HAI

1. Mitigation of Green house emission by
Carbon capture from Pre & Post Combustion
of Natural gas and fixation to chemical
fertilizer in a typical fertilizer industry
Pradip Ghosh ,( M.Tech) ,
Petroleum Engineering branch

2. Green House Emission a possible cause for climate change
Climate change is one of the key issues facing mankind today. Climate change is defined as,
"change of climate that is attributed directly or indirectly to human activity that alters the
composition of global atmosphere and which is in addition to natural climate variability
observed over comparable time periods."
The vast majority of climate change research strongly confirms a direct relation between
human activity, the rising levels of greenhouse gases (GHG) in the atmosphere and Climate
Change.
A Greenhouse Gas (GHG) is a gas in an atmosphere that absorbs and emits radiation within
the thermal infrared range. This process is the fundamental cause of the Greenhouse effect
which is the prime contributor for Global Warming
"Global warming" refers to the increase of the Earth's average surface temperature, due to
a build-up of greenhouse gases in the atmosphere. Global Warming Potential (GWP) is a
measure of how much a given mass of greenhouse gas is estimated to contribute to global
warming. It is a relative scale which compares the gas with respect to CO2.
The impacts of growing GHG emissions such as higher average temperature, rising sea
water level, submerging of low-lying areas and unpredictable changes in climatic conditions.

3. Green House Emission a possible cause for climate change
Importance of global climate Change
Climate change is one of the most fundamental challenges ever to confront humanity. Its
impacts are already showing and will intensify over time if left unchecked. There is
overwhelming scientific evidence, as shown in the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change (IPCC), that climate change will threaten
economic growth and long-term prosperity, as well as the very survival of the most
vulnerable populations.
IPCC projections indicate that if emissions continue to rise at their current pace and are
allowed to double from their pre-industrial level, the world will face an average temperature
rise of around 3°C this century. Serious impacts are associated with this scenario, including
sea-level rise, shifts in growing seasons, and an increasing frequency and intensity of extreme
weather events such as storms, floods and droughts.
The United Nations climate change negotiations offer a historical opportunity to step up
international action on climate change. A comprehensive, ambitious and effective deal is
essential to the global transition into green economic growth, and, most urgently, to help the
world, especially the most vulnerable, adapt to impacts that are now inevitable.

4. Mitigation of GHE in a typical Fertilizer industry NFCL, Kakinada
The integrated industrial facility of NFCL consists of 2×1350 Metric Tons per Day (MTPD)
Ammonia plants based on Haldor Topsoe process technology and 2×2350 MTPD Urea plants
based on Snamprogetti process technology along with all the required supporting facilities.
NFCL, Kakinada started production back in 1992 from Unit-I (Ammonia-I & Urea-I) and in
1998 from Unit-II (Ammonia-II & Urea-II). It has two Ammonia manufacturing facilities –
Ammonia I & Ammonia II. Both Ammonia Plants were designed for Natural Gas (NG) Feed
Stock.NG is used in the Ammonia Plant both as feed & fuel. Most of the CO2 generated from
reformation of NG feed will be usually recovered by using the conventional methods such as
hot potash process, amine process etc and will be used in Urea production as raw material.
Where as the CO2 generated by the combustion of NG as fuel in the furnace is normally not
recovered and will be released into the atmosphere.
NFCL installed a Carbon Dioxide Recovery (CDR) Unit to recover Carbon Dioxide from the
reformer furnace flue gases to recover CO2 and thereby to maintain the same levels of Urea
production instead of reforming excess NG in an increased (higher) capacity reformer. NFCL
has therefore not only reduced CO2 emissions taking place due to reforming of NG feed but
also reduced the emissions from NG firing as fuel in the reformer furnace. The 450 MTPD
installed capacity CDR plant use to recover CO2 from flue gases of primary reformer of
Ammonia Plant I and supply the recovered CO2 as raw material for Urea production.
Thus, NFCl reduces fossil fuel consumption in Urea manufacturing process leading to direct
reduction of Green house gas (GHG) emissions. The installation of the CDR plant would lead
to estimated emission reductions of 82574 Ton of CO2 equivalent i.e. a total of 825740 Ton of
CO2 over a ten year crediting period.

5. Carbon capture from Flue gas generated
from post combustion of Natural gas at
Primary Reformer &
Fixation to Urea, A chemical Fertilizer
at NFCL, Andhra Pradesh (India)

6. Carbon di oxide recovery plant at NFCL, Kakinada, Andhrapradesh

7. NFCL CDR Unit Layout Animation

8. CO2 Recovery process
M/S NFCL implemented Carbon Dioxide Recovery unit to mitigate the CO2 emissions by
CO2 recovery from flue gas stream (Post combustion of natural gas at furnace) for
urea production, with the optimum use of Feedstock.
CO2 Recovery process consists of following unit operations
The CDR plant shall consist of three main sections;
•Flue gas cooling section,
•CO2 recovery section and
•Solvent regeneration section.
The following block flow diagram shows the plant configuration.

10. Process Description of
Carbon Di Oxide recovery (CDR) Plant
The raw flue gas enters the direct contact cooler where it is cooled from 190°C to
50°C. Prior to entering the absorber, the gas is compressed to 15.84 psia (1.113
Kg/cm2 abs).
The cooled gas enters the absorber and flows up through the packed bed absorber
counter current to the solvent solution. The solvent reacts chemically with the carbon
dioxide in the absorber to remove 90% of the CO2 from the flue gas.
The gas enters the wash section of the absorber at 145°F (63 °C) where water and
solvent are removed and returned to the absorber packed section.
The washed gas is vented to the atmosphere at 126°F (52°C). The rich solution leaves
the absorber at 131°F (55°C) and is pumped to the lean/rich cross exchanger.
In the cross exchanger the rich stream is heated to 237°F (114 °C). The carbon
dioxide is removed from the rich solution in the stripper using a kettle type reboiler
with 50 psig (3.5 kg/cm2, gauge) steam.
Steam and solvent vapors leave the reboiler at 252 °F (122 °C) and enter the stripper
below the packed section. The vapors move up the stripper condensing as the CO2 is
liberated and the solvent solution is heated. Steam and carbon dioxide enter the wash
section of the stripper where entrained solvent is removed.

11. The steam and carbon dioxide leave the stripper at 217°F (103°C) and enter
the reflux condenser where steam is condensed and the carbon dioxide is
cooled to 108°F (42 °C).
The mixture then enters the reflux drum where carbon dioxide is separated
from the condensate. The condensate is returned to the stripper as reflux.
The lean solvent solution leaves the reboiler at 252°F (122 °C) and enters the
cross exchanger where it is cooled. The lean solution is then pumped to the
lean solvent cooler where it is further cooled to 108°F (42°C) by cooling water.
A ten- percent side stream of the cool, lean amine solution goes through a
carbon bed system to remove any of the solution contaminants.
The produced CO2 is used for production of Urea.

12. Mitigation of GHE by Carbon capture
from Pre combustion of Natural gas &
fixation to chemical Fertilizer, Urea,
A pathway to decarburization in a
typical fertilizer industry, at NFCL,
Andhra Pradesh (India)

13. Production of Syn gas for Ammonia manufacture by SMR process
and fixation of by product CO2 as nitrogenous fertilizer
Today most of us are aware how increased anthropogenic sources of CO2
emissions are affecting the global climatic conditions. Increased population,
Energy usage & industrialization are enhancing the emission levels, which is
affecting the Climate. Hence, adoption of advanced & cleaner technologies and
use of best available feedstock is essential by the industries to control the
emission levels.
M/S NAGARJUNA FERTILISERS AND CHEMICALS LIMITED is South
India’s first Natural Gas based fertilizer plant situated in Kakinada, Andhra
Pradesh,a Urea manufacturing Fertilizer Unit,uses Natural Gas as feed stock for
producing Syn gas for production of Ammonia via SMR process
(Precombustion of Natural gas ) and CO2 as byproduct for urea manufacture.

14. A typical Urea manufacturing unit requires Ammonia & CO2 as raw materials. Ammonia is
produced by the reaction of Hydrogen & Nitrogen. Hydrogen is produced from the steam
reforming of Hydrocarbon Feedstock while the Nitrogen is extracted from atmospheric Air.
In the Process of generating Hydrogen from Hydrocarbon Feedstock Carbon Dioxide will be
generated as byproduct, which will be used as Raw material for Urea Production. Thus, both
Ammonia & CO2 the required for Urea manufacture will be generated from Ammonia
Plants. In a Urea manufacturing plant, Hydrocarbon Feedstock will be used as both feed &
fuel. Hydrocarbon fuel will be used for processing hydrocarbon feedstock in to Hydrogen &
CO2.
Depending upon the characteristics of Feedstock, the generation of Ammonia & CO2 will
vary. Urea reactor converts Ammonia and CO2 into urea solution. Unconverted urea
solution is fed and decomposed into ammonia, water and carbon dioxide vapors at high
pressures in the urea stripper, and recycled back to urea reactor.
Overview of Carbon fixation process to UREA,a chemical Fertilizer
at NFCL Kakinada Plant

15. Ammonia & Urea Manufacturing Facility at M/S Nagarjuna fertilizers &
chemicals , Kakinada Andhrapradesh ( India )

16. SMR process for synthesis of Ammonia & byproduct CO2
General Process description of AMMONIA Production
A useful description of the methane steam reforming process comprising the following steps:
• Purification of the feedstock from reforming catalyst poisions;
• Primary methane steam reforming
• Secondary reforming, with the addition of air, conventionally called auto thermal
reforming
• Shift conversion of CO and H2O to produce syngas composing CO2 and H2;
• Removal of CO2 from syngas
• Methanation (a process that removes trace CO and CO2upon reaction with H2 in a
reactor)
• Synthesis of Ammonia
Purification of the feedstock from reforming catalyst poisons
The feed stock natural gas, is desulphurised by conversion of stable organic sulphur
compounds into Hydrogen Sulphide in presence of Nickel Molybdenum catalyst
R-SH + H2  R-H + H2S
R-S-R1 + 2H2  H + R1-H + H2S
R-S-S-R1 + 4H2  R-H + R1-H + 2H2S
followed by absorption of Hydrogen Sulphide on Zinc Oxide bed
ZNO + H2S  ZNS + H2O

17. General Process Description of AMMONIA Production

18. The desulphurised natural gas is mixed with super heated steam to give steam to Carbon ratio
of 3.3:1, preheated and fed to the catalyst tubes in Primary Reformer. The Primary Reformer
is a side-fired furnace with radiant wall mounted burners. The natural gas which is
predominantly methane undergoes following reactions producing Hydrogen and Carbon
Oxides:
CH4 + H2O 3 H2+ CO - Heat
CO + H2O CO2 + H2 + Heat
The process gas from the tubes is gathered by a collector system and sent to the Secondary
Reformer.
The Secondary Reformer is a refractory lined vessel containing Nickel catalyst. Air from
atmosphere comes in contact with the process gas from Primary Reformer. Combustion of
some part of Hydrogen and Methane occurs consuming the total oxygen in the air and the
temperature rises to about 1300 deg. C. This supplies the heat needed for completion of the
endothermic reaction in the catalyst bed.
Nitrogen needed for ammonia synthesis gets introduced in to the system in the Secondary
Reformer through the process air. The gas leaving Secondary Reformer contains residual
Methane of 0.6%. The exit gas from Secondary Reformer is cooled to about 380 deg. C in the
Waste Heat Boiler where high-pressure steam is generated.
Primary & Secondary Methane steam reforming

19. Shift conversion to produce syngas
The carbon monoxide formed in the reforming step is converted to CO2 by water gas shift
reaction in two stages, namely, high temperature shift conversion and low temperature shift
conversion.
The HT shift reaction takes place in presence of iron oxide chromium oxide catalyst and
LT shift reaction takes place in presence of copper oxide zinc oxide catalyst. The shift
conversion reaction being exothermic, steam is produced by heat recovery.
The reaction-taking place in the shift conversion can be represented as:
CO + H2O CO2 + H2 + Heat
The process gas leaving the CO conversion step contains in addition to Hydrogen and Nitrogen,
large quantity of CO2 and small quantities of CO, Argon and Methane.
Syn gas production by capturing CO2 by Giammarco Vetrocoke solution
The CO2 present in the process gas is removed in the CO2 removal section using Giammarco
Vetrocoke solution.
The main constituents of GV solution are K2CO3, V2O5, DEA and GLYCINE ( NH2-
CH2COOH),. V2O5 acts as the corrosion inhibiter and DEA, GLYCINE are the Activator &
promoter of the reaction.
H2O + CO2  H2CO3
K2CO3 + H2CO3  2KHCO3
-------------------------------
K2CO3 + H2O + CO2 -> 2 KHCO3
Here, CO2 absorbed in potassium Carbonate solution is regenerated by reducing the pressure
and addition of heat in two stage regenerators. The regenerated solution is pumped back to the
absorber.

20. Syn gas production by capturing CO2 by Giammarco Vetrocoke solution
First Step reaction
H2O + CO2  HCO3- + H+
H2O + CO3-  HCO3- + OH-
-----------------------------------
H2O + CO3- + CO2  2HCO3
Second Step reaction
H2NCH2COO- + CO2 -OOCHNCH2COO- + H+
-OOCHNCH2COO- + H20  H2NCH2COO- + HCO3-
-------------------------------------------------------------
CO2 + H2O  HCO3- + H+
Thus, the system operates in closed circulation. The CO2 gas stripped from the solution in
the regenerators is cooled and sent to Urea plant.
Methanation to decarbonize syn gas
The process gas exit absorber which contains only traces of CO and CO2, Since carbon
oxides act as poison to the ammonia synthesis catalyst, the residual carbon oxides present in
the process gas are converted into methane in a methanator reactor containing nickel
catalyst.
This step is the reverse of reforming reaction and consumes a small amount of hydrogen.
CO + 3H2  CH4 + H20
CO2 + 4H2  CH4 + 2H20
CO + CO2 + 7H2  2CH4 + 3H20

21. Ammonia synthesis
The Methanator exit gas after cooling and removal of condensate is the synthesis gas
with some inert. This gas is compressed from 24 Kg/Cm2g to 134 Kg/Cm2g in a
centrifugal syn gas compressor.
Also, there is a recirculation stage in the compressor where the recycle of unconverted
gas along with the compressed make up gas are further compressed to about 142
Kg/Cm2g.
This gas after pre-heating is admitted to ammonia synthesis converter containing
promoted iron catalyst, where Hydrogen and Nitrogen combine to form ammonia with
evolution of heat.
N2 + 3H2 2NH3 – Δ H
Bird eye view of AMMONIA Plant at M/S Nagarjuna fertilizers & chemicals ,
Kakinada Andhra Pradesh ( India )

22. Carbon fixation as chemical Fertilizer,UREA
Process description of UREA production
The following operations are involved in the Urea process,
• Urea Synthesis and high pressure recovery
• Urea purification and low pressure recovery
• Urea Concentration
• Urea Prilling
• Process Condensate Treatment
Bird eye view of UREA Plant at M/S Nagarjuna fertilizers & chemicals ,
Kakinada ,Andhra Pradesh ( India )

23. General Process Description of UREA Production

24. Carbon Footprint Study of NFCL Complex, Kakinada
In June 2008, the GoI released the National Action Plan on Climate Change, a
policy document outlining a number of steps and measures that focus on achieving
GHG mitigation and adaptation to climate change in ways that also promote the
country’s development objectives. The National Plan discusses GHG mitigation
options in the industry and ways to promote energy efficiency in residential &
commercial sector. According to the Plan, CO2 emissions from fuel and electricity
use in the industrial sector can be reduced by 16% in 2031 compared to the business
as usual scenario.
Carbon Footprint can be defined as a measure of the impact human activities have on
the environment in terms of the amount of green house gases produced. In the case of
an organization, business or enterprise, carbon footprint is the amount of C02
equivalent emitted as a part of their everyday operations. It is often expressed as tons of
C02 or tons of carbon emitted, usually on an annual basis.
With increasing importance to climate change and GHG issues, NFCL being an eco friendly
industry, pursuing GHG management in a big way. The following are the drivers for
compiling a GHG inventory and monitoring carbon footprint:
• Managing GHG risks and identifying cost-effective reduction opportunities
• Employee satisfaction and Public reporting
• Participating in GHG markets and recognition for early voluntary action
• Environmental co-benefits

25. Carbon Footprint Study of NFCL Complex, Kakinada
Measurement of NFCL's GHG / Carbon Footprint: NFCL has taken the services of
M/s CII, who have rich experience in the field of GHG emission monitoring; for
developing the tool for estimation and Inventory Management of all GHG
emissions within the Complex.
NFCL & CII has explicitly adopted the 5 overarching accounting & reporting
principles (Relevance, Completeness, Consistency, Transparency & Accuracy)
highlighted in the GHG Protocol Corporate Standard for developing the Excel
based tool for assessing present GHG emissions as well as for monitoring future
business activities
The following two measures were the prime contributors for NFCL Carbon
Emission Intensity reduction by 21.3% from 2008-09 to 2009-10:
• Installation of Carbon Dioxide Recovery Unit. This Unit recovers the CO2 from
Fluegas, which is otherwise let to atmosphere. The CO2 thus recovered from this
Unit is used for Urea production.
• Changeover of entire Complex operations to Natural Gas mode.

26. Carbon Footprint Study of NFCL Complex, Kakinada
The CDR project as implemented in NFCL plant, contributes positively to the “sustainable
development of India” in following ways:
Environmental well being: The project activity recovers CO2 from flue gases (which were
earlier released to atmosphere) – resulting in positive environmental effects like reduction of
GHG emissions. It also helps in conserving non-renewable resources like Naphtha and
Natural gas, which can be used for important processes in future.
Socio – economic well being: Project activity would marginally increase employment
opportunity for semi-skilled, skilled labour and professionals in the region during
construction and operation phase. Therefore contributing social well being aspects. The
project will create a business opportunity for local stakeholders such as suppliers,
contractors, bankers, etc. Moreover, the project will facilitate in enhancing the knowledge
base and skills of employees of NFCL.
Technological well being: The project uses “state-of-the–art” technology and will help the
company to maintain its status of being one of the most progressive fertilizer companies in
India by adopting the latest technology and its efforts for sustainability. The project
implementation will aid in knowledge and skill development of the employees. Further, the
project activity has good replication potential in other fertilizer plants of India and the world.

27. Classification of GHE
GHG emission broadly be divided into
three categories:
The Primary GHG emissions / Footprint
(Scope-1): It is a measure of direct
emissions occurring due to activities
owned and controlled by the
organization.
The Secondary GHG emissions /
Footprint (Scope-2): It is a measure of
indirect emissions occurring from
purchase of various forms of energy.
The Tertiary GHG emissions / Footprint
(Scope-3): It is a measure of indirect
emissions occurring from activities like
business travel, travel of employees to
office, outsourced activities, etc
These are essentially activities earned
out in premises or circumstances not
owned, governed or controlled by the
organization.
Year 2008-09 2009-10 2010-11
Scope 1 0.624 0.487 0.479
Scope 2 0.002 0.002 0.001
Scope 3 0.01 0.012 0.011
Overall 0.636 0.501 0.492
% Reduction over
Previous Year
21.3 1.8
NFCL’s Emission Intensity (MT CO2
Equivalent / MT Urea)
0.636
0.501 0.492
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
2008-09 2009-10 2010-11
Year
CO2e
Emissions,
MT
of
CO2
/
MT
of
Urea

28. Thank you