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.
GAS FRACTIONATION PLANTS
Four main methods can be used to produce gas spirit:
1. Cooling
2. Deep cooling
3. Absorption with denuded oil
4. Hard surface absorption.
In the cooling method gas containing liquid is cooled down to temperatures in the interval from -10°C to -40°C. At such temperature about 90% of propane and all butane (and also heavier compounds) are liquefied and can be separated during fractionation.
In the deep cooling method more complete ethane separation is performed. For that purpose temperature of gas containing liquid is decreased to the interval from -100°C to -140°C. In such conditions 95% of ethane and all propane (and also heavier compounds) are separated from the gas.
Absorption with denuded oil is performed in older gas fractionation plants the same way as it is done in appropriate refinery units. Standard procedure allows producing about 70% of propane and 100% of butane and heavier compounds. Using cooled denuded oil can in addition provide for 50-75% of ethane.
Hard surface absorption is an interesting process, which is used in cases when only dew point must be changed (i.e. remove only the heaviest compounds, which can condense during transportation). Many gas sale contracts include requirements for dew point (temperature at which drops start to settle out) to be not higher than -10°C with gas line pressure about 800 psi. Depending upon specific gas flow this may require complete removal of petroleum gasoline and partial removal of butanes.
Some porous materials, such as absorbent carbon, silica gel and alumina, may make big volumes of vapors condense on their surface. As liquid stays on the surface of hard substance, this process is called “adsorption” but not “absorption” (in the last case liquid gets inside the material). When sufficient volume of liquid is condensed (in this case, gas spirit) the process is stopped or the flow is directed to different tank containing new portion of adsorbent. Liquids are removed from adsorbent surface by treating it with superheated steam, collected and condensed.
Hard surface absorption produces 10-15% of butanes and 50-90% of petroleum gasoline.
The words to be memorized:
1. Gas fractionation plant – газофракционирующая установка (ГФУ)
2. denuded oil – отбензиненное абсорбционное масло
3. gasoline – бензин (газолин)
4. silica gel – силикагель
5. straight-run residue – прямогонный остаток
6. alumina – оксид алюминия