Distillation bottoms

Comp. Feed Distillate Bottoms 1. 0.1400 0.4295 0.0159 Case Reflux ratio Reboil ratio Feed composition Distillate composition Bottoms composition... 

In order to reduce fresh-water consumption in the scrubber, the usage of distillation bottoms and the off-gas condensate should be maximized since diey have the least ammonia content. The flowrate resulting from combining these two sources (5.8 kg/s) is sufflcient to run the scrubber. However, its ammonia composition as determined by the lever-arm principle is 12 ppm, which lies outside the zone of permissible recycle to the scrubber. As shown by Fig. 4.7, the maximum flowrate of the off-gas condensate to be recycled to the scrubber is determined to be 4.1 kg/s and the flowrate of fresh water is 0.9 kg/s (5.8 — 0.8 — 4.1). Therefore, direct recycle can reduce the fresh-water consumption (and consequently the... 

Used oil distillation bottoms. When used oil is recycled, residues (called distillation bottoms) form at the bottom of the recycling unit. To promote the recycling of used oil and the beneficial reuse of waste materials, U.S. EPA excluded these residues from the definition of hazardous waste when the bottoms are used as ingredients in asphalt paving and roofing materials. 

Temperatures of feed, distillate, bottoms, and water in and out of the condenser... 

To predict the composition, a density meter is installed beside the column. Samples from the feed, distillate, bottoms, and trays 2, 4, 6, 8, 10, and 12 are sent to this density meter through a sampling pump. The samples can be selected from different points by the use of several valves available on the sampling lines. In order to make this sampling continuous, a Taylor Control Language program has been written in... 

Raw and treated waste water from metal manufacturing, paint and ink formulation, and rubber processing industries has been found to contain some carbon tetrachloride (USEPA Verification Program). Manufacturing distillation bottoms are typically incinerated. 

Since fermentation takes place in a dilute aqueous solution, the reaction continues until the alcohol concentration approaches about 14%. At higher concentrations, the process becomes self-inhibitory. By-products from starch fermentation to ethanol can include higher-molecular-weight alcohols, glycerine, and ethers. Usually no more than 10% starch is converted to these compounds. Atmospheric distillation, vacuum distillation, and membrane separation techniques can be used to recover ethanol from the final fermented product. The distillate bottoms, called stillage, are recovered as a by-product for animal feed. A biomass fermentation flow diagram is provided in FIGURE 12-2. 

The whole Illinois H-Coal syncrude was redistilled at 600°F cut point to yield a rerun Illinois H-Coal syncrude and distillation bottoms (Table XIII). The yield of the rerun syncrude is 83.3 wt % (87.1 vol %). Although the nominal cut point of the distillation was 600°F, the products appear to be cut at close to 550°F. The distillation bottoms could perhaps be used to manufacture hydrogen by partial oxidiation or used as refinery fuel since it contains only 0.18 wt % sulfur. 

PROPERTIES OP THE RERUN ILLINOIS H-COAL SYNCRUDE AND DISTILLATION BOTTOMS... 

Component Feed Mole % distillate Bottoms Moles per 100 moles or Teed Distillate Bottoms ... 

Component Feed Distillate Bottoms Distillate Bottoms... 

Distillate bottoms (above 25°API), gas oil or liquid naphtha below 500°F, scrubbing oil, refrigerant vapors, air (dust) 500... 

While originally designed for cracking the overhead stream from vacuum distillation units, known as vacuum gas oil (4), most FCC units currently operate with some higher boiling vacuum distillation bottoms (Resid) in the feed. Table 5.1 illustrates the difficult challenges faced by refiners, process licensors and FCC catalysts producers the resid feeds are heavier (lower API gravity), contain many more metals like Ni and V as well as more polyaromatic hydrocarbons prone to form coke on the catalysts (Conradson Carbon Residue, or CCR). 

Figure 6.9 Common types of columns and controls, ia) Stabilizer ismall distillate flow) (b) superfractionator with distillate-bottoms control structure.

The flow rate of the distillate/bottoms product stream... 

Table 1. DPR compositions at feed to distillation and at distillation bottoms.

Elutable high boilers DPR compositioii at distillatioii feeds [%1 DPR composition at distillation bottoms [% ... 

Because both zinc and magnesium are volatile, these acceptor alloy elements are separated from the actinides by vacuum distillation. The zinc-magnesium overhead product from vacuum distillation is recycled. After the volatile solvent metals are removed, the resultant distillation bottom products (U-Pu for core fuel and U for blanket fuel) are converted to suitable oxides by reaction with oxygen. The oxide products are available for refabrication into new fuel. The FP-3 elements that follow plutonium and the... 

D,B = Distillate, bottoms flows, mols/hr K = Equilibrium K-value = Y/X... 

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