Hydrogen donating hydroaromatics have been applied as inhibitors against deterioration of hydrocarbon products. Multi-component type additives were produced from coal tar fractions and heavy petroleum fractions, and their additive effects were investigated towards petroleum products, rubbers and plastics. Obvious inhibiting effects were observed against deterioration by heat, oxygen, radiation and UV-ray. Evident radical scavenging abilities were observed for the hydroaromatics including the multi-component additives by the experiments using N, N-diphenyl-N'-picrylhydrazyl at 50°C in air. From these results, the inhibiting abilities of the additives can be attributed to their radical scavenging ones. In conventional autoxidation studies, hydroaromatics have been considered to be easily oxidized, and they have never been applied as inhibitors. However, prominent inhibiting abilities of hydroaromatics were found even in the presence of oxygen, depending on oxygen partial pressure. In addition, it was also confirmed that hydroaromatics were durable to heat and radiation, and they are expected to be used in wide variety of fields where the conventional radical scavengers are not used, for instance, prevention of coke and sludge formation.
Six Kinds of coke oven waste-waters produced in Japanese ironmaking works were analysed before and after the deammonia and active sludge treatment by means of UV, gel-and high performance liquid chromatography to characterize the organic substances and their changes in the treatment. The substances was found with chromatography to consist of five components, of which quantities varied with TOC, reflecting the coking conditions and coal pretreatment as well as the treatment. Among the components, the lightest two components were completely digested by the active sludge and the heaviest two were partly removed by the deammonia step where they may be precipitated on the coke filter probably through the oxidative condensation. The oxidative decomposition of the component appears to help its digestion in the successive active sludge treatment. In contrast, a significant part of the intermediate component stayed undigested. The waste water in the formed coking carried the largest amount of whole organic substances and the undigestiable intermediate component. The dry coalcharge tends to produce more organic substances and the intermediate component, although the sludge treatment suffered small influence. Detail correlation between the organic component distribution in the waste water and its coking variables can be obtainable by the present approach, providing a basis for the operation of active sludge adjustable to the variable quality of the waste water.
A method for reduction of carbon dioxide emission due to the use of hydrocarbons as fuels consisting in a pre-deposition of part of the carbon content in the fuel into soot was tested for industrial application. As a basic research, the influences of the amount of air added to the fuel and the temperature to which the mixture is heated up on the soot pre-deposition when methane is the fuel were investigated. Below 1500K, addition of 30% of air led to the largest soot pre-deposition; the addition of this relative large amount of air promotes soot formation because the active species needed for the first step of that process, the conversion of methane into methyl radicals, are produced through reactions activated by oxygen; further addition of air promotes the oxidation of carbon into carbon monoxide and carbon dioxide, lowering the soot deposition. At temperatures higher than 1500K, thermal decomposition of methane causes the reactions to proceed very fast, and the addition of air reduces the soot deposition. Concretely, conversion of 30% of the carbon content in the fuel into soot can be easily controled at temperatures below 1500K with addition of convenient amounts of air; and the conversion of 50% of the carbon into soot can be obtained at reaction temperatures above 1550K.
The cyclodextrin (CD) was applied as an exfoliating agent to extract bitumen from tar sand. The effectiveness of CD as an exfoliating agent was demonstrated by an increase in recovered amounts of bitumen (primary recovery 16.4wt%, total recovery 5.1wt%) compared with that using conventional sodium hydroxide as an exfoliating agent. The optimun experimental conditions to recover bitumen have been investigated. A sedimentation velocity of the clay in the waste fluid was higher with CD than with sodium hydroxide. Effectiveness of CD after repeated used has also been established.