3 Driving Force in Hydrocarbon Separation
Generally, operation of membrane separation process does
not involve any heating, thus making this technology
required less energy to operate compared to the thermal
conventional separation such as distillation, sublimation or
crystallization. Membrane technology is widely applicable in
most industry including food technology, biotechnology and
pharmaceutical industries. Nowadays, this technology
becomes extensively important in the wastewater treatment
process with the help of ultra or microfiltration process. This
such development had solved most of the wastewater issues
by protecting the water from the infection via the elimination
of particles, colloids and also macromolecules.
Apart from removing unnecessary substance from the
wastewater, separation of hydrocarbon with water became
another concern that needs an urgent care. Basically, water is
one of the main contaminants in a hydrocarbon fluid system
and one of the most damaging agents. This problem usually
occurs during the oil and gas processing and water inevitably
usually being collected as part of stream. This collected
water is known as a produced water (PW). PW not only
needs to be removed; PW should be treated before releasing
to the environment. PW treatment will differ according to its
dumping purpose or reuse reason. Traditionally, PW management has been a three-step process, from water–oil separation to secondary treatment to final filtration. With the all
experts and knowledge, the treatment of the PW became
more advanced with the help of the membrane technology
by separating the hydrocarbon from the PW.
An emerging membrane separation technology not only
could treat the oily wastewater, but it also increased the
production of oil, consequently. Most of the oily wastewater
or PW comprise various polycyclic aromatic hydrocarbons
(PAHs). The advantages of this membrane technology in
separating hydrocarbon are having no addition of chemicals
involved, only low energy required, easy to be handled and
have well-arranged process conductions. In hydrocarbon
membrane separation, various mechanism could be involved
such as microfiltration, ultrafiltration, nanofiltration, reverse
osmosis, vapour permeation, pervaporation, membrane distillation and membrane contactor. All of these mechanisms
will operate with the help of driving force. Driving force
usually comes from the system’s surrounding, where the
membrane technology operated. It also depends on what
type of mechanism involve during the separation process.
There are several driving forces involved during the
hydrocarbon separation process including thermal-driven,
electrical-driven and biological-driven.
3.1 Thermal-Driven Membrane
Thermal-driven in membrane separation system occurs when
there are thermal difference exits between a hot feed stream
and a cold permeate stream during the separation process.
Both feed stream and permeate stream are separated by a
hydrophobic, microporous membrane (Wang and Chung
2015). There are several processes that involved in the
thermal-driven membrane separation such as membrane
distillation (MD), membrane evaporation, membrane crystallization (MCr) and pervaporation. In MD process, feed
salinity gives an effect on the cell performance where it
permits a desalination process for high salinity of produce
water (Shaffer et al. 2013). Air gap MD, direct contact MD,
sweeping gas MD, AND vacuum MD are typical module
configuration in MD system. Furthermore, most commonly
studied is the DCMD configuration. While, flat sheet is the
MD membrane configuration that most widely examined
among the other membrane configurations i.e., flat sheet,
hollow fibre, capillary, tubular and spiral wound (González
et al. 2017). Besides, polytetrafluoroethylene (PTFE),
polypropylene (PP) and polyvinylidene fluoride (PVDF) are
the materials that usually used in the fabrication of the MD
membrane.
MD system can operate at lower temperatures (30–90 °C)
with pressures relative to conventional desalination technologies and treat wastewaters with TDS up to
350,000 mg/L. In contrast, Rao and Li (2015) indicated that
MD might be a suitable method in treating FPW in range
medium to high TDS. However, the high energy consumption required in the MD system making it less attractive than
RO for low-TDS FPW. Li et al. (2014) reported that diluted
FO draw solution can be treated by using vacuum MD, and
the quality of product from this technique was comparable to
bottled drinking water. However, due to the high content of
inorganic or organic particles in the recovered water being a
factor of the decreased in the MD performance. Moreover,
Jang et al. (2017) found that MD performance more better
than RO and evaporative crystallization in treating PW with
the outstanding removal result of above 99% efficiencies for
all tested ions (Ca
2+ , Li
+
, Mg
2+ , K
+ , Na
+
, Sr
2+ , Ba
2+ , Cl
− and
Br
− ).
After all, there are two major obstacles facing in the MD
applications which include membrane fouling and pore
wetting conditions. In MD operation, primary fouling
mechanism that usually occurred is inorganic scaling,
organic fouling and biofouling (Razaei et al. 2018). Despite,
limited effort has been taken in order to produce anti-fouling
MD membranes. Currently, membrane modification only
Hydrocarbon Separation and Removal Using Membranes
83
Generally, operation of membrane separation process does
not involve any heating, thus making this technology
required less energy to operate compared to the thermal
conventional separation such as distillation, sublimation or
crystallization. Membrane technology is widely applicable in
most industry including food technology, biotechnology and
pharmaceutical industries. Nowadays, this technology
becomes extensively important in the wastewater treatment
process with the help of ultra or microfiltration process. This
such development had solved most of the wastewater issues
by protecting the water from the infection via the elimination
of particles, colloids and also macromolecules.
Apart from removing unnecessary substance from the
wastewater, separation of hydrocarbon with water became
another concern that needs an urgent care. Basically, water is
one of the main contaminants in a hydrocarbon fluid system
and one of the most damaging agents. This problem usually
occurs during the oil and gas processing and water inevitably
usually being collected as part of stream. This collected
water is known as a produced water (PW). PW not only
needs to be removed; PW should be treated before releasing
to the environment. PW treatment will differ according to its
dumping purpose or reuse reason. Traditionally, PW management has been a three-step process, from water–oil separation to secondary treatment to final filtration. With the all
experts and knowledge, the treatment of the PW became
more advanced with the help of the membrane technology
by separating the hydrocarbon from the PW.
An emerging membrane separation technology not only
could treat the oily wastewater, but it also increased the
production of oil, consequently. Most of the oily wastewater
or PW comprise various polycyclic aromatic hydrocarbons
(PAHs). The advantages of this membrane technology in
separating hydrocarbon are having no addition of chemicals
involved, only low energy required, easy to be handled and
have well-arranged process conductions. In hydrocarbon
membrane separation, various mechanism could be involved
such as microfiltration, ultrafiltration, nanofiltration, reverse
osmosis, vapour permeation, pervaporation, membrane distillation and membrane contactor. All of these mechanisms
will operate with the help of driving force. Driving force
usually comes from the system’s surrounding, where the
membrane technology operated. It also depends on what
type of mechanism involve during the separation process.
There are several driving forces involved during the
hydrocarbon separation process including thermal-driven,
electrical-driven and biological-driven.
3.1 Thermal-Driven Membrane
Thermal-driven in membrane separation system occurs when
there are thermal difference exits between a hot feed stream
and a cold permeate stream during the separation process.
Both feed stream and permeate stream are separated by a
hydrophobic, microporous membrane (Wang and Chung
2015). There are several processes that involved in the
thermal-driven membrane separation such as membrane
distillation (MD), membrane evaporation, membrane crystallization (MCr) and pervaporation. In MD process, feed
salinity gives an effect on the cell performance where it
permits a desalination process for high salinity of produce
water (Shaffer et al. 2013). Air gap MD, direct contact MD,
sweeping gas MD, AND vacuum MD are typical module
configuration in MD system. Furthermore, most commonly
studied is the DCMD configuration. While, flat sheet is the
MD membrane configuration that most widely examined
among the other membrane configurations i.e., flat sheet,
hollow fibre, capillary, tubular and spiral wound (González
et al. 2017). Besides, polytetrafluoroethylene (PTFE),
polypropylene (PP) and polyvinylidene fluoride (PVDF) are
the materials that usually used in the fabrication of the MD
membrane.
MD system can operate at lower temperatures (30–90 °C)
with pressures relative to conventional desalination technologies and treat wastewaters with TDS up to
350,000 mg/L. In contrast, Rao and Li (2015) indicated that
MD might be a suitable method in treating FPW in range
medium to high TDS. However, the high energy consumption required in the MD system making it less attractive than
RO for low-TDS FPW. Li et al. (2014) reported that diluted
FO draw solution can be treated by using vacuum MD, and
the quality of product from this technique was comparable to
bottled drinking water. However, due to the high content of
inorganic or organic particles in the recovered water being a
factor of the decreased in the MD performance. Moreover,
Jang et al. (2017) found that MD performance more better
than RO and evaporative crystallization in treating PW with
the outstanding removal result of above 99% efficiencies for
all tested ions (Ca
2+ , Li
+
, Mg
2+ , K
+ , Na
+
, Sr
2+ , Ba
2+ , Cl
− and
Br
− ).
After all, there are two major obstacles facing in the MD
applications which include membrane fouling and pore
wetting conditions. In MD operation, primary fouling
mechanism that usually occurred is inorganic scaling,
organic fouling and biofouling (Razaei et al. 2018). Despite,
limited effort has been taken in order to produce anti-fouling
MD membranes. Currently, membrane modification only
Hydrocarbon Separation and Removal Using Membranes
83