CSEC Chemistry: Extracting Sucrose from Sugarcane

Summary

This video from the Caribbean Toots series dives into the process of extracting sucrose from sugarcane, covering the steps from harvesting to centrifugation. It begins with cutting sugarcane at a feeder table, crushing it in a roller mill, and spraying with water to release sucrose. The process continues with burning bagasse for energy, using calcium hydroxide in a settling tank to precipitate impurities and neutralize acidity, filtering through a rotary filter, and concentrating the juice in evaporators. The syrup then crystallizes in a vacuum pan, and finally, molasses and sugar crystals are separated by centrifugation, yielding sucrose and byproducts like molasses for further use.

Takeaways

• 🌿 The process of extracting sucrose from sugarcane involves several steps, starting with obtaining sugarcane from the fields.
• ✂️ At the feeder table, sugarcane stalks are cut into smaller pieces to facilitate easier manipulation.
• 🔧 The roller mill crushes the small pieces of sugarcane and sprays them with water to help dissolve the sucrose from the sugarcane cells.
• 🔥 The crushed sugarcane, or bagasse, is used as fuel in furnaces, which generates heat for evaporation and electricity.
• 💧 The dilute juice from the roller mill is treated in a settling tank with calcium hydroxide to precipitate impurities and neutralize acidity.
• 🚱 The rotary filter is used to separate solid particles from the liquid, removing the mud impurities from the juice.
• 🔬 The clear juice is then sent to boilers or evaporators where vacuum distillation occurs to concentrate the sugar and remove excess water.
• 🍯 The concentrated juice, or syrup, is sent to a vacuum pan where crystallization takes place to form sugar crystals.
• 🌀 Centrifugation is used to separate molasses from sugar crystals, resulting in a mixture that can be further processed.
• 🔄 The molasses can be reprocessed in the vacuum pan for further crystallization to extract more sugar crystals.

Q & A

What is the primary goal of the process described in the script?

The primary goal of the process is to extract sucrose from sugarcane.

What is the first step in the process of extracting sucrose from sugarcane?

The first step is to get sugarcane from the fields and cut the stalks into smaller pieces at a feeder table.

What happens to the sugarcane stalks after they are cut into smaller pieces?

The smaller pieces are crushed and sprayed with water in a roller mill to release the sucrose from the sugarcane cells.

What is the purpose of the bagasse produced after the crushing process?

The bagasse is sent to a furnace where it is burned to generate heat for evaporating water and producing electricity.

Why is calcium hydroxide added to the dilute juice in the settling tank?

Calcium hydroxide is added to precipitate impurities and neutralize the acidity of the juice, preventing the sucrose from breaking down into glucose and fructose.

How are the mud impurities removed from the juice after the settling tank process?

The mud impurities are removed through filtration using a rotary filter.

What happens to the clear juice after filtration?

The clear juice is sent to boilers or evaporators for vacuum distillation to concentrate the juice by removing most of the water.

What is the main process that occurs in a vacuum pan?

The main process in a vacuum pan is crystallization, where the concentrated juice is turned into sugar crystals.

What is the final step in the extraction process described in the script?

The final step is centrifugation, which separates the molasses from the sugar crystals.

What can be done with the molasses after it is separated from the sugar crystals?

The molasses can be further processed to produce alcohol or used as animal feed, and the sugar crystals can be sent to supermarkets or stores.

Outlines

00:00

🌿 Introduction to Sugarcane Processing

The video begins with an introduction to the chemistry syllabus, focusing on section A 2.6, which is about extracting sucrose from sugarcane. The presenter suggests watching the previous video on separation methods for better context. The process starts at the sugarcane fields, where stalks are cut into smaller pieces at a feeder table. These pieces are then crushed in a roller mill, where they are also sprayed with water to dissolve the sucrose from the sugarcane cells. The crushed material, now called bagasse, is considered waste but is actually valuable for generating heat in furnaces, which can be used for electricity and in later stages of the process.

05:01

🚰 Settling and Filtration of Sugarcane Juice

After crushing, the dilute juice is treated in a settling tank where calcium hydroxide is added to precipitate impurities and neutralize the acidity, preventing the breakdown of sucrose into glucose and fructose. The settled impurities are then filtered out using a rotary filter, which separates the solid particles from the liquid. The filtered juice, now clear, is sent to boilers or evaporators for further processing, while the impurities are washed and returned to the fields.

10:03

🔥 Evaporation and Crystallization of Sugar Syrup

The clear juice undergoes vacuum distillation in boilers or evaporators to remove most of the water, resulting in a concentrated syrup. This syrup is then sent to a vacuum pan where crystallization occurs, separating the solid sugar crystals from the solution. The process is carried out at low pressure to prevent caramelization and ensure the formation of sugar crystals rather than caramel. The outcome is a mixture of molasses and sugar crystals, called massecuites.

🌀 Centrifugation and Final Separation

The final stage involves centrifugation, where the massecuites are spun at high speeds to separate the molasses from the sugar crystals. The heavier sugar crystals are forced outward, leaving the molasses behind. The molasses can be further processed for various uses, such as alcohol production or animal feed, while the sugar crystals can be sent to markets. The process is concluded with a recap of the steps taken to extract sucrose from sugarcane, emphasizing the importance of each stage in the overall process.

Keywords

💡Sucrose

Sucrose, commonly known as table sugar, is a disaccharide composed of glucose and fructose. In the context of the video, sucrose is the desired product being extracted from sugarcane. The process of extraction involves several steps aimed at separating sucrose from other components in the sugarcane. The video emphasizes the importance of preserving sucrose and preventing its breakdown into simpler sugars like glucose and fructose.

💡Sugarcane

Sugarcane is a tropical grass from which many commercial sugar products are produced. It is the starting material in the video's discussion of sucrose extraction. The video describes the initial step of obtaining sugarcane from fields and processing it through various stages to ultimately extract sucrose.

💡Vita Table

A vita table, also known as a feeding table, is a piece of equipment used in the initial stages of sugarcane processing. It cuts the sugarcane stalks into smaller pieces to facilitate easier manipulation and processing. The video mentions the vita table as the first step after harvesting sugarcane, highlighting its role in preparing the cane for further processing.

💡Roller Mill

A roller mill is used to crush the small pieces of sugarcane into a fibrous pulp. In the video, the roller mill is described as the equipment where the crushed cane is mixed with water, allowing the sucrose to dissolve into the water, forming the juice. This is a critical step in the extraction process as it begins the separation of sucrose from the fibrous material.

💡Bagasse

Bagasse refers to the fibrous residue left after the juice has been extracted from sugarcane. The video explains that bagasse, while not the desired product, is still valuable as it can be used as fuel in furnaces to generate steam and electricity, which can power other parts of the sugar production process.

💡Settling Tank

A settling tank is used to allow impurities in the sugarcane juice to precipitate out. The video describes adding calcium hydroxide to the juice in the settling tank to help precipitate impurities and neutralize the acidity of the juice, which is crucial for preventing the breakdown of sucrose.

💡Calcium Hydroxide

Calcium hydroxide, also known as lime, is used in the settling tank to precipitate impurities and neutralize the acidity of the sugarcane juice. The video emphasizes its role in maintaining the integrity of sucrose by preventing it from converting into glucose and fructose, which are not the desired end products.

💡Rotary Filter

A rotary filter is a type of filtration equipment used to separate solid particles from the liquid in the sugarcane juice. The video explains that after the juice has been treated in the settling tank, it is passed through a rotary filter to remove the remaining impurities, resulting in clear juice.

💡Evaporators

Evaporators are used to remove water from the sugarcane juice through a process called vacuum distillation. The video describes how the clear juice is concentrated by boiling off the water in evaporators, which operate under reduced pressure to increase the efficiency of water removal and concentrate the sucrose.

💡Vacuum Pan

A vacuum pan is a vessel where the concentrated juice, or syrup, undergoes crystallization. The video explains that the syrup is further concentrated in the vacuum pan under low pressure to encourage the formation of sugar crystals, which is the next step towards obtaining pure sucrose.

💡Centrifugation

Centrifugation is a process used to separate the sugar crystals from the molasses. The video describes how the mixture of molasses and sugar crystals, known as massecuites, is spun at high speeds in a centrifuge, causing the heavier sugar crystals to be separated from the molasses. This step is crucial for obtaining pure sugar and molasses for further use.

Highlights

Introduction to the process of extracting sucrose from sugarcane.

Explanation of the importance of previous knowledge on separation methods.

Description of the first step: obtaining sugarcane from the fields.

Use of a feeder table to cut sugarcane stalks into smaller pieces.

Crushing sugarcane in a roller mill to release sucrose.

The role of water in dissolving sucrose from the crushed sugarcane.

Utilization of bagasse, the fibrous residue, for energy production.

The process of settling to precipitate impurities and neutralize acidity in the juice.

Addition of calcium hydroxide to the settling tank.

Use of a rotary filter to separate solid particles from the liquid juice.

The practice of returning mud impurities to the fields for soil enrichment.

Concentration of sucrose by evaporation in boilers or evaporators.

Application of vacuum distillation to remove water from the juice.

Transformation of concentrated juice into syrup.

Crystallization process in a vacuum pan to separate sugar crystals from syrup.

Centrifugation to separate molasses from sugar crystals.

Further processing of molasses for different uses.

Recap of the entire sucrose extraction process from sugarcane.

Transcripts

hey guys welcome back to caribbean toots

we are continuing the chemistry syllabus

and this is section a 2.6 today and we

are looking at

extracting sucrose from sugarcane in the

previous video we looked at different

separation methods

so you can just check that video out

before

watching this video to have a better

understanding on the methods that we're

using today

but we are looking at several steps and

there are

several methods of separation in the

process of extracting sucrose

functionality

so this should be really fun we're going

to look at

all these steps and finally finish at

centrifugation

okay so if you want to extract sucrose

if you want to extract

sucrose from sugarcane the first thing

that you need

is sugarcane so we're starting at the

sugarcane fields

we get some sugarcane from the sugarcane

fields

and we put this sugarcane stalks of

sugarcane

into what we call a vita table where the

sugarcane stocks are

are actually cuts into smaller pieces so

at the feeder table

the stocks are cut into smaller pieces

so that they're easier to manipulate

so we have these small pieces of cane

and now we're going to crush them

so the small pieces of cane small pieces

of cane

are going to go into what we call a

roller mill

so when we have the small pieces of cane

we push it

we put it in what we call a roller mill

and

in the roller mill the cane socks are

crushed

and sprayed with water so that the

sucrose from the cane

the sugarcane cells can actually

dissolve in this water

so we have crushing hair which is the

first major step

in this um extraction process

crushing and then we spray it with

water so that the sucrose from the cells

can just dissolve in it because we're

really looking for juice

spray with water so after we crush it

we're gonna have some trash and this

trash

is what we call badass

[Music]

is not what we're looking for

this is really trash however it's very

useful

because what they do they send it to the

furnace

and the heat from the furnace is used to

evaporate some water

and this water can help generate some

electricity

for the rest of the processes taking

place so we heat up the gas

and the steam can be used to generate

some electricity

also this heat can be used later on

in boilers or evaporators you'll see

what the purpose of those are

so we have we dealt with our vegas and

now we have some

dilute juice because you remember we

crushed the sugar cane sprayed with

water and now we have some sucrose

in some water so we say that's dairy

juice

dilutes diluted juice

juice juice

all right before i get to that i just

want main

one of the major steps all right so now

we have some dilute juice and we're

going to put it in a settling tank

now the purpose of this settling tank is

one

to precipitate the impurities and two

to neutralize the acidity of the juice

so we're going to precipitate some

impurities

how do we do that we add some calcium

hydroxide

so to the setting in a settling tank

we're going to add our diet

juice and we add some calcium

hydroxide which helps to

precipitate the impurities

and it also helps to neutralize

the juice to neutralize the acidic

juice so that the sucrose

won't break down into glucose and

fructose because those aren't the sugars

that we're looking for

we're looking for sucrose and because we

don't want it to break down

we neutralize its acidity so what do we

have now

we have some dilute juice with its muddy

impurities

kind of um precipitated

so we're going to say that we have some

money impurities

and in order for us to get rid of these

muddy impurities out of the juice

we're going to put it through a rotary

filter

now this rotary filter just in

simple just like in simple filtration

we're going to use it to separate

the solid particles from the liquid

particles because they're miscible

so we use the rotary total

we pass it through and we filter out

these money impurities

you filter out the money impurities from

or juice and sometimes they wash they

actually

wash the body impurities just so that it

can extract

all of the sucrose so sometimes they

wash

these money inferences to extract all

sucrose

that that could possibly be left in it

so let's wash impurities

and then they return these money

impurities to the fields

so they send the money immigration back

to the fields

all right great so now

what we have is some clear juice

so i'm going to call this clear juice

so we're sending the claire juice from

the rotary filter

to the boilers or evaporators so

remember

our juices clear but it's still bad root

and what we're looking for

is sugar crystals or molasses so

remember

what we have right now is clear dilute

juice so we're going to send it through

the boilers or evaporators to get to

help us

get that concentration that we're

looking for because

most of what we have right now is just

water that's not what we're looking for

we're looking for sugar

so we send it to the boilers or

evaporators

so at the boilers or evaporations the

main process taking place here is vacuum

distillation

what we're trying to do is get rid of

that solvent that water

and separate it from the or sugar or

crystals of sugar

so we we pass it through the bottles or

evaporation

or evaporators at high temperatures

so it's very high very high temperatures

and we try to evaporate or boil off

that solvent that water that's

dissolving your sugar

and this takes place at um reduced

pressure this usually takes place that's

on reduced

pressure so this process just

highlights i can do this on this

filtration

filtration

this was sedimentation

and this is now vacuum distillation

all right and you can see

our hair coming from the furnace the

heat from the furnace helps us to boil

or evaporate the solvent from our clear

juice

all right so now we have some

concentrated juice or some syrup

so the syrup is really concentrated we

boil off most of the solvents of natal

so it really concentrates it on

juice we have here so we call this syrup

[Music]

syrup concentrated juice

so now we're sending our syrup or

concentrated juice into what we call a

vacuum pan

now in a vacuum pan a process called

crystallization

takes place crystallization is basically

a process we use to separate

a solid solute from a solution

so in a vacuum pan we have the process

of crystallization taking place

all right so in a vacuum pan we have a

process called crystallization

and the syrup is crystallized that low

pressure just to prevent

um caramelization of the syrup because

we don't we're not looking for

caramelization we're looking for

real sugar crystals here so we have

crystallization taking place

to life crystallized

at low pressure and this low pressure is

just to prevent caramelization

because as i said before we're looking

for crystals not caramel

all right so now we've run our syrup

through a vacuum pan

what are we left with we're left with

something called

masquerade masquerade is a combination

of molasses and sugar crystals

so we have masculine let me write that

word for you guys

m a s s

e c u i t e

masculine and this mass device is going

to be centrifuge

now in centrifugation what basically

happens is that the mixture

is spun at really high speeds and the

the heavier particle which in this case

would be the solid crystal

kind of fly out of the centrifuge

leaving the molasses inside so in

centrifugation

we are separating the molasses from the

sugar

now that we have centrifuges mixture of

molasses and sugar

we can separate them we can get our

molasses and we can get some sugar

molasses can be further processed to get

alcohol wrong more for animal feed

and or sugar can just be sent to the

supermarkets

or the stores sometimes

when we have the mixture of molasses i

mean when we have the molasses separated

from the sugar crystals

we put it back into the vacuum pan for

further crystallization so we can get

even more

sugar crystals so this is really honor

find the sugar that we're getting here

and molasses let me just write that

[Music]

or you can also call it brown sugar

that's unbleached sugar and

molasses oh

this process is centrifugation

great so let's recap really quickly

so you're trying to extract some sucrose

from sugarcane the first thing we need

to do

is get the sugar cane we put it through

our feeder table

the stalks are cut into smaller pieces

the smaller pieces go to a roller mill

they're crushed and sprayed with water

that's the first main step crushing um

the gas is burned in a furnace

but the dilute juice from the crushing

method is put in a settling tank

where calcium hydroxide or lime helps

precipitate

impurities and neutralize the acidic

juice

just to prevent it from breaking down

into fructose and glucose

then we have our mud impurities that are

sent through a rotary photo

the filter it filters money impurities

and we wash the impurities for further

dilution of the sucrose if you want more

and these money increases are sent back

into the fields

we are now that was a process of

filtration

yes so we have one crushing

two segmentation at the settling time

three filtration at the rotary photo

the clear juice is sent to the boilers

or evaporators

with a process of vacuum distillation

and then after this we have some

concentrated syrup

sent to a vacuum pan where it is

crystallized

and this mixture massive eyes

masculine is going to be sent to be

centrifuged or separated

um that's molasses separated from sugar

so we have centrifugation

and then we can sew the molasses and sew

the brown sugar

all right so that's the end of this

video guys