Properties of feed

Reversible Processes. Distillation is an example of a theoretically reversible separation process. In fractional distillation, heat is introduced at the bottom stiUpot to produce the column upflow in the form of vapor which is then condensed and turned back down as Hquid reflux or column downflow. This system is fed at some intermediate point, and product and waste are withdrawn at the ends. Except for losses through the column wall, etc, the heat energy spent at the bottom vaporizer can be recovered at the top condenser, but at a lower temperature. Ideally, the energy input of such a process is dependent only on the properties of feed, product, and waste. Among the diffusion separation methods discussed herein, the centrifuge process (pressure diffusion) constitutes a theoretically reversible separation process. 

The type of evaporator to be used and the materials of construc tion are generally selected on the basis of past experience with the material to be concentrated. The method of feeding can usually be decided on the basis of known feed temperature and the properties of feed and produc t. However, few of the listed variables are completely independent. For instance, if a large number of effects is to be used, with a consequent low temperature drop per effect, it is impractical to use a natural-circiilation evaporator. It expensive materials of construction are desirable, it may be found that the forced-circulation evaporator is the cheapest and that only a few effec ts are justifiable. 

As in hydrocracking, this reaction increases the gas yield and changes the relative equilihrium distrihution of the aromatics in favor of benzene. Table 3-7 shows the properties of feed and products from Chevron Rheiniforming process. 

Properties of feed and products from Chevron Rheiniforming process ... 

Measurement of the physieal properties of feed and produet phases (e.g., mass densities, viseosities, surfaee tensions, and wettability) and their dependenee on temperature on typieal equipment materials Qualitative examination of the mass transfer intensity of a single droplet (kicking drop)... 

A feasibility study on the application of H-NMR petroleum product characterization to predict physicochemical properties of feeds and catalyst-feed interactions has been performed. The technique satisfactorily estimates many feed properties as well as catalyst-feed interactions to forecast products yield. There are, however, limitations that have to be understood when using the H-NMR method. The technique, in general, is not capable either to estimate the level of certain contaminants such as nitrogen, sulfur, nickel, and vanadium when evaluating feed properties or the effect of these contaminants on products yields while testing catalyst-feed interactions. 

Fig. 5.6. Flow and compression properties of feed solids for theoretical roll press design [15]. (a) Shear cell to measure internal friction of granular solid, (b) Cell to measure angle of friction between roll face and granular solid, (c) Pressure-density relationship of feed material.

Pilot plant tests over 2500 h long were performed using hexane deasphalted oil of Orinoco crude (8 API). Properties of feed and products are shown in Table 1. The amount of vanadium (180 ppm) is representative of a high metal feedstock with low asphaltene content. 

Properties of feed and product of HOM pilot plant tests... 

Step 2—assign invariant intrinsic properties of feeds as inputs (Rule 1)... 

Table V. Properties of Feed, Concentrate (Cone) and Permeate (Perm) Streams for Orange, Grapefruit and Lemon Juices Concentrated by Reverse Osmosis...

Knowledge of the compression properties of feed materials can indicate the type of force most likely needed in size reduction. A friable or crystalline structure can be reduced through fracture along cleavage planes using compressive forces. However, if new crack tips must be formed, impact and shear forces may be more effective. For food materials of fibrous structures, shredding or cutting should be considered for the desired size reduction. 

Properties of Feeds to the Puerto llano, Spain, Plant... 

Feed slurries were prepared fresh daily by blending the required amounts of ground grass and demineralized water. The properties of feed slurries prepared about 4 months apart are presented in Table III. The pH of the digester contents was maintained in the 6.8 to 7.2 range as much as possible by adding a pre-determined amount of 1.0 N NaOH solution to the feed slurry before dilution to the required volume with water. When added nutrient solutions were used, the compositions of which are shown in Table IV, preselected amounts were also blended with the feed slurries before dilution to the final feed volume. 

Such product characteristics majorly depend on the physical properties of feed, equipment components, and processing parameters (Table 21.4). 

The important parameters of composting are temperature, pH, moisture content, and oxygen transfer, which is regulated by aeration, free airspace, and agitation. The main properties of feed materials include C/N ratio, ratio size, rigidity, and nutrient and lignin compost. 

PROPERTIES OF FEED MATERIALS AFFECTING THE SIZING PROCESS... 

The milling or sizing process is affected by a variety of factors and has a direct effect on the quality of the final product. The properties of feed material and the finished product specifications determine the choice of equipment to be used for the process of comminution. The properties of feed material include melting point, brittleness,... 

Properties of feed material Size, shape, moisture content, physical and chemical properties, temperature sensitivity, grindability, and material compatibility... 

Physical Properties of Feeding Material - Flowability, Packing and Friction... 

In the real world, feedstock properties and product slates are changing continually. In AFCC and AHYC, proprietary feed-adjust models skew the base-case component distribution to match the measured properties of feeds... 

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