Plenary Lecture

Green Diesel from Fischer-Tropsch Synthesis: Challenges and Hurdles

Professor Nicolas Abatzoglou
Professor, Chemical Engineering
Universite de Sherbrooke, Quebec, Canada

Abstract: Kyoto's protocol respect within the context of worldwide preservation and improvement of the quality of life is impossible without bringing forward new technologies. Energy is perhaps the most contributing vector and it is, consequently, intrinsically linked to near all environmental actions. Liquid fuels, as diesel, for transport and heating needs are in the middle of these preoccupations. Fischer-Tropsch Synthesis is an old technology but it can be adapted to be used with syngas, biosyngas or biogas for the production of diesel. Such diesel, when coming from renewable sources like biomass, is called "green diesel".
This plenary lecture presents the actual status of the FTS technology and details the scientific challenges and the technical hurdles associated with the use of renewable feedstock. A recently started Canadian R&D project in this area is also briefly presented.
When biomass is used as a renewable raw material for FTS, depending on the gasification agent (air or oxygen-enriched air) the so produced biosyngas is a mixture of the desired H2 and CO but contains also typically 5 to 10% carbon dioxide, less than 10% hydrocarbons, 25-55% N2 and some acidic (H2S), alkaline (NH3) and metallic (K, Na) contaminants. Although FTS is a mature technology for CO/H2 mixtures coming from coal and natural gas gasification (i.e. Shell and Sasol technologies), little is known on the process efficiency when diluted biosyngas is used. Besides, the available commercial catalysts are very sensitive to the presence of sulphur and halogens and the gas purification down to the ppb level is difficult and expensive. The situation is similar when biogas from fermentation is the FTS feedstock. In this case the average feedstock composition is 50%vol CH4-50%vol CO2 but impurities such as siloxanes, NH3, H2S/mercaptans and light halogenated compounds pose considerable technical hurdles.
Regarding the reactors, fluidized bed and multitubular fixed-bed reactors have been developed and used commercially for FTS. Since 1980 three-phases slurry continuous stirred tank reaction systems have been studied and proposed as an alternative reaction system for FTS; the basic advantages of the slurry reactors are their higher ability in removing efficiently the heat produced during exothermic FTS reaction and the solvent action of the inert heat carrier liquid phase on the waxes deposited on the catalysts surfaces. Their major disadvantage, which is the slower gas/liquid-solid interface diffusion rates compared to the fixed and fluidized bed reactors are the main drawbacks.
In all gas to liquid (GTL) FTS technologies, Cobalt and Iron based catalysts are currently preferred because of their activity, relatively high life expectancy and low cost. Co is 1000 times more costly than Fe but it is more efficient, more selective, no or less deactivated by product water and has a longer life. Regarding the efficiency and robustness of the used catalytic formulations, although there are several literature references on catalyst deactivation studies, there are few data on the reaction mechanisms as function of the surface properties and its chemical composition.
In a new CRD/NSERC Canadian project, new nanosized high external surface catalyst formulations are prepared and tested in lab and bench scale fixed bed and slurry reactors.

Brief Biography of the Speaker:
Dr. Nicolas Abatzoglou is full professor at the department of Chemical Engineering of the Universite de Sherbrooke.
He has earned his Ph.D from the NTU Polytechnic School Metsovion, Athens, Greece in 1989. He is co-founder with Professor Chornet of the company Enerkem Technologies Inc., a spin-off of the Universite de Sherbrooke; Enerkem commercializes technologies in the field of energy from renewable resources. N. Abatzoglou has fulfilled the role of vice-president, technology, from 1999 to 2002 to insure the start-up and the necessary technology transfer during the first three years of the company.
He has a career of many years at both the academic and industrial levels. He is a known researcher in the field defined at the junction of Energy & Environment. He represented Canada at the International Energy Agency (Gasification Task) from 1997-2001 and was the secretary of the Board of Directors and the Executive Committee of the AQME from 1996-2000. A specialist of the chemical reactors and the use of granular materials in reactive and non-reactive environments Prof. N. Abatzoglou has focused his research activities during the six last years to:
a) Establish industry-university R&D collaborative programs with pharmaceutical companies (Wyeth and Merck-Frosst) to study the mechanisms of particulate matter segregation and develop new prediction tools in order to improve the Design and operation protocols of industrial processes within a process Analytical technologies (PAT) context.
b) Design, optimize, model and scale-up of a H2S reactive adsorption process for biogas purification in collaboration with an industrial partner (commercialized by Bio-Terre).
c) Study water and dry reforming of methane, ethanol and biofuels for catalyst-supported SOFC application (recent US Patent application).
d) Develop a technology for Carbon sequestration through CO2 (dry) reforming (recent US patent Application).
e) Establish a knowledge base for the study and improvement of technologies leading to higher alcohols and green diesel synthesis from biosyngas (recently approved CRD/NSERC Project).
f) Study and simulate the behavior of a new granular hot gas mobile bed filter, patented lately (USA & Canada).
His production as a researcher includes more than 50 publications in scientific reviews, international conferences, patents and a book chapter. He currently supervises or co-supervises 10 graduate students, a post-doc fellow and 3 undergraduate students in specialty projects or training sessions. He has won twice the first price in environmental R&D at the Quebec Eastern Townships.
He is a recognized chemical engineering teacher (2002, 2003, 2004, 2005, 2006 Bazinet awards for the best Chem. Eng. Professor) at the department of Chem. Engineering of the Universite de Sherbrooke. He teaches mainly: Design of Chemical Processes, Reactor Engineering and Pharmaceutical Process Engineering.
Prof. Abatzoglou is trilingual (French, English, Greek) with an average but functional knowledge of Spanish. He has a wide cultural education and a natural ability in team motivation and hard work.