Petroleum Refining (Технологии и продукты переработки нефти). Учебное пособие

7.Прочитайте и переведите текст, используя лексический материал предыдущих упражнений.

Исходная смесь (жидкость), состоящая из двух компонентов, поступает в колонну. Ректификационная колонна имеет цилиндрический корпус, внутри которого установлены контактные устройства в виде тарелок. Из ребойлера (кипятильника) в нижнюю часть колонны поступают пары, которые движутся вверх. Это восходящий поток. Пары проходят через слой жидкости на тарелках. Компонент смеси, имеющий меньшую точку кипения, в виде пара поступает в верхнюю часть колонны, а затем в конденсатор, где конденсируется. Полученная жидкость, проходя через сборник орошающей фракции, подается на верхнюю тарелку колонны. Это нисходящий поток. Жидкость, выходящая из низа колонны делится на две части. Одна часть направляется в кипятильник, другая – в сборник.

8.Передайте на русском языке основное содержание текста упражнения 4.

9.Переведите с листа на русский язык следующий отрывок.

Fractionation towers use various liquid contacting methods to provide the required number of equilibrium stages. Such devices are commonly known as “plates” or “trays”. Each of these plates or trays is at different temperature and pressure. The stage at the tower bottom has the highest pressure and temperature. Progressing upwards in the tower, the pressure and temperature decreases for each succeeding stage.

Another way of improving the separation in a distillation column is to use packing material instead of trays. These offer the advantage of a lower pressure drop across the column.

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10.Переведите на слух по предложению следующий отрывок.

The column can be fed in different ways. If the feed is from a source at a pressure higher than the fractionation column pressure, it is simply piped into the column. Otherwise, the feed is pumped or compressed into the column. The feed may be a superheated vapor, a saturated vapor, a partially vaporized liquid-vapor mixture, a saturated liquid or a sub-cooled liquid. If the feed is a liquid at a much higher pressure than the column pressure and flows through a pressure let-down valve just ahead of the column, it will immediately expand and undergo a partial flash vaporization resulting in a liquid-vapor mixture as it enters the fractionation column.

11.Подберите из текстов английские эквиваленты к следующим словосочетаниям и выучите их наизусть.

перепад давления однократное испарение смесь жидкость-пар в противном случае насыщенный пар

смесь поступает в колонну улучшить процесс разделения температура уменьшается орошающая фракция перегретый пар частично испарившийся

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12.Подберите русские эквиваленты к следующим словосочетаниям и выучите их наизусть.

pressure let-down valve partially

fractionation column pressure vaporization

exit from the top of the column saturated liquid

equilibrium stage under vacuum

13.Переведите письменно на русский язык следующие предложения.

1.A fractionating column is an essential unit used in the distillation of liquid mixtures.

2.It is used to separate the mixture into its component parts, or fractions, based on the differences in their volatilities.

3.At steady state conditions, the vapor and liquid on each tray is at equilibrium.

4.The separation may be enhanced by the addition of more trays.

5.Fractionation is a process which is used in the petroleum processing, petrochemical production, natural gas processing, coal tar processing, brewing, liquified air separation, and hydrocarbon solvents production.

6.The amount of heat entering the column from the reboiler and with the feed must equal the amount of heat removed by the overhead condenser.

7.Inside the column, the downflowing reflux liquid provides cooling and condensation of upflowing vapors thereby increasing the efficacy of the distillation tower.

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8.The design and operation of a fractionating column depends on the composition of the feed and as well as the composition of the desired products.

9.Sometimes the packing material is used in the column instead of trays, especially when low pressure drops across the column are required, as when operating under vacuum.

10.Differently shaped packings have different surface areas and void space between packings.

14.Переведите письменно на английский язык следующие предложения.

1.Ректификационная колонна – аппарат, предназначенный для разделения жидких смесей, компоненты которых имеют различную температуру кипения.

2.Если исходный продукт состоит из двух компонентов, конечными продуктами являются дистиллят, выходящий из верхней части колонны и кубовый остаток, скапливающийся в нижней части колонны.

3.В ректификационных колоннах в качестве контактных устройств применяются тарелки и насадки.

4.Эффективность процесса ректификации зависит от структуры потоков на тарелках.

5.Пары жидкости поднимаются снизу, а навстречу парам сверху стекает жидкость, подаваемая в верхнюю часть аппарата в виде флегмы.

6.Процесс ректификации может протекать при атмосферном давлении, а также при давлениях выше и ниже атмосферного.

7.Процесс ректификации осуществляют в ректификационной установке, включающей ректификационную колонну, дефлегматор, холодильник- конденсатор, подогреватель исходной смеси, сборники дистиллята и кубового остатка.

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8.Ректификационная колонна имеет цилиндрический корпус, внутри которого установлены контактные устройства в виде тарелок.

9.Насадочные колонны получили широкое распространение в промышленности.

10.В зависимости от скорости потока в колонне возможны три гидродинамических режима: ламинарный, промежуточный и турбулентный.

15.Переведите на слух в быстром темпе следующие словосочетания.

Fractionation – линия отходящего газа – reflux drum –

нисходящая жидкость – bubble-cap – тарелка – instead of –

насадка – bottoms – конденсатор – pressure drop –

насыщенный пар – equilibrium stage – в противном случае – partially – однократное испарение – under vacuum –

перегретый пар – result in – немедленно – feed – извлекать – progress.

16.Ответьте на вопросы по содержанию текстов данного урока.

1.What is the main application of the fractionation processes?

2.Can you name the types of fractionation columns?

3.What are the most important factors for the column construction?

4.What is the operation principle of continuous fractionating column?

5.What contacting devices are used in the fractionation columns?

17.Передайте основное содержание текстов урока на русском и английском языках.

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Unit 7

CRACKING

1.Прочитайте следующие интернациональные слова вслух и, основываясь на значениях соответствующих русских слов, определите их значение.

Form, cracking, catalytic, fluid, thermal, hydrocracking, molecular, hydrogen, unstable, spontaneously, type, control, conversion, gasoline, olefinic, originally, octane, configuration, reactor, regenerator, schematic, diagram.

2. Прочитайте и переведите следующие глаголы.

To reprocess, to break, to aim, to tend, to vary, to remain, to convert, to replace, to base, to become, to combine, to vaporize, to crack into, to enter, to regenerate, to pass, to refer, to recycle back.

3.Подберите эквивалентный перевод слов и словосочетаний из колонки А в колонке В.

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4. Прочитайте и переведите текст.

Intermediate products such as gasoils can even be reprocessed to break a heavy, long-chained oil into a lighter short-chained one, by various forms of cracking such as fluid catalytic cracking, thermal cracking, and hydrocracking.

Thermal cracking is the oldest and the simplest cracking process. It basically aims at the reduction of molecular size by application of heat without any additional sophistication such as catalyst or hydrogen. At a temperature level of 450-500°C, the larger hydrocarbon molecules become unstable and tend to break spontaneously into smaller molecules of all possible sizes and types. By varying the time, temperature and pressure under which a particular feedstock remains under cracking conditions, the desired degree of cracking can be controlled.

Fluid catalytic cracking (FCC) is the most important conversion process used in petroleum refineries. It is widely used to convert the high-boiling, high-molecular weight hydrocarbon fractions of petroleum crude oils to more valuable gasoline, olefinic gases and other products. Cracking of petroleum hydrocarbons was originally done by thermal cracking which has been almost completely replaced by catalytic cracking because it produces more gasoline with a higher octane rating. It also produces byproduct gases that are more olefinic, and hence more valuable, than those produced by thermal cracking.

Basically, there are two different configurations for an FCC unit: the “stacked” type where the reactor and the catalyst regenerator are contained in a single vessel with the reactor above the catalyst regenerator and the “side-by-side” typ e where the reactor and catalyst regenerator are in two separate vessels. The schematic flow diagram of a typical modern FCC unit in Figure 6.1 is based upon the “side-by-side” configuration.

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Fig. 7.1. Fluid catalytic cracking process

5.Пользуясь технологической схемой, представленной на рис. 7.1, переведите на русский язык следующие слова и словосочетания.

flue gas

catalyst fines separator

electrostatic precipitator

catalyst fines hoppers

combustion air

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slurry oil cracked naphtha fuel oil

phenolic sour water sidecut stripper slurry settler turbo-expander cyclones

catalyst withdrawal well catalyst riser

regenerated catalyst slide valve spent catalyst slide valve

6. Переведите с листа на русский язык следующий текст.

The preheated high-boiling petroleum feedstock (see fig. 7.1) consisting of long-chain hydrocarbon molecules is combined with recycle slurry oil from the bottom of the distillation column and injected into the catalyst riser where it is vaporized and cracked into smaller molecules of vapor by contact and mixing with the very hot powdered catalyst from the regenerator. The hydrocarbon vapors “fluidize” the powdered catalyst and the mix ture of hydrocarbon vapors and catalyst flows upward to enter the reactor. The reactor is in fact merely a vessel in which the cracked product vapors are separated from the spent catalyst and hydrocarbon vapors.

Since the cracking reactions produce some carbonaceous material that deposits on the catalyst and very quickly reduces the catalyst reactivity, the catalyst is regenerated by burning off the deposited coke with air blown into the regenerator.

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The hot catalyst leaving the regenerator flows into a catalyst withdrawal well where any entrained combustion flue gases are allowed to escape and flow back into the upper part to the regenerator. The hot flue gas exits the regenerator after passing through multiple sets of two-stage cyclones that remove entrained catalyst from the flue gas.

The reaction product vapors flow from the top of the reactor to the bottom section of the distillation column where they are distilled into the FCC end products of cracked naphtha, fuel oil and offgas. After further processing for removal of sulfur compounds, the cracked naphtha becomes a high-octane component of the refinery's blended gasolines.

The main fractionator offgas is sent to the gas recovery unit where it is separated into butanes and butylenes, propane and propylene, and lower molecular weight gases (hydrogen, methane, ethylene and ethane).

The bottom product oil from the main fractionator contains residual catalyst particles which were not completely removed by the cyclones in the top of the reactor. For that reason, the bottom product oil is referred to as a slurry oil. Part of that slurry oil is recycled back into the main fractionator above the entry point of the hot reaction product vapors so as to cool and partially condense the reaction product vapors as they enter the main fractionator. The remainder of the slurry oil is pumped through a slurry settler. The bottom oil from the slurry settler contains most of the slurry oil catalyst particles and is recycled back into the catalyst riser by combining it with the FCC feedstock oil. The socalled clarified slurry oil or decant oil is withdrawn from the top of slurry settler for use elsewhere in the refinery or as a heavy fuel oil blending component.

7.Определите, являются ли следующие утверждения верными в соответствии с текстами упражнения 4 и 6.

1.The oldest and the simplest cracking process is fluid catalytic cracking.

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