A series of carbon molecular sieves (CMSs) has been prepared, either as powders or monoliths, from petroleum pitch using potassium hydroxide as the activating agent. The CMS monoliths are prepared without the use of a binder based on the self-sintering ability of the mesophase pitch. Characterization results show that these CMSs combine a large apparent surface area (up to ca. 3100 m(2) g(-1)) together with a well-developed narrow microporosity (V(n) up to ca. 1.4 cm(3) g(-1)). The materials exhibit high adsorption capacities for CO(2) at 1 bar and 273 K (up to ca. 380 mg CO(2) g sorbent(-1)). To our knowledge, this is the best result obtained for CO(2) adsorption using carbon-based materials. Furthermore, although the CO(2) adsorption capacity for activated carbons has usually been considered lower than that of zeolites, the reported values exceed the total amount adsorbed on traditional 13X and 5A zeolites (ca. 230 mg and 180 mg CO(2) g sorbent(-1), respectively), under identical experimental conditions. Additionally, the narrow pore openings found in the CMS samples (ca. 0.4 nm) allows for the selective adsorption of CO(2) from molecules of similar dimensions (e.g., CH(4) and N(2)).

Activated carbon binderless monoliths with high consistency and large porosity, synthesised from a mesophase pitch, are studied as electrodes for supercapacitors. The electrochemical cells prepared provided high capacitance values in sulphuric acid media (334 F g-1) and very low electrical resistivity, which results in a very efficient energy storage device (12 Wh Kg-1 maximum energy density and 12,000 W Kg-1 maximum power density). Long-term cycling experiments showed excellent stability with a reduction of the initial capacitance values of 19 % after performing 23,000 galvanostatic cycles at ∼300 mA g-1 .

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Activated carbons (AC) prepared from mesophase-based materials usually possess high surface area and micropore volume, making them adequate for adsorption, catalysis and gas or energy storage. Chemical activation with KOH or NaOH is one of the most common methods to produce these materials [1,2], usually as a fine powder [3,4], thus making its conforming to pellets or monoliths an important area of research. The manufacture of monoliths normally involves the use of a binder, which implies a reduction of porosity due to partial blocking, the extent of which depends on the kind and proportion of binder used [3,4]. As mesophase-based materials have self-sintering ability, these materials are good candidates to produce monoliths of activated carbon of high surface area without using a binder, but no success has been reported up to now [5]. This paper reports the use of mesophase pitch (MP) and mesophase self-sintering carbon (MSC) for the synthesis of activated carbon monoliths (ACM) with high consistency and large porosity, without the need for a binder.For the preparation of the MP a petroleum residue (ethylene-tar) [6] was pyrolyzed in a laboratory pilot plant at 440ºC and a pressure of 1.0 MPa, using a heating rate of 10ºC/min and a soak time from 2 to 4 hours. MSC was the solid obtained after extraction of the MP with THF at its boiling point.The synthesis of the ACMs involved several steps: i) mixture of the MP or MSC with KOH in a ball mill during 30 minutes; ii) uniaxial conforming at room temperature to produce monoliths (25×25×5mm), conforming pressure varying from 100 to 400 MPa (the mixture of the carbon * Corresponding Author. Fax: 34 965 90 3454. E-mail adress: manolo.m@ua.es (M.Martínez Escandell) precursors and the activating agent can be consolidated because of its high plasticity); iii) heat treatment at 800ºC under nitrogen atmosphere, soak time of 2h and heating rate of 2ºC/min; and iv) washing of monoliths with a solution of 1M HCl, followed by extensive washing with distilled water until pH=7. The final step consists on drying of the monolith at 100-110ºC for 24 hour. Bulk densities of the monoliths were determined by measuring the dimensions of the samples and their dry weight. Table 1 summarises the characterization of some of the precursors studied in order to achieve ACMs with good mechanical resistance coupled with high surface area. The low ash content of the MP and MPC has to be pointed out, ash being mainly composed by Si, Al, Fe and Ca. For the first screening, the activation was carried out using a KOH/carbon ratio of 2 for all samples.The first activation tests were carried out using MSCs. This kind of material has the highest mesophase and carbon content, coupled with low volatile matter, but it also exhibits the highest softening point and viscosity upon melting of all tested materials. All the monoliths produced with this precursor had low consistency and could not be manipulated without breaking down to a powder, thus indicating that sintering of the grains had not been suffic...

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