390
N. T. Mathew et al.
called a crude preheat train (CPT) (Müller-Steinhagen et al. 2009). The decreased
efficiency of these heat exchangers due to fouling is estimated to have a 10% increase
in fuel usage (Müller-Steinhagen et al. 2009). The article states that, at a global scale,
this corresponds to approximately 88 million tons per annum of CO 2 emissions in
the oil refinery operations alone (Müller-Steinhagen et al. 2009).
In the case of marine heat exchangers that are used for cooling purposes, seawater
is mainly used to absorb the excess heat generated. Biofouling causes the narrowing
of the flow area and thereby result in reduced water flow or a pressure drop inside
the heat exchanger (Kronholm 2018; Bertilsson 2018; Radicone 2009). This will
also result in reduced heat transfer and energy loss. In order to compensate for the
reduced heat transfer, more seawater has to be pumped. This will directly result in
additional water consumption. Apart from that, the water pump consumes additional
energy (electrical energy) to supply more seawater (Hansen 2018; Kronholm 2018).
In most cases, electrical energy utilized for running the pumps is obtained through
the burning of fossil fuels (Hansen 2018; Kronholm 2018). This will also increase
CO 2 emissions and thereby an equivalent rise in the global warming potential.
Several other scientific studies and conferences like ‘Heat Exchanger Fouling and
Cleaning X—2013’ & ‘Heat Exchanger Fouling and Cleaning XI—2015’ estimated
that the heat exchanger fouling is responsible for 1 to 2.5% of overall global CO 2
emissions (Malayeri et al. 2015; Müller-Steinhagen et al. 2009, 2011). However,
it is highly difficult to attain a cumulative value on the overall percentage of CO 2
emissions due to biofouling. This is because, the values will always vary according to
factors like the severity of fouling, heat exchanger operating conditions, plant energy
source and so forth (Müller-Steinhagen et al. 2009). Apart from that, the global
energy consumption rate by the offshore industries is not declining but increasing
every year. Therefore, the actual percentage of CO 2 emissions due to heat exchanger
fouling could be much higher in reality.
Category 2: Heat Exchanger corrosion and environmental issues
Another major issue with marine biofouling is the corrosion that happens on the heat
exchanger surface (Hansen 2018). The deposition of biofilms (either micro fouling
or macro fouling) will lead to the development of special chemical environments
that speeds up corrosion of heat exchanger metallic surface. If such biofouling is left
unchecked, it will eventually result in material erosion on the heat exchanger surface
and causes leaks, which requires effective maintenance and repairs. Frequent maintenance and repairs will reduce the equipment’s operational lifetime and lead to
early scrapping/disposal of the product. Common heat exchanger materials are Titanium, Stainless Steel, Stainless Steel alloys, Copper alloys, Aluminium alloys, among
others (Hjalmars 2014; Michels et al. 1979; Darby 1984; Kapranos and Priestner
1987). Thus biofouling corrosion leads to undesired material wastage. Moreover,
in the case of corrosion, metal or heavy metal oxides could be also released to the
atmosphere as by-products of fouling (Müller-Steinhagen et al. 2009). This could
cause serious health issues that affect human and animal welfare (Müller-Steinhagen
et al. 2009).
N. T. Mathew et al.
called a crude preheat train (CPT) (Müller-Steinhagen et al. 2009). The decreased
efficiency of these heat exchangers due to fouling is estimated to have a 10% increase
in fuel usage (Müller-Steinhagen et al. 2009). The article states that, at a global scale,
this corresponds to approximately 88 million tons per annum of CO 2 emissions in
the oil refinery operations alone (Müller-Steinhagen et al. 2009).
In the case of marine heat exchangers that are used for cooling purposes, seawater
is mainly used to absorb the excess heat generated. Biofouling causes the narrowing
of the flow area and thereby result in reduced water flow or a pressure drop inside
the heat exchanger (Kronholm 2018; Bertilsson 2018; Radicone 2009). This will
also result in reduced heat transfer and energy loss. In order to compensate for the
reduced heat transfer, more seawater has to be pumped. This will directly result in
additional water consumption. Apart from that, the water pump consumes additional
energy (electrical energy) to supply more seawater (Hansen 2018; Kronholm 2018).
In most cases, electrical energy utilized for running the pumps is obtained through
the burning of fossil fuels (Hansen 2018; Kronholm 2018). This will also increase
CO 2 emissions and thereby an equivalent rise in the global warming potential.
Several other scientific studies and conferences like ‘Heat Exchanger Fouling and
Cleaning X—2013’ & ‘Heat Exchanger Fouling and Cleaning XI—2015’ estimated
that the heat exchanger fouling is responsible for 1 to 2.5% of overall global CO 2
emissions (Malayeri et al. 2015; Müller-Steinhagen et al. 2009, 2011). However,
it is highly difficult to attain a cumulative value on the overall percentage of CO 2
emissions due to biofouling. This is because, the values will always vary according to
factors like the severity of fouling, heat exchanger operating conditions, plant energy
source and so forth (Müller-Steinhagen et al. 2009). Apart from that, the global
energy consumption rate by the offshore industries is not declining but increasing
every year. Therefore, the actual percentage of CO 2 emissions due to heat exchanger
fouling could be much higher in reality.
Category 2: Heat Exchanger corrosion and environmental issues
Another major issue with marine biofouling is the corrosion that happens on the heat
exchanger surface (Hansen 2018). The deposition of biofilms (either micro fouling
or macro fouling) will lead to the development of special chemical environments
that speeds up corrosion of heat exchanger metallic surface. If such biofouling is left
unchecked, it will eventually result in material erosion on the heat exchanger surface
and causes leaks, which requires effective maintenance and repairs. Frequent maintenance and repairs will reduce the equipment’s operational lifetime and lead to
early scrapping/disposal of the product. Common heat exchanger materials are Titanium, Stainless Steel, Stainless Steel alloys, Copper alloys, Aluminium alloys, among
others (Hjalmars 2014; Michels et al. 1979; Darby 1984; Kapranos and Priestner
1987). Thus biofouling corrosion leads to undesired material wastage. Moreover,
in the case of corrosion, metal or heavy metal oxides could be also released to the
atmosphere as by-products of fouling (Müller-Steinhagen et al. 2009). This could
cause serious health issues that affect human and animal welfare (Müller-Steinhagen
et al. 2009).