Preparation of high metal content nanoporous carbon

Activated carbons with high metal content have been prepared by the pyrolysis of ethylene tar with dissolved metal acetylacetonates (Ti, V, Fe, Co, Ni and Cu) and subsequent activation with KOH of the pitch obtained in pyrolysis. These metal compounds decompose during the pyrolysis of ethylene tar yielding metal nanoparticles formed by metal and/or oxide which are homogeneously distributed in the pitch and remain in the activated carbon, so that the concentration of metal is, in most cases, 4–5 times higher than in the pristine ethylene tar. Since KOH is an effective activating agent, all activated carbons combine a high porosity development with a high metal content. In some of the carbons, such as P2FeA (3.3% Fe, pore volume 1.84 cm3/g, BET surface area 3270 m2/g), there is even an increase in the pore volume when compared to the activated carbon prepared in the same way without metal, in spite of the fact that the metal increases the weight of carbon without contributing to the adsorptive capacity. It seems that iron, on the one hand modifies the pyrolysis to give a pitch with larger mesophase content and on the other hand it locally catalyzes carbon gasification with the CO2 produced along the synthesis of the carbon. In addition to its influence on activation, iron promotes the formation of graphitic carbon fibers.

Very high methane uptake on activated carbons prepared from mesophase pitch: A compromise between microporosity and bulk density

Two petroleum residues were pyrolyzed under two different conditions to obtain pitches with low or high mesophase content. The effect of the KOH: precursor ratio and the activation temperature on the packing density and porous texture of the carbons have been studied and optimized. Activated carbons combining high micropore volume (>1 cm3/g) and high packing density (0.7 g/cm3) have been successfully prepared. Regarding excess methane adsorption capacities, the best results (160 cm3 (STP)/cm3 at 25 °C and 3.5 MPa) were obtained using the pitch with the higher content of the more organized mesophase, activated at relatively low temperature (700 °C), with a medium KOH: precursor ratio (3:1). Some of the activated carbons exhibit enhanced adsorption capacity at high pressure, giving values as high as 175 cm3 (STP)/cm3 at 25 °C and 5 MPa and 200 cm3 (STP)/cm3 at 25 °C and 10 MPa (the same amount as in an empty cylinder but at half of the pressure), indicating a contribution of large micropores and narrow mesopores to adsorption at high pressure. The density of methane in pores between 1 and 2.5 nm at pressure up to 10 MPa was estimated to understand their contribution to the total adsorption capacity.

A forest of the coal age / by B. E. Dahlgren, Acting Curator, Dept. of Botany.

no.14(1933)

William Blair Townsend letter and receipt books, 1743-1805, bulk 1744-1777

The collection consists of two volumes, which date from 1743 to 1805, spanning his whole career as a merchant. Volume one is a letter book containing Townsend's business correspondence from November 23, 1743 to December 12, 1774. Most of the letters were written to American (many in North Carolina) and British (predominately in London) merchants. His earliest letters document his efforts to establish himself as a trader. Over time his letters turn to illustrate the common problems faced by many merchants: damaged goods, overpriced goods, embargos, and high freight costs. Particularly enlightening are his comments on the challenges of doing business throughout the French and Indian War and the years leading up to the American Revolution. He most frequently corresponded with London merchants Champion & Hayley, Lane & Booth, Lane Son & Fraser, Harrison & Ansley, and Leeds merchant Samuel Elam. In addition he frequently corresponded with Eliakim Palmer, colonial agent and merchant in London, as well as Dr. Walley Chauncy of North Carolina. He dealt in a wide variety of goods including molasses, rum, tar, medicines, pitch, saddles, tallow, hides, skins, pickled beef and pork, and wine. The letters also document Townsend's involvement in the slave trade through his occasional purchases of slaves.

Kitāb al-tarīqah al-wāḍiḥah ilá al-bayyinah al-rājiḥah

tartīb Maḥmūd ibn Ḥamzah.

Hādhihi risālat Tāj al-tarājim / min muṣannafāt Qāsim ibn Quṭlūbughā : manuscript, 1635

Title from caption.