What You Need to Know About Distillation

Distillation is an essential separation process used across a broad range of sectors including the food and beverage, petrochemical, specialty chemicals, pharmaceutical, water treatment, and agriculture industries. Distillation involves separating two or more components or substances from a liquid mixture based on the variance in their boiling points. Depending on the industry, the distillation process can be used to perform several operations including concentration enhancement, purification, devolatilization, and resource recovery.

Below are some of the distillation equipment, technologies, and processes that are currently being leveraged across industries.

Single Stage & Multiple Stage Technologies

Distillation processes are typically done in single or multiple stages. Single-stage thermal distillation is a continuous operation where a liquid mixture is fully or partially vaporized in one single phase. The solution is heated to its boiling point, causing the more volatile components to evaporate, where it is subsequently cooled and condensed. In multi-stage distillation, portions of the liquid are vaporized and cooled/condensed in successive stages, usually with decreasing pressure and temperature.

In another type of separation technique, known as scrubbing, volatile components in a gaseous phase contact and combine with a counterflowing liquid via absorption. Molecular sieve dehydration is another well-known separation method and uses a system of sieves that allows the molecules of a particular substance to fit into its pores, where it adheres to the sieve; this process is called adsorption. Molecular sieve dehydration is typically used after alcohol/ethanol distillation.

Distillation Basics

All distillation processes, regardless of the technologies employed, operate by exploiting the differences in the volatility of a mixture’s various components. This volatility is related to a compound’s vapor pressure or boiling point. The boiling point of a liquid is directly proportional to the applied external pressure. For instance, at 14.7 psia, water will boil at 212oF; however, at 1.94 psia, the boiling point changes to 125oF. The variance in vapor pressures and boiling points between liquids are referred to as relative volatility. The distribution coefficient is another critical component of distillation and is related to the composition and concentration of the vapor in equilibrium with the liquid mixture.

Design Procedures

The distillation process, though relatively simple in concept, requires careful analysis and meticulous calculations to ensure its success and efficiency at an industrial scale. Over the years, several calculation procedures, equations, diagrams, and mathematical models have been developed to represent the various stages of the process.

One of several design methods presented in our eBook is the McCabe-Thiele Diagram. This graphical method is commonly used to determine the ideal number of stages and the location of feed trays for a particular distillation process. To ensure the efficiency of the distillation process, all design procedures must consider a number of factors including:

  • Calculation of the number of equilibrium stages
  • Determination of tray hydraulics
  • Selection of tray or packing efficiencies

Equipment Components of the Distillation System

Distillation systems consist of numerous components; with each playing a different role in the process. In our eBook, we look at the various elements of several distillation systems and describe the factors that influence their design. Some of the components we cover include:

  • Contacting equipment
    • Sieve tray
    • Valve tray
    • Bubble cap tray
    • Dual-flow tray
    • Packing
  • Downcomer design
  • Columns
  • Feed distribution and redistribution systems
  • Column intervals


The team at Thermal Kinetics has recently released their new eBook, “Distillation 101 a Guide to Distillation and Separation Technologies”. This publication gives an in-depth look at the distillation process and its various elements, including:

  • Distillation design procedures
  • Distillation equipment and essential components
  • Industrial applications

If you would like to dive deeper into the distillation process, click here to download our free eBook.


Sodium Sulfate Mine and Anhydrous Crystal Production Project

Thermal Kinetics has recently completed design and supply of equipment for the production of anhydrous sodium sulfate.

crystallization equipmentOur involvement included preparation of the processing plant’s material and energy balance, design layout of all major equipment from receipt of raw ore, ore dissolving, purification, clarification, crystallization, centrifugation, and drying operations.

We designed and supplied the evaporative crystallization equipment including heat exchangers, crystal bodies, axial flow pumps, controls, and supporting equipment. The system was configured as a quadruple effect operation for minimum steam usage. Advanced controls and processing allows crystal size distribution to be managed by operations. Each effect operates at a different temperature influencing crystal growth and nucleation kinetics. Control of slurry density and crystallizer body levels for each effect balances the temperature impact for consistent crystal size control in each effect.

The plant is nearing completion of construction for Somin Compañia Minera in Hermosillo, Sonora, Mexico.

Advanced Bioeconomy Leadership Conference

The Advanced Bioeconomy  Leadership Conference took place in Washington, DC on March 11 – 13th.

bioeconomy expertsIt was a mind boggling gathering of the best and brightest executives in the renewables sector. The hot topic was low cost oil, but most remain steadfast on their chosen path, although financing may be even tougher to land. This most interesting article speaks directly to the impact of oil prices and an emerging industry that remains resolute.

The (oil price) Crash of ’14: what lessons can we learn?

As part of our Silver Level Sponsorship we had a total of six passes. Thanks to the idea of our Board Advisor Bob Helenbrook (former President ATSI Engineering) we used four of our passes for our clients and business allies. Chris Brown (TKE – President) and Steve Healey (TKE – Director of Business Development) were privileged to be joined by:

  1. Arnold R. Klann, CEO/President, Bluefire Renewables, Inc.
  3. Michele Jalbert, COO, RE:CHEM
  4. Thomas D. Kohler, Director, Downs Rachlin Martin PLLC

As interesting as this crew was it was enhanced even more when Brian invited his friend James Woolsey, Jr. to join us. As soon as the conference organizer Jim Lane realized James was at the conference he was asked to give a short talk on this topic:

Turning Oil Into Salt: Energy Independence Through Fuel Choice

James’s talk was most entertaining and enlightening. And as if this wasn’t enough imagine going out to dinner with this group of players joined by James Woolsey. It was fascinating!

We hope to see you at the next ABLC.


Steve Healey
Director Business Development
Thermal Kinetics Engineering, PLLC

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