International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
Applications of Hydrate Technology in Food Industry: A
Review of Experimental Studies
Sapna Kungrani#1 Ketan Joshi*2 Guide: Prof. S. L. Bhagat#3, Prof. R. S. Jadhao*4
#1,2
Student, 3,4Faculty, Department of Chemical Engineering
3
Pravara Rural Engg.College, Loni
Abstract:
Gas hydrate formation as a separation technology shows tremendous potential, both from a physical feasibility
(in terms of effecting difficult separations) as well as an envisaged lower energy utilization criterion. It is
therefore a technology that should be considered as a future sustainable technology and will find wide
application, possibly replacing a number of current commercial separation processes. In this article, we focus
on presenting a brief description of the positive applications of clatharate hydrates and a comprehensive survey
of experimental studies performed on concentration process using gas hydrate formation technology. Thus a
new tomato and orange juice concentration technology using CO2 hydrate formation is Presented. The CO2
hydrate equilibrium conditions were measured by the isochoric pressure search method and tomato juice
concentration experiments were carried out in a high-pressure stirred reactor. Moreover, the dehydration ratio
was defined and CO2 hydrate formation rate constants were calculated. . The effects of feed pressure,
temperature, and juice volume on the dehydration ratio were investigated. The results show that the tomato and
orange juice used in this work has almost no effect on CO2 hydrate phase equilibrium conditions, but can
accelerate CO2 hydrate formation and the results also demonstrated that removal of water with the help of CO2
hydrate is an efficient technology for tomato and orange juice concentration.
Keywords: carbon dioxide, clathrate hydrate, concentration, orange juice, separation, tomato juice.
I.
Å and is relatively large, so that it is too big for the
small cavity of structure I.[3]
INTRODUCTION:
Gas hydrates (clatharate hydrates) are
crystalline solid structures consisting of water and
small molecules such as CO2, N2, CH4, H2, etc.
which are formed under conditions of low
temperature and specified (generally high) pressure
[1].
They belong to a general class of inclusion
compounds commonly known as clatharate. A
clatharate is a compound of molecular cage structure
made of host molecules encapsulating guest
molecules. It is also considered a chemical substance
consisting of a lattice of one type of molecule
trapping and containing a second type of molecule.
Natural gas clatharate owe their existence to the
ability ofH2O molecules to assemble via hydrogen
bonding and form polyhedral cavities.[8]
Natural gas hydrate is a naturally occurring ice-like
solid, which is made of water molecules as the cage
forming host and other molecules (mostly methane
and carbon dioxide) as the guest. The guest
molecules, like methane or carbon dioxide, are of an
appropriate size such that they fit within cavities
formed by the host material. Common clatharate
compounds of interest are those formed from
CO2/H2O and CH4/H2O mixtures.[2]
CO2 hydrates can be formed at moderate
temperature and pressure conditions (such as 5
°C,15 bar); at room temperature and ambient
pressure they decompose again. Simple pure carbon
dioxide hydrates form I type hydrates with large
cavities. The CO2 molecule has a diameter of 5,12
ISSN: 2231-5381
Figure 1: Structure I hydrate (sI) withCO2 molecule
Fresh fruits and fresh juices from vegetables and
fruits are very good sources of valuable nutrients
and
completed
our
diet
with
essential
vitamins(especially hydro soluble vitamins) and
minerals, dietary fibers, small quantities of lipids
and proteins, being in the same time good sources of
carbohydrates.[5]. Thus it is really important to
bring them in our daily diet.
Orange juice is made by squeezing the fresh orange,
drying and later re-hydrating the juice, or
concentration of the juice and later adding water to
the concentrate. It is known for its health benefits,
particularly its high concentration of vitamin C. A
cup serving of raw, fresh orange juice, amounting to
248 grams or 8 ounces, has 124 mg of vitamin C
http://www.ijettjournal.org
Page 215
International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
(>100% RDI).It has 20.8 g of sugars and has
112 Calories. It also supplies potassium, thiamin,
and folate.
Citrus
juices
contain flavonoids (especially in the pulp) that may
have health benefits. Orange juice is also a source of
the antioxidant hesperidins. Because of its citric
acid content, orange juice is acidic, with a
typical pH of around 3.5.[4,5]
Fruit juice concentration is recognized worldwide
as a way to preserve fruit and reduce transport costs.
Despite recent advances in fruit juice concentration,
there remain numerous challenges. Evaporation,
membranes (ultra filtration, reverse osmosis and
membrane distillation), and freeze concentration
have been developed for concentrated juice
processing [1--4]. However, the evaporation process
is usually carried out in evaporators at high
temperature, which causes valuable constituent
losses (for example aroma compounds) and
decreases the final product quality. Membrane
concentration is regarded as a good alternative to the
thermal methods of juice concentration, but the
membrane could get dirty as the product is
concentrated and the concentration process is costly
[2,3]. Regarding the third method, concentrate
quality is also satisfactory but it consumes a lot of
energy, in particular during the ice nucleation step
[4].
The concentration of dilute aqueous
solutions using clatharate hydrate formation is,
similar to but, more economically feasible than
freeze concentration because clatharate hydrates can
be formed at temperatures above the normal freezing
point of water.[1]
In this paper various applications of hydrate
technology in the food industry are considered.
Applications such as concentration of orange and
tomato juice are discussed. As the juice
concentration is necessary to reduce the transport
cost and also the concentrated juice acquires less
space and hence the minerals, vitamins and other
acids are retained even after concentration.
II.
PROCEDURE
FORMATION
FOR
HYDRATE
The procedure for concentration of orange
juice as well as tomato juice follows the same
technique. The reactor was designed to produce
hydrates in rapid manner, with hydrate formation
times of few minutes. Moreover the new-improvedconfiguration is suitable for hydrate formation both
through bubbling gas into the liquid phase and
through spraying aqueous solution into the gas phase
as shown in fig. In this set of experiments, the
reactor was used to produce carbon dioxide hydrates
through spraying aqueous solution into the gas phase
according to the procedure described below [6].
ISSN: 2231-5381
Figure 2: process of concentrating
The same principle works for the tomato
juice. The established amount of aqueous solution is
firstly uploaded and the reactor is filled with carbon
dioxide from gas bottles until the internal pressure
equals the experimental pressure and then cooled.
Gas is bubbled into the liquid phase through five
check valves.
A Seafloor Process Simulator (SPS)
consisting of a 72 L vessel was used for mesoscale
experiments investigating the nature of hydrate
nucleation and dissociation at pressures and
temperatures required for stability of hydrates of
CO2. The same experiments were duplicated in a
smaller (0.45 L). it was found that experiments in
the SPS resulted in hydrates consistently forming at
lower over pressures and in shorter induction times
than equivalent experiments in the smaller vessel.
The variability of pressure and/or induction time for
hydrate formation was not eliminated by using the
SPS, but it appeared to be less dramatic (small
coefficients of variation) when compared with a 450
mL. Parr vessel. The observed differences were
attributed to increased bubble surface area, gas
concentration, lifetime of bubbles, total volume of
the SPS, or a combination of the above. Thus
conclusion comes that mesoscale experiments such
as those in the SPS, may perhaps be more
representative of hydrate accumulation in the natural
environment.(Oak Ridge National Laboratory)
investigated formation of a sinking carbon dioxide
(CO2) hydrate composite as an alternative to direct
liquid CO2 injection and pure CO2 hydrate
formation for ocean carbon sequestration. Raman
spectroscopy was used as a tool to understand the
formation and spectroscopy of a semi-solid sinking
CO2hydrate composite formed using a co flow
injector in the 72 L and 0.45 L pressurized vessels at
pressure and temperature conditions equivalent to
approximately 1.3 km depth in the ocean. The
temperature is controlled in order to achieve
relatively uniform values inside the reactor.
http://www.ijettjournal.org
Page 216
International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
III.
DISSOCIATION OF CO2 HYDRATES
After CO2 is separated from juice as
hydrates at the hydrate formation chamber, CO2
hydrates are transported to the separator, where CO2
hydrates are dissociated to water and gaseous CO2
again. It is also possible to send CO2 hydrates to the
deep sea bottom without dissociation. The heat is
242,200MJ/h that needs to decompose hydrates. The
hydrate phase can be later dissociated by
depressurization and/or heating and consequently
CO2 can be recovered [1]
Where z is the compressibility factor of CO2 gas
calculated by the SRK equation of state, and
subscripts and e refer to component of the feed gas
and equilibrium gas. The volume of CO2 gas was
assumed constant throughout the hydrate formation
process (volume changes due to the phase transitions
were neglected).
Physio-chemical properties
The contents of reducing sugar, total acid, vitamin c,
soluble solid and water content of orange and
tomato juice used in this study are given in Table1
and 2 resp.
Reducing sugar
(g/100g)
4.42
Total acid (g/kg)
6.08
Vitamin C (mg/100g)
49.96
Soluble solid
10.5%
Water cut
87.7%
Figure 3: Carbon dioxide hydrates on the internal
heat exchanger.
Dehydration ratio.
CO2 connects with water to form CO2 hydrate
based on the following reaction equations:
Table1: For orange juice
Reducing sugar
(g/100g)
2.51
Total acid (g/kg)
3.31
Vitamin C (mg/100g)
16.85
Soluble solid
5.5%
Water cut
94.2%
Table2: For tomato juice
IV. CALCULATION METHOD
The moles of gas consumed. The number of moles
of CO2 gas that has been consumed during hydrate
formation can be calculated as
Where n is the hydrate number of CO2 hydrate.
V. ECONOMY OF THE CLATHARATE
TECHNOLOGY
 Hydrate technology requires 151kJ/kg,
where the evaporation requires 2055kJ/kg
water.

As less heat is required hence less energy is
consumed
The thermodynamic analysis of the process enable
us to estimate capacities, sizes, abilities, and so on
of necessary equipments like the compressor, the
heat exchanger, the hydrate formation chamber, and
so on. According to these specifications the cost of
facilities can be decided. Also energy cost can be
calculated.
VI. RESULTS AND DISCUSSION
A first set of experimental runs were carried
out for CO2 hydrate production. Effects of additives,
such as THF and SDS, were tested. The amount of
additives was chosen according to the optimal
ranges of concentration. Typical profiles of internal
ISSN: 2231-5381
http://www.ijettjournal.org
Page 217
International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
pressure and temperature for an experimental run of
15 min are shown in Fig. Those profiles are for
experimental run 2. In particular, internal
temperature is calculated as the average of the two
temperature values measured by two thermocouples
in two different positions.[6]. Both SDS and THF
promote formation of gas hydrates with a short
reaction time, suitable for industrial in-continuo
applications
X.
DISADVANTAGES OF
CONCENTRATED JUICE
 As the time elapses between making of
juice and its consumption, more vitamins
are lost.

XI.


in SDS 300 ppm—experimental run 2 Water
spraying starts at t = 2 Fig.
Pressure and
temperature profile with elapsing time for CO2
hydrate formation min.
VII.
ADVANTAGES OF THE HYDRATE
TECHNOLOGY
 High product quality due to lowtemperature operation

Absence of a vapor-liquid
maintaining original flavors.

Hydrate technology produces a superior
product.

process at low temperature,

High retention of volatile aroma
interface
VIII. DISADVANTAGES OF THE HYDRATE
TECHNOLOGY
 Uniform maintenance of temperature and
pressure values sometimes becomes
difficult.
IX.
ADVANTAGES OF CONCENTRATED
JUICE
 the concentrated juice reduces space
requirements

it also reduces time requirements
ISSN: 2231-5381
However essential antioxidants and
vitamins are volatile and are lost with the
passing time
CONCLUSION
The dehydration ratios were 20.2 and
99.3% with initial pressure at 2.10 and 4.43
MPa, respectively.
The results demonstrated that removal of
water by formation of CO2 hydrate is a
potential technology for orange juice
concentration.
The concentrated orange juice always saves time
and space requirements. The more amounts of
nutrients are present in concentrated juice. The
present investigation on Studies on Development of
orange soy RTS beverage were undertaken to
remove the beany flavor, to formulate the product
that is soy RTS beverage, to analyze the different
proportions blends of Orange RTS beverage with
respect to physico-chemical composition and
analyze the Organoleptic characteristics of prepared
orange RTS beverage. Organoleptic evaluation of
beverages showed that orange concentrated
beverage prepared from 80% orange juice proved to
be best according to physico- chemical properties.
Followed by the 70% orange juice blend, 60, and
50% orange juice blended in found to have good
taste and overall acceptability. Study reveals that
fruits could be used in making the beany flavor thus
promoting acceptability of soymilk. This could be
beneficial to communities where cow’s milk is
unacceptable, unavailable or unaffordable or due to
lactose intolerance.
A novel separation process was developed for
tomato juice concentration on the basis of CO2
hydrate formation. The CO2 hydrate equilibrium
conditions in the presence tomato juice were
measured by the isochoric pressure search method.
The tomato juice concentration experiments were
carried out in a high-pressure stirred reactor under
different conditions of feed pressure, temperature,
juice volume, and
stirring speed. The hydrate equilibrium results show
that the tomato juice used in this work has little
effect on CO2 hydrate phase equilibrium conditions,
but can accelerate CO2 hydrate formation. The
dehydration ratio increased with increasing the feed
pressure and decreasing the temperature. The
optimum tomato juice volume was 80 mL and the
http://www.ijettjournal.org
Page 218
International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
stirring speed has almost no effect on the
dehydration ratio. The CO2 hydrate formation
constants in tomato juice were the same order of
magnitude as the results of CH4 hydrate in the
presence of surfactants.
XII.
REFERENCES
[1] Ali Eslamimanesha, Dominique Richona February 2012,
―Application of gas hydrate formation in separation processes: A
reviewof experimental studies”, J. Chem. Thermodynamics 46
(2012) 62–71
[2] An introduction to natural gas hydrate/ clatharate, Journal of
Petroleum Science and Engineering 56 (2007) 1–8
[3] BaerbelEgenolf-Jonkmanns,Stefano Bruzzano, ―Properties
And Application Of Additiveenhanced Co2 Hydrates”, 7th
International Conference on Gas Hydrates (ICGH 2011)
[4] Shifeng Li,Yanming, ―Experimental Study Ofconcentration Of
tomatojuice By Co2 Hydrate Formation”, Chem. Ind. Chem.
Eng. Q. 21 (3) 441−446 (2015)
[5] Laura Corpas, Ariana-Bianca Velciov ―Physico-chemical
characterization of some fruits juices fromRomanian hypermarket
fruits,”, Journal of Agroalimentary Processes and Technologies
2012, 18 (1), 95-99
[6] Beatrice Castellani, ―Carbon Dioxide Capture Using Gas
Hydrate Technology”,Journal of Energy and Power Engineering
(2013) 883-890
[7] Fumio Kiyono, Akihiro Yamazaki, and Keiichi
Ogasawara,”Cost Estimation Of Co2 Recoverytechnology Using
Hydrates”,Fuel Chemistry Division Preprints 2002, 47(1), 78
[8] Veronica R. Blackwell,‖ Formation of clathratehydratesof
carbon dioxide and methane”, California institute of technology
Pasadena, California, 1998
ISSN: 2231-5381
http://www.ijettjournal.org
Page 219