French research consortium in biomass-to-liquids project - analyses three gasification technologies

France's chief research agency concerned with agronomy and development in the developing world (CIRAD) announces [*French] that a consortium of research organisations is finalizing a project aimed at developing an industrial process capable of transforming any type of lignocellulosic biomass into liquid biofuel that can be used in today's automotive engines, at a competitive cost. The technical pathway selected is thermochemical conversion by steam and liquefaction via the Fischer-Tropsch process - this 'biomass-to-liquids' (BtL) chain results in so-called 'synthetic biofuels'.

The project, known as 'GASPAR' is funded by the French Agency for Environment and Energy Management (ADEME), and is part of a larger national program which focuses on producing ultra-clean next generation biofuels for aviation, road and marine transport from France's abundant biomass resources. But results are transferable to biomass rich developing countries in the tropics and subtropics (see below), hence the participation of scientists from the Biomass Unit of the CIRAD (Centre de coopération internationale en recherche agronomique pour le développement). Other GASPAR researchers include scientists from Commissariat à l'Energie Atomique (CEA, nuclear energy agency), the Institut Français du Pétrole (IFP) and the Groupe de recherche sur l'Environnement et la Chimie Atmosphérique (GRECA) at the Université Joseph Fourier in Grenoble.

The consortium currently estimates that BtL fuels can replace 15% of France's liquid fossil fuel consumption 'easily' and at 'highly competitive' prices (with oil at $96 per barrel), even though a 45% substitution over the longer term would be feasible.

Via a range of pilot programs, GASPAR will analyse different gasification methods and technologies with the goal to obtain the most optimal types of syngas useable for further transformation into liquid fuels.

Biomass gasification is beginning to take a considerable share in co-generation plants that produce both heat and power, with several large facilities currently operational in France. For the production of synthetic biofuels, these gasification processes are currently unsatisfactory. The quality of the gas must be improved so that a hydrogen and carbon monoxide rich syngas is produced in a cleaner and more straightforward manner. The synthesis steps (Fischer-Tropsch) have progressed further and need less research.

In search for a better syngas, GASPAR looks at four different technologies: (1) gasification in fixed bed reactors, (2) gasification in entrained bed reactors, (3) in fluidized bed reactors and (4) at the treatment of tars at a temperature of 1000 degrees celsius:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: gasification :: synthesis :: Fischer-Tropsch :: synthetic biofuels :: biomass-to-liquids :: developing countries :: France ::

Phases 1 to 3 are aimed at comparing the three gasification processes and to determine their optimal operational conditions for the production of a syngas, without analysing the resulting tars. The pilot trials will be conducted at the relatively large scale reactors at the CIRAD and the CEA.

The fourth phase consists of analysing the cracking of tars which result from the biomass gasification. In this step, experiments in a gas treatment reactor will be conducted to lower the tar contents of syngases which must allow for a more efficient production of biofuels.

The research consortium is optimistic about the potential of the technology for France, estimating that synthetic biofuels can replace around 25 million tons of oil equivalent per year, with a first objective of replacing 8 million tons (which is 15% of France's liquid fossil fuel consumption) deemed 'very feasible'. GASPAR will result in fuels that can be utilized immediately in existing infrastructures and engines without any adaptation - synfuels can replace 100% of gasoline/diesel in a fuel tank (unlike first generation biofuels like ethanol and biodiesel). The BtL process thus promises to substitute a very significant part of France's transportation fuel needs.

Key CIRAD researchers in the project are Laurent Van de Steene, Eric Martin, Ghislaine Volle, François Broust, Ferdinand Fassinou, Jean-Philippe Tagutchou.

Developing countries
Interest in this technology is growing, because it could allow developing countries with a large biomass potential to export Fischer-Tropsch fuels easily. A recent article in Energy & Fuels, to cite just one example, documents the potential and hurdles of this vision. In "The impact of biomass pretreatment on the feasibility of overseas biomass conversion to Fischer-Tropsch products" researchers compare different biomass densification options (pelletisation, pyrolysis into bio-oil, or local BtL production).

The study concludes that large-scale, central, overseas BtL synthesis plants would be the most attractive route for the export of biomass. However, local logistic aspects require the construction of several small-scale synthesis plants, causing significant economical disadvantages due to economy of scale. The FT product can be produced from overseas biomass for 15 euro/GJ (or 55 euro ct/L of diesel equivalent). At the crude oil prices of late 2005 (around $60/bbl), large-scale BtL was considered as an economically feasible technology. WIth oil prices currently at US$96 per barrel, the option has become quite attractive.

Picture: one of the biomass gasification reactors utilized for GASPAR. Credit: CIRAD.

References:
CIRAD: "Gazéification de la biomasse pour la synthèse et la production de carburants renouvelables" - project overview.

Zwart Robin, Boerrigter Harold, Van Der Drift Abraham, "The impact of biomass pretreatment on the feasibility of overseas biomass conversion to Fischer-Tropsch products", Energy & Fuels , 2006, vol. 20, no5, pp. 2192-2197