science

Petrosix

Petrosix is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Petrosix rather than just read about it. In short: Petrosix is the world's largest surface oil shale pyrolysis retort with an 11 metres (36 ft) diameter vertical shaft kiln, operational since 1992. It is located in São Mateus do Sul, Brazil, and it is owned and operated by the Brazil energy company Petrobras.

Key takeaways

Petrosix belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Petrosix to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Petrosix from memory before moving on to harder problems.

Reference excerpt

Petrosix is the world's largest surface oil shale pyrolysis retort with an 11 metres (36 ft) diameter vertical shaft kiln, operational since 1992. It is located in São Mateus do Sul, Brazil, and it is owned and operated by the Brazil energy company Petrobras. Petrosix means also the Petrosix process, an externally generated hot gas technology of shale oil extraction. The technology is tailored to Irati oil shale formation, a Permian formation of the Paraná Basin.

History Petrobras started oil shale processing activities in 1953 by developing Petrosix technology for extracting oil from oil shale of the Irati formation. A 5.5 metres (18 ft) inside diameter semi-works retort (the Irati Profile Plant) with capacity of 2,400 tons per day, was brought on line in 1972, and began limited commercial operation in 1980. The first retort that used current Petrosix technology was a 0.2 metres (0.7 ft) internal diameter retort pilot plant started in 1982. It was followed by a 2 metres (6.6 ft) retort demonstration plant in 1984. A 11 metres (36 ft) retort was brought into service in December 1991, and commercial production started in 1992. The company operates two retorts which process 8,500 tons of oil shale daily.

Retort The Petrosix 11 metres (36 ft) vertical shaft retort is the world's largest operational surface oil shale pyrolysis reactor. It was designed by Cameron Engineers. The retort has the upper pyrolysis section and lower shale coke cooling section. The retort capacity is 6,200 tons of oil shale per day, and it yields a nominal daily output of 3,870 barrels of shale oil (i.e., 550 tons of oil, approximately 1 ton of oil per 11 tons of shale), 132 tons of oil shale gas, 50 tons of liquefied oil shale gas, and 82 tons of sulfur.

Process Petrosix is one of four technologies of shale oil extraction in commercial use. It is an above-ground retorting technology, which uses externally generated hot gas for the oil shale pyrolysis. After mining, the shale is transported by trucks to a crusher and screens, where it is reduced to particles (lump shale). These particles are between 12 millimetres (0.5 in) and 75 millimetres (3.0 in) and have an approximately parallelepipedic shape. These particles are transported on a belt to a vertical cylindrical vessel, where the shale is heated up to about 500 °C (932 °F) for pyrolysis. Oil shale enters through the top of the retort while hot gases are injected into the middle of the retort. The oil shale is heated by the gases as it moves down. As a result, the kerogen in the shale decomposes to yield oil vapor and more gas. Cold gas is injected into the bottom of the retort to cool and recover heat from the spent shale. Cooled spent shale is discharged through a water seal with drag conveyor below the retort. Oil mist and cooled gases are removed through the top of the retort and enter a wet electrostatic precipitator where the oil droplets are coalesced and collected. The gas from the precipitator is compressed and split into three parts. One part of the compressed retort gas is heated in a furnace to 600 °C (1,112 °F) and recirculated back to the middle of the retort for heating and pyrolyzing the oil shale, and another part is circulated cold into the bottom of the retort, where it cools down the spent shale, heats up itself, and ascends into the pyrolysis section as a supplementary heat source for heating the oil shale. The third part undergoes further cooling for light oil (naphtha) and water removal and then sent to the gas treatment unit, where fuel gas and liquefied petroleum gas (LPG) are produced and sulfur recovered. One drawback of this process is that the potential heat from the combustion of the char contained in the shale is not utilized. Also oil shale particles smaller than 12 millimetres (0.5 in) can not be processed in the Petrosix retort. These fines may account for 10 to 30 per cent of the crushed feed.

Worked examples

Example 1 — a first encounter with Petrosix

Start with the simplest possible case. Write down what Petrosix claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Petrosix before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Petrosix ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Petrosix

In research: Petrosix appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Petrosix in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Petrosix is common in secondary-school and first-year university syllabi. It links to neighbouring topics Oil shale in Brazil, Oil shale technology, Petrobras, so understanding it makes those chapters shorter.
In everyday life: Look for Petrosix outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Petrosix” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Petrosix in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Petrosix means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Petrosix out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Petrosix in simple terms?

Why does Petrosix matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Petrosix?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Petrosix.