Feedstock preparation

Intermediate feedstock preparation processes such as direct hydroconversion of vacuum residues, solvent deasphalting, improved coking will also make their appearance. 

Electrochemical processes require feedstock preparation for the electrolytic cells. Additionally, the electrolysis product usually requires further processing. This often involves additional equipment, as is demonstrated by the flow diagram shown in Figure 1 for a membrane chlor-alkali cell process (see Alkali AND chlorine products). Only the electrolytic cells and components ate discussed herein. 

Frequent changes in contaminant type and concentration in the feed soil can disrupt the efficiency of the soil-washing process. To accommodate changes in the chemical or physical composition of the feed soil, modifications to the wash fluid formulation and the operating settings may be required. Alternatively, additional feedstock preparation steps, such as blending soils to provide a consistent feedstock may be appropriate.77,83... 

Additional details on the feedstock preparations can be found in the patents (2,3). All chemicals used in the preparation of the above feedstock solutions were reagent grade materials obtained from the following sources ... 

The cost and impact on injectors are key concerns for feedstock preparation. There are difficulties in injecting alternative materials into high-pressure gasifiers. 

Anyone who is seriously involved in catalytic cracking, whether as an operator, a catalyst manufacturer, or a researcher, soon learns how severely sodium, vanadium, nickel, iron, and copper act as poisons. In the past, FCC feedstock preparation via vacuum distillation was to a considerable extent, determined by metal carryover. Generally, metal carryover to the fluid unit was limited to 0.1 ppm or less of each of these metals. 

Vanadium was considered much less of a poison with about 1/5 the selectivity detriment of nickel. Iron, especially in the absence of sulfur, was considered even less of a poison. Copper and sodium were of little consequence if proper care was taken to avoid them in FCC feedstock preparation. 

By the hydrogenation of BD/IP-copolymer feedstocks fully and partially hydrogenated rubbers with low crystallinities and low glass transition temperatures are obtained. For the preparation of highly amorphous hydrogenated rubbers a random copolymer composition is essential. In this respect feedstock preparation by the use of the Nd-carboxylate-based system NdV/DIBAH/EASC yielded better results than BD/IP copolymer feedstocks prepared by anionic polymerization with BuLi [484,485]. 

The most common upstream processing methods for producing regular coke feedstocks are atmospheric and vacuum distillation. Another upstream feedstock preparation process is visbreaking. 

Figure 7. Amortized costs of phenolics and neutrals fraction from pine sawdust pyrolysis calculated as a function of feedstock cost and plant size. Note that the calculations include costs associated with all feedstock preparation as if this were an independent plant.

J. H. Brophy and S. Hardmann, Low-temperature pyrolysis for feedstock preparation, In Recycling and Recovery of Plastics, Hanser Publishers, New York, pp. 422-433, 1996. 

Feedstock preparation Sugarcane or sorghum must be crushed to extract their simple sugars. Starches are converted to sugars in two stages, liquefaction and saccharification, by adding water, enzymes, and heat (enzymatic hydrolysis). 

In the feedstock preparation section of a plant manufacturing natural gasoline, isopentane is removed from butane-free gasoline. Assume for purposes of simplification that the process and components are as shown in Fig. E2.28. What fraction of the butane-free gasoline is... 

It is also believed that nozzle life is affected by feedstock characteristics. Although the dry-feed system may be more difficult to operate at high pressures, nozzle life may be longer in the absence of large amounts of evaporating water. Deeper understanding is needed to identify the effect of feedstock preparation. 

Modern nitric acid production uses catalytic oxidation of ammonia in air followed by absorption of the oxidation products in water to yield nitric acid. Unlike the reactions for ammonia feedstock preparation, all of the reaction steps in this sequence are exothermic. 

One of the main advantages of thermoplastic systems for ceramic extrusion is the lower abrasivity of the feedstock material relative to other binder systems. The lower abrasivity of a extrusion feedstock prepared with a thermoplastic hinder system compared to one with a solvent-based binder for a given ceramic powder, in this case AI2O3, is shown Fig. 1. In this study a feedstock with 58 vol.-% coarse AI2O3 powder was extruded through a steel die. Looking at the surfaces of the tubes, discoloration of the material stemming from abrasion of the die can he clearly... 

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