Case Study

Steam Distillation Figure

Pharmacia & Upjohn Steam Stripper Case Study 1993 by Dr. Anthony Cooper, APV Americas In 1990, The Upjohn Company In Kalamazoo, Michigan, USA had a problem with the release of small quantities of methylene chloride into the atmosphere. The methylene chloride was actually in a waste water stream and was released during certain process operations on this water. Although the water contained other volatile organic chemicals, it was only necessary to design a process to remove the methylene...

Solvent Extraction

Essentially a liquid liquid process where one liquid is used to extract another from a secondary stream, solvent extraction generally is performed in a column somewhat similar to a normal distillation column. The primary difference is that the process involves the mass transfer between two liquids instead of a liquid and a vapor. During the process, the lighter i.e., less dense liquid is charged to the base of the column and rises through packing or trays while the more dense liquid descends....

Solvent Recovery

The term solvent recovery often has been a somewhat vague label applied to the many different ways in which solvents can be reclaimed by industry. One approach employed in the printing and coatings industries is merely to take impure solvents containing both soluble and insoluble particles and evaporate the solvent from the solids. For a duty of this type, APV offers the Paraflash evaporator, a compact unit which combines a Paraflow plate heat exchanger and a small separator. As the solvent...

Principal Of Operation

Alcohol Stripping Systems

For water miscible and water immiscible high volatile compounds, the process is a relatively straight forward distillation system. For many of the systems, vapor liquid equilibrium data are available in the literature and in the many process simulation software programs. Steam stripping can also be used to remove low volatile components when the components have low miscibility with water. Those compounds can all be effectively removed from water by steam stripping, even though they have a lower...

Modular Systems

Azeotropic Distillation Column

Many distillation systems are suitable for modular construction. The main advantage to modular construction is that most of the assembly of equipment and piping is carried out in the factory. This is far more efficient and generally much more economical than field construction. Also, this results in much shorter installation times on site. For columns of 3 ft 900mm diameter or smaller, it is usually possible to mount the column and all auxiliary equipment onto a single module. This can be...

Azeotropic Distillation Without an Entraining Agent

Distillation Alcohol

Certain binary systems form vapor azeotropes that, when condensed, form a two phase liquid without the presence of a third component. The separation is achieved with the combination of an organic column and an aqueous column coupled with a decanter. This is shown schematically in Figure 24. The vapors from each column are condensed, and the resulting two phase liquids are combined and decanted in a single vessel. The organic phase is returned as reflux to the organic column and the aqueous...

Azeotropic Distillation With an Entraining Agent

Ethanol Distillation Flow Sheet

The most common form of azeotropic distillation is adding a third component to the azeotropic mixture in a distillation column. This third component essentially changes the vapor liquid relationship between the two components and allows separation. Using ethanol water as the example, the column is usually operated with a continuous feed of the azeotrope into the column, which contains the third component. This causes a ternary azeotrope to form in the vapor at the top of the column. When this...

Valve Tray

Valve Trays

While the valve tray dates back to the rivet type first used In 1922, many design Improvements and innumerable valve types have been introduced in recent years. Two types of valves are illustrated in Figure 7. These valves provide the following 1. Throughputs and efficiencies can be as high as sieve or bubble cap trays. 2. Very high flexibility can be achieved and turndown ratios of 4 to 1 can be obtained without having to resort to large pressure drops at the high end of the operating range....

Batch Distillation

When particularly complex or small operations require recovery of the more volatile component, APV can offer batch distillation systems of various capacities. Essentially a rectification type process, batch distillation involves pumping a batch of liquid feed into a tank where boiling occurs. Vapor rising through a column above the tank combines with reflux coming down the column to effect concentration. This approach is not too effective for purifying the less volatile component since there is...

Tray Devices

Downcomer Distillation

While there are perhaps five basic distillation trays suitable for industrial use, there are many design variations of differing degrees of importance and a confusing array of trade names applied to their products by tray manufacturers. The most modern and commonly used devices include sieve, valve, bubble cap, dual flow, and baffle trays - each with its advantages and preferred usage. Of these, the sieve and valve type trays currently are most often specified. For a better understanding of...

Dual Flow Tray

The dual flow tray is a high hole area sieve tray without a downcomer. The liquid passes down the same holes through which the vapor rises. Since no downcomer is used, the cost of the tray is lower than that of a conventional sieve tray. In addition, the less complex design allows for easier cleaning. In recent years, use of the dual flow tray has declined somewhat because of difficulties experienced with partial liquid vapor bypassing of the two phases, particularly in larger diameter columns....

Ponchon Savarit

Ponchon Savarit

Where Pa and Pb are the vapor pressures of components a and b at a given temperature. The partial pressure p of component a above a binary ideal solution can be calculated by Where xa is the mole fraction of component a in the liquid. Similarly in a binary mixture, for component b. pb Pb-xb Notice that the sum of the partial pressures must equal the total system pressure P pb pa. For non ideal mixtures usually the case with steam stripping duties , the partial pressure is calculated from Where...