Infrared thermal destruction

Infrared thermal destruction technology is a thermal processing system that uses electrically powered silicon carbide rods to heat organic wastes to combustible temperatures. Any remaining combustibles are incinerated in an afterburner. One configuration made by ECOVA Corporation consists of four components65 ... 

T0711 Shirco Infrared Systems, Inc., Shirco Infrared Thermal Destruction System... 

T0711 Shirco Infrared Systems, Inc., Shirco Infrared Thermal Destruction System T0717 Smith Technology Corporation, SoilTech Anaerobic Thermal Processor (ATP) T0719 Soil/Sediment Washing—General... 

The IT Corporation thermal destruction unit is a mobile unit that uses infrared incineration technology. The main objective of this process is to transform the feedstock into another form (an ash acceptable for delisting) while assuring safe discharge of exhaust gas products to the environment. The unit is capable of on-site remediation of wastes and soils contaminated with polychlorinated biphenyls (PCBs) and other organics. This technology is based on a conveyor belt furnace process. 

Effect of thermostabilizers on the polymer properties was studied by different physicochemical methods. For example, in the work [260] method of DSS (differential spectroscopy) was used to define the effect of polyester-imide on thermo-physical properties of PETP. By this method it was found out that polyester-imide reduces PETP ability to crystallization. Methods of thermogravimetric analysis (TGA) and infrared spectroscopy in the nitrogen atmosphere were used in the work [261] to define thermal stability of the mixture of PETP and polyamide with the additive - modifier - polyethylene. It has been found that introduction of the additive decreases activation energy which positively tells on the ability of PETP to thermal destruction. 

Performance Assessment of a Portable Infrared Incinerator Thermal Destruction Testing of Dioxin... 

Daily, P. L. 1987. Performance assessment of a portable infrared incinerator thermal destruction testing of dioxin. ACS Symp. Ser. 338 311-18 cited in Chem. Abstr. CA 707(10) 83345t. 

Burns result from exposure to extremes of heat. The lowest temperature at which a burn can occur has been estimated to be 44 °C (111 °F) (Moritz and Henriques 1947). Burns may be of industrial, domestic or environmental origin. Industrial burns are common (Moritz and Henriques 1947 Cason 1981) and may have characteristic occupational patterns (Renz and Sherman 1994 Woods et al. 1996). Apart from direct contact with hot objects or radiation heat [infrared radiation (IR)], accidental exposure to laser energy may cause thermal destruction through absorption by skin chromophores such as melanin and haemoglobin, well known from the therapeutic application of different lasers in dermatology. Classification of burns is based on the depth of the burn as first, second, or third degree (Table 1) (Burke and Bondoc 1993). 

Gas evolution practically ceases 5-15 min after the beginning of the reaction. However, the process of thermal destruction continues, liquid products of comparatively low molecular weight distilling off from the polymer. In the case of unhardened epoxide resins, the liquid destruction products, according to the data of infrared spectroscopy, represent a mixture of low-molecular fractions of the resin, capable of being converted to the infusible and insoluble state under the influence of hardeners. 

Infrared (IR) thermography is one of the most advanced non-destructive (NDT) methods based on the fact that all bodies whose absolute temperature is above zero emit electromagnetic radiation over a wide spectrum of wavelengths depending on the temperature. Recently, several researchers have applied it to micro-scale temperature measurement. Hetsroni et al. (2001a) constructed a thermal micro-system... 

In contrast to polymerisates, polycondensates can not be depolymerized under inert conditions. Decomposition usually leads to the destruction of the chemical structure and the monomers. The thermal decomposition of PET starts at about 300°C in an inert atmosphere [25]. Between 320 and 380°C the main products are acetaldehyde, terephthalic acid, and carbon oxides under liquefaction conditions. The amounts of benzene, benzoic acid, acetophenone, C1-C4 hydrocarbons, and carbon oxides increase with the temperature. This led to the conclusion that a P-CH hydrogen transfer takes place as shown in Eigure 25.8 [26]. Today the P-CH-hydrogen transfer is replaced as a main reaction in PET degradation by several analytic methods to be described in the following sections. The most important are thermogravimetry (TG) and differential scanning calorimetry (DSC) coupled with mass spectroscopy and infrared spectroscopy. 

The Portable Unit has successfully demonstrated its capability for thermal treatment of hazardous wastes at the source of the material. This type of on-site treatment would eliminate the need of transportation of hazardous materials to a distant site of stationary treatment equipment. The Portable Unit also has demonstrated that it can be moved to a site and be ready to treat material very quickly, a capability which will be very important in operation of full scale equipment. The on-site treatment of the Times Beach dioxin contaminated soil resulted in no dioxin detected in any of the incinerator effluent streams. The product of the testing activity was soil with no detectable level of dioxin. Dioxin contaminated soil thermally treated in this manner will yield soil which can be disposed as non-hazardous material. The decontamination was performed without exceeding RCRA requirements for particulate emissions and with dioxin destruction efficiencies surpassing the required percentage. The overall conclusion was that the infrared incinerator can very effectively remove dioxin from contaminated... 

In the characterization of building and construction materials, the most frequently analytical tool performed have been X-ray diffraction but also, thermal analysis and microscopic techniques. Nowadays, infrared and other spectroscopic techniques have become as a useful, non-destructive and easy technique to study the phase composition of initial but also the evolved materials due to their exposure to the climatic conditions. Moreover, by using this tool is possible the detection of crystalline but also the amorphous phases very frequently developed on certain cementitious materials, mainly at early ages. The infrared spectroscopy is used both to gather information about the structure of compoimds and as analytical tool to assess in qualitative and quantitative analysis of mixtures. 

Based on X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), electron spin resonance (ESR), Mbssbauer, and extended X-ray absorption fine structure spectroscopy (EXAFS) , van Veen and collaborators concluded that the thermal treatment at temperatures where catalytic activity is maximum ( 500-600°C) does not lead to complete destruction of the macrocycles, but rather to a ligand modification which preserves the Me-N4 moiety intact. Furthermore, the stability of this catalytic site is improved because the reactive parts of the ligands are bound to the carbon support and thus are no longer susceptible to an oxidative attack. Thermal treatments at higher temperatures (up to 850°C) led to some decomposition of the Me-N4 moiety, and thus to a decrease of the catalytic activity, and to the reduction of some of the ions to their metallic state. 

Chemical analysis of polymers typically deals with monomers or functional groups rather than constituent atoms. Thermal infrared and laser optical Raman spectrometry are the typical tools (36) (see Test Methods Vibrational Spectroscopy), but frequently, specific specimen size or form is required. For physical properties, mechanical and sonic/ultrasonic NDT methods are available (see above). Molecular mass distribution and related properties of polymers, or fiber or particle volume fraction and distribution for PMC, are usually determined destructively (see Test Methods). 

On-site soil treatment is an alternative to excavation, removal, and incineration. The JM Huber Corporation has developed a mobile advanced electric reactor (AER) for decontamination of soil. The pyrolytic process uses thermal radiation (near infrared) at 2473-2773 K and has a PCB destruction efficiency of 99.9999%. Operating under reducing conditions minimizes the possible formation of PCDD and PCDF, and lessens the change of explosion. Costs are about the same as that of rotary kiln incineration. 

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