Block refinery

AH commercial processes for the manufacture of caprolactam ate based on either toluene or benzene, each of which occurs in refinery BTX-extract streams (see BTX processing). Alkylation of benzene with propylene yields cumene (qv), which is a source of phenol and acetone ca 10% of U.S. phenol is converted to caprolactam. Purified benzene can be hydrogenated over platinum catalyst to cyclohexane nearly aH of the latter is used in the manufacture of nylon-6 and nylon-6,6 chemical intermediates. A block diagram of the five main process routes to caprolactam from basic taw materials, eg, hydrogen (which is usuaHy prepared from natural gas) and sulfur, is given in Eigute 2. 

Ethane is used by petrochemical plants to make ethylene, a primary building block for many plastic products. Butane and condensate are used by refineries producing automotive fuel. For production of NGL s (natural gas liquids), die plant s recovery rate of 98% of ediane and 100% of all odier liquid products contained in natural gas, is among die best in die world. 

The basis for design overpressure described in this section is related to the ASME Boiler and Pressure Vessel Codes and ANSI B31.3, Code for Petroleum Refinery Piping. Compliance with these codes is a requirement, or is recognized as the equivalent of a requirement in many locations. Where more stringent codes apply, the local requirements must be met. Therefore, local codes must be checked to determine their requirements. For example, some countries do not permit the use of block valves underneath pressure relief valves, unless dual valves with interlocks are installed. Also, in some cases, 20% accumulation under fire exposure conditions is not permitted, and accumulation allowed may be lower than the ASME Codes. In the United States, the ASME Code is mandatory, since it is a requirement under the Occupational Safety and Health... 

The ASME code requires every pressure vessel that can be blocked in to have a relief valve to alleviate pressure build up due to thermal expan sion of trapped gases or liquids. In addition, the American Petroleum Institute Recommended Practice (API RP) 14C, Analysis, Design, Installation and Testing of Basic Surface Safety Systems on Offshore Production Platforms, recommends that relief valves be installed at vari ous locations in the production system and API RP 520, Design and Installation of Pressure Relieving Systems in Refineries, recommends various conditions for sizing relief valves. 

Figure 14.6 Schematic diagram of a five-column cliromatographic refinery analyser system SL, sample loop V1, two-way valve to block the sample line V2 and V5, ten-port valves V3 and V4, six-way valves Cl C5, packed columns R, restriction TCD, thermal conductivity detector-.

Then, establish the same concept for all other unit or block processing systems. This is often helpful for large projects, such as refinery or grass roots chemical processes. 

The catalytic conversion of heavy hydrocarbons, such as heavy oil or sulphurous organic residues, from the oil industry via steam reforming is not feasible because solid carbon starts to be deposited at temperatures above 800 °C, which renders the catalyst inactive in a short period of time and, furthermore, blocks the gas flow in the reactor. Heavy hydrocarbons are, therefore, converted to hydrogen using partial oxidation (POX). Note that in refineries the term gasification is more commonly used partial oxidation is the scientific terminology. 

Figure 19 Bay area refinery effluent treating block flow diagram. This refinery has a complicated wastewater treatment scheme because of the toxicity characteristics rule to separate streams with higher benzene concentrations for treatment in aboveground biotreater. (From Ref. 72.)...

Figure 1.1 Block flow diagram of a modern refinery.

Olefins are hydrocarbon compounds with at least two carbon atoms and having a double bond. Their unstable nature and tendency to polymerize makes them one of the very important building blocks for the chemical and petrochemical industry (Gary and Handwerk, 1994). Although olefins are produced by fluid catalytic cracking in refineries, the main production source is through steam cracking of liquefied petroleum gas (LPG), naphtha or gas oils. 

Figure 2.2. Block flowsheet of the revamp of a 30,000 Bbl/day refinery with supplementary light stocks (The C. IV. Nofsinger Co )... 

Figure 13.21. Petroleum refinery block diagram. Several of the processes identified by blocks include distillation or are followed by distillation (Gary and Handwerk, Petroleum Refining, Dekker, New York, 1975).

Ethylene is a key building block for the petrochemical industry. It is usually made by thermally cracking gases—ethane, propane, butane, or a mixture of these—as they exist in refinery off-gases. When gas feedstocks are scarce or expensive, naphthas and even whole... 

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