Petroleum, refining

The petroleum refining industry is undergoing intense scrutiny in the United States of America from regulatory agencies and environmental groups. The total cost of corrosion control in refineries is estimated at 3,692 billion. The costs associated with corrosion control in refineries include both processing and water handling. 

Corrosion-related issues regarding processing are handling organic acids [also referred to as naphthenic acid corrosion (NAC)] and sulfur species at high temperatures as well as water containing corrosives such as H2S, CO2, chlorides, and high levels of dissolved solids. 

The first step in refining petroleum is distillation the object here is to separate the petroleum into fractions based on the volatility of its components. Complete separation into fractions containing individual compounds is economically impractical and virtually impossible technically. More than 500 different compounds are contained in the petroleum distillates boiling below 200°C, and many have almost the same boiling points. Thus the fractions taken contain mixtures of alkanes of similar boiling points (see the table below). Mixtures of alkanes, fortunately, are perfectly suitable for uses as fuels, solvents, and lubricants, the primary uses of petroleum. 

A petroleum refinery. The tall towers are fractioning columns used to separate components of crude oil according to their boiling points. 

The highly branched compound 2,2,4-trimethylpentane (called isooctane in the petroleum industry) burns very smoothly (without knocking) in internal combustion engines and is used as one of the standards by which the octane rating of gasolines is established. 

According to this scale, 2,2,4-trimethylpentane has an octane rating of 100. Heptane, CH3(CH2)5CH3, a compound that produces much knocking when it is burned in an internal combustion engine, is given an octane rating of 0. Mixtures of 2,2,4-trimethylpentane and heptane are used as 

Nonvolatile liquids C20 and higher Refined mineral oil, lubricating oil, and grease 

before we proceed to consider flow reactors, we will completely change topics and discuss two examples the refining of petroleum and the production of polyester. Our first purpose is to describe these reactions and the reactors that are used in order to acquaint students with these very important processes. 

The following sections will be purely descriptive with no equations except for the chemical reactions, and even the chemical reactions listed will be highly simplified. As we proceed through this course, the principles by which these reactors are operated will become clearer, such that by the final chapter we will have considered most of these reactors and the principles of their operation in more detail. 

The processing of cmde oil into gasoline, other fuels, and chemicals has always been the bread-and-butter employer of chemical engineers. The discipline of chemical engineering had its origins in producing fuels and chemicals, and these tasks remain the dominant topic of the chemical engineer. 

The widespread use of coal started the Industrial Revolution, and in the nineteenth century wood and then coal were the major energy and chemical sources, while whale oil was our energy source for lighting as lamps replaced candles. Then in the late nineteenth and early twentieth century petroleum replaced aU of these. Now natural gas is becoming very important, and coal may someday see a revival. 

Renewable energy sources such as trees and plants have always had a niche market in energy and chemicals. In fact, all energy except nuclear energy is ultimately derived from solar energy in some form or other. 

Petroleum is rarely used in its raw form but must instead be processed into its various products, generally as a means of forming products with a hydrogen content different from that of the original feedstock. Thus the chemistry of the refining process is concerned primarily with the production not only of better products but also of salable materials. 

Petroleum contains many thousands of different compounds that vary in molecular weight from 16 (methane, CHi,) to more than 2000 (Speight, 1999, 2001 and references cited therein). This broad range in molecular weights results in boiling points that range from -160°C (-288°F) to temperatures in excess of 1100°C (2000°F) (Speight, 2001). 

In briet a refinery must be recognized as a complex network of integrated unit processes for the purpose of producing a variety of products from petroleum (Fig. 2.2) (Speight, 1999 Speight and Ozum, 2002). Each refinery has its own range of preferred petroleum feedstock from which a desired distribution of products is obtained. Nevertheless, refinery processes can be divided into three major types  

Separation division of petroleum into various streams (or fractions) depending on the nature of the crude material. 

Conversion production of salable materials from petroleum, usually by skeletal alteration, or even by alteration of the chemical type, of the petroleum constituents. 

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American Petroleum Institute, "Technical Data Book—Petroleum Refining," 3rd ed., API, Division of Refining, Washington, 1976. 

In the petroleum refining and natural gas treatment industries, mixtures of hydrocarbons are more often separated into their components or into narrower mixtures by chemical engineering operations that make use of phase equilibria between liquid and gas phases such as those mentioned below ... 

Biedermann, J.M., J.-P. Peries and J. Bousquet (1987), SOLVAHL an attractive way to provide conversion units with high quality feedstocks . National Petroleum Refiners Association (NPRA) paper No. AM-87-41, Annual meeting, San Antonio, TX. 

Edmister, W.C. and K.K. Okamoto (1959), Applied hydrocarbon thermodynamics. Part 12 equilibrium flash vaporization correlations for petroleum fractions . Petroleum Refiner, Vol. 38, No. 8, p. 117. 

The series Petroleum Reflning" will comprise five volumes covering the following aspects of the petroleum refining industry ... 

Cracking (Section 2 16) A key step in petroleum refining in which high molecular weight hydrocarbons are converted to lower molecular weight ones by thermal or catalytic carbon-carbon bond cleavage... 

ALKANOLAMNES - ALKANOLAMINES FROM OLEFIN OXIDES AND ALETONIA] (Vol 2) -in petroleum refining [PETROLEUM - REFINERY PROCESSES, SURVEY] (Voll8)... 

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