Thermal, temperature treatment

The extracts were then atomised and fed into the ROTARC reactor for high temperature treatment. In the first case the atomised extract was mixed with the torch gas (Argon) only. It was a pure pyrolysis, which was effective in the sooting of the reactor walls and it was making the scrubber fluid dirty. The disadvantage of the pure pyrolysis process confirmed our theoretical considerations on thermal destruction of PCB s presented in [9]. To avoid sooting, we fed steam into the reaction chamber in the amount of 10% above the stoichiometry. In this case, which we call the wet pyrolysis , we obtained the destruction efficiency of oil- PCB s at least 99.99%. The offgas analysis on the concentration of oil-PCB s were below the detection limit 0.2 ppm. 

Some of these low-temperature treatments meet the hydro-thermal conditions of classic starch annealing procedures. Annealing is normally conducted below gelatinization temperatures in the presence of excess water (Jacobs and Delcour, 1998 Tester and Debon, 2000 Ozcan and Jackson, 2003). 

The Royal (or Royale) process was originally developed as a method for drying timber, in which the wood is heated in oil under vacuum. The temperatures used are low (60-90 °C) compared to other thermal oil treatments, and although sufficient to lead to some curing of the oil itself, there is no direct modification of the wood as a result of this process. The oil does not penetrate the cell wall. In this process, wet timber is placed in a treatment vessel and oil is then introduced, which is heated to the desired temperature, whilst a vacuum is applied. Water is removed from the timber and the vapour is transported away by the vacuum system. When the wood has reached the desired MC, the oil is removed from the treatment vessel. After this, a vacuum is applied to removed excess oil from the wood. Some dimensional stability is imparted to the timber due to the water repellency of the oil. This treatment is marketed by Osmose as the Royale process. 

Thermal desorption treatment is generally considered to be an alternative to incineration. Thermal desorption operates at much lower temperatures than incineration and keeps the heating systems independent of the wastes, which minimizes off-gas production. The technology can be used as a waste minimization process, isolating and concentrating waste constituents, or as a product recovery process. Thermal desorption can also be used to separate contaminants in mixed waste streams by removing volatile constituents. 

The Remediation Technologies, Inc. (RETEC), Thermatek thermal desorption system is an ex situ high-temperature treatment technology that treats soils, sediments, and sludges contaminated with volatile organic compounds (VOCs) and polychlorinated biphenyls (PCBs). The process uses a conventional Holo-Flite thermal desorption unit with RETEC s proprietary modifications, using an indirect heating source. 

Thermal treatment of polyacrylonitrile at 200-300 °C leads to the appearance of conjugated bonds and electronic semiconductor properties. The main photoconductivity maximum is situated at 420 nm. An increase of the temperature treatment shifts the photosensitivity to the long wavelengths. The estimated mobilities were from 10" 7 to 104m2 V"1 s"1. The main results obtained proved the sufficiency of the conjugated bonds for the appearance of the semiconductive properties. 

For thermal-catalytic treatment, benzoyl peroxide was used as a free radical initiator in concentrations varying between 0.2 and 5 wt %. For methyl methacrylate, at a temperature of 75 °C, polymerization is complete in about 30 minutes with 5 wt % catalyst and in about 70 minutes when 1% catalyst is present. 

In other cases, thermal decomposition is used to prepare the active layer which is then activated either by a high temperature treatment in H2 atmosphere, or by in situ reduction under cathodic load. It has been reported that for molybdate-activated cathodes the latter procedure is less satisfactory than the former [153]. Thus, temperature, procedure of preparation and activation are all crucial parameters which can dramatically influence the final activity. 

The initial surface composition of boiler tubing, prior to its installation will have an important impact on the amount and type of activated corrosion products in an aqueous reactor coolant. Consequently, the type of thermal pre-treatment the tubing undergoes, for example, for mechanical stress release,will affect the surface oxide film, and ultimately, the corrosion behavior. This particular work has been directed toward characterization of surface oxide films which form on Inconel 600 (nominal composition 77% Ni, 16% Cr, 7% Fe, — a tradename of Inco Metals Ltd., Toronto Canada) and Incoloy 800 (nominal composition 31% Ni, 19% Cr, 48% Fe 2% other, — a tradename of Inco Metals Ltd., Toronto, Canada) heated to temperatures of 500-600°C for periods of up to 1 minute in flowing argon. These are conditions equivalent to those experi enced by CANDU(CANadian Deuterium Uranium)ractor boiler hairpins during in situ stress relief. 

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