Pyrolysis Furnace Research Articles

Analysis of Ethylene Unit Pyrolysis Furnace Effluent Gases by Gas Chromatography

Analysis of Ethylene Unit Pyrolysis Furnace Effluent Gases by Gas Chromatography

Experimental method for evaluating the decomposition of fluorocarbon plastics by heat.

Abstract In studying the toxicity of pyrolysis products of fluorocarbons, a time-of-flight mass spectrometer was selected for identification of decomposition fragments. Quantitative measurements were made by gas chromatography except for COF, which was collected in 0.5 N NaOH followed by determination of the fluoride. Monel metal tubes were used in the pyrolysis furnaces and temperatures were measured by thermocouples shielded with stainless steel. A cubical chamber (aluminum) of 1245-liter capacity and equipped with an airlock was used for exposure of animals to the pyrolysis products.

Additional reactor connected to the pyrolysis furnace

1. An additional industrial pilot reactor has been constructed on the basis of an experimental study. The reactor has operated successfully for more than a year. The duration of a furnace run is not restricted by the state of the reactor. 2. Depending on the operation regime, the furnace output is increased by 12 to 20% through supply of starting material to the reactor, and the total concentration of ethylene and propylene rises to 16.8%. 3. The concentration of acetylene hydrocarbons in the pyrolyzed gas passed through the reactor drops by a factor 4–5. 4. Combination of the furnace with an additional reactor should be recommended for industrial practice.

Proper criterion to use for optimum operation of a pyrolysis furnace

Proper criterion to use for optimum operation of a pyrolysis furnace

Automatic control of pyrolysis furnaces

1. Application of the system of multicircuit temperature control warrants a high accuracy of the temperature regime of the pyrolysis process. 2. When the optimization system was worked out, a property of the object to be controlled-the resistance of the pyrolysis coil-was used to analyze the feed quality and the amount of coke deposited. 3. The optimization system can be used with a large variety of feed qualities, since it contains a replaceable element-a curved program transmitter specially manufactured for each feed type. 4. The optimization system introduced is built from control and regulation devices manufactured in series, which permits us to recommend the system also for automation of other pyrolysis furnaces in plants in our country.

High-temperature method for coke burn-out in tubular pyrolysis furnaces

High-temperature method for coke burn-out in tubular pyrolysis furnaces

Steels for pipes of furnaces for pyrolysis of gaseous hydrocarbons

1. The mechanical characteristics of Kh20N14S2 steel and the resistance to prolonged exposure at 700, 800, 850, 900, and 950\dgC are similar to those of Kh23N18 steel. The decrease in the concentration of carbon and the increase in the silicon concentration in Kh20N14S2 steel decreases the strength. 2. During prolonged heating at 700\2-950\dgC Kh20N14S2 steel undergoes structural transformations with formation of the \gs-phase, which decreases the impact strength and the ductility and somewhat increases the hardness. The impact strength of the aged steel is considerably higher at the aging temperature than at 20°C. 3. Kh20N14S2 steel with 2.2\2-3% Si has good resistance to carburization. The resistance to carburization increases with increasing concentrations of silicon in the steel. The resistance of Kh20N14S2 steel to scale formation is considerably higher than that of Kh23N18 steel. 4. Kh20N14S2 steel containing up to 0.12% C and 2.2\2-3% Si can be used for pipes in pyrolysis furnaces in place of Kh23N18 steel.

A mechanism of interaction of triethyl aluminum with tetrabutyl titanium and the structure of resulting complexes

Trimethyl aluminum (TMA) is an important precursor used for metal-organic chemical vapor deposition (MOCVD) of most Al-containing structures, in particular of nitride structures. The reaction mechanism of TMA with ammonia is neither clear nor certain due to its complexity. Pyrolysis of trimethyl metal is the start of series of reactions, thus significantly affecting the growth. Experimental study of TMA pyrolysis, however, has not yet been conducted in detail. In this paper, a reflectron time-of-flight mass spectrometer is adopted to measure the TMA decomposition from room temperature to 800 °C in a special pyrolysis furnace, activated by soft X-ray from the synchrotron radiation. The results show that generation of methyl, ethane and monomethyl aluminum (MMA) indicates the start of the pyrolysis process. In the low temperature range from 25 °C to 700 °C, the main product is dimethyl aluminum (DMA) from decomposition of TMA. For temperatures larger than 700 °C, the main products are MMA, DMA, methyl and ethane.