797
1 INTRODUCTION
Nowadays, global climate change is a significant
issue. It causes the planet's average yearly
temperature to gradually rise, an event that started
with the industrial revolution (Mikhaylov et al., 2020).
The primary source of greenhouse gas (GHG)
emissions into the atmosphere is the production and
consumption of energy. Global warming and climate
change have been dramatically impacted by the rise in
emissions caused by the increased usage of fuel-
burning energy sources (Elmallah et al., 2023). By
2050, the world's temperature is expected to rise by
roughly 1.5 degrees Celsius, and by 2100, it will rise
by 2-4 degrees (Meinshausen et al., 2009). As a result,
international policies and the majority of research
have focused on the need to reduce global warming
through the implementation of laws, the use of
innovative technologies, and the utilization of clean,
renewable energy sources. Carbon dioxide (CO2),
methane (CH4), nitrogen oxides (NOx),
hydrofluorocarbons (HFCs), perfluorocarbons (PFCs),
and sulfur oxides (SOx) are the six GHGs listed in the
Kyoto Protocol. CO2, CH4, and NOx contribute more
than half of the GHG impact. Between 1990 and 2014,
global annual CO2 emissions rose from 22.15 Gt to
36.14 GT, and the amount of CH4 emissions rose from
6.67 to 8.01 Gt CO2 equivalent (Liu et al., 2019).
According to climate impact and global warming,
CH4 is considered to be 30 times equivalent to CO2
(IPCC, 2021). Due to the ongoing growth in emissions
and atmospheric concentrations of CH4, early
reduction of CH4 would significantly increase the
chances of mitigating global warming (Mar et al.,
Reducing Methane Emissions on Livestock Ships
in Order to Mitigate Greenhouse Gas Emissions
and Promote Future Maritime Sustainability
M. Elmallah
1
, M. Shouman
1
& M. Elgohary
2
1
Arab Academy for Science, Technology, and Maritime Transport, Alexandria, Egypt
2
Alexandria University, Alexandria, Egypt
ABSTRACT: One of the main causes of climate change and global warming is greenhouse gas emissions.
Livestock makes up 15% of the world's greenhouse gases (GHG), whereas maritime shipping accounts for 3%.
Cattle can produce about 500 grams of methane a day per cow. This study demonstrates that livestock ships are
an extremely high source of methane emissions. This study also offers innovative scientific techniques for
lowering methane gas emissions from livestock ships. The MV Gelbray Express Livestock ship is selected to
investigate the overall emissions generated by the main engine and the livestock on board. Main engine CO2
emissions and livestock CO2 equivalent emissions are theoretically calculated during 24-hour sailing under
engine full load and livestock full capacity. The study revealed that livestock CO2 equivalent emissions account
for 43% of the total CO2 emissions emitted by the engine and the livestock. To decrease livestock methane
emissions, ZELP (Zero Emissions Livestock Project) has patented a unique catalytic technique for capturing and
neutralizing methane generated during enteric fermentation in ruminant animals such as cows. Theoretical
results show that using the ZELP mask reduces CO2 equivalent emissions by 58 000 kg per day at a livestock
capacity of 4000 cattle onboard the MV Gelbray Express Livestock ship.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 18
Number 4
December 2024
DOI: 10.12716/1001.18.04.05
798
2022). Approximately 3% of the world's GHG
emissions are produced by maritime transport
(Lindstad et al., 2021). In 2018, the International
Maritime Organization (IMO) adopted the Initial
Strategy on reduction of greenhouse gas (GHG)
emissions from ships, which commits the IMO to
reduce the overall GHG emissions of shipping by at
least 50% by the year 2050 (Serra & Fancello, 2020).
The IMO controversy focused on mitigating the
emissions of CO2 from the ship's main engine, which
is considered the first direct source of emissions,
although there are other crucial indirect emission
sources, especially in livestock ships. Livestock
produces about 15 percent of the total emissions of
greenhouse gases (Króliczewska et al., 2023). In
comparison to 2010, agricultural CH4 emissions are
expected to rise by roughly 30% in 2050. The rising
human population and rising demand for animal
protein are the causes of these increases (Reisinger et
al., 2021). Livestock methane emissions are 90%
through burps and only 10% through animal manure,
and these emissions are a result of enteric
fermentation (Brouček, 2014). Domesticated animals,
such as cattle, sheep, and goats, naturally produce
CH4 during their physiological digestive processes. A
cow emits 500 g of methane emissions daily, which is
considered a high amount, especially when it comes
to livestock ships that can carry more than 4000 cattle.
In an attempt to decrease the negative impacts of
methane emissions from the livestock industry, ZELP
(Zero Emissions Livestock Project), a startup company
in the UK, invented a methane-reduction device and
certification system. ZELP has created a patented
wearable apparatus that instantly oxidizes methane
emissions into carbon dioxide (Grove & Clouse, 2021).
As the IMO is concerned about providing low-
emission shipping by implementing many regulations
regarding the ship's propulsion system and its energy
and operational measures, it is also essential to be
concerned about indirect emission sources, especially
the emissions that are caused by livestock ships. This
study demonstrates the CO2 emissions of the main
engine and the CH4 emissions of the livestock
onboard the MV Gelbray Express Livestock ship. The
study represents the total CO2-eq emissions of the
main engine and livestock during a 24-hour sailing
period under full engine load and full livestock
capacity. The study also highlights the significant
environmental effects of using the ZELP burp-
catching mask.
Nomenclature
EM Total ship emission
t Operation trip time
Pw Main engine power
Lf Load factor
Pf,i Pollution factor
i Type of emission
f Type of fuel
Pco2 Fuel carbon content
SFC Specific fuel consumption
CF Conversation factor
ME CO2 emissions CO2 emission for main engine
PME Output power
ECH4 Total cattle methane emission
MCH4 Methane emission per cow
Ncattle Number of cattle
MMTCDECH4 Million Metric Tonnes of
Carbon Dioxide Equivalents
MMTCH4 Million Metric Tonnes of a CH4
GWPch4 Global Warming Potential of
CH4
Abbreviations
GHG Greenhouse gas
CO2 Carbon dioxide
CH4 Methane
NOx Nitrogen oxides
HFCs Hydrofluorocarbons
PFCs Perfluorocarbons
SOx Sulfur oxides
IMO International Maritime Organization
ZELP Zero Emissions Livestock Project
CCS Carbon Capture and Storage
CCU Carbon Capture and Utilization
MBOE Million Barrels of Oil Equivalent
MtCO2eq Million Tons of Carbon Dioxide Equivalent
EEDI Energy Efficiency Design Index
SEEMP Ship Energy Efficiency Management Plan
EEOI Energy Efficiency Operational Indicator
EEXI Energy Efficiency Existing Ship Index
CI Carbon Intensity
2 AN OVERVIEW OF GREENHOUSE EMISSIONS
IN THE MARITIME TRANSPORTATION
SECTOR
The primary source of air pollution and the
greenhouse effect in the maritime industry is the
excessive worldwide production of greenhouse gases
(mostly carbon dioxide, CO2, and methane, CH4),
particularly as a result of the burning of fossil fuels for
energy and power generation. This has ultimately led
to several types of hazards that will impact people's
daily lives, such as global warming and climate
change (Jeffry et al., 2021). Numerous strategies, such
as Carbon Capture and Storage (CCS), Carbon
Capture and Utilization (CCU), reducing the use of
fossil fuels, and promoting the use of clean and
renewable energy, have been contributed forth in an
effort to tackle and conquer the sharp increase in
GHG emissions (Alqarni et al., 2021; Hussin & Aroua,
2020). Maritime transport remains the most
economical means of shipping goods around the
globe and continues to be the backbone of global
trade. More than four-fifths of all trade, by volume, is
transported by sea. These days, the use of fossil fuels
by maritime vessels is equivalent to around 2.2
million barrels of oil equivalent (MBOE) or over 1000
million tons of carbon dioxide equivalent (MtCO2eq)
(Santos et al., 2022). There are several approaches to
reduce emissions in the maritime sector, some
emphasize the use of alternative energy, while others
emphasize on other decarbonization strategies (Al-
Enazi et al., 2021; Xing et al., 2020). To reduce GHG in
the maritime sector, most studies took into account
the ship's propulsion system and looked at the key
features of several propulsion systems in terms of fuel
consumption and emissions production, while other
studies assessed how operational research methods
were used in the energy sector (Huan et al., 2019;
Fazlollahi & Maréchal, 2013; Sangaiah et al., 2019;
Hwangbo et al., 2017; Fazlollahi et al., 2012). The IMO
is playing a significant role in decreasing GHG
799
emissions caused by shipping. As stated in the IMO
Initial Strategy, the organization is committed to
lowering greenhouse gas emissions from international
shipping and will persist in its efforts to phase them
out over the duration of the next century. The Initial
Strategy aims to mitigate the volume of total annual
greenhouse gas emissions from international shipping
by at least 50% by 2050, compared to 2008. The IMO
recently implemented stricter controls on
international maritime transport activities. In an effort
to reduce greenhouse gas (GHG) emissions, the IMO
has started to implement obligatory measures such as
the Energy Efficiency Design Index (EEDI), the Ship
Energy Efficiency Management Plan (SEEMP), the
Energy Efficiency Operational Indicator (EEOI), and
the Energy Efficiency Existing Ship Index (EEXI).
Enhancing energy efficiency, lowering the Carbon
Intensity (CI) of new ships, enhancing the Energy
Efficiency Design Index (EEDI), and improving
Energy Efficiency Operation Index (EEOI) are the
major methods used to accomplish the goals (Joung et
al., 2020; Rehmatulla et al., 2017). In their
implementations, the IMO primarily focuses on
lowering GHG emissions from the primary engine;
however, there are other parameters that have a
significant impact on the environment as well.
Livestock ships have a magnificent source of CH4 that
need to be considered. Cattles are considered as a
major source of global methane emissions. Figure one
shows the sources of global human-induced methane
emissions. The agriculture source represents 40% ,33%
from livestock and 27 from cultivation of rice
(Mundra & Lockley, 2023).
Figure 1. Sources of global human-induced methane
emissions
To encourage the transition towards a sustainable
maritime transport sector, Policymakers should start
to pay more attention to the harmful environmental
impact of cattle emissions onboard livestock ships.
Growing levels of methane cause stratospheric water
vapor to rise, which lowers the ozone layer. This is
because stratospheric water vapor causes polar
stratospheric clouds and hydrogen oxide radicals
(HOx), which accelerate ozone depletion (Revell et al.,
2016). (Mundra & Lockley, 2023). Microbiological
digestion in the rumen emits 90% of livestock
methane emissions through breathing (Burping)
(Mundra & Lockley, 2023; Kumari et al., 2016; Thorpe,
2008; Chow et al., 2020). ZELP mask is a novel
strategy to decrease the environmental impact of
livestock methane. Produced by ZELP™, this
wearable device is utilized to identify, capture, and
catalytically oxidize methane (Mundra & Lockley,
2023). An adjustable harness covers the cow's head,
and the mask initiates the oxidation process by
detecting burps through sensors.
3 METHODOLOGY
This study provides a new method to decrease the
methane emissions on livestock ships since the
methane environmental impact is 30 times greater
than the CO2 impact. Encouraging livestock ships to
require mask-wearing among their cows will reduce
methane impact by 30 times since the burp-catching
masks will convert methane to carbon dioxide. Figure
two shows the design of the mask.
Figure 2. The design of ZELP burp-catching mask
In this study, the MV Gelbray Express Livestock
ship is selected to study the total emissions generated
by the main engine and the cattle onboard. MV
Gelbray Express is the third livestock carrier built by
Cosco Guangdong Shipyard, based in China. Vroon
Offshore Services, a Dutch company, contracted with
Cosco Guangdong Shipyard, to build six livestock
ships at an estimated cost of $28.25 million in 2011.
With five decks and a total gross pen area of around
4,500 m², the vessel can accommodate about 4,000
cattle at a weight of 350 kg each. There is around 495
m² of deck area available to hold up to 1,200 m³ of
feed. Table 1 shows the general ship particulars.
Table 1. Ship particulars MV Gelbray Express carrier
________________________________________________
GENERAL
________________________________________________
Year built 2014
Builder Cosco Guangdong, China
Flag Portugal
IMO 9621211
________________________________________________
PRINCIPAL DIMENSIONS
________________________________________________
Length Overall (LOA) 134.80 m
Beam Moulded 19.60 m
Depth 14.80 m
Summer Draft 6.80 m
________________________________________________
MACHINERY & PROPULSION
________________________________________________
Main Engine 6090 kW Wartsila W7X35
Service speed Auxiliary Engines 16.75 knots
Auxiliary Engines 3x1100 kW
Shaft Generator 1050 kW
Bow Thruster 750 kW
________________________________________________
TONNAGES
________________________________________________
Dead Weight Tonnage (DWT) 5225 t
Scantling Draft 6.8 m
Design Draft 5.8 m
Gross Tonnage 10421 t
Net Tonnage 3126 t
800
________________________________________________
CARGO CAPICITIES & EQUIPMENTS
________________________________________________
Total Gross Pem Area 4511 m2
Number of Decks 5
Deck Space Fodder 495 m2
Fodder (Silo) 1200 m3
________________________________________________
MV Gelbray Express is propelled by 6090 kw of
power produced by Wärtsilä X35 engines. The
smallest low-speed engine in Wärtsilä's lineup is the
Wärtsilä X35. It is a low-speed, electronically
controlled two-stroke marine engine that is among the
most efficient in its class. Compact engine size,
straightforward engine operation, and the ability to
power ships with shallow draft requirements were the
key goals in the design of the Wärtsilä X35. The power
output of the engine ranges from 3,475 to 6,960 kw,
with a cylinder arrangement of 5-8 cylinders. The
specific fuel consumption (SFC) of the engine is 170
g/kwh. Table 2 shows the main engine characteristics
of MV Gelbray Express.
Table 2. The characteristics of the main engine
________________________________________________
Wärtsilä X35
________________________________________________
Cylinder bore 350 mm
Piston stroke 1550 mm
Speed 142–167 rpm
Mean effective pressure 21.0 bar
Stroke / bore 4.43
Number of cylinders 7
Rated power 6090 KW at 167 rpm
Weight in tonnes 95
________________________________________________
A calculation of the engine and cattle emissions
during a 24-hour sailing under engine full load and
livestock full capacity will take place to show the
results of the CO2-eq emissions.
Equation (1) can be used to determine the total
emission for ships during a single voyage (Ammar &
Seddiek, 2020).
( )
, , ,trip i f w f f i
EM t P L P
=
(1)
where EM is the total ship emission, t is the operation
trip time in (hours), Pw is the main engine power in
(kW), Lf is the load factor, Pf,i fuel pollution factor in
(g/kWh), i is the type of emission, and f the type of
fuel.
Equation (2) determines the fuel carbon content
(Elkafas et al., 2020). The primary factor used to
determine a fuel's pollution factor for CO2 emissions
is the fuel's carbon content.
2co
P SFC CF=
(2)
where CF is the conversation factor, and SFC is the
specific fuel consumption (g/kwh).
Equation (3) shows the CO2 emission for main
engine.
( ) ( ) ( )
2
1
nME
ME i FME i ME i
i
ME CO emissions P C SFC
=
=
(3)
where PME is the Power output from main engine.
CFME is the fuel conversation factor from fuel
consumption to CO2 emission SFCME is the specific fuel
consumption for main engines.
Equation (4) shows the total amount of methane
emission per livestock capacity
44CH CH cattle
E M N=
(4)
The total amount of cattle methane emission is
calculated by multiplying the mass of CH4 emitted by
each cow with the total number of cows. Where ECH4 is
the total CH4 cattle emission MCH4, the mass of CH4
emitted per cow, and Ncattle is the total number of
cows.
A carbon dioxide equivalent (CO2-e) is a metric
measure that is used to convert amounts of other
gases to an equivalent amount of carbon dioxide with
the same Global Warming Potential (GWP) in order to
compare emissions from different greenhouse gases
based on their GWP. Million Metric Tons of Carbon
Dioxide Equivalent (MMTCDE) is the standard way
to represent carbon dioxide equivalents.
Equation (5) shows the CO2-e of CH4 gas.
4 4 4CH CH CH
MMTCDE MMT GWP=
(5)
The carbon dioxide equivalent of methane is
calculated by multiplying its tons by the
corresponding GWP. Where MMTCDECH4 is the
million metric tonnes of carbon dioxide equivalents,
MMTCH4 is the million metric tonnes of CH4, and
GWPCH4 is the global warming potential of CH4.
4 RESULTS AND DISCUSSION
This study shows a comparison between the cattle
methane emissions and the main engine emissions
and highlights the high amount of cattle methane
emissions on livestock ships. The study highlights the
positive environmental impact of using the ZELP
burp-catching mask on reducing methane emissions
on livestock ships and the importance of developing
this novel strategy and considering it in maritime
transport regulations. The results show a high
percentage of livestock emissions among the total
emissions caused by the main engine and the
livestock onboard the MV Gelbray Express. The
results demonstrate the role of ZELP masks in
reducing the number of livestock CO2-eq emissions.
Figure three shows the CO2 emissions of the main
engine. The highest amount of CO2 can be reached
during sailing at an engine load of 6090 kw. The
results show that the engine CO2 emissions are about
80000 kg at engine load 6090 kw and about 52224 kg
at engine load 4000 kw.
Figure four represents the amount of livestock
methane emissions. The maximum amount of CH4
emissions is about 2000 kg per day at a livestock
capacity of 4000 cattle.
Figure five shows the CO2-eq emissions generated
by livestock onboard. The CO2-eq at full capacity of
801
livestock is about 60000 kg, which is about 75% of the
engine's maximum CO2 emissions. These results
indicate the high danger of the livestock emissions
since they are as high as the CO2 emissions of the
main engine.
Figure 3. CO2 emission of the main engine
Figure 4. Methane emissions from cattle
Figure 5. CO2-eq emissions of cattle
Figure six shows a comparison between CO2-eq
engine emissions and CO2-eq livestock emissions.
These emissions are calculated at full livestock
capacity and a different engine’s load. The
environmental impacts of livestock emissions are just
as hazardous as those from engine emissions.
Figure seven shows the total CO2-eq emissions of
the engine and cattle together. The cattle CO2-eq
emissions are 43% of the total emissions. The
maximum CO2-eq engine emissions are about 80000
kg per day, and the maximum CO2-eq livestock
emissions are about 60000 kg per day.
Figure 6. CO2-eq emissions from engine and cattle
Figure 7. Total CO2-eq emissions of the engine and cattle
together
Figure eight shows the CO2-eq of livestock
methane emissions during the use of the ZELP burp-
catching mask. The findings demonstrate the huge
reduction of cattle methane CO2-eq emissions during
the use of the ZELP mask. The maximum CO2-eq of
cattle methane emissions without using the ZELP
mask is about 60000 kg per day, while the maximum
CO2-eq of cattle methane emissions while using the
ZELP mask is about 2000 kg per day. The ZELP mask
enhanced the reduction of CO2-eq emissions by 58000
kg. These findings prove the importance of this novel
innovation and the importance of developing and
applying this technology as a mandatory regulation
for these types of ships.
Figure 8. CO2-eq of livestock methane emissions during the
use of the ZELP
802
Figure nine shows the total CO2-eq emissions of
the engine and the cattle during the use of the ZELP
mask. The results of figure nine are calculated during
24 hours of sailing under the engine full load and the
livestock full capacity while using the ZELP mask to
illuminate the huge reduction in CO2-eq livestock
emissions.
Figure 9 CO2-eq emissions of the engine and the cattle
during the use of the ZELP mask
Figure ten shows the total CO2-eq emissions of the
engine and cattle together. The cattle CO2-eq
emissions during the use of ZELP are 2.4% of the total
emissions.
Figure 10. CO2-eq emissions of the engine and cattle
together during the use of ZELP
Figure eleven shows the livestock CO2-eq
emissions with and without the ZELP mask.
Figure 11. Livestock CO2-eq emissions with and without the
ZELP mask
Table three clarify the results of the theoretical
CO2-eq calculations per 24-hours of sailing under
engine full load and livestock full capacity.
Table 3. Theoretical results of CO2-eq emissions without the
use of ZELP mask
________________________________________________
Engine full load 6090 KW
Cattle capacity 4000 Cattle
Main engine CO2 emission 79500 Kg
Cattle CO2-e emission without the use of ZELP 59640 Kg
Cattle emissions as a percentage of the total 43%
emissions of CO2-eq
________________________________________________
Table four demonstrates the results of the
theoretical CO2-eq calculations per 24-hours of sailing
under engine full load and livestock full capacity,
during the use of ZELP mask.
Table 4 Theoretical results of CO2-eq emissions during the
use of ZELP mask
________________________________________________
Engine full load 6090 KW
Cattle capacity 4000 Cattle
Main engine CO2 emission 79500 Kg
Cattle CO2-e emission during the use of ZELP 1988 Kg
Cattle emissions as a percentage of the total 2.4%
emissions of CO2-e
________________________________________________
5 CONCLUSION
The world is presently making scientific, political, and
environmental contributions towards mitigating
climate change and global warming. climate change
and global warming are triggered by the release of
GHG emissions into the atmosphere. Reducing
methane emissions could achieve the 1.5°C global
warming target set forth in the Paris Agreement. The
IMO is working hard to develop legislation and plans
that contribute to lowering emissions in the maritime
sector, in order to slow down the rate of emissions
that are predicted to rise in the future. One of the most
popular kinds of vessels employed in maritime
transportation is the livestock vessel. The purpose of
this study was to determine the rate of emissions from
the main engine and the livestock on board the MV
Gelbray Express Livestock ship during the 24-hour
period of sailing. The analysis demonstrates that
livestock CO2-eq emissions are higher than 60,000 kg
per day at a capacity of 4000 cattle. The results
emphasize that the main engine CO2-eq emissions are
about 80000 kg during a 24-hour sailing period at full
engine load. According to the study, the quantity of
livestock emissions is massive and practically as
hazardous as engine emissions. The ZELP mask
increased the reduction of CO2-eq emissions by 58,000
kg. These results highlight the significance of this
innovative innovation as well as the need to develop
and implement this technology as a mandatory policy
for these sorts of ships. These theoretical results
illuminate the importance of cooperation between
policymakers and ZELP to provide maritime
sustainability by decreasing the emissions impact of
livestock ships.
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