Comprehensive Report: Cryo-Desalination and Propane Gas Application

This report focuses on Cryo-Desalination using propane gas, a freeze desalination method for extracting fresh water from saline sources. It details the process, which involves freezing saltwater, separating ice and brine, and melting the ice. The report discusses the concept, rise, and required parts of Cryo-Desalination, including the use of propane gas as a freezing agent. It explains the working procedure, emphasizing ice-brine separation using cryosol. The report also covers the cost aspects, comparing Cryo-Desalination with reverse osmosis, and highlights the benefits of the process, such as its environmental friendliness. The report concludes with a summary of the findings and references to relevant literature.

Running head: CRYO-DESALINATION USING PROPANE GAS
Cryo-Desalination Using Propane Gas
Name of the Student
Name of the University
Author Note

1CRYO-DESALINATION USING PROPANE GAS
Abstract:
The main aim of this paper is discussing the application of Cryo-Desalination using the
propane gas. The Cryo-Desalination is a specific type of process of freezing desalination
where the main component used for the freezing purpose is the propane gas. The Cryo-
Desalination is one of the efficient and cost-effective process of extracting the fresh water
from the seawater source. The Cryo-Desalination process works in three different steps. In
the first step, freezing of the source water or the seawater is done which forms ice and brine.
In the second step, this ice and the brine is separated from each other and in the third step, the
ice is melted which provides the complete fresh water. The concept of this Cryo-Desalination
is not actually new, where the main concept behind the Cryo-Desalination has been identified
in this report. Several of parts are also required for the process of Cryo-Desalination which
has been identified. Separation of the ice and the brine needs to be done carefully to achieve
the desired fresh water. The important process of this separation has been identified within
this report section. Several of benefits is also achieved by the use of Cryo-Desalination which
has been discussed within this report.

2CRYO-DESALINATION USING PROPANE GAS
Table of Contents
Introduction:...............................................................................................................................3
The Concept of Cryo-Desalination:...........................................................................................3
The Rise of Cryo-Desalination Technology:.............................................................................4
Parts Required for the Cryo-Desalination:.................................................................................5
Working Procedure of the Cryo-Desalination:..........................................................................6
Separation of the Ice-Brine:...................................................................................................8
Cost Regarding Cryo-Desalination:...........................................................................................9
Cost Comparison of Cryo-Desalination and RO Plant:.........................................................9
Production Cost:...................................................................................................................11
Consumption of Energy:......................................................................................................11
Benefits of using the Cryo-Desalination:.................................................................................12
Conclusion:..............................................................................................................................13
References:...............................................................................................................................15

3CRYO-DESALINATION USING PROPANE GAS
Introduction:
The Cryo-Desalination is the process of freeze desalination and it is based on a
specific phenomenon that is found in the nature. This phenomenon is the extraction of the
fresh water from the saltwater through the procedure of saltwater freezing. In this case, fresh
water is extracted from the saltwater by freezing of the saltwater, which first produces the
salt-free ice and then melting of this salt-free ice provides the fresh water (Tsironi et al.
2020). In the process of Cryo-Desalination, liquid propane is injected directly to the aqueous
saline solution and it adequately forms the ice. Then the ice is separated from the brine by
flotation. In the last stage the ice is melted against the condensing propane and in this way
salt-free fresh water is produced. Here, the whole process is the Cryo-Desalination process
where propane gas is used for freezing the saline water.
The Cryo-Desalination plants can be developed on the skids. The mobile units of the
Cryo-Desalination generally, have the capacity up to 100 GPM per unit. The larger plants of
the Cryo-Desalination get the benefit due to the major economies of the scale. This happens
as when capacity of the Cryo-Desalination plant is increased, the cost is increased by only
three to four times (Tsironi et al. 2019). That means the more capacity of the plant is
increased, the more cost effectiveness is achieved in the operations. In the following section
of the report, this Cryo-Desalination process is described more briefly and various of aspect
of the Cryo-Desalination using the propane gas is discussed.
The Concept of Cryo-Desalination:
The main concept of the Cryo-Desalination is freeing technology for desalinating the
water. This concept is not a new concept, rather than this concept was developed several
decades ago. The main point of interest to the freezing technology for desalinating the water
given during the 1960s (ONER 2019). At that time the interest was at the highest level due to

4CRYO-DESALINATION USING PROPANE GAS
the inherent efficiency of the freezing process. Also, another reason due to which the freezing
process got a high amount of attention is the cost effectiveness nature of its. The process of
freezing is very much simple and efficient while it requires a less capital investment and
equipment when compared with other type of processes. Also, the process of freezing is less
corrosive as the operating temperature in this type of t3echnology is very low and also, no
extra harmful chemicals are used in this process, which makes the overall process extremely
environment friendly. But at that time one difficulty was also present there which waned the
interests from this freezing technology. The main difficulty that was present during that time
was the separation of the ice form the residual brine (Indiran 2019). At that time the other
available technologies for the becomes much more popular which includes albeit and the
reverse osmosis.
The Rise of Cryo-Desalination Technology:
The technology of Cryo-Desalination was benefitted hugely by performing a valuable
research and development regarding the freezing technology which happened about fifty
years ago. At that time the technology of Cryo-Desalination was already having its base and
important data for this technology was also developed. At the very initial stages, the Cryo-
Desalination was similar with technology of 15,000 GPD Struthers Scientific plant (Kucera
2019). However, the original freezing process of the Cryo-Desalination was added to this
technology later by some with the help of innovation. In this aspect, not only the freezing
process was introduced to the Cryo-Desalination technology, but also several of other design
modifications were added to this technology and a novel method of ice-brine separation was
introduced which made the Cryo-Desalination technology the most attractive and effective
process of desalination.

5CRYO-DESALINATION USING PROPANE GAS
Parts Required for the Cryo-Desalination:
There are some specific ways for performing the Cryo-Desalination. There are mainly
three different steps, through which the fresh water is obtained from the saline source. These
basic three steps are the ice formation by using the saline water, ice separation from the brine
and the final step is melting the ice so that fresh water can be obtained. As almost all type of
freezing technique uses the same procedure, including the Cryo-Desalination, there are some
basic part which are required for the process. For the Cryo-Desalination these four basic parts
are the washer, freezer, heat removal systems and melter (Politano et al. 2017). Specifically,
for the Cryo-Desalination process as a freezer the propane gas is used. So, in this aspect, the
propane gas is one of the most important part that is require for performing the Cryo-
Desalination. Here, mainly a vessel is used where both vapour and ice crystals are formed in
a continuous manner. As a vessel, for the Cryo-Desalination a chamber is used so that the
propane gas can be used effectively without any types of wastages. Like the freezer part,
there is also a melter part for the Cryo-Desalination where it is used for melting the separated
ice from the brine and ultimately the fresh water product is achieved.
Proper source of energy is another important requirement for the Cryo-Desalination.
In the process of Cryo-Desalination, the most of the energy is required regarding melting and
freezing of the ice. For this reason, a reliable and constant source of energy is another
important part for the Cryo-Desalination process. In this aspect, an external thermal bath can
be used for the energy source for the melting of the ice (Gude 2016). In this aspect, the
current technology is applicable for both the warm and the cold climates. Also, another
important part that needed to be implemented with the system is an appropriate water-salt
separation mechanism. In this aspect an appropriate technological solution is required which
will be able to separate these two with higher amount of efficiency. In this way, high amount
of fresh water can be achieved from the Cryo-Desalination process. For these reasons proper

6CRYO-DESALINATION USING PROPANE GAS
salt-water separation mechanism is another important part that is required for the Cryo-
Desalination.
Therefore, the above discussed parts are the most important part which are extremely
needful for completing the process of Cryo-Desalination successfully.
Working Procedure of the Cryo-Desalination:
In the following section of this report, a specific type of Cryo-Desalination process
flow schematic is presented which is applicable for all type of salinity conditions. The
conditions of salinity can vary depending upon different type of water desalination plant. This
type of differences occurs due to the seawater, produced water, mining or due to any other
industrial applications. The presented Cryo-Desalination process flow schematic is
irrespective of all these conditions and is applicable for most of the cases (Alyousef, Goosen
and Elakwah 2017). The only difference that can occur for the different water desalination
plant are the temperatures and the operating pressures. There are functions for the salinity of
the rejected brine.
(Figure 1: Cryo-Desalination Process Flow Schematic)

7CRYO-DESALINATION USING PROPANE GAS
(Source: Dong et al. 2018)
In the above diagram it can be seen that there are some white lines, which are actually
representing the flow of the water. Also, in the diagram there are some yellow lines which are
representing Cryosol, which is actually the non-toxic flotation medium. The dashed line
within the figure represents the ice mixture in Cryosol or the water (Alavi, Chennaoui and
Cerri 2019). The red line in the diagram is the most important here, which actually represents
the propane circuit of the overall Cryo-Desalination process. The propane is used in the Cryo-
Desalination for the refrigeration purpose.
The overall process starts from the intake of the seawater in the circuit and from there
the water is cooled by outgoing fresh water stream. From there the seawater enters within the
crystallizer and after that the seawater is mixed with the liquid propane. By the contraction of
the propane gas with the seawater, vaporisation is done and ice is created. Within the
crystalliser the propane vapour gets condensed, compressed and recycled. There is a mixture
formed within the crystalliser where the main component are the brine and ice (Crabeck et al.
2019). This mixture exits from the crystalliser and after that cryosol added to the stream of
mixture. After adding the cryosol the whole mixture enters within the separation column.
There are some differences in the density of the ice and brine and using that difference in the
density cryosol successfully separates the brine and the ice. After the separation, the brine
flows from the bottom of the column and after that it directly goes to the disposal. As the
brine goes to the disposal, both of the cryosol and the ice leaves the top of the column and
after that they flow through the propane condenser. In this way, the formed ice got melted
and it is further carried by the cryosol (Lieblappen et al. 2018). Further, it moves towards the
decanter and in the decanter, steam is applied for separating the cryosol and water. The steam
effectively separates the water and the cryosol as cryosol is immiscible with the water. After

8CRYO-DESALINATION USING PROPANE GAS
the separation, the same cryosol recycles again in the process. Fresh water is taken out from
the system as the final product.
Separation of the Ice-Brine:
In the overall working procedure of the Cryo-Desalination separation of the ice-brine
is one important aspect, which needs to be discussed in detail. In the Cryo-Desalination the
separation of the ice-brine is done by following a simple mechanism without use of any types
of mechanical items, centrifuges or the filters. The mixture of the ice and the brine is first
contacted with a column of cryosol. The cryosol is the main substance which will be playing
an extremely vital for the separation of the ice and brine (Peterson 2018). There are some of
the specific reason for using the cryosol in this case. First of all, the cryosol is non-toxic, it
means the final water product will not be affected by anyhow. Secondly, the cryosol is
immiscible with water and it does have the specific physical characteristics through which it
can overcome the hydrophilic forces of both brine and ice. Also, the viscosity and the density
are the crucial characteristics of the cryosol which makes it absolutely perfect for the current
situation. The density of the cryosol is actually in between of density of ice and water. The
specific gravity of the cryosol is 0.95. All of these characteristics makes the cryosol
appropriate for the current context.
For the separation of the brine and the ice, the ice mixture is sent to the cryosol. Here,
the cold ice-cryosol steam is used for condensing recycled compressed propane. After that,
the condensing propane successfully melts the ice and after that it leaves the cryosol steam
with the water (Wongpan et al. 2018). Then this mixture of the cryosol and water is decanted
which is actually a very easy process. Through the decant process, the cryosol is recirculated
within the circuit again leaving only the desalinated water, which is the main output of the
whole process.

9CRYO-DESALINATION USING PROPANE GAS
Cost Regarding Cryo-Desalination:
Considering the cost associated with the Cryo-Desalination is comparatively quite less
when it compared with the other processes of the fresh water production. In this case, the cost
of the Cryo-Desalination will be analysed in several of important aspects and the cost
effectives of the Cryo-Desalination will be assessed.
Cost Comparison of Cryo-Desalination and RO Plant:
RO or the reverse osmosis is another important process through which fresh water can
be achieved. The RO process is one of the popular process for extracting the fresh water and
it is used widely. While the operational cost is compared between a RO plant and the Cryo-
Desalination process it has been analysed that the cost of a RO plant is way too much higher
(Mudgal and Davies 2016). More specifically, to increase the capacity of a Cryo-Desalination
plant by ten times, the operational cost will be increased by three to four times. If the same is
compared with a RO plant then to increase the capacity of the RO plant by ten times the
operational cost will be increased by nine to ten times, which is way too much higher when
compared with the Cryo-Desalination. In the following section graph is presented which will
clearly define the cost comparison of the Cryo-Desalination with the RO plants.

10CRYO-DESALINATION USING PROPANE GAS
(Figure 2: Cost Comparison of Cryo-Desalination and RO Plants)
(Source: Srivastava et al. 2018)
The above presented graph clearly shows the cost of unit plans vs the daily capacity
of the plant in gallons. In this graph the cost of the RO plant is shown by the purple line,
which is at the top. The remaining three line shows the cost trend regarding the Cryo-
Desalination in high, medium and low projection of the cost. From the analysis of the graph it
has been also assessed that operational cost of the RO plants is directly proportional with the
capacity of the RO plants (Nagaraj et al. 2017). Here, the it has been also assessed that the
graph nature of the Cryo-Desalination has provided a cost-effective indication compared with
the RO plants and it is mainly due to the equipment used in the Cryo-Desalination plants. The
main equipment that are used in a Cryo-Desalination plant are the pumps, tanks and
compressors, due to which the operational cost of the Cryo-Desalination is relatively lower.

11CRYO-DESALINATION USING PROPANE GAS
Production Cost:
In the above section, already an idea has been provided regarding the costs associated
with the Cryo-Desalination plants. The Cryo-Desalination has achieved a high amount of cost
effectiveness due to its lower costs of the plants, maintenance and the lack of chemical
components. These three are the main reason, due to which the Cryo-Desalination has
achieved a lower cost regarding production of the desalinated water. There are various types
of costs are associated with a typical type of RO plants which includes the chemical costs,
filtering costs and the cost regarding membranes (Yu et al. 2017). In the Cryo-Desalination
this type costs are mainly not present, due to which the Cryo-Desalination is able to produce
fresh water from a comparatively lower price. Also, the labour and maintenance cost in the
Cryo-Desalination plants are relatively low which helps to achieve the fresh water in a very
competitive price point.
Consumption of Energy:
All type of processes requires some minimum amount of energy to become
functional. In this case the Cryo-Desalination is also requires a certain amount of energy to
run the plants but these energy requirements are relatively less compared with the other
processes. The main reason due to which the Cryo-Desalination requires a lower amount of
energy is its recovery of energy that is expanded for making the ice. In this case, during the
process of ice melting the cold energy of the ice is used for condensing the recycled propane
(Van den Abbeel 2017). As the produced ice provides a lower condensing temperature,
propane compressors need to operate in a lower temperature while the compression ratio is
also low. In this way, the Cryo-Desalination plants are able to save a high amount of energy
that is nearly equal to enthalpy change of the molten ice. The overall concentration of the salt
also plays an important role regarding the consumption of the power. If the concentration of
the salt increases, then the overall consumption of the power also increases as there is drop