Chapter III oil refining

EXERCISE 1 Read and translate the texts "Heat content" and "Refining methods", using the words after the texts.

Heat content

Many economic considerations effecting production of different petroleum products are related to the amount of heat escaping when they burn. To select which flows should be used as refinery fuels we should take into consideration market price of petroleum products and also their heating value.

Two processes take place during hydrocarbon burning – chemical reaction and calorification. Chemical reaction usually means turning of hydrocarbon and oxygen into carbon dioxide and water.

Amount of heat escaping during the process varies for different hydrocarbons. Amount of heat in refining industry is normally measured in British Thermal units (1 BTU=1054,8Joules=252 calories).

One British Thermal unit equals to amount of heat needed for heating of one pound of water to 1°F.

There are two types of heating value. So called the highest heating value demonstrates total amount of heat, which escapes during chemical reaction (heat of combustion), and the lowest heating value shows condition of water generated during the reaction. Part of the chemical reaction heat is spent for water evaporation. Besides, not all the heat can be used, as it comes through the burner and out of the stack. The heavier is the fuel, the lower is ratio between hydrogen and carbon in its composition, and the less water is generated when it is burnt. This situation is reflected in heat efficiency value, which is calculated as ratio of net heat to total heating value.

Refining methods

The most complex are refining methods including production of special valuable products, for example, lube oils or petrochemical products. Corresponding units have high complexity coefficients, which reflect CAPEX level for their construction. For example, complexity coefficient for aromatic hydrocarbons plant equals 33, and for production of olefins it is 10-20 (depending upon type of raw material and method of output product treatment). Pretty often refining method with output of chemical products (ethylene, propylene and aromatics) about 10% with complexity coefficient at least 16 is used. The idea of the analysis was to have a possibility to develop and use the chart reflecting dependability of refining costs upon its complexity accounting production scale effects.

The words to be memorized:

1. Carbondioxide – диоксид углерода (СО₂)

2. fueloil – котельное топливо

3. refinery – нефтеперерабатывающий завод

4. lubeoils – смазочные масла

5. Aromatic hydrocarbons – ароматические углеводороды

6. Olefin – олефин

EXERCISE 2 Answer the following questions.

1. What is related to the amount of heat?

2. Why should we take into consideration market price of petroleum products?

3. How many processes take place during hydrocarbon burning? What are they?

4. How is amount of heat in refining industry normally measured?

5. Are there two or three types of heating value?

6. What is spent for water evaporation?

7. Can all the heat be used as it comes through the burner and out of the stack?

8. What are the most complex refining methods?

EXERCISE 3 Decide whether the statements are true or false. Correct them if necessary.

1. Cracking is a very dangerous process during crude distillation as it can result in a complete destruction of the rectifying column.

2. Each of the crude fractions has its boiling temperature interval.

3. Lower pressure is used during vacuum distillation because products boil at lower temperatures if pressure is lower.

4. Initial products for thermal cracking are mostly gases.

5. Hydrocracking unit produces high quality gasoline.

6. Prior to distillation the crude is tasted by one of the operators. If sweet enough it can be used for refining, sour oil is usually rejected.

7. Downcomer is a maintenance person servicing rectifying plates starting from the top of the column.

8. Both light and heavy vacuum distillates can be used for lube oil production.

9. Used catalyst can be restored in the regenerator for repeated use.

10. Coke dehydration is called calcination.

EXERCISE 4 Translate from Russian into English.

1. Обычно сырая нефть содержит такие фракции, как углеводородные газы, бензин, нафта, керосин, газойль и мазут.

2. Прямогонный бензин направляется на компаундирование для получения автомобильного бензина.

3. Процесс вакуумной перегонки был разработан с целью правильного использования крекинга.

4. Остаток вакуумной перегонки используется в качестве сырья для производства битума.

5. Температура, при которой фракция начинает кипеть, называется точкой начала кипения, а температура, при которой фракция полностью испарилась, называется точкой выкипания.

6. Установка гидрокрекинга производит высококачественный бензин, при этом повышается качество компонентов бензина и дистиллята.

7. Лёгкий вакуумный дистиллят и тяжёлый вакуумный дистиллят иногда получают как отдельные продукты.

8. Прямогонный остаток подаётся на вакуумную перегонку.

9. В крекинг установке прямогонные фракции тяжёлого газойля нагревают при повышенном давлении в контакте с катализатором.

10. Часть углеводородов, которая в процессе каталитического крекинга превращается в кокс, оседает в виде отложений на катализаторе.

EXERCISE 5 Read and translate the text "Gas fractionation plants", using the words after the text.