Production of Xylose from Corncobs

Siddharth Bhandari. Int. Journal of Engineering Research and Application www.ijera.com
ISSN : 2248-9622, Vol. 6, Issue 9,(Part-4) Sep.2016, pp.77-84
www.ijera.com 77|P a g e
Production of Xylose from Corncobs
Dr.N.Anil, K.Sudarshan, N.Narasimha Naidu, Mohseen Ahmed
(Department of Chemical Engineering, Anurag Group of Institutions, Hyderabad, Telangana, India)
I. INTRODUCTION
A. Xylose:
Xylose ( xylon, "wood") is a sugar first isolated
from wood, and named for it. Xylose is a pentose
processing, the molecular formulae C5H10O5, which
is found in Hemi-cellulose of natural substance of
fibrous vegetables and fruit, as well as in Corn
Cobs, Bagasse and various hard wood trees like
Birch. Although xylose taste and looks exactly like
sugar, which is really sugars mirror image.
The corn cobs materials containing 20 % of xylan,
which is synthesis by acid hydrolysis and converted
to xylose having a low calorific valve and
exhibiting a sweetening power, having
approximately equivalent to 67% that of sucrose.
Xylose has 40 percent fewer calories and 75
percent fewer carbohydrates then sugar and it is
slowly metabolized, resulting in very negligible
changes in insulin.
Structure:
The acyclic form of xylose has chemical
formula HOCH2(CH(OH))3CHO. The cyclic
hemiacetal isomers are more prevalent in solution
and are of two types: the pyranoses, which feature
six-membered C5O rings, and the furanoses, which
feature five-membered C4O rings (with a pendant
CH2OH group). Each of these rings subject to
further isomerism, depending on the relative
orientation of the anomerichydroxy group.
Crystalline Xylose is composed of white crystals
which are odorless and slightly hygroscopic.
Figure-Crystalline xylose
Physical Properties of Xylose:
Specific Gravity: 1.525
Other Name : Wood Sugar
Density : 1.525g/cm3
(at 20°C)
Colour : White
Melting Point : 153-158o
C
Solubility : Water -125% w/w
RESEARCH ARTICLE OPEN ACCESS

Occurrence
Xylose is the main building block for the
hemicellulose xylan, which comprises about 30%
of some plants (birch for example), far less in
others (spruce and
pine have about 9% xylan) it is the first
saccharide in biosynthetic pathways of most
anionic polysaccharides such as heparan sulfate and
chondroitin sulfate
Hydrolysis of Xylan:
C5H8O4 + H2O C5H10O5
Xylan Water H2SO4 Xylose
Uses of Xylose:
Xylose is a versatile product having applications in
various fields.
 Xylose is used as a source to prepare food for
diabetic patients.
 It is used as an environmental friendly non-
toxic water solution cleaning component.
 It is used in dying i.e., textile industry.
 It is used in tanning i.e., leather industry.
 It is used as a non-nutritive sweetener in
pharmaceutical industry.
II. EQUIPMENTS
Xylose:
A. Autoclave
 High torque zero leakage magnetic drive
coupling.
 Maximum working pilot plant upto 210kg/𝑐𝑚2
& temperature upto 673K.
 It is complete pilot plant with gas charging
liquid closing, vaccum plant, Auto cooling
system chiller, condenser for distillation or
reflux, thermic fluid heating system etc.
 Size of the vessel used is 2lit capacity.
 The vessel which is used is made up of SS-
316. Hastelloy B/C., M.O.C-S.S-316, Monel,
Nickel, Titanium, Alloy 20 and Teflon coated
SS-316.
 The autoclave system is continuously
monitors, control and record various
parameters.
 Fixed head reactor with bomb raising and
lowering arrangements.
 GMP(Good Manufacture Practice) model
panel & trolley of SS.
Applications:
It is used for reactions like Alklation,
Amination, Carboxylation, Catalytic reduction,
Chlorination, Dehyrogenation, Esterification,
Etoxylation halogenations, Hyrgenation,
Methylation, Nitration, Oxidation, Polymerisation,
Sulphonation etc., at high pressure and
temperature.
 To invent chemicals.
 To produce chemicals in small quantity.
 For pilot plant purpose.
 For quality control and process improvements.
 To study reaction parameters.
 For heterogenous mixing.
120°C

B. Vacuum pump:
A compressor that takes suction at a
pressure below atmospheric and discharges against
atmospheric pressure, it is called a vacuum pump.
As the absolute pressure at the suction
decreases, the volumetric efficiency drops and
approaches at the lowest absolute pressure
attainable at the pump. It consists of a diaphragm
pump in which reciprocating member is a flexible
diaphragm, which is made of metal, plastic, or
rubber. It can develop a discharge pressure of
3.0m3
/hr.
Reactor:
The Diameter of the reactor = 31cm = 1.2 ft
The Height of the reactor = 68. 58cm = 2.3 ft
C. Resin Column
Description:
Resin is a macro-porous weakly basic
anion resin having a tertiary amine functionality
attached to polymeric styrene Di-vinyl benzene
matrix, Resin is supplied in free base form ready
for immediate use. The combination of macro-
porous structure and tertiary amine functionality
results in fast reaction rates, high regeneration
efficiency, low rinse requirements and excellent
chemical and physical stability. Resin can be
effectively regenerated with sodium hydroxide,
water and hydrogen peroxide, Resin can be used to
treat water/process stream to remove free mineral
acidity (Chlorides, Sulphate and nitrates). Resin
particle size range from 0.3 to 1.2mm.
Packing: Resin are supplied in 50 lts, plastic bags.
It can be supplied in 180 lt mild steel drums with
plastic liner. The resin is always supplied in the
free base form.
Purpose of Resin: Here, Resin is used for removal
of acid content, color from the xylose reaction
mixture and after passing through the resin, the
xylose reaction mixture is neutral, color less and
resin absorbs other sugars except xylose.
The resin is to be regenerated, for purpose
of regeneration, taken 225gms of sodium hydroxide
(NaOH) pellets and diluted in 7 lts of water
(manjeera) thoroughly. Then after the dilution, the
NaOH solution was passed through the 12 lts of
resin in a resin column, air compressor
(fluidization) also given to the resin in a resin
column and kept for 30 min because for the proper
mixing of the resin with NaOH solution in the
presence of the fluidization. Then it is discharged
slowly into a container. The purpose of using
NaOH solution is to remove the colour, from the
resin which is absorbed during the Xylose reaction
mixture passed through the resin. To it, several
washing with water is given to remove alkali and
finally it is regenerated with H2O2. Take
approximately 100ml H202 which is diluted in 6lts
of water and it is passed through the 12 lts of resin
in a resin column, after discharging the H202
solution from the resin column. Again several
washings is done with water, until we get the resin
to be neutral in nature. The neutral nature which is
obtained, after regeneration of resin can be check
by using PH
paper ranges (2 – 11).
Pressure Gauge
Steam
Steam Inlet Valve
Container
Discharging Valve
Thermo well
Flanged coupling
Water
Applying
Vacuum Pump
Water
Inlet Valve

Figure: Resin column
D. Rotary Evaporation:
Figure- rotary evaporator
Rota vapor is used for the removal of Solvent
(water, methanol) from the solute by vaporization.
It can also used for other purposes like
Recrystallisation, synthesis and cleaning of fine
chemicals and Soxhlet extractions.
Principle:
With a vacuum rotary evaporator, single step
distillations are performed and in a product friendly
manner. The basis of this procedure is the
evaporation and condensation of solvents using a
rotating evaporating flask.
Distillation can be performed under vacuum. This
increases performance and helps to protect
products. Distillations can be performed under
vacuum and atmospheric pressure.
Operation:
 Evaporation area:
The solvent is heated over a heating bath.
In the rotating evaporating flask, a thin solvent film
forms on the inside of the flask, resulting in
increased evaporation rate. Rotation also results in
even mixing of the material and thus, prevents
stationary over heating in the flask.
 Rotation drive:
The drive unit makes sure that the
evaporating flask rotates evenly with the resulting
advantages.
 Cooling area:
The solvent vapor flows very quickly in
the condenser. Here, the energy in the solvent
vapor is transferred to cooling medium (mostly
water) and the solvent condenses.

 Receiving flask:
The receiving flask receives the
condensing solvent.
 Vacuum:
Vacuum reduces the boiling temperature
and thus increases performance of distillation.
Evaporating performance is influenced by
distillation, pressure (vacuum), heating bath
temperature, rotation speed and size of evaporating
flask.
E. Cryostat (Julabo):
The julabo-refrigerated circulators employ
a circulator head and a cooling machine with bath
tank, and have been designed for heating and
cooling of liquids in a bath tank. Besides the
cooling aggregate, the main functional elements are
the heater, circulation pump and control
electronics. The medium used is water and the
temperature range is 50
C-800
C and has a capacity
of 5litres of water.
In the experiments, the Cryostat (julabo) is
used to circulate chilled water in the condensers of
rotavapor, Soxhlet extractor and stirred vessel. The
purpose of the Cryostat (julabo)is to supply the
chilled water to the condenser, to condense the
vapours of the solvent.
III. MATERIALS & METHODOLOGY
A. Materials Used For Xylose:
 Corncobs:
A corn cob, is the central core of an ear of
maize (Zea mays ssp. mays). It is the part of the ear
on which the kernels grow. The ear is also
considered a "cob" or "pole" but it is not fully a
"pole" until the ear is shucked, or removed from the
plant material around the ear.
Young ears, also called baby corn, can be
consumed raw, but as the plant matures the cob
becomes tougher until only the kernels are
edible.The innermost part of the cob is white and
has a consistency similar to foam plastic
Figure : Corn cobs
Corncobs are an important by product of
the sweet corn processing industry in Egypt, where
they represent about 15% of the total corn
production and the total volume of this by-product
generated from the total volume of corn was
estimated to be 54,424 ton in 2008 (personal
communication, Egyptian Directorate of
Agriculture). Worldwide, corncobs are either used
as animal feed or returned to the harvested field as
fertilizer.
Corncobs contain: 39.1% cellulose,42.1%
hemicellulose,9.1% lignin,1.7% protein and 1.2%
ash .
Due to their chemical composition, corn
residues show great potential as a renewable raw
material for producing a variety of added-value
chemicals, such as lactic acid, citric acid, sugars,
and ethanol . On the other hand, the secondary
metabolites and constituents of corncobs remain
unclear. Development of an efficient way to utilize
corncobs will require additional research into the
chemical nature of this environmental agro-waste
and its potential application to the production of
valuable chemicals and pharmaceuticals.
Uses
Corncobs find use in the following applications:
 Industrial source of the chemical furfural
 Fiber in fodder for ruminant livestock (despite
low nutritional value)
 Water in which corncobs have been boiled
contains thickeners and can be added to soup
stock or made into traditional sweetened
corncob jelly

 Bedding for animals – cobs absorb moisture
and provide a compliant surface
 A mild abrasive for cleaning building surfaces,
when coarsely ground
 Raw material for bowls of corncob pipes
 As a bio-fuel
 Charcoal production
 Sulphuric Acid:
Sulfuric acid is a highly corrosive strong
mineral acid with the molecular formula H₂SO₄
and molecular weight 98.079 g/mol. It is a
pungent-ethereal, colorless to slightly yellow
viscous liquid that is soluble in water at all
concentrations.
 Resin:
Resin the removes the color when a fluid
is passed through it.it acts as a good adsorber.
 Methanol:
Methanol, also known as methyl alcohol,
wood alcohol, wood naphtha, methyl hydrate, or
wood spirits, is a chemical with the formula
CH₃OH.
Boiling point: 64.7 °C
Density: 792 kg/m³
Formula: CH3OH
Molar mass: 32.04 g/mol
Melting point: -97.6 °C
Vapor pressure: 13.02 kPa
Procedure:
Extraction of xylose from corn cobs
1. Washing
2. Acid Hydrolysis
3. Extraction
4. Centrifuge
5. De-colorization & Neutralization
6. Rota evaporation
7. Crystallization
8. Filtration
9. Drying (Finished Product)
1. Washing:
2kgs of the corn cobs (dry) was fed into
the reactor and to it 8lts of water (manjeera) was
added. Then the heat is supplied to the reactor by
means of the steam and maintained at a pressure of
1 - 1.2kg/cm2
. After obtaining the temperature of
120o
C, it was maintained for ½ hr i.e., 30 min, it is
washed for several times for removal of impurities
such as dust, lignin, sand and other foreign bodies,
after washing the discharge is collected out.
2. Acid hydrolysis:
To the above wet corn cobs, 120 gms of
concentrated sulphuric acid (98.9%) was diluted in
8lts of water (manjeera), after dilution the
concentration is 1: 6 ratio with respective to Corn
cobs basis, the diluted sulphuric acid was fed to the
reactor by means of vacuum pump, heating is given
by means of steam and maintained at 120o
C at a
pressure of 1- 1.2 kg/cm2
throughout the reaction
period i.e., 3hrs in the mean for every ½ hr reaction
we have collected samples which were sent for
HPLC analysis. After completion of the reaction
period, the reaction material was discharged and it
was collected in a container.

3. Extraction:
To the above reacted corn cobs, 8lts of the
water was charged into the reactor for Crude
Xylose Extraction, it was collected and recycled for
about 30 min. After completion of extraction, the
extracted material was collected in a container.
4. Centrifuge:
The above reaction material (Acid
Hydrolysis + 1st, 2nd extraction) was passed
through the centrifuge for the removal of
suspended particles and makes the material to be
clear.
5. De-Colourization & Neutralization:
After completion of the centrifuge, it is
then passed through the Ion-Exchanger resin for
the removal of acid, colour, other sugar and salts
from the reaction material and makes the material
to be neutral and Colour less.
6. Rota evaporation:
The filtrate neutralized from resin column
is taken as a feed to the Rota Vapor. Here
complete distillation or evaporation of water from
the feed takes place and to it a methanol wash is
given so that to remove the left-out moisture from
the product. Thus after completion of the Rota
Evaporation, Crude product is obtained.
7. Crystallization:
To the Crude Product a measured quantity
of methanol is added which is about one third of
the crude product obtained and mixed it
thoroughly, a pinch of fine powdered pure Xylose
is seeded and kept aside for crystallization process.
8. Filtration:
After completion of the crystallization, it
is filtered under G3 filter funnel by using a
measured quantity of methanol, in the presence of
vacuum pump for filtration purpose. Mother liquor
is collected at the bottom and filtered xylose at the
top.
9. Drying (finished product):
After completion of filtration, the finished
product is kept under vacuum, to make the product
complete dry.
Figure-Powder xylose
IV. ANALYSIS
Material Balance for Xylose:
Experiment:
Material input Quantity (kgs) Material output Quantity (kgs)
Washing:
Wet corn cobs +
Water
16.8 Crude Xylose Extract 16
Wet corn cobs+
Water
15.6 Crude Xylose Extract 15.2
Acid Hydrolysis:
Water + H2S04ACID+
Corn cobs
10kgs + 0.18kgs+
6.41kgs=16.59
Reaction Mixture 16

V. RESULTS
Washing:
Wash-1:
Input:
Weight of dry corn cobs = 7.3kgs
Amount of water used for washing = 40kgs
Output:
Weight of filtrate = 35.5kgs
LOSS = INPUT-OUTPUT
= 40-35.5 4.5kgs
Wash-2:
Input:
Amount of water used for washing = 35.5kgs
Output:
Weight of filtrate = 30kgs
LOSS = INPUT-OUTPUT
=35.5-30 5.5kgs
Wash-3:
Input:
Amount of water used for washing = 30kgs
Output:
Weight of filtrate = 20kgs
LOSS = INPUT-OUTPUT
=30-20 10kgs
Wash-4:
Input:
Amount of water used for washing =20kgs
Output:
Weight of filtrate = 13.5kgs
LOSS = INPUT-OUTPUT
=20-13.5 6.5kgs
Weight of wet corn cobs=15.6kg
Weight of dry corncobs per kg=2.13kg
Acid hydrolysis:
Total input 16.59kgs output 16kgs
Weight of corn cobs = 6.41kg
Weight of water = 10kgs
Weight of acid = 0.18kg
Others = 0.59kg
VI. CONCLUSION
During the process development for the preparation
of xylose maximum amount of yield was achieved.
REFERENCES
[1]. https://en.wikipedia.org/wiki/Rotary_evap
orator
[2]. Hand Book of Cane Sugar Technology, by
R. B. L. Mathur.
[3]. Encyclopedia of Chemical Technology, by
Kirk & Othmer.
[4]. Perry’s Chemical Engineering Hand
Book.
[5]. Unit Operations of Chemical Engineering,
by Warren. L. Mc Cabe.
[6]. Environmental Engineering, by C. S. Rao.
ACID HYDROLYSIS

Production of Xylose from Corncobs

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