Effect of the stabilisation time of pitch fibres on the molecular sieve properties of carbon fibres

Abstract

The stabilisation of pitch fibres (PFs) is the most important step for their subsequent use in the preparation of carbon fibres (CFs) and their resulting characteristics. The present work studies the influence that the stabilisation time has on the porosity of the CFs, and on the subsequent properties as carbon molecular sieve (CMS). The increase of the stabilisation time carried out at 573 K, from 2 to 8 h favours their CMS properties producing a decrease in the microposity accessible to N 2 , which gets completely blocked after 6 and 8 h, while the narrow microporosity (V-DR CO 2 ) remains accessible. Adsorption kinetic studies with CH 4 and CO 2 were performed to assess the possibility of using these CFs as CMS by comparing them with Takeda 3A CMS. The results suggest that there is an optimal stabilisation time which allows the preparation of CFs from an abundant raw precursor with properties similar to Takeda 3A CMS.

Effect of the Pre-oxidation of Coals in the Preparation of Chemically Activated Carbon Pellets

“…The preparation of CMS pellets is a complex process that usually involves several steps. − In general, these steps include (i) pretreatment [i.e., demineralization (by acid washing), carbonization, etc. ], (ii) activation (with the purpose of obtaining a high pore volume), (iii) molding (using a binder), (iv) carbonization (to confer mechanical integrity to the pellets), and (v) a final control of the pore size by means of chemical vapor deposition (CVD) of carbon or controlled gasification (dependent upon the effect of carbonization of the binder produces to the porosity of the AC).…”

Production of carbon molecular sieves from palm shell through carbon deposition from methane

“…Coal, pitch and polymers such as polyvinylidene chloride, polyacrylonitrile and phenol formaldehyde have been used as carbonaceous raw material for CMS production [2,3]. Coal, pitch and polymers such as polyvinylidene chloride, polyacrylonitrile and phenol formaldehyde have been used as carbonaceous raw material for CMS production [2,3].…”