Let's talk about the steam cracker, which is the heart of the petrochemical plant. This is the main unit that produces most of the petrochemicals in the plant. Okay, so steam cracker. Remember that we will be using naphtha as a raw material, and

what we want to do is obtain the most amount of ethylene, propylene, ethylene, and butane. Okay, so how do we do this? We're going to be using two main stages. The first one will be high in temperature and average in pressure.

Some even state the compression stage is a stage per se, but I actually prefer to group it into the second part, which is the cold stage. The cold stage must be high pressure, low in temperature. The main idea is to produce lots of olefins,

which must have double bonds in their carbon chains. The typical feedstock is naphtha, and it will be fuel oil, or even natural gas.  Even chemical processes exist to convert heavier components into more useful materials. So you have CₓHᵧ, which you don't know, you don't care. You're going

to have water and oxygen, and what you want to do is maximize ethylene, ethane, acetylene. Hydrogen gas is a byproduct.  These are selected carbon materials. Methane...well, technically you don't want that, but that's a byproduct. This is pro-

pylene.  This is what you want the most. This is what you want.  Ethane, propane. Propane production is also very important.  Butane has a double bond. Hexane...technically this is benzene. Some carbon leftovers, heavy oils, and so on.

Important parts right here. Let me highlight the important ones: This is the most important. Secondly, will be this one right here. Third will be these guys right here, and lastly, this one and this one right here.

Going as natural gas or to find petroleum gases. These can be used as seen gas, and this is benzene. If you want to separate that, you want to take away the carbon solid material (coke) and the heavy oils must be removed. Record temperatures that inform us...

between 700 to 800 Celsius. The reaction is pretty complex because we are producing a lot of material. In Iran, so it will be of no use to state each individual kinetic and individual material, because you're using bulk material chemistry. So just assume that...

you're getting this material. Talking about the structure, we've got the hot section. You have little furnaces—technically not furnaces, but they are the reactors which are producing the olefins—then you have the compression, quenching, and this is the cold section.

What you want is low temperature and plenty of distillation towers in order to remove the ethane, butane, propane, methane, and so on. Talking about that, let me show you this image. So this is a steam cracking unit in Wilton, in the northeast...

of England. You can see there are plenty of towers. What are those towers? Well, first I want you to answer this question: Is this the hot section or the cold section?  Since these are the distillation columns, therefore this must be the cold section. Okay, so this is the cold...

Section one: This tower separates C4 from C16 mixtures.  These are volatile materials. First, remove all C3 material.

Next, the depropanizer removes C3.  This leaves C1 and C2. We'll discuss C1-C3 in more detail later, but the main concept is shown here.

Then, the deethanizer separates C2 hydrocarbons.  C1 and C2 will be removed here.

This removes ethane, ethylene, and acetylene. Next is the demethanizer, which separates methane.

Stage 5, the splitter, separates propane from propylene (propylene has a double bond, propane has single bonds).

Stage 6 separates ethylene from ethane (ethylene has double-bonded carbons).

Plenty of separations, especially between C1, C2, C3, and C4 materials. These are the units; again, this is just an overview. Okay, so let's see how it goes. We've got a pyrolysis furnace; those are here and here. You have fuel because you

must increase the temperature. You have water; remember that this is steam cracking, and you get naphtha. You got here; there is reaction, then you bring the material here. There will be some more, let's say, cooling, and then you scrub the waste oil. Remember that we're going

to have some oils, and we are going to remove all other materials. Then we also have this C2, C3, C4, which are recycled. So remember, from here we're going to have these materials. This saturates—what we imply with 'saturates' is that this is a

same propane and butane materials. Okay, very important: we are going to apply the same pyrolysis, then we're going to clean these (scrubbing), and then now that we're ready, we are going to compress this. We compress this; we separate the light materials, which typically are hydrogen

gas, carbon monoxide, and the C1, C3 materials; some C3, C4. What shall we go down? And then we've got a washer. Essentially, what we want to do is to remove all the leftover material. We dry them, and we have only C1 versus C3.

We've got the demethanizer, which will take away methane. Here we have C2, C3. We have the de-ethanizer here. We have C2 cut and C3 cut. And the important part is that we need to ensure that we remove the... Here it goes, the

Ethane goes to the splitter. This splitter has a double bottom and triple-bonded material.  It goes down to the acetylene tower. From the acetylene, we separate and settle. This stripper recycles material here.

Remember, this is C2 material. Acetylene (C≡C) is topping still, and then we have pure ethylene (C=C). Remember, this is 60% of the material we use in petrochemicals. Now let's get back to the nicely separated C2 from the C3 cut.

You'll see here that we have C3, and from here C3 and C4. So we are...

mixing these C3 and C4.  This is going to have C4 here. This C3 cut is deeper. This will have the single-bonded three-carbon molecule, and you have propylene here. The C3 splitter ensures that...

propylene is purified, and all the material is recycled. Now, talking about C4, it goes directly here, and we purify C4 and بوتان (butane) at the end. These are very important. This is the double-bonded butene, and...

this will be the single-bonded butane. All leftover material will be saturates.  Before C2, C3, and C4 go back to pyrolysis, all this gets recycled, and technically, the yield increases. Okay, this was just an overview.

Make no worries, we're going to see this part by part. Actually, we're going to separate this into the hot section, called section A, and so on. Okay, this is a cycling sent. You've got your feed, furnace, steam, leftover material, cleaning, compression, caustic soda for cleaning.

And then you've got like gases. You've got the secondary method: is gasoline, ethylene, ethane. It's exactly the same, just a different arrangement. Important part right here: to detect and be sure that you can separate the hot section from the cold section. Okay, so now let's go more technical; let's

strip this process and let's see why it's so interesting and why do we get that many olivines from it. [Music]

Steam Cracker -  Overview (Lec031)

Chemical Engineering Guy

증기 분해는 석유화학 공장의 핵심 공정으로, 주로 나프타에서 석유화학 제품을 생산합니다.

이 프로세스에는 고온, 평균 압력 단계와 고온, 저온 단계의 두 가지 주요 단계가 포함됩니다.

목표는 올레핀(이중 결합을 가진 화합물)의 생산을 극대화하는 것입니다.

나프타, 연료유, 천연가스 등 다양한 공급 원료가 사용됩니다.

원하는 제품에는 에틸렌, 프로필렌, 에탄, 프로판, 부탄이 포함되며 메탄과 중질유는 부산물입니다.

가장 중요한 제품은 에틸렌과 프로필렌이며, 에탄, 프로판, 부탄이 그 뒤를 잇고 있습니다.

이 공정은 700~800°C의 온도에서 작동합니다.

이 반응은 벌크 물질 화학을 포함하는 복잡한 반응입니다.

이 프로세스에는 고온 섹션(반응기)과 저온 섹션(증류)이 포함됩니다.

수많은 증류탑이 있는 저온 섹션은 다양한 탄화수소를 분리합니다.

특정 타워는 C4와 C16 혼합물을 분리하고, C3 물질을 제거하며, C2 탄화수소를 분리합니다.

추가 분리 단계에는 메탄 제거, 프로필렌에서 프로판 분리, 에탄에서 에틸렌 분리 등이 포함됩니다.

이 프로세스는 C1, C2, C3 및 C4 자료를 분리하는 데 중점을 둡니다.

핫 섹션 및 전체 프로세스 흐름

고온 섹션에는 올레핀을 생성하기 위해 나프타, 증기 및 연료를 사용하는 열분해로가 포함됩니다.

폐유는 제거되고 C2, C3, C4 재료는 재활용됩니다.

이 과정에는 압축, 가벼운 물질 분리, 남은 물질 제거를 위한 세척이 포함됩니다.

추가 분리 단계에는 순수한 에틸렌 및 기타 제품을 얻기 위한 탈메탄화, 탈에탄화 및 분리가 포함됩니다.

C2 및 C3 탄화수소의 상세한 분리

에탄은 스플리터로 이동하여 아세틸렌을 분리하고 순수한 에틸렌을 생산합니다.

에틸렌은 석유화학 원료의 약 60%를 차지하는 주요 제품입니다.

C3와 C4 물질을 혼합하고 추가로 분리하여 프로필렌과 부탄을 정제합니다.

이 과정에는 부텐과 부탄을 정제하고 남은 물질을 재활용하여 수율을 높이는 것이 포함됩니다.

공급, 용광로, 증기, 세척, 압축 및 분리 단계를 강조하여 전체 프로세스가 요약되어 있습니다.

핫 섹션과 콜드 섹션을 구분하는 것의 중요성이 강조됩니다.