FERMENTATION USING nPARAFFINS Single Cell Protein SCP
The term single cell protein is used to represent a group of microbial cells such as algae and yeast that have high protein content. The production of these cells is not generally considered a synthetic process but microbial farming via fermentation in which n-paraffins serve as the substrate. Substantial research efforts were invested in the past two decades to grow algae, fungi, and yeast on different substrates such as n-paraffins, methane, methanol, and even carbon dioxide. The product SCP...
Sulfur
Sulfur is a reactive, nonmetallic element naturally found in nature in a free or combined state. Large deposits of elemental sulfur are found in various parts of the world, with some of the largest being along the coastal plains of Louisiana. In its combined form, sulfur is naturally present in sulfide ores of metals such as iron, zinc, copper, and lead. It is also a constituent of natural gas and refinery gas streams in the form of hydrogen sulfide. Different processes have been developed for...
The Furnace Black Process
This is a more advanced partial combustion process. The feed is first preheated and then combusted in the reactor with a limited amount of air. The hot gases containing carbon particles from the reactor are quenched with a water spray and then further cooled by heat exchange with the air used for the partial combustion. The type of black produced depends on the feed type and the furnace temperature. The average particle diameter of the blacks from the oil furnace process ranges between 200-500...
SULFONATION OF nPARAFFINS Secondary Alkane Sulfonates SAS
Linear secondary alkane sulfonates are produced by the reaction between sulfur dioxide and n-paraffins in the range of C15-C17. R-H 2SO2 2O2 H2O r RSO3H H2SO4 The reaction is catalyzed by ultraviolet light with a wave-length between 3,300-3,600A.21 The sulfonates are nearly 100 biodegradable, soft and stable in hard water, and have good washing properties. Sodium alkanesulfonates for detergent manufacture can also be produced from the free-radical addition of sodium bisulfite and alpha olefins
Solvent Extraction
Liquid solvents are used to extract either desirable or undesirable compounds from a liquid mixture. Solvent extraction processes use a liquid solvent that has a high solvolytic power for certain compounds in the feed mixture. For example, ethylene glycol has a greater affinity for aromatic hydrocarbons and extracts them preferentially from a reformate mixture a liquid paraffinic and aromatic product from catalytic reforming . The raffinate, which is mainly paraffins, is freed from traces of...
Cracking Liquid Feeds
Liquid feedstocks for olefin production are light naphtha, full range naphtha, reformer raffinate, atmospheric gas oil, vacuum gas oil, residues, and crude oils. The ratio of olefins produced from steam cracking of these feeds depends mainly on the feed type and, to a lesser extent, on the operation variables. For example, steam cracking light naphtha produces about twice the amount of ethylene obtained from steam cracking vacuum gas oil under nearly similar conditions. Liquid feeds are usually...
Hydrocracking Process
Hydrocracking is essentially catalytic cracking in the presence of hydrogen. It is one of the most versatile petroleum refining schemes adapted to process low value stocks. Generally, the feedstocks are not suitable for catalytic cracking because of their high metal, sulfur, nitrogen, and asphaltene contents. The process can also use feeds with high aromatic content. Products from hydrocracking processes lack olefinic hydrocarbons. The product slate ranges from light hydrocarbon gases to...
HYDRATION OF ETHYLENE Ethanol Production
Ethyl alcohol CH3CH2OH production is considered by many to be the world's oldest profession. Fermenting carbohydrates is still the Figure 7-6. The PPG Industries Inc. Chloroethylene process for producing perchloro- and trichloroethylene 15 1 reactor, 2 graphite exchanger, 3 refrigerated condenser, 4 scrubber, 5 phase separation of perchlor from trichlor, 6, 7 azeotropic distillation, 8 distillation train, 9-11 crude trichlor separation purification, 10-16 crude perchlor separation purification....
Aromatics Production
Liquefied petroleum gas LPG , a mixture of propane and butanes, is catalytically reacted to produce an aromatic-rich product. The first step is Figure 6-5. The DuPont butane to maleic anhydride process.' Figure 6-5. The DuPont butane to maleic anhydride process.' assumed to be the dehydrogenation of propane and butane to the corresponding olefins followed by oligomerization to C6, C7, and C8 olefins. These compounds then dehydrocyclize to BTX aromatics. The following reaction sequence...
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Figure 2-3. Flow diagram of the Mobil xylene isomerization process.1 Figure 2-3. Flow diagram of the Mobil xylene isomerization process.1 by incorporating an isomerization unit to isomerize o- and m-xylenes to p-xylene. An overall yield of 90 p-xylene could be achieved. Figure 2-3 is a flow diagram of the Mobil isomerization process. In this process, partial conversion of ethylbenzene to benzene also occurs. The catalyst used is shape selective and contains ZSM-5 zeolite.12 Benzene C6H6 is the...
Nonhydrocarbon Intermediates
From natural gas, crude oils, and other fossil materials such as coal, few intermediates are produced that are not hydrocarbon compounds. The important intermediates discussed here are hydrogen, sulfur, carbon black, and synthesis gas. Synthesis gas consists of a nonhydrocarbon mixture H2,CO obtainable from more than one source. It is included in this chapter and is further noted in Chapter 5 in relation to methane as a major feedstock for this mixture. This chapter discusses the use of...
Liquid Petroleum Fractions And Residues
Liquid Petroleum fractions are light naphtha, heavy naphtha, kerosine and gas oil. The bottom product from distillation units is the residue. These mixtures are intermediates through which other reactive intermediates are obtained. Heavy naphtha is a source of aromatics via catalytic reforming and of olefins from steam cracking units. Gas oils and residues are sources of olefins through cracking and pyrolysis processes. The composition and the properties of these mixtures are reviewed in the...
Aniline C6H5NH2
Aniline aminobenzene is an oily liquid that turns brown when exposed to air and light. The compound is an important dye precursor. The main process for producing aniline is the hydrogenation of nitrobenzene The hydrogenation reaction occurs at approximately 270 C and slightly above atmospheric over a Cu Silica catalyst. About a 95 yield is obtained. An alternative way to produce aniline is through ammonolysis of either chlorobenzene or phenol. The reaction of chlorobenzene with aqueous ammonia...
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The hydrolysis reaction occurs at a temperature range of 50-100 C. Contact time is approximately 30 minutes. Di- and triethylene glycols are coproducts with the monoglycol. Increasing the water ethylene oxide ratio and decreasing the contact time decreases the formation of higher glycols. A water ethylene oxide ratio of 10 is normally used to get approximately 90 yield of the monoglycol. However, the di- and the triglycols are not an economic burden, because of their commercial uses. A new...
Chemicals From Butadiene
Butadiene is a diolefinic hydrocarbon with high potential in the chemical industry. In 1955, it was noticed that the assured future of butadiene CH2 CH-CH CH2 lies with synthetic rubber . . . the potential of butadiene is in its chemical versatility . . . its low cost, ready availability, and great activity tempt researchers.20 Butadiene is a colorless gas, insoluble in water but soluble in alcohol. It can be liquefied easily under pressure. This reactive compound polymerizes readily in the...
Ammonia Production Haber Process
The production of ammonia is of historical interest because it represents the first important application of thermodynamics to an industrial process. Considering the synthesis reaction of ammonia from its elements, the calculated reaction heat AH and free energy change AG at room temperature are approximately -46 and -16.5 KJ mol, respectively. Although the calculated equilibrium constant Kc 3.6 x 108 at room temperature is substantially high, no reaction occurs under these conditions, and the...
Chemicals From Xylenes
Xylenes dimethylbenzenes are an aromatic mixture composed of three isomers o-, m-, and p-xylene . They are normally obtained from catalytic reforming and cracking units with other C6, C7, and C8 aromat-ics. Separating the aromatic mixture from the reformate is done by extraction-distillation and isomerization processes Chapter 2 . para-Xylene is the most important of the three isomers for producing terephthalic acid to manufacture polyesters. m-Xylene is the least used of the three isomers, but...
OXIDATION OF PARAFFINS Fatty Acids and Fatty Alcohols
The catalytic oxidation of long-chain paraffins Ci8-C30 over manganese salts produces a mixture of fatty acids with different chain lengths. Temperature and pressure ranges of 105-120 C and 15-60 atmospheres are used. About 60 wt yield of fatty acids in the range of Cl2-Cl4 is obtained. These acids are used for making soaps. The main source for fatty acids for soap manufacture, however, is the hydrolysis of fats and oils a nonpetroleum source . Oxidation of paraffins to fatty acids may be...
STEAM CRACKING OF HYDROCARBONS Production of Olefins
The main route for producing light olefins, especially ethylene, is the steam cracking of hydrocarbons. The feedstocks for steam cracking units range from light paraffinic hydrocarbon gases to various petroleum fractions and residues. The properties of these feedstocks are discussed in Chapter 2. The cracking reactions are principally bond breaking, and a substantial amount of energy is needed to drive the reaction toward olefin production. The simplest paraffin alkane and the most widely used...
Reactions And Chemicals Of Benzene
Benzene C6H6 is the most important aromatic hydrocarbon. It is the precursor for many chemicals that may be used as end products or inter mediates. Almost all compounds derived directly from benzene are converted to other chemicals and polymers. For example, hydrogenation of benzene produces cyclohexane. Oxidation of cyclohexane produces cyclohexanone, which is used to make caprolactam for nylon manufacture. Due to the resonance stabilization of the benzene ring, it is not easily polymerized....
Production Of Diolefins
Diolefins are hydrocarbon compounds that have two double bonds. Conjugated diolefins have two double bonds separated by one single bond. Due to conjugation, these compounds are more stable than mono-olefins and diolefins with isolated double bonds. Conjugated diolefins also have different reactivities than monoolefins. The most important industrial diolefinic hydrocarbons are butadiene and isoprene. Product composition from cracking atmospheric gas oil and vacuum gas oil44,48,50 Product...
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Deriatives and Uses of Propylene Oxide Similar to ethylene oxide, the hydration of propylene oxide produces propylene glycol. Propylene oxide also reacts with alcohols, producing polypropylene glycol ethers, which are used to produce polyurethane foams and detergents. Isomerization of propylene oxide produces allyl alcohol, a precursor for glycerol. The 1994 U.S. production of propylene oxide, the 35th highest-volume chemical, was approximately 3.7 billion pounds. Table 8-3 shows the 1992 U.S....
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1. Hatch, L. F. and Matar S., Petrochemicals from Methane From Hydrocarbons to Petrochemicals, Gulf Publishing Co., Houston, 1981, p. 49. 2. Chemical and Engineering News, Aug. 16, 1999, p. 7. 3. Stevenson, R. M., Introduction to the Chemical Process lndustries, Reinhold Publishing Corporation, 1966, p. 293. 4. Al-Najjar, I. M., CFC's Symposium Phase out Chlorofluorocarbons Chamber of Commerce and Industry, Dammam, Saudi Arabia. No. 24, 1992, pp. 398-441. 5. Shahani, G. H., et al., Hydrogen and...
Hydrodealkylation Process
This process is designed to hydrodealkylate methylbenzenes, ethyl-benzene and C9 aromatics to benzene. The petrochemical demand for benzene is greater than for toluene and xylenes. After separating benzene Figure 3-8. Flow diagram of a Cheveron hydocracking unit 29 1,4 reactors, 2,5 HP separators, 3 recycle scrubber optional , 6 LP separator, 7 fractionator. Figure 3-8. Flow diagram of a Cheveron hydocracking unit 29 1,4 reactors, 2,5 HP separators, 3 recycle scrubber optional , 6 LP separator,...
Uses of Acrylonitrile
Acrylonitrile is mainly used to produce acrylic fibers, resins, and elastomers. Copolymers of acrylonitrile with butadiene and styrene are the ABS resins and those with styrene are the styrene-acrylonitrile resins SAN that are important plastics. The 1998 U.S. production of acrylonitrile was approximately 3.1 billion pounds.10 Most of the production was used for ABS resins and acrylic and modacrylic fibers. Acrylonitrile is also a precursor for acrylic acid by hydrolysis and for adiponitrile by...
Viscosity Breaking Visbreaking
Viscosity breaking aims to thermally crack long-chain feed molecules to shorter ones, thus reducing the viscosity and the pour point of the product. In this process, the feed is usually a high viscosity, high pour point fuel oil that cannot be used or transported, especially in cold climates, due to the presence of waxy materials. Wax is a complex mixture of long-chain paraffins mixed with aromatic compounds having long paraffinic side chains. Vis-breaking is a mild cracking process that...
References Pqv
1. Chemical and Engineering News, April 10, 1995, p. 17. 2. Roberts, R. and Khalaf, A., Friedel-Crafts Alkylation Chemistry, Marcel Dekker, Inc. New York, 1984, Chapter 2. 3. Petrochemical Handbook, Hydrocarbon Processing, Vol. 70, No. 3, 1991, p. 154. 4. Lewis, P. J. and Dwyer, F. G., Oil and Gas Journal, Sept. 26, 1977, pp. 55-58. 5. Dwyer, F. G., Lewis, P. J., and Schneider, F. H., Chemical Engineering, Jan. 5, 1976, pp. 90-91. 6. Hummel, H. K., DeWit G. B., and Maarleveld, A., The...
Isoprene H2CCCHCH2
Isoprene 2-methyl 1,3-butadiene is the second most important conjugated diolefin after butadiene. Most isoprene production is used for the manufacture of cis-polyisoprene, which has a similar structure to natural rubber. It is also used as a copolymer in butyl rubber formulations. Crude Oil Processing and Production of Hydrocarbon Intermediates 105 Production There are several different routes for producing isoprene. The choice of one process over the other depends on the availability of the...
Olefinic Hydrocarbons
The most important olefins used for the production of petrochemicals are ethylene, propylene, the butylenes, and isoprene. These olefins are usually coproduced with ethylene by steam cracking ethane, LPG, liquid petroleum fractions, and residues. Olefins are characterized by their higher reactivities compared to paraffinic hydrocarbons. They can easily react with inexpensive reagents such as water, oxygen, hydrochloric acid, and chlorine to form valuable chemicals. Olefins can even add to...
Introduction
In general, primary raw materials are naturally occurring substances that have not been subjected to chemical changes after being recovered. Natural gas and crude oils are the basic raw materials for the manufacture of petrochemicals. The first part of this chapter deals with natural gas. The second part discusses crude oils and their properties. Secondary raw materials, or intermediates, are obtained from natural gas and crude oils through different processing schemes. The intermediates may be...
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Many metals occur in crude oils. Some of the more abundant are sodium, calcium, magnesium, aluminium, iron, vanadium, and nickel. They are present either as inorganic salts, such as sodium and magnesium chlorides, or in the form of organometallic compounds, such as those of nickel and vanadium as in porphyrins . Calcium and magnesium can form salts or soaps with carboxylic acids. These compounds act as emul-sifiers, and their presence is undesirable. Although metals in crudes are found in trace...