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Advanced carbons and refractories by optimisation of petroleum synthetic precursors-clean scfe processing


Distillation, thermal processing, and super-critical fluid extraction (SCFE) processing routes have been set up and processing variables have been established in order to control the chemical and physical properties of the PSP product. These properties have been extensively characterised and correlated with processing parameters. Production batches of PSP materials have been evaluated in each of the three key application areas. In each application, this has enabled the appropriate criteria pertaining to pitch production and properties to be identified. Once these criteria were identified, progress in the development of the PSP processing route was led by the users due to the different specialised properties required of these materials.

In summary, the main achievements to date are:
- The design, modification and commissioning of pilot-scale plant and laboratory-scale apparatus for batch processing of PSP materials by distillation and SCFE and of laboratory-scale apparatus for batch processing of PSP materials by thermal treatment;
- The adaptation of pilot-scale plant for continuous processing of PSP materials by distillation and SCFE and of laboratory-scale plant for continuous processing of PSP materials by SCFE;
- The successful laboratory-scale evaluation of new PSP materials as binder material for high volume carbon-bonded steelmaking refractories. Development of a batch industrial process for the production of binder pitch from petroleum refining residues. Production of a petroleum pitch at industrial scale suitable for carbon bonded refractories;
- Development of a batch laboratory thermal treatment process for the production of pitch from petroleum refining residues suitable for carbon fibre elaboration;
- Development of a mathematical model to predict the properties of PSP - Softening Point, Coke Yield, and Toluene Insoluble - in relation to the operation conditions - P, T, and reaction time - used in the pilot plant;
- Completion of patents and publications survey and analysis concerning SCFE technology for pitch treatment;
- Development of a patent presented in Spain on 01.03.00 with the title: "Procedimiento de obtención de breas de petróleo no contaminantes para su uso en la fabricación de electrodos y otros compuestos grafíticos";
- The production and detailed characterisation of systematic series of processed PSP materials in order to identify working ranges of processing variables and their effect on chemical and physical properties;
- Several successful production trials to manufacture PSP-based bricks for use in steel ladles with identical / improved properties cf. existing coal tar pitch technology;
- Environmental assessment of PAH content of pitch-bonded MgO-C-bricks has been completed and shows that use of PSP can reduce the B(a)P-content by a factor of at least 10;
- The development of a new CC liquid infiltration processing route through which to evaluate new PSP materials;
- A hybrid composite produced by CVI, pitch impregnation and further CVI shows promising results for friction and wear;
- The establishment of unambiguous characterisation methods to assess the suitability of pitches for ACF preparation; the defining of processing parameters for monofilament spinning, stabilisation and carbonisation of carbon fibres prepared from PSP obtained by thermal treatment; and the preparation of activated carbon fibres;
- Examination of ACF prepared from PSP by gas adsorption techniques to characterise porous texture, methane adsorption capacity and investigation of performance of ACF in a catalytic application;
- A technical assessment of the potential of pitch-based activated fibres and an appraisal of the applicability and marketability of ACF has been completed;
- Significant steps made towards the aim of correlating physical properties, particularly rheological behaviour, with chemical composition;
- Microthermal analysis has been established as a useful method for characterisation of carbon composite structure and local thermal behaviour;
- Successful exploitation of the new PSP materials will safeguard employment hitherto based on coal tar pitch.
The highly competitive European carbon / graphite and refractory industries req uire continuous technological advances in order to maintain and improve profita bility and share in the world market: advanced carbonaceous binders are require d for refractory products; new, rapid, low cost processing routes are required for carbon-carbon composites for aircraft brake linings; whilst the production of activated pitch-based fibres is an emerging technology which is likely to ha ve impact in gas separation and catalytic processes. It is essential that these new technologies incorporate non-polluting production methods in order to ensu re the efficient use of resources and improvements to the workplace environment . An enabling technology which is key to the achievement of these goals is the development of new high quality and 'clean' synthetic organic carbon-precursors Council Directives on the protection of workers from the risks related to expo sure to carcinogens at work require the employer to both reduce levels of the e xposure of carcinogens to the workforce and, where possible, to replace toxic p roducts with less toxic ones; coal tar pitch is specifically targeted. Petroleu m based synthetic carbon-precursors promise to be the only real alternative to coal tar pitch, particularly given their notably low Poly-Aromatic Hydrocarbon (PAH) content.The main aim of this programme is therefore to develop and introd uce to the market a new generation of low toxicity, high quality precursors-to- carbon which are based on the upgrading of petroleum refining residues and ta d efine the processing routes to achieve significant property advantages in the r ange of enhanced high value materials created from them. To this end, two route s will be followed; these are thermal processing and the new application of cle an Super-Critical Fluid Extraction (SCFE) processing technology. This second ro ute requires the new design of pilot plant for extracting pitches at a relative ly high temperature. By control of the processing conditions and the blending o f fraction cuts, the properties of the precursor materials will be tailored to meet the various requirements for the fabrication of new and improved carbon-bo nded steelmaking refractories, carbon-carbon composite aircraft brakes and acti vated carbon fibres. A consortium covering all relevant aspects of the programm e has been formed with the following specific objectives: The development of continuous and batch production processes, using methods of distillation, ther mal treatment and SCFE, for the upgrading of petroleum refining residues to for m petroleum synthetic precursor (PSP) materials. The design and evaluation o f PSP materials for use as a low-emission quality binder / impregnant for carbo n bonded refractories. The design and evaluation of PSP as a matrix precurso r material in the development of alternative processing routes for the fabricat ion of CC aircraft brakes. The development of activated carbon fibres suitab le for speciality filtration products and other novel processes from PSP materi als.

Funding Scheme

CSC - Cost-sharing contracts


Repsol Petróleo SA
.,Valle De Escombreras
30350 Cartagena

Participants (7)

Dunlop Ltd
United Kingdom
Holbrook Lane
CV6 4AA Coventry
United Kingdom
Woodhouse Lane 175
LS2 3AR Leeds
Freudenberg Nonwovens LP
United Kingdom
Ellistone Lane
HX4 8NJ Halifax
Separex Chimie Fine SA
Rue Jacques Monod
54250 Champigneulles
S/n,universidad De Alicante, Facultad De Ciencias
03080 Alicante
United Kingdom
Woodhouse Lane
LS2 9JT Leeds
Veitsch-Radex AG
8700 Leoben