Hydrocarbons partial combustion

Additives function by reacting with hydrocarbon partial oxjdation products by stoppihg the oxidation chain reaction that would otherwise driye the combustion. 

The electric discharge processes can supply the necessary energy very rapidly and convert more of the hydrocarbons to acetylene than in regenerative or partial combustion processes. The electric arc provides energy at a very high flux density so that the reaction time can be kept to a minimum (see... 

Flame or Partial Combustion Processes. In the combustion or flame processes, the necessary energy is imparted to the feedstock by the partial combustion of the hydrocarbon feed (one-stage process), or by the combustion of residual gas, or any other suitable fuel, and subsequent injection of the cracking stock into the hot combustion gases (two-stage process). A detailed discussion of the kinetics for the pyrolysis of methane for the production of acetylene by partial oxidation, and some conclusions as to reaction mechanism have been given (12). 

In summary, the bad features of partial combustion processes are the cost of oxygen and the dilution of the cracked gases with combustion products. Flame stability is always a potential problem. These features are more than offset by the inherent simplicity of the operation, which is the reason that partial combustion is the predominant process for manufacturing acetylene from hydrocarbons. 

The carbon black (soot) produced in the partial combustion and electrical discharge processes is of rather small particle si2e and contains substantial amounts of higher (mostly aromatic) hydrocarbons which may render it hydrophobic, sticky, and difficult to remove by filtration. Electrostatic units, combined with water scmbbers, moving coke beds, and bag filters, are used for the removal of soot. The recovery is illustrated by the BASF separation and purification system (23). The bulk of the carbon in the reactor effluent is removed by a water scmbber (quencher). Residual carbon clean-up is by electrostatic filtering in the case of methane feedstock, and by coke particles if the feed is naphtha. Carbon in the quench water is concentrated by flotation, then burned. 

The oil-fiimace process, based on the partial combustion of Hquid aromatic residual hydrocarbons, was first introduced in the United States at the end of World War II. It rapidly displaced the then dominant channel (impingement) and gas-furnace processes because it gave improved yields and better product quahties. It was also independent of the geographical source of raw materials, a limitation on the channel process and other processes dependent on natural gas, making possible the worldwide location of manufacturing closer to the tire customers. Environmentally it favored elimination of particulate air pollution and was more versatile than all other competing processes. 

The recycling of PVC by hydrothermal techniques is described, in which PVC is thermally converted in a steam atmosphere into hydrogen chloride, hydrogen, carbon dioxide, carbon monoxide and some gaseous and liquid hydrocarbons. Whilst gasification with only steam is an endothermic reaction, partial combustion of PVC by the addition of small amounts of air, enables autothermic operation of the process to take place. This work deals... 

Carbon blacks are manufactured from hydrocarbon feedstocks by partial combustion or thermal decomposition in the gas phase at high temperatures. World production is today dominated by a continuous furnace black process, which involves the treatment of viscous residual oil hydrocarbons that contain a high proportion of aromatics with a restricted amount of air at temperatures of 1400-1600 °C. 

The low temperature of operation of the DMFC, i.e. 60- 120°C, ensures that no emission of NO or partially combusted hydrocarbons takes place. 

SMR (reaction 2.4) and shift (reaction 2.6) reactions. Reactions between N2 and hydrocarbon radicals leading to the formation of such by-products as NH3 and HCN can also take place in the thermal zone. By proper adjustment of 02/CH4 and H20/CH4 ratios, the partial combustion in the thermal zone provides the heat for the subsequent endothermic steam reforming reaction taking place in the catalytic zone [40]. Thus, simplistically, ATR of methane at temperature T can be represented as follows ... 

PCC [Partial combustion cracking] Not to be confused with precipitated calcium carbonate. A process for cracking crude petroleum or heavy oil to a mixture of olefins and aromatic hydrocarbons. The heat carrier is steam, produced by the partial combustion of the feed. Developed by Dow Chemical Company. It was piloted in 1979 and a larger plant was built in Freeport, TX, in 1984. 

In the temperature regime below 600°C, a more linear response is obtained. This is demonstrated in the response to hydrogen at 300°C compared with that at T> 600°C in Figure 2.5(b). In the lower temperature regime it is postulated that only partial combustion of the gas molecules occurs on the metal surface. This also means that at these lower temperatures, the various hydrocarbons are dissociated to different degrees and give substantially different responses at critical temperatures. 

The composition of the synthesis gas, particularly the concentrations of hydrogen, carbon monoxide, and carbon dioxide, affects the atmosphere throughout the reactor directly, and also indirectly by its effect on the composition of the recycle gas. Synthesis gas, prepared by partial combustion of methane or some less hydrogen-rich carbonaceous material, lacks sufficient hydrogen for the conversion of all the carbon monoxide to hydrocarbons, and in this sense the synthesis gas is deficient in hydrogen. Stoichiometrically methane has sufficient hydrogen to convert all its carbon to olefins by the two-step process ... 

Carbon black [1333-86-4 and soot are formed either by pyrolysis or by partial combustion of vapors containing carbon. Soot as an unwanted byproduct of combustion (e.g., in chimneys or diesel engines) is a poorly defined material. Besides carbon black particles, it often contains significant amounts of ash and high amounts of polycyclic aromatic hydrocarbons (PAH) [4.1]. Residual hydrocarbons, which can be determined by extraction with solvents (e.g., toluene), can account for 30 wt%. 

Production of acetylene from natural gas and other petroleum hydrocarbons has grown sharply and it is predicted to exceed that from carbide within about 10 years (26). One of two important processes, the Sachsse process (3, 6, 8, 10, 36, 63) involves the formation of acetylene in flames in the partial combustion or oxidation of methane. 

The term carbon black includes furnace black, colloidal black, thermal black, channel black, and acetylene black. Carbon black is mostly derived from petroleum and involves partial combustion or a combination of combustion and thermal cracking of hydrocarbons, and to a lesser extent natural gas, at 1200 tol400°C. 

Partial oxidation processes rank next to steam-hydrocarbon processes in the amount of hydrogen made. They can use natural gas, refinery gas, or other hydrocarbon gas mixtures as feedstocks, but their chief advantage is that they can also accept liquid hydrocarbon feedstocks such as gas oil, diesel oil, and even heavy fuel oil. All processes employ noncatalytic partial combustion of the hydrocarbon feed with oxygen in the presence of steam in a combustion chamber at flame temperatures between 1300 and 1500°C. For example, with methane as the principal component of the feedstock ... 

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