8. Pick up the key words from the text “Chemical engineering and chemistry”. Make up your own sentences with them.

9. Write an abstract to the text “Chemical engineering and chemistry”.

10. Get ready for presenting the topic “Chemical engineering and chemistry” at the conference ”Innovations in Science and Engineering” based on questions of Task 4. Lesson 2

1. Read and memorize the following words:

	to sum up	узагальнювати
	evaporation	випаровування
	pulverization	подрібнення в порошок
	screening	просіювання
	sieving	просіювання, відсіювання
	flotation	спливання, флотація
	kiln	обпалювальна піч
	thawing	розморожування, декристалізація

2. Read and memorize the following word combinations

	unit operations	окремі циклічні дії
	fluid flow processes	обробка потоку рідин
	solids fluidization	псевдорозрідження твердих речовин
	mass transfer processes	процеси масопередачі, масообміну
	gas liquefaction	розрідження газу
	electrostatic precipitation	електростатичне осідання
	solvent extraction	екстрагування розчинниками

3. Read and translate the text into Ukrainian. Unit operations in chemical engineering

The individual processes used by chemical engineers (e.g. distillation or chlorination) are called unit operations and consist of chemical reaction, mass-, heat- and momentum- transfer operations.

In chemical engineering and related fields, a unit operation is a basic step in a process. A process may have many unit operations to obtain the desired product.

In 1923 William H. Walker, Warren K. Lewis and William H. McAdams wrote the book “The Principles of Chemical Engineering” and explained the variety of chemical industries have processes which follow the same physical laws. They summed-up these similar processes into unit operations. Each unit operation follows the same physical laws and may be used in all chemical industries. The unit operations form the fundamental principles of chemical engineering. Most unit operations are based mechanistically upon the fundamental transport processes of mass transfer, heat transfer, and fluid flow (momentum transfer). Unit operations based on fluid mechanics include fluid transport (such as pumping), mixing/agitation, filtration, clarification, thickening or sedimentation, classification, and centrifugation. Operations based on heat transfer include heat exchange, condensation, evaporation, furnaces or kilns, drying, cooling towers, and freezing or thawing. Operations that are based on mass transfer include distillation, solvent extraction, leaching, absorption or desorption, adsorption, ion exchange, humidification or dehumidification, gaseous diffusion, crystallization, and thermal diffusion. Operations that are based on mechanical principles include screening, solids handling, size reduction, flotation, magnetic separation, and electrostatic precipitation.

Therefore, chemical engineering unit operations consist of five classes:

1. Fluid flow processes, including fluids transportation, filtration, solids fluidization

2. Heat transfer processes, including evaporation, condensation

3. Mass transfer processes, including gas absorption, distillation, extraction, adsorption, drying

4. Thermodynamic processes, including gas liquefaction, refrigeration

5. Mechanical processes, including solids transportation, crushing and pulverization, screening and sieving

Chemical engineering unit operations also fall in the categories such as combination (mixing); separation (distillation); reaction (chemical reaction). Chemical engineering unit operations and chemical engineering unit processing form the main principles of all kinds of chemical industries and are the foundation of designs of chemical plants, factories and equipment used.