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Internship project- Carbon Dioxide Sequestration

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1 Summer Internship at National Institute of Ocean Technology, Chennai Internship on Gas Hydrates and Carbon dioxide sequestration Under the guidance of Dr. S. Ramesh- Scientist E Submersibles & Gas Hydrates National Institute of Ocean technology Chennai, INDIA
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Page 1: Internship project- Carbon Dioxide Sequestration

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Summer Internship at National Institute

of Ocean Technology, Chennai

Internship on Gas Hydrates and Carbon dioxide

sequestration

Under the guidance of

Dr. S. Ramesh- Scientist E

Submersibles & Gas Hydrates

National Institute of Ocean technology

Chennai, INDIA

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Acknowledgement

We are grateful to the Director, National Institute of Ocean Technology for

granting us permission to do the Summer Internship at NIOT. We thank

Dr.G.A.Ramadas, Group Head, Deep Sea Technologies, for his support during

the course of internship and Mr.Raju Abraham, Scientist E, HRD in-charge for

facilitating us to do the internship and Dr. S. Ramesh, Scientist E for guiding us

throughout the project. We are thankful to Dr. Hema Achyuthan, Head of the

Department and Dr. C. Lakshmi Narasimhan, Associate Professor, Department

of Geology, Anna University, Chennai, for encouraging us to apply for

internship at National Institute of Ocean Technology (NIOT), Chennai.

We also thankful to Mr. N Thulasi Prasad, Scientist and Mr. K.N.V.V. Murthy,

Scientist in Submersible and Gas Hydrate program for their support during the

internship.

Finally, we are thankful to our parents for co-operation.

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INDEX

S. No.

Contents

1 Deep Sea Mineral Resources

2 Introduction to Gas Hydrates

3 Occurrence

4 Gas Hydrates in India

5 Gas Hydrates Exploration

6 Gas Hydrates as Energy Resource

7 Problems in Exploitation

8 Organizations working in Gas Hydrates research

9 Carbon dioxide sequestration

10 Carbonation process

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Deep Sea Mineral resources:-

Poly-metallic Manganese nodules- 3000 to 6000 m water depth

Cobalt Crusts- 2500-4000 m water depth

Poly-metallic sulphides- 2000-4000 m water depth

Phosphorites- 400-500 m water depth (The hydrothermal vents create

sulfide deposits which contain valuable metals such as silver, gold, copper,

manganese, cobalt and zinc)

Coastal Placer deposits – 50 m water depth

Gas hydrate Deposits – 1000-3000 m water depth

Advancement of deep sea technologies such as ROV, AUV and Manned

Submersibles had brought out the many new facts about the ocean mineral

resources. These vehicles are used for exploration and collecting samples from

deep sea floors.

Introduction to Methane Hydrates:-

What is Methane Hydrates?

Methane Hydrates are ice like crystalline clathrate, formed in a rigid cage of

water molecule and entrap hydrocarbon. It consists of 99.9% gases and water.

• The growing demand of carbon emission-free energy resources and

depletion of fossil fuels necessitate for an alternate source of energy

Besides, Nuclear and Solar energy, Methane Hydrates have attracted the

global attention due to their wide spread occurrences in the outer

continental margins and permafrost regions and their huge energy

potential.

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Occurrence:-

One volume of Methane hydrates release 164 m3volumes of methane gas and 0.8m3 volume of fresh water at standard temperature and pressure.

Unlike natural gas, oil and minerals, gas hydrates are not stable at STP.

Gas Hydrates exists only at high temperature and moderately low temperature.

The huge volume of methane trapped within global gas hydrates seems to be viable major energy resources of future.

Best known gas hydrates associated with offshore (marine, lakes) and onshore permafrost accumulations in the world are Black Ridge (USA), Cascadia margin (Canada), Nankai Trough (Japan), Northern Slope of Alaska, Lake Baikal (Russia) and Mackenzie Delta in Canada (Collett 2002).

Probable locations of gas hydrates in India are Kerala – Konkan region, Krishna Godavari Basin, Mahanadi Basin, Andaman Arc Basin (NGHP-01 expedition). Proven results are available from KG basin at a depth of ~950 m. Gas hydrates recovered in the range of 40 mbsf to 160 mbsf (about 120 m thick) at 1050 m water depth (Petroview, 2006)

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Gas Hydrates in India

Source: www.niobioinformatics.in/nonliving4.php

Gas Hydrates were first recognized in India by an ONGC personnel, Chopra in 1985 in the Andaman region.

By analyzing Multi Channel Seismic data, the Bottm Simulating Reflector (BSR) had been identified in Krishna- Godavari, Mahanadi and Andaman regions in the eastern and Kerela- Konkan regions in the western Indian margin.

The bathymetry, seafloor temperature, total organic carbon (TOC) content, sedimentary thickness, rate of sedimentation, geothermal gradient indicate good prospects of gas hydrates along the Indian margin.

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Gas Hydrates formation:-

Gas hydrates forms when methane and water combine at pressure and temperature conditions that are common in marine sediments of Earth’s continental margins and below about the 200m depth in the permafrost areas.

Globally, gas hydrates has been recovered inferred in many continental margin settings and in onshore permafrost or offshore relict permafrost that was flooded by sea level rise over the past ~15000 years.

Gas Hydrates has also been recovered from sediments beneath Lake Baikal (Earth’s largest freshwater Lake).

Gas Hydrates Exploration:-

Gas Hydrates have been identified from geophysical, geochemical and geological surveys and by drilling and coring.

Geophysically, gas hydrates can be found out by identifying an anomalous seismic reflector, known as the Bottom Simulating Reflector (BSR).

BSR are identified based on its characteristic features of 1. Mimicking the shape of seafloor. 2. Cutting across the sedimentary strata, and 3. Exhibiting large amplitude opposite polarity with respect to

seafloor reflection.

Thus, the BSR is a physical boundary between hydrate bearing sediments above and gas saturated sediments below, and is often associated with base of gas hydrates stability field.

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Gas Hydrates as Energy Resource:-

Since, methane is the cleanest of all hydrocarbons fuels, use of gas hydrates as fuels will cause less pollution.

Only 15% recovery from this gigantic reserve may be sufficient to meet the global energy requirement for about 200 years . Thus, Gas Hydrates research is gaining momentum to understand this resource for extraction.

The total volume of ~1900 trillion cubic meter of methane gas, stored in the form of gas hydrates, has been prognosticated within the Indian exclusive economic zone (EEZ).

This Volume of gas is more than 1500 times of India’s present natural gas reserve, and it is envisaged that 10% recovery from this huge cache of energy can meet India’s overwhelming energy requirement for about a century.

Therefore, the identification and quantitative assessment of gas hydrates along the Indian margin has been very essential

Problems in Gas Hydrates Exploration:-

When hydrates are removed from their high pressure and low temperature

environment and they decompose and release the hydrocarbon gas contained

within it at Standards Temperature and Pressure (STP). To take advantage of

gas hydrates as a resource, we need to find efficient methods of dissociating

the hydrates in a safe and controlled manner, and there are three main

challenges we are currently looking into:

Temperature control

Sand control

Water handling

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Organization Working on Gas hydrates:-

Directorate General of Hydrocarbons(DGH), Noida

Oil and Natural Gas Corporation(ONGC), Limited at Dehradun

Oil India Limited(OIL) at Delhi

Gas Authority of India Limited(GAIL) at Delhi

National Geophysical Research Institute(NGRI), Hyderabad

National Institute of Oceanography(NIO), Goa

National Institute of Ocean Technology, Chennai

Indian Institute of Technology(IIT) at Chennai, Kharagpur and Kanpur

Indian School of Mines(ISM), Dhanbad

Institute of Engineering and Ocean Technology (ONGC), Mumbai.

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Carbon dioxide Sequestration

The concentration of CO₂ in our atmosphere is promoted by the combustion of

fossil fuels for the generation of electricity and industrial processes. Most

agree therefore that carbon capture and sequestration(CCS) from the point

sources i.e. the industries are necessary for meaningful greenhouse gas

reduction in the immediate future. The generally accepted and likely optimistic

goal is to limit the global temperature increase to 2.1⁰C above the preindustrial

levels by 2100, which the Inter- Governmental Panel on Climate Change(IPCC)

has estimated would require a 50-85% emission reduction from present levels

by 2050, with no emission speaking later than 2015.

Capturing CO₂ from flue-gas streams is an essential parameter for the carbon

management for the sequestrating of CO₂ from our environment. The physical

and chemical adsorption of CO₂ can be achieved by using the solvents,

cryogenic techniques, membranes and solid sorbents. The large scale

operation of these technologies is energy intensive when applied to capturing

CO₂ in dilute stream, such as flue gas, which consists of 15% CO₂ by volume for

most coal combustion system. Captured CO₂ are to be sequestrated with

suitable processes for the long term mitigation process. Storage options

involved geological, biological and ocean sequestration process.

Carbon sequestration means capturing carbon dioxide from the atmosphere or

capturing anthropogenic CO2 from large-scale stationary/point sources like

power plants before it is released to the atmosphere. Once captured, the

CO2 gas is put into long-term storage. CO2 sequestration has the potential to

significantly reduce the level of carbon that occurs in the atmosphere as

CO2 and to reduce the release of CO2 to the atmosphere from major stationary

human sources, including power plants and refineries.

Carbon dioxide (CO2) capture and sequestration (CCS) is a set of technologies that can greatly reduce CO2 emissions from new and existing coal and gas fired power plants and large industrial sources. This process includes following steps:-s

Capture of CO2 from power plants or industrial processes Transport of the captured and compressed CO2. Underground injection and geologic sequestration of the CO2 into

deep underground rock formations. These formations are often a mile

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or more beneath the surface and consist of porous rock that holds the CO2. Overlying these formations are impermeable, non-porous layers of rock that trap the CO2 and prevent it from migrating upward.

The various types of sequestration are as follows:-

1. Terrestrial Sequestration:-

Terrestrial (or biologic) sequestration means using plants to capture CO2 from the atmosphere and then storing it as carbon in the stems and roots of the plants as well as in the soil.

In photosynthesis, plants take in CO2 and give off the oxygen to the atmosphere as a waste gas. The plants retain and use the carbon to live and grow.

It is important to remember that terrestrial sequestration does not store CO2 as a gas but stores the carbon portion of the CO2.

If the soil is disturbed and the soil carbon comes in contact with oxygen in the air, the exposed soil carbon can combine with O2 to form CO2 gas and reenter the atmosphere, reducing the amount of carbon in storage.

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2. Geologic Sequestration:-

Geologic sequestration is putting CO2 into long-term storage in geologic zones deep underground.

Geologic sequestration is the method of storage that is generally considered for carbon capture and storage (CCS) projects.

CCS is the practice of capturing CO2 at anthropogenic sources before it is released to the atmosphere and then transporting the CO2 gas to a site where it can be put into long-term storage.

In India, saline aquifer in the Ganges basin has the greatest amount of geological storage capacity for long term.

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3. Ocean Sequestration:-

Oceans have been identified as the natural sink for atmospheric CO2. Ocean acidification and consequential impact on the natural carbon cycle were identified as the impact for the increase in the atmospheric carbon content.

Direct injection and fertilization using iron and nitrogen were some of the concepts pursued for Ocean sequestration but stopped due to environmental concerns.

Disposal of CO2 at 2800m below the sea level creates a locally stable pool of carbon dioxide under the heavy water column.

Based on the pressure-temperature conditions on the ocean basin, CO2 can be effectively stored on the ocean floor beyond 2800m water depth with local conditions favoring the formation of a stable pool. But environmental concern has to be addressed.

The technique of CO2 replacement with CH4 hydrates has been developed recently, because it has one that the hydrate structure remains the same and mechanical stability of the reservoir is not disturbed. CO2 hydrates are thermodynamically more stable than CH4 hydrates. This technique is one of the identified methodology for hydrate extraction.

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Carbonation Experiment:-

Mineral carbonation is a prospective option of CO2 storage to fix the CO2 in

thermodynamically stable form in an inorganic carbonate which is well-known

as industrial mineral carbonation technique (IPCC Special Report, 2005).

Fifty million tons per year of steel slag is produced worldwide. Owing to the

intensive research work during the last 30 years about 65% of the produced

steel slag is used today on qualified fields of applications. But the remaining

35% of the slag is still dumped (Motz & Geiseler, 2001). India is the seventh

largest steel producer in the world. Indian steel sector is one of the highest

energy consuming and CO2 emitting industry designated as one of the 17

highly polluting industries in India. One ton of crude steel requires 3.5-5 tonnes

of raw material. The remaining 2.5-4 tonnes as a by-product (waste or

emissions in air and water).

Using the industrial waste CO2 sequestration may be possible, which is one of

the safest and longest storage of CO2. For Example considering the reaction

with the CO2 with the steel slag to produce carbonate and silica is one o the

best options. In this processes, reactive nature of CO2 with the minerals and

other wastes materials are to be understood by applying different combination

of experimental approach to industrial wastes such as steel slag, fly ash, pulp

industry waste etc.

Compared to other carbon dioxide storage routes, mineral CO2 Sequestration

has number of advantages:-

Mineral carbonation is a chemical sequestration route of which the formed products are thermodynamically stable and environmentally benign.

The formed mineral products are end products of geologic processes and are known to be stable over a geological time periods. Therefore the storage of CO2 is permanent and inherently safe.

The carbonation reaction is exothermic. The reaction energy may be potentially applied usefully. The potential CO2 Sequestration capacity of mineral carbonation s very large.

Considering the different CO2 options available and the environment concern towards the disposal into ocean, optimised indirect method had been taken up in the form of carbonation process.

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The steel slag contains more percentage of oxides of calcium, magnesium, iron along with silica and can be used for the storing CO2.

These oxides reacts with CO2 forms the carbonate which is safe storage for carbonates. The obtained carbonates are used for making the marine blocks, carbonation techniques and utilize as coastal protective measures, artificial coral reef growth, island formation etc.

The carbonation experiment is carried out using High Pressure Chemical

Reactor at NIOT. The specifications of the Reactor are as follows:-

Volume: 1 lit

Material of construction-Stainless steel: 316L

Pressure – Max: 125bar

Temperature – Max: 250C

2000 rpm.

High pressure chemical reactor facility setup is developed at NIOT to work for carbonation experiment for the operating conditions of 100⁰ c and 20 bar pressure. The laboratory setup developed can be seen in the picture clearly. Steel slag were grinded to less than 63 micron and utilized for carbonation by introducing the CO₂ into the high pressure reactor setup by converting to the carbonates. Carbonated material are analyzed in SEM and Fourier Transform Infrared Spectroscopy. Results are encouraging for carbonation experiment. Further experiment are underway with combinations of acid/reactants for energy efficiency and effective conversion process. Converted slag materials are used to preparing the marine blocks.

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High Pressure Chemical Reactor at NIOT

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Conclusion of Carbonation Experiment:-

By comparing the various options CO₂ sequestration process and with

reference to the Indian scenario of storage potential with the need of

industrial development, Ocean technology seems to be a potential option

by indirect methodology.

Studies indicate that the carbonation from industrial wastes can be

optimized for energy efficiency.

It can utilized as artificial reef blocks to store the CO₂ for the longer

period.

Storage in marine environment as marine blocks will be eco-friendly to

marine biotic life cycle.

Options of CO₂ storage in micro algae will give added benefits for bio-

diesel production.


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