Sour feed

The hydrogen-rich gas stream from the high-pressure separator is recycled back to the reactor feed by using a recycle compressor. Sometimes with sour feeds, the first-stage recycle gas is scrubbed with an amine system to remove hydrogen sulfide. If the feed sulfur level is high, this option can improve the performance of the catalyst and result in less costly materials of construction. 

Figure 4 Schematic of the basic principal of the C3sep technology. The sour feed gas is routed through a turbo expander. The expansion cools the gas and the largest part of the H2S is condensed. The liquid H2S is separated from the gas stream and the treated gas is recompressed. Expander and compressor are on the same shaft so that no additional energy is required for the re-compression.

Crude oil is a mixture of hydrocarbons, clay, water, and sulfur. Some crude mixtures have higher concentrations of sulfur than others these mixtures are referred to as sour feed. Hydrodesulfurization (Figure 11-10) is a process used by industrial manufacturers to "sweeten" or remove the sulfur. Hydrodesulfurization units use the following equipment during operation ... 

During operation, sour feed is mixed with hydrogen and heated in a fired furnace. The heated mixture is sent to a reactor where the hydrogen combines with the sulfur to form hydrogen sulfide. When the temperature is lowered slightly, the sweet crude condenses, leaving the hydrogen sulfide in a vapor state. This vapor-and-liquid mixture is sent to a separator where the low-sulfur sweet... 

Other components in the feed gas may react with and degrade the amine solution. Many of these latter reactions can be reversed by appHcation of heat, as in a reclaimer. Some reaction products cannot be reclaimed, however. Thus to keep the concentration of these materials at an acceptable level, the solution must be purged and fresh amine added periodically. The principal sources of degradation products are the reactions with carbon dioxide, carbonyl sulfide, and carbon disulfide. In refineries, sour gas streams from vacuum distillation or from fluidized catalytic cracking (FCC) units can contain oxygen or sulfur dioxide which form heat-stable salts with the amine solution (see Fluidization Petroleum). 

The delayed coking feed stream of residual oils from various upstream processes is first introduced to a fractionating tower where residual lighter materials are drawn off and the heavy ends are condensed. The heavy ends are removed and heated in a furnace to about 900 to 1,000 F and then fed to an insulated vessel called a coke drum where the coke is formed. When the coke drum is filled with product, the feed is switched to an empty parallel drum. Hot vapors from the coke drums, containing cracked lighter hydrocarbon products, hydrogen sulfide, and ammonia, are fed back to the fractionator where they can be treated in the sour gas treatment system or drawn off as intermediate products. 

The catalyst dust is then separated from the resulting carbon dioxide stream via cyclones and/or electrostatic precipitators and is sent off-site for disposal or treatment. Generated wastewater is typically sour water from the fractionator containing some oil and phenols. Wastewater containing metal impurities from the feed oil can also be generated from the steam used to purge and regenerate catalysts. 

Hydrotreating generates sour wastewater from fractionators used for product separation. Like most separation processes in a refinery, the process water used in fractionators often comes in direct contact with oil and thus can be highly contaminated. It also contains hydrogen sulfide and ammonia and must be treated along with other refinery sour waters. In hydrotreating, sour wastewater from fractionators is produced at the rate of about I.O gallon per barrel of feed. 

Another commercial trail of MIP-CGP for processing intermediate-based sour residual feed has been put on stream in SINOPEC Cangzhon Company in 2005. Table 5.6 shows the commercial comparison of CGP-2 and CGP-1. After shifting to CGP-2 the propylene yield increased by 1.15%, and the light ends yield increased by 0.57%. The snlfnr content of gasoline was decreased from 840 to 580 J,g/g. The olehn content, RON and MON of gasoline remained essentially constant. 

Flavourings are a major category of ingredients intentionally added to food and feeding stuff. Flavourings are concentrated preparations with the primary purpose to impart flavour except for substances that have an exclusively sweet, sour or salty taste. They are added in small amounts to food or feeding stuff but are not intended to be consumed as such. 

Bitumen feed to the fluid cokers contains approximately 4.9% sulphur. During coking, the sulphur is redistributed into sour gas, sour water, coke and hydrocarbon streams. Figure 3 indicates a circulating coke stream between the coker and coke burner. 

The economics of thermal reforming and hydroforming of sweet and sour heavy straight-run naphthas have been compared recently by McLaurin, McIntosh, and Kaufman (15). They concluded that the relative economics of the two processes were virtually the same for both feed stocks. 

You Are What You Eat 95 Feeling Hot, Hot, Hot 99 The Evolution of Margarine 103 A Different Twist on Licorice 108 Chocolate Lovers Rejoice 112 Berry Good News 116 Just Give Me the Flax 120 Remember This 124 Cheers for Sour Cherries 128 Bitter Water and Sweet Science 132 Feeding the Diet Industry 136 Green Peas, Please 140... 

Sewage wastes contain as much as 4 ppm of vitamin Bi2 (Hoover et al. 1952B Miner and Wolnak 1953). Although frowned on for aesthetic reasons as a source of vitamin Bi2 for human nutrition, wastes from activated sludge processes may well provide the cheapest source for preparation of vitamin Bi2 concentrates used in cattle feed. Symbiotic growth of lactic and acetic acid bacteria has been recommended for producing sour milk products biologically enriched with vitamin Bi2 (Rykshina 1961). Acetic acid bacteria cultured in whey fortified with cobalt salts led to an 80-fold increase in vitamin B12. Propionic acid bacteria in skim milk supplemented with dimethylbenzimidazole increased the vitamin content by 300-fold. 

Normal vertical knockout drums are designed for a K value of about 0.20 to 0.25. If we are installing a KO drum ahead of a reciprocating compressor—and they really hate liquids in their feed—a K value of 0.14 might be selected. If we really do not care very much about entrainment, a K value of 0.4 might be selected. An example of this would be venting waste gas to the flare from a sour-water stripper reflux drum. 

The peel, internal membranes, ruptured juice vesicles and seed residue remaining after juice extraction represent the raw material for production of dried citrus pulp. This residue, in its wet state, contains 75-85% water and ferments or sours readily because of the presence of soluble sugars. The difficulty of handling this wet material necessitates dehydration to a moisture content in the range of 107. water. Once dried, if proper precautions are taken to maintain dry conditions, the product may be handled, stored, and shipped in a manner similar to other dry feed stuffs. 

This product consists of milk from which most of the fat has been removed but which contains all the protein. The protein has a high biological value and is very digestible. Skim milk is a good source of B vitamins, but the fat-soluble vitamins (A and D) are removed with the fat. Skim milk should either be fresh or always at the same degree of sourness. Attention should be paid to the cleanliness of the equipment used for feeding. Normal bacterial acidification can be used as an effective and convenient method of stabilization. 

Hydrogen sulfide may be removed from polymerization feed stock by scrubbing with ethanolamine or sodium hydroxide. When the mercaptan content of the feed is sufficiently high to give a Doctor-sour polymer, a regenerative caustic wash usually is inserted in the feed-preparation train to remove them. Mercaptan scrubbers ordinarily are not necessary on polymerization feed streams from catalytic-cracking units, but are required on feeds produced from sour crudes by thermal cracking. 

The shift from carbon monoxide to carbon dioxide generally occurs in two steps - first a High Temperature Shift Conversion and then a Low Temperature shift conversion. In some cases the two steps may be combined in one isothermal or adiabatic step called Medium Temperature Shift Conversion. When the feed gas to the CO conversion is not desulfurized, the CO conversion is called Sour Gas Shift and a special type of sulfur-resistant catalyst is used166. 

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