Steam cracking Furnaces

Dicyclopentadiene (DCPD) is usually recovered as a high value product from the byproduct pyrolysis gasoline stream that is generated in steam cracking furnaces (see Ethylene and Propylene by Steam Cracking ). U.S. 6,258,989 (to Phillips Petroleum) gives a typical pyrolysis gasoline composition and describes a suitable... 

In order to understand the critical role of burners in a steam cracking furnace it is important to keep in mind... 

Ghashghaee, M. and Karimzadeh, R. Dynamic modeling and simulation of steam cracking furnaces. Chemical engineering technology, 30(7) 835-843, 2007. 

Ethylene is produced using ethane in a steam cracking furnace at 800°C. Assume that the reaction takes place in an isothermal conversion reactor where ethane single-pass conversion is 65%. Develop a process flow sheet for the production of ethylene from pure ethane. Use existing software package in your university to perform the material and energy balance of the entire process. 

Limitations in the material of constmction make it difficult to use the high temperature potential of fuel hiUy. This restriction has led to the insertion of gas turbines into power generation steam cycles and even to the use of gas turbines in preheating air for ethylene-cracking furnaces. 

Most gas turbine appHcations in the chemical industry are tied to the steam cycle, but the turbines can be integrated anywhere in the process where there is a large requirement for fired fuel. An example is the use of the heat in the gas turbine exhaust as preheated air for ethylene cracking furnaces as shown in Figure 4 (8). 

PYROCAT A steam cracking process for converting petroleum into light olefins in which a catalyst is deposited on the walls of the heat-exchanger coils in the cracking furnace. The... 

Steam-cracking reactors typically consist of several steel tubes, perhaps 100 m long and 4 in. in diameter in a tube furnace with reactants and steam fed through the several tubes in parallel. The ceramic fined furnace is heated by burning natural gas at the walls to heat the tubes to 900°C by radiation. The reactor is fed by ethane and steam in a ratio of 1 1 to 1 3 at just above atmospheric pressure. The residence time in a typical reactor is approximately 1 sec, and each tube produces approximately 100 tons/day of ethylene. We will return to olefins and steam cracking in Chapter 4. 

Modem steam cracking reactors use 4-in. steel tubes 100 ft long in a tube furnace heated to -850°C. Pressures are approximately 2 atm (sufficiently above 1 atm to force reactants through the reactor), and residence times are typically 1 sec. Water (steam) interacts very httle with the hydrocarbons by homogeneoirs reactions, but more water than alkane is typically added to reduce coke formation. 

Steam cracking (Fig. 2), consists of a furnace in which the cracking takes place is at 815 to 870°C (1500 to 1600°F). As many as 6 to 20 furnaces are in parallel to increase ethylene production. Steam is used as a diluent to inhibit coking in the tubes and to increase the percentage of ethylene formed. The amount of steam changes with the molecular weight of the hydrocarbon feedstock and varies from 0.3 kg steam/kg ethane to 0.9... 

At PPG Industries in Lake Charles, Louisiana, numerous instrument loops provide critical safety, alarm, and shutdown functions. These protective instruments are located on reactors, oil heaters, incinerators, cracking furnaces, compressors, steam-heated vaporizers, kettles, distillation columns, boilers, turbines, and other critical equipment. Process analyzers and flammable vapor detectors also enhance the overall process safety environment. [8]... 

Application Increase the value of steam cracker C4 cuts via low-temperature selective hydrogenation and hydroisomerization catalysis. Several options exist removal of ethyl and vinyl acetylenes to facilitate butadiene extraction processing downstream conversion of 1, 3 butadiene to maximize 1-butene or 2-butene production production of high-purity isobutylene from crude C4 cuts total C4 cut hydrogenation and total hydrogenation of combined C3/C4 and C4C5 cuts for recycle to cracking furnaces or LPG production. 

PYROCAT A steam cracking process for converting petroleum into light olefins in which a catalyst is deposited on the walls of the heat-exchanger coils in the cracking furnace. The catalyst is a proprietary promoter on an alumina-calcia base. Based on the THERMOCAT process, PYROCAT was developed jointly by Veba Oel and Linde from 1996 but has not yet been commercialized. 

Description Feeds are sent to USC cracking furnaces (1). Contaminants removal may be installed upstream. A portion of the cracking heat may be supplied by gas turbine exhaust. Pyrolysis occurs within the temperature-time requirements specific to the feedstock and product requirements. Rapid quenching preserves high-olefin yield and the waste heat generates high-pressure steam. Lower temperature waste heat is recovered in the downstream quench oil and quench water towers (2) and used in the recovery process. Pyrolysis fuel oil and gaso-... 

Technip Ethylene/cracking furnaces Ethane to HVGO Thermal cracking of hydrocarbons in the presence of steam by highly selective GK and SMK cracking furnaces 500 2001... 

The reactors employed display many similarities to those used for steam cracking (Section 2.1.4.1). These reactors are tubular furnaces, which can be divided today into four main types ... 

In industrial practice, however, the most widespread technique consists in passmg a mixture of hydrocarbons and steam through tubes placed in a furnace. The hydrocarbons, which are raised to high temperature, are pyrolysed and the resulting products are separated after a rapid quench. Coke deposits are periodically removed by controlled combustion. This is the technology of steam cracking, which is the main focus of this chapter. 

The complexity of the steam-cracking plant is largely coimected with the type of feedstock treated. Among the various altemati es, how ever, the choice of naphtha oSers the most complete, and hence the most representative case study. This is because this petroleum cut constitutes one of the most wklelv used raw materials for the manufacture of ethylene, and also because its treatment includes that of ethane, by recycling in special furnaces. 

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