructure of petroleum refineries is well-suited for the production of biofuels, allowing us to rapidly transition to a more sustainable economy without large capital investments for new reaction equipment. This Review discusses the chemistry, catalysts, and challenges involved in the production of biofuels.

/pdf/synergies-between-bio-and-oil-refineries-for-the-production-2q18cylabz.pdf

Synergies between Bio‐ and Oil Refineries for the Production of Fuels from Biomass

http://www.chtf.stuba.sk/~szolcsanyi/education/files/Chemia%20heterocyklickych%20zlucenin/Prednaska%207/Doplnkove%20studijne%20materialy/Hydroxymethylfurfural/Conversion%20of%20biomass%20platform%20molecules%20into%20fuel%20additives%20and%20liquid%20hydrocarbon%20fuels.pdf

Conversion of biomass platform molecules into fuel additives and liquid hydrocarbon fuels

https://samson.chem.umass.edu/pub_pdf/pap88.pdf

Investigation into the shape selectivity of zeolite catalysts for biomass conversion

Renewable liquid alkanes can be produced by hydrotreating of vegetable oils and vegetable oil‐heavy vacuum oil (HVO) mixtures at standard hydrotreating conditions (i.e. 300‐450 8C) with conventional hydrotreating catalysts (sulfided NiMo/Al2O3). The reaction pathway involves hydrogenation of the C C bonds of the vegetable oils followed by alkane production by three different pathways: decarbonylation, decarboxylation and hydrodeoxygenation. The straight chain alkanes can undergo isomerization and cracking to produce lighter and isomerized alkanes. The carbon molar yield of straight chain C15‐C18 alkanes was 71% on a carbon basis (the maximum theoretical yield for these products is 95%) for hydrotreating of pure vegetable oil under optimal reaction conditions. The rate of alkane production from pure sunflower oil is greater than the rate of hydrodesulfurization of a HVO with a 1.48 wt% sulfur content (e.g. 100% conversion of sunflower oil at 350 8C compared to 41% conversion of sulfur). The yield of straight chain alkanes increases when sunflower oil is mixed with HVO, illustrating that dilution of HVO can improve the reaction chemistry. For example, with a 5 wt% sunflower oil‐95 wt% HVO feed the maximum theoretical straight chain C15‐C18yield from the sunflower oil was higher (87%) than it was with the pure sunflower oil (75%). Mixing the sunflower oil with HVO does not decrease the rate of desulfurization indicating that sunflower oil does not inhibit the hydrotreating of HVO. # 2007 Elsevier B.V. All rights reserved.

Processing biomass in conventional oil refineries: Production of high quality diesel by hydrotreating vegetable oils in heavy vacuum oil mixtures

Processing biomass-derived oxygenates in the oil refinery: Catalytic cracking (FCC) reaction pathways and role of catalyst

Biomass to chemicals : Catalytic conversion of glycerol/water mixtures into acrolein, reaction network

A process is disclosed for fluid catalytic cracking of oxygenated hydrocarbon compounds such as glycerol and bio-oil. In the process the oxygenated hydrocarbon compounds are contacted with a fluid cracking catalyst material for a period of less than 3 seconds. In a preferred process a crude-oil derived material, such as VGO, is also contacted with the catalyst.

Fluid catalytic cracking of oxygenated compounds

A process is disclosed process for converting a solid or highly viscous carbon-based energy carrier material to liquid and gaseous reaction products, said process comprising the steps of: a) contacting the carbon-based energy carrier material with a particulate catalyst material b) converting the carbon-based energy carrier material at a reaction temperature between 200° C. and 450° C., preferably between 250° C. and 350° C., thereby forming reaction products in the vapor phase. In a preferred embodiment the process comprises the additional step of: c) separating the vapor phase reaction products from the particulate catalyst material within 10 seconds after said reaction products are formed. In a further preferred embodiment step c) is followed by: d) quenching the reaction products to a temperature below 200° C.

Paul O'connor

Papers

Processing biomass in conventional oil refineries: Production of high quality diesel by hydrotreating vegetable oils in heavy vacuum oil mixtures

Processing biomass-derived oxygenates in the oil refinery: Catalytic cracking (FCC) reaction pathways and role of catalyst

Biomass to chemicals : Catalytic conversion of glycerol/water mixtures into acrolein, reaction network

Fluid catalytic cracking of oxygenated compounds

Process for converting carbon-based energy carrier material