Integrated production/use of ultra low-ash coal, premium liquids and clean char. Interim final technical report, 1 September, 1992--31 August, 1993

The ultimate objective of this project is to attain high-value, coal-derived products, especially varieties of char, from Illinois coal. The chars (carbons) made in this study, because of their special properties, could become the marketable materials having the highest value in the product set. Tests this quarter followed up on an unexpected correlation of surface properties of a variety of oxidized carbons with adsorption phenomena. Additional oxidized carbons were made at the ISGS and tests to establish the reproducibility of results were begun. Work will be continued through December on a no-cost extension

The spanning ratio of the delaunay triangulation is greater than =2

Consider the Delaunay triangulation T of a set P of points in the plane. The spanning ratio of T, i.e. the maximum ratio between the length of the shortest path between this pair on the graph of the triangulation and their Euclidean distance. It has long been conjectured that the spanning ratio of T can be at most =2. We show in this note tha

Almost all Delaunay triangulations have stretch factor greater than φ/2

Consider the Delaunay triangulation T of a set P of points in the plane as a Euclidean graph, in which the weight of every edge is its length. It has long been conjectured that the stretch factor in T of any pair p, p′ ∈P, which is the ratio of the length of the shortest path from p to p′ in T over the Euclidean dist

Integrated production/use of ultra low-ash coal, premium liquids and clean char. Final technical report, September 1, 1991--August 31, 1992

The objective of this research is to invert the conventional scale of values for products of coal utilization processes by making coal chars (carbons) that, because of their unique properties, are the most valuable materials in the product slate. A unique type of coal-derived carbon studied in this project is oxidized activated coal char having both adsorptive and catalyst properties. Major program elements were (a) preparation and characterization of materials (b) characterization of carbons and catalyst testing (c) completion of diesel engine testing of low-ash coal and (d) initiation of a two-year adsorption study. Materials prepared were (a) two low-ash coal samples one via ChemCoal processing of IBC-109 and the other by acid dissolution of IBC-109`s mineral matter, (b) coal char (MG char), (c) activated low-ash carbon (AC), (d) oxidized activated carbon (OAC). Amoco continued its support with state-of-the art analytical capabilities and development of catalyst testing procedures. Diesel engine tests were made with low ash coal dispersed in diesel fuel at solid loadings of 20% and 35%. The slurry was successfully burned in cylinder 2 of a two-cylinder diesel engine, after modifications of the engine`s fuel injection system. The higher speed proved to be more favorable but the slurry burned with a slightly improved thermal and combustion efficiency at both speeds with respect to diesel fuel alone. Adsorption studies included preparation of seven base-line carbon samples and their characterization, including their N{sub 2} BET surface areas and apparent densities. Paranitrophenol (PNP) adsorption isotherms were determined for the six controls. Oxidation of carbon with nitric acid decreases activated carbon`s PNP adsorption capacity while air oxidation increases adsorption capacity