Laurent Sauvanaud

Bio: Laurent Sauvanaud is an academic researcher from Polytechnic University of Valencia. The author has contributed to research in topics: Fluid catalytic cracking & Cracking. The author has an hindex of 13, co-authored 25 publications receiving 1665 citations.

Different process schemes for converting light straight run and fluid catalytic cracking naphthas in a FCC unit for maximum propylene production

Abstract: Light straight run (LSR) and fluid catalytic cracking (FCCN) naphthas were cracked in a transported bed reactor (MicroDowner) and in a fixed bed reactor (MAT) over a commercial Y zeolite based catalyst, over a commercial ZSM-5 zeolite based additive, and over a mixture of both at selected conditions. Based on the mechanisms through which naphtha hydrocarbons are converted, we evaluated the best alternatives for processing these streams to produce light olefins and/or to reduce olefins content in commercial gasoline. The experimental set-up allowed us to simulate the cracking behaviour of the different naphtha streams in a fluid catalytic cracking (FCC) unit by different processing schemes. Results indicate that LSR only cracks at high severity, yielding large amounts of dry gas. Despite its high olefins content, FCCN practically does not crack when it is fed together with gas oil feed. When cracking FCCN alone at typical gas oil cracking conditions, olefins are transformed preferentially into naphtha-range isoparaffins and aromatics, and when cracking FCCN at high severity, olefins are transformed preferentially into propylene and butylenes. Finally, cracking naphtha in the stripper produces some propylene and increases the aromatics in the remaining gasoline.

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

Abstract: 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.

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

Abstract: 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.

Bright Side of Lignin Depolymerization: Toward New Platform Chemicals

Abstract: Lignin, a major component of lignocellulose, is the largest source of aromatic building blocks on the planet and harbors great potential to serve as starting material for the production of biobased products. Despite the initial challenges associated with the robust and irregular structure of lignin, the valorization of this intriguing aromatic biopolymer has come a long way: recently, many creative strategies emerged that deliver defined products via catalytic or biocatalytic depolymerization in good yields. The purpose of this review is to provide insight into these novel approaches and the potential application of such emerging new structures for the synthesis of biobased polymers or pharmacologically active molecules. Existing strategies for functionalization or defunctionalization of lignin-based compounds are also summarized. Following the whole value chain from raw lignocellulose through depolymerization to application whenever possible, specific lignin-based compounds emerge that could be in the fu...

Supported Iron Nanoparticles as Catalysts for Sustainable Production of Lower Olefins

Abstract: Lower olefins are key building blocks for the manufacture of plastics, cosmetics, and drugs. Traditionally, olefins with two to four carbons are produced by steam cracking of crude oil-derived naphtha, but there is a pressing need for alternative feedstocks and processes in view of supply limitations and of environmental issues. Although the Fischer-Tropsch synthesis has long offered a means to convert coal, biomass, and natural gas into hydrocarbon derivatives through the intermediacy of synthesis gas (a mixture of molecular hydrogen and carbon monoxide), selectivity toward lower olefins tends to be low. We report on the conversion of synthesis gas to C(2) through C(4) olefins with selectivity up to 60 weight percent, using catalysts that constitute iron nanoparticles (promoted by sulfur plus sodium) homogeneously dispersed on weakly interactive α-alumina or carbon nanofiber supports.