decarbonization of fossil: pathway to hydrogen economy · decarbonization of fossil: pathway to...

1

JNCASR-I@CAM energy school,

Bangaluru

Nov30, 2017

Decarbonization of fossil: Pathway to

Hydrogen Economy

R. R. SondeExecutive VP, Thermax Global Ltd.Formerly with Atomic Energy Commission, India & NTPC Ltd.

COAL IS THE BACK BONE OF ENERGY & INDUSTRIAL REVOLUTION SINCE 16 th CENTURY.

Coal and Crude oil both of fossil origin meet almost 89% of global energy needs.

Both have carbon –carbon bonds, hydrogen- carbon bonds hybridized in various ways. SP3, cleavage, co valent bonds with energy from 400 kJ/kgmol to 800 k j/kgmol.

Coal is hydro carbon with a formula CH0.14

While oil is with an average formula of C8 H16 and gas is methane CH 4

Fossil Fuel Emissions

0

5

10

15

20

25

30

1750 1850 1950 2050 2150 2250 2350 2450 2550

Year

Em

issio

ns

(G

tC/y

r)

"Data"

"Logistic Fit"

Fossil fuels are going to be mainstay of energy security of the globe

Source for “all fossil fuel”: Bryan Mignone

IS92a

scenario

GtC/yr

Today

xxxxx xxx x

Hubbert oil curve:

3 GtC/yr peak today,

230 GtC (2000x109bbl) total

OIL

ALL FOSSIL

FUEL

Hubbert (logistic) curve for

all fossil fuel: 5600 GtC total,

fit to IS92a

x

PEAKING OF FOSSIL: AN UNENDING

RESOURCE? OR APOCALYPSE OF THE GLOABE

Fossil Energy Conversion: Corner stone in the great discoveries

James Clerk Maxwell Michael Faraday

Maxwell introduced the concepts of electro-

magnetism.

Faraday – Maxwell Equations talk about the

generation of electricity through a magnetic field

and the concepts of Electrodynamics

The modern steam turbine invented by Sir Charles Parsons in 1887 today generates

about 80 percent of the electric power in the world using a variety of heat sources.

Charles Algernon ParsonsFirst compound steam turbine, built by Parsons in 1887

Sir Charles Algernon

Parsons, invented the first

steam turbine in 1887

Very complex way of conversion “chemical– thermal-mechanical-electricity”

Combustion – Heat Transfer – Roto dynamics - Electromagnetism

https://en.wikipedia.org/wiki/File:Charles_Algernon_Parsons.jpg

Carnot Engine: All heat can not be converted to work

Nicolas Léonard Sadi Carnot

Carnot sought to answer two questions about heat engines

"Is the work available from a heat source potentially

unbounded?“

"Can heat engines in principle be improved by replacing the

steam with some other working fluid or gas?"

Carnot Engine Diagram

PV and TS diagram of Carnot cycle

The motive power of heat is independent of the

agents employed to realize it.

Its quantity is fixed solely by the temperatures

of the bodies between which is effected, finally,

the transfer of caloric.

• Turbine exhaust has to be dry.

• This limits point 4 for a steam

cycle.

• Point 4 determines efficiency

THERMODYNAMIC CYCLE OF EXTRACTION OF FOSSIL ENERGY

Boiler (steam generator)

island

Steam Turbine cycle Electricity

Condensing Cycle

Condensing Cycle

FOSSIL FUEL

(HC)

Reject heat

Efficiency = Electricity (kWhr) /Heat input (kWhr)

CO2

The thermodynamic

efficiency is just

about 30-45%!Ash

Improve Thermal Efficiency in PC and USCPC

Current Level

35-

36%

37-38%Increasing

steam

Parameter

s

38-40%Super

critical

42%Second

Reheat

43%Supercritical

+

45%Ultra-

Supercritical

+

Novel

Technologie

s

T

E

M

p

535 deg C

580 deg C

620 deg C

660 deg C

Efficiency VS AVAILABILITY

Thermal to Electrical Conversion process

Sink temperature is

critical while higher

temperature of

steam (and the

supercritical cycles)

increase the

efficiency

The lower efficiency has two

impacts : Higher fuel

consumption and consequent

higher CO2 emissions

HOW DO WE CALCULATE CO2 FROM SUCH A CYCLE

1. Once we fix the steam temperature (source), for a given cooling water (sink) temperature, we can calculate the efficiency of the cycle

2. Then calculate the fossil fuel energy needed for generating 1 unit of electricity (kWhr)

3. Based on the heat content of the fossil fuel, now calculate the mass of fossil required for generating 1 unit of electricity

4. Now using the bond energy and moles of carbon bonds we can now calculate the CO2 generated from the mass of fuel foe 1 unit of electricity

5. The efficiency of the steam generating boiler will also need to be considered in this calculations

Clean Technology: Those technologies which emit near zero

pollutants in its process of energy conversion are by definition are

clean technologies. Zero emission can be achieved by ensuring

that the process is efficient (in strict thermodynamic sense of

reversibility) plus disposing of the residual pollutants.

CO2 Emissions from fossil fuel

Efficiency (%) Technology Specific CO2

emission, kg/KWh

100 Nil 0.3156

80 Nil 0.3945

60 DC+FC (*) 0.5260

50 IGCC +FC 0.6312

45 IGCC 0.7014

40 USC 0.7819

35 PC 0.9018

Gas Levels GHG

Potential

Net GHG

impact

CO2 12-13% 1 95%

NOx 250-400

ppm

288

(N2O)

5%

SOx 400-800

ppm

Nil Nil

SPM 120-150

ppm

Nil Nil

Table2. Variation of specific CO2 emission with efficiency

Table1. Typical emission levels from a coal fired power station

NGCC

(380)

(850)

The Stabilization Triangle:

Beat doubling or accept tripling

Values in parentheses are ppm. Note the identity (a fact about

the size of the Earth’s atmosphere): 1 ppm = 2.1 GtC.

14

7

21

1955 2055 21052005

Flat = Act Now

1.9

(320)

(470)

(530) (750)

(500)(500)

(500)

(850)

2155 2205

GtC/yr

Historical

emissions

Stabilization

triangle

THIS ONE PICTURE SHOULD BRING UP THE

RESOLVE BEYOND ANY DOUBT

CLIMATE CHANGE AND ITS POTENTIAL FOR DESTRUCTIVE IMPACT IS NOW

UNDISPUTED.

AMITAVA GHOSH CALLED IT AS “ GREAT DERANGEMENT”

“Extreme Events” happening with regularity

37.8 Giga Tonnes of anthropogenic CO2 and 5 MT of ODP sitting in the earth’s

atmospheric crust is the root of all these

WE ARE AT THE TIPPING

POINT

CONSIDER THIS: HOW MANY OF US CAPTURED THE TWO RECENT HEAD LINES- OCT 2016

1. On 19 th October, CO2 (gold standard from the Lab Mauna Loa in Hawaii) , concentration touched 400 PPM – TIPPING POINT.

2. On 23 rd October, Scientists accidently discovered a process that turns CO2 into ethanol !!

400 ppm

Now how do we de carbonize the fossil but still get the energy ?

FOSSIL SOURCENON FOSSIL SOURCE

(NUCLEAR) RETAINS

CARNOT PRINCIPLE

RENEWABLE SOURCE

(NEW METHOD OF GENERATION

FOSSIL SOURCECARBON CAPTURE AND

SEQUESTRATION – CCS

TECHNOLOGIES

FOSSIL SOURCEHYDROGEN OR ITS

CARRIERS

CO2 TO FUEL

RENEWABLE SOURCE

SOLAR + WIND

De-

carbonizing

the fossil

Sources : WCI; Scientific American

Ref. : World Coal Institute

CARBON CAPTURE AND SEQUESTRATION : CCS TECHNOLOGIES

DECARBONIZING FOSSIL ENERGY

Boiler (steam generator)

island

Steam Turbine cycle Electricity

Condensing Cycle

Condensing Cycle

FOSSIL FUEL

(HC)

Reject heat

Efficiency = Electricity (kWhr) /Heat input (kWhr)

CO2

The thermodynamic

efficiency is just

about 30-45%!Ash

CO2 Transportation

CO2 Sequestration

CO2/AGR Capture

Pre-Combustion

IGCC

Post Combustion

Physical Separation

Chemical Separation

Membrane Separation

Hybrid Separation

During Combustion

Oxy-Fuel Combustion

CFBC

Hi-Pressure Transportation

Cryogenic Transportation

Carbon capture Technologies

CO2 Capture

CO2 SequestrationCO2 Transportation

The 3-Point Triangle

Deep Ocean Storage

Underground Coal Mines

Enhanced Coal Bed Methane

Enhanced Oil Recovery

Bio Technological Path

Underground Aquifers

Large R&D

Required

Advanced

chemistry

plays a major

role

Depleted Oil & Gas Fields;

? Availability ?

Enhanced coal bed

methane

? Net GHG mitigation ?

“Unmineable” coal seams

? Injectivity ?

Deep Saline Reservoirs

e.g. Sleipner, In Salah,

SnohvitEnhanced Oil Recovery e.g. Weyburn;

? limited total capacity ? Source IPCC

Sequestration issues: Well known concerns

Typical parameters for a 210 MW Indian Coal Unit

Coal : 130 ton / hr

Air : 700 ton / hr

Volume of flue gas : 800 ton/ hr or 410-430 m3/sec

CO2 Emission : 170 ton/hr

Temperature : 140-170 °C

Pressure : 350-500 mmwc

Excess oxygen : 3-4%

CO2 : 13 - 15 %

Moisture : 4-5%

SOx : 700-1200 mg/Nm3

NOx : 300-500 mg/Nm3

Fly ash : 65000 mg/Nm3 (before ESP)

About 120 mg/ Nm3 (after ESP)

Huge Quantities of Flue Gases

from a Typical Power Plant

Challenges in Carbon Capture in PC Fired Boiler

Challenges in Carbon Capture

Combustion in boiler at

Atmospheric pressure

Low CO2 concentration in

Flue Gas: GT / Gas fired

boiler is 4-5%

Low CO2 concentration in

Flue Gas: Coal fired boiler:

13-15%

Low Discharge pressure of

Flue Gas: 350-500 mmwc

Combustion in boiler at

Atmospheric pressure

Facts

High Energy

for

pressurization

Bulky equipment

- Higher capital

costs

High partial pressure

based CO2 separation

process like Benefild or

Catacrab cannot be used

Issues

Low partial pressure of CO2

1. Low partial pressure

of CO2


2. High temperature of flue gases

Facts

Flue gas temperature

is generally 140-160 °C

Present solvent based

process operates at 40-

50 °C

CO2 laden solvent is

regenerated at 120 °C -

130 °C

Issues

Cooling is

required for

CO2 separation

Flue gas

cooling below

50°C is required

for membrane

or PSA process

Concerns

Cooling is very

energy intensive

process

Lower

temperatures

also pose risk of

acid corrosion


3. SOx Removal

Flue gases from coal fired units contains 700-1200 mg/Nm3 of SOx

In amine process, SO2 reacts with amines to form thermally stablecorrosive salt.

SO3 forms sulfuric acid mist in cooler causing corrosion

SOx may adversely reacts with membrane materials or solidadsorbent or may get adsorbed on adsorbent

Facts:

The acceptable limits of SO2 for solvent process is 10 ppmv

A lime stone or wet FGD system followed by caustic soda or soda ash based scrubber is must for SO2 removal

Issues:

Cost of FGD (not mandatory otherwise), results in

higher cost of CO2 capture

Concerns:


Level in flue gas 500-

800 mg/Nm3

In amine process,

solvent degradation

due to formation of

thermally stable salts

Corrosion due to nitric

acid formation

Adverse reaction or

adsorbed in solid

absorbents

Facts

NOx may degrade

membrane materials

NOX is removed by

SCR process at 250-

300 °C

Plugging of catalyst by

fly ash is a problem

Flue gas heating to

reaction temperature

not possible when

SCR is after

Economizer.

Issues

SNCR at high

temperature is an

option

Cost of NOx removal

results in higher cost

of CO2 capture

Development of Nox

/ corrosion resistant

process will be

better option

Concern

4. NOx Removal

Mercury is yet

another aspect


5. Oxygen

in Flue

Gases

Issues:

Corrosion in solvent based process,

particularly at high temperature

Solvent degradation

Degradation of membrane due to oxidation

Oxygen may get adsorbed on solid absorbent

thus reducing its adsorption capacity

In solvent based process, corrosion inhibitor

or oxygen scavenger is used

Facts:

Corrosion in solvent based process, particularly

at high temperature

Concerns:

Screening of Oxygen may be a very cost

intensive process


6. Fly Ash in Flue Gas

Facts:

About 100 -150 mg/Nm3 of fly ash present

in flue gases

Issues:

This causes plugging, erosion, solvent

degradation etc. in solvent based process

Fly ash may also plug membranes and

solid adsorbents

Generally Direct Contact Cooler or FGD

removes most of the fly ash

Technologies for CO2 Separation

CO2

Capture

Process

Physical

Separation

Chemical

Separation

Advanced

Separation

Biological

Separation

Hybrid

Separation

Cryogenic

Distillation

High

Pressure

Separation

• Originally developed for CO2

separation in urea plant

• CO2 is absorbed into aq. solution of

MEA at room temperature

• CO2 is separated out at 120-125 °C

in stripper

Na2CO3

MEA Reclaimer

Blower FGD

Absorber

Stripper

Reflux Drum

Reboiler

Sludge

Filtration

Vent Gas CO2

Fluegas

MEA

Na2CO3

MEA Reclaimer

Blower FGD

Absorber

Stripper

Reflux Drum

Reboiler

Sludge

Filtration

Vent Gas CO2

Fluegas

MEA

Present State of Art for CO2 Separation

Energy Intensive Solvent Recovery

(Typical values for 210 MW unit)

Steam requirement : 1.5-1.6 Ton / Ton of CO2

Power requirement : 7-8 Mwe

Total energy requirement : 65 MWe (approx.)

Electrical efficiency Drop to : 23-25%

Corrosion

Solvent Degradation

MEA Technology: Limiting Factors

The Amine Process

Research Areas:

• New Solvents

• Improved Equipment

• Energy Integration

Basic chemistry in solvent absorption

2RNH2+CO2------ R-NH-COO-+ RNH3 + (MEA)

R2NH3 + CO2--- R2NCH4+ + HCO3- (MDEA)

Salient features

1.Kinetics vs. equilibrium absorption

2.Selectivity for Acidic gases

3.Degradation issues

New R&D directions

New engineered hindered amines, additives,

hybrids

Modified amines (sterically hindered amines where molecular structures of

these amines are generally similar except that amino group is attached to a

bulk alkyl group. 2AMP (2 Amino-2-methyl-1-propanol) is one such example

CO2 + RNH2 ------ RNH2+COO – (carbamate)

CO2 + R1R2NH <-------- R1R2NH +COO – (carbamate)

CO2 + R1R2R3N ---- R1R2R3NHCO3- (bicarbonate)

Solvent Development

R-NH2 R1R2NH R1R2NR3

Primary Amine Secondary Amine Tertiary Amine

Heat of Equilibrium Rate of

reaction capacity Reaction

(kcal/kg ) (mole/kg mole) kmol/m3kPa

Primary amine (MEA) : 455 0.45 5000

Secondary amine (DEA) : 360 0.50 2300

Tertiary amine (MDEA) : 320 0.80 100

Typical Properties of Amines

Low temperature

• Zeolites Molecular Sieves

• Activated Carbon

• Carbon Molecular Sieves

• Modified Silica

• Ion Exchange Resins

• -Complexation

• Activated alumina

High Temperature

• CaO, Ca(OH)2

• Hydrotalcite

• Lithium Zirconate

Alternate to solvents (PSA)

Alternate process on PSA

PH

I

PH

II

PM

III

PM

IV

PL

V

Off Gas

Flue gas

Power

Plant 1-3 atm

CO2 for

sequestration

• Preliminary estimate shows power consumption : 0.2 kwh/kg

Material Development

Property N2 O2 CO2

Kinetic

Diameter, A°

3.65 3.47 3.33

Polarizability,

A°3

1.72 1.55 2.91

Quadruple

Moment

Esu[-1X10-26]

1.2 0.4 4.2

Comparison of activated Carbon and 13X for CO2 Recovery

0

2

4

6

0 200 400 600 800

Partial Pressure (mm Hg)

Am

ou

nt

Ad

sob

ed

(m

ol/

kg

)

N

C

0

1

2

3

0 200 400 600 800

Patial Pressue (mmHg)

Am

oun

t A

dso

bed (

mo

l/kg

)

N

C

CO2 adsorption at 288K in zeolite NaX and Activated carbon

NaX Activated carbon

Heats of adsorption (kJ/mol)of CO2 and N2 in 13X and Activated Carbon

13X Activated carbon

CO2 36 30

N2 25 16

Zeolite

• Cation Exchange

• Surface Functionalisation

With Amine

• Pore Engineering to

Control Diffusion of

CO2

Hydrotalcite

• Anionic Clay

• Mg based Octahedral

Layered Structure

• Increase in Positive Charge

• Replacing Al+3, Mg+2 ions

• Changing Ratio of Al+3/Mg+2


Metal Organic

Frame Work

• Metal Organic Legand

• Complex Geometry with 3D

Channel

• MOF is Highly Selective to CO2

• Gate Opening Pressure

CO2 = 0.4 atm.

N2 = 50 atm

O2 = 53 atm

Mesoporous

Molecular Baskets

Carbon Molecular

Sieve

Surface

Functionalization

with Amines


Ionic Liquid

Non-Corrosive molten organic salts

Alkyl Ammonium, Alkyl Phosphonium,

Alkyl Imidazolium,alkylpyridinium halide salt

No definite melting point

No Measurable Vapour Pressur

Low viscosity

Process Development

Ionic LiquidDialkyl Imidazolium salt

based

• Synthesis

• Characterization & Screening

• CO2 Absorption-desorption

isotherm study

Membrane Cellulose Acetate based

• Fabrication of Membrane

• Optimization of Membrane

Preparation Parameter

• Analysis of CO2 and N2

Permeation property

• Compatibility of membrane with Ionic Liquid

• Incorporation of Ionic Liquids into Membrane

• CO2 & N2 Permeation Study Using Ionic

Liquid-Membrane System

• Fabrication of Pilot Scale Membrane and

Permeability of CO2 Study with Ionic Liquid

CONVERT FOSSIL INTO HYDROGEN (FROM WATER) AND FIX CO2 TO A FUEL

Convert fossil fuel to synthesis gas (CO + hydrogen ) using coal steam partial oxidation. The

endothermic gasification reaction ( hydrogen ) is balanced with exothermic reaction ( CO2).

CO2 can then be further converted to fuel using renewable hydrogen

This is a complete new way of de carbonizing fossil

Gasifier Synthesis gas

(CO + H2)

Methanol

Hydrogen

CO2

New way for decarbonizing the fossil:

CH3OH

Wood

Alcohol

In Internal Combustion

Engines

In Direct Methanol Fuel Cells

Conversion to olefins-gasoline,

diesel, etc.

Dimethyl Ether (Diesel and Household Fuel)

The Methanol Economy: Methanol to de-carbonize the fuel

High octane (ON= 100)

clean burning fuel,

15.8 MJ/liter.

M-85 Fuel

CH3OCH3, high cetane

clean burning diesel fuel, LNG

and LPG substitute.

* Electricity production by combustion in existing gas

turbines or boilers

Interesting for local power generation especially

for nations composed of many islands such as Indonesia

and The Philippines where the construction cost of a

national grid might be prohibitive.

* Electricity generation through fuel cells

Fuel cells not limited by weight and space: other types of

fuel cells can be used; PAFC, MCFC and SOFC

* Use of methanol as cooking fuel in developing

countries (Indian Market: 35 Billion litres of methanol)

Much cleaner burning and efficient than wood

or kerosine

* Methanol for the production of chemicals:

formaldehyde, MTBE, acetaldehyde, polyethylene,

polypropylene and any other chemical obtained from

methanol today

* Methanol is a feed for single cell proteins- as a feed

for animals

Methanol as a fuel and feedstock

Methanol, a one carbon solution for a one

carbon problem

Methanol

Acetic Anhydride

Acetaldehyde

Polyacetal

Formaldehyde

Methyl tert-butyl ether

(MTBE)

Ethanol

Methyl formate

Acetic acid

Methyl amines

Single cell proteins

Biochemicals

Hydrogen H2

Dimethyl terephthalate

(DMT)

Others

Polymethyl methacrylate (PMMA)

Paraformaldehyde

Hexamine

Phenol resins

Urea resins

Polyols

Melamine resin

Methane-di-isocyanate (MDI)

Butanediol

Isoprene

Methyl methacrylate (MMA)

Dimethyl formamide (DMF)

Dimethylacetamide (DMAC)

Methylethanolamine

Tetramethyl ammonium hydroxide (TMAH)

Carbamates

Higher amines

Polyethyleneterephthalate (PET)

Chloromethanes

Xylene resin

Methacrylates

Coating resins

Formamide HCN

Formic acid

Others

Dimethyl ether (DME) Olefins Gasoline

Ethylene, Propylene

Polyethylene, PolypropyleneMethanol consumption

Already one of the most important

product in the chemical industry

Methanex mega-methanol plant

Methanol

MTO and MTG Processes

METHANOL AS A MEANS TO “TOTAL” CLEAN ENERGY

India is coal dependent for its electricity generation and India generates annually about 800 TWHR from its 300 GW Power Plants; simultaneously total energy consumption from other fossil fuel consumption is close to ~415 MTOE. And if we have to develop clean and green energy and meet our NDCs as well as keep our developmental momentum high, we need to target clean technologies at both levels.

Solar PV / CSP - electricity sector

Ethanol / bio diesel - fuel sector

Methanol perhaps has the capability to be part of both sectors and also can work with the India’s predominant power coal and make it as clean coal

Clearly energy is not electricity alone…..

Approximately 80% of energy is for transport, industry and buildings outside electricity consumption

India’s leap into Methanol Economy5th-6th September-2016 R R Sonde

HOW BOTH SECTORS (POWER & TRANSPORT) IS POSSIBLE

Electricity sector

Fossil : coal & gas

Solar (PV/CST)Fuel sector

Fossil : Oil

Bio diesel / Ethanol

Fossil to Liquid Fuels ( MeOH)

Solar to Hydrogen to MeOH

ElectricityUsing Fuel cells

& power engines

Fossil to MeOH

Solar, Bio waste to MeOH

Fuel segmentIn IC enginesFuel cells for automobile applications

1.Hybridising fossil and renewable gives high efficiency and fix CO2 as well2. Fuel cells can generate electricity at 50% plus efficiency and hence lower CO2 emissions per kWhr. Fuel cells in CHP mode can boost up efficiency to 75% plus


KEY DRIVERS

Basis for Methanol economy for India is

1. Methanol based fuel cells will deliver very high power generation efficiency compared to DG sets- which continue to pollute but also proliferate. Fuel cell on Methanol would reduce carbon emissions, reduce import dependence on crude and enable faster deployment of distributed energy solutions for buildings, telcom towers, off-grid applications, agricultural pumping system

2. Methanol – FC combination for automobile applications will be the next foray which will again bring alternate to battery driven cars. High efficiency and capability for larger mileage will tilt scales in favour of Methanol-FC hybrid

3. Gasoline engine running on Methanol is the quick way to introduce Methanol for transport sector. High efficiency and better environmental performance

India’s leap into Methanol Economy5th-6th September-2016; R R Sonde

KEY DRIVERS (CONTD.)

Basis for Methanol economy for India (continued)

4. Methanol is used as vehicle for transfer of hydrogen and hence developments of small reformers will be yet another development which will give right momentum to kick-in Methanol economy

5. CO2 capture and hydrogen from renewable energy will enable synthesis of Methanol and make CO2 a closed cycle carbon neutral cycle leading to meeting the carbon issue

DG set

Fuel cell

Methanol enables this efficiency enhancement


HYDROGEN (METHANOL) FROM FOSSIL (option 1)

Coal Gasification (80% efficiency)

Coal Gas clean up + Methanol conversion

island1 kWhr 0.8 kWhr 0.45 kWhr

Methanol

Fuel cell (with CHP)0.225 kWhr(0.34 kWhr)

Some excess CO2; possible for additional methanol if hydrogen is available


Go away from Carnot Engine to new combined cycle: Coal gasification

Electricity plus Air conditioning

Methanol from Solar : Option2

0.4 kWhr0.25 – 0.35 kWhr

ElectrolysisThermal

Split

SolarPV/CST

HydrogenH2-

MeOH

End use for electricity

or fuel1 kWhr0.7-0.8 kWhr


CO2 FROM SOME SOURCE

Getting CO2 from atmosphere is an issue and will involve energy penalty

This may be a future destination when generation and point of use are adjacent and CO2 can be recycled, But this is not the scenario presented now.

ENHANCED METHANOL BY HYBRID DESIGN

ElectrolysisThermal

Split

SolarPV/CST

HydrogenH2-

MeOH

End use for electricity

or fuel1 kWhr0.7-0.8 kWhr

1 kg/hr (3.7 kWhr)Biomass or India’s high ash coal

2.6 kWhr0.64 kgs of methanol

Bio mass + waste to synthesis gas (CO +

Hydrogen)

Hybridising solar with biomass or fossil greatly enhance the yield and efficiency to methanol conversion. Efficiency is boosted nearly double by this process.


Renewable plus Waste biomass (plus fossil to begin with)

Methanol Generation Technology

Technology provider Operating condition Catalyst

BASF 300-500 bar, >340oC Zn-Chromium oxide

Johnson Matthey Davy (Prv. ICI:Imperial Chemical Industries)

Linde

50 bar Cu-Zn-Chromium oxide

Haldor Topsoe Flexible, MK-151, FENCE Cu-Zn oxide, alumina

WHAT IS PROPOSED?Focus on indigenous development where critical technology control remains (inside the country) but balance the indigenous risks with non-critical (non-control) technology elements (already available as commercial) to hasten the process.

COAL TO MEHANOL

Building blocks in this are as follows:

Gasification Island (A)

Gas clean up island(B)

ASU Island (E)

Methanol reactor island (C)

Final Methanol purification and transport island

(D)

• India has abundant coal which can be used for meeting the demand of fuel methanol

• With the overall trend of decreasing coal thermal power plants, India’s coal will be available for other use → Methanol is a viable “clean coal” energy option

• Going forward, other carbonaceous feedstocks like agro-residues, biomass, MSW, etc. can also serve as raw feedstocks, thereby adding credibility to India’s climate change commitments

• Currently there is no plant (technology) available for demonstration of high ash coal to methanol

52

India’s coal and methanol

Project Overview: Coal to MethanolIndian coal

Gasification island

Air separation unit

Gas cooling

Particulate Separation Acid gas /

trace metal removal

Gas clean-up island

MeOH ReactorIsland

Blue print for 100 tpd MeOH

pilot plant

Ash

Hydrodynamics & Reactor Engineering R&D• Plant scale measurements (with BARC)• Cold flow measurements • Development of models for scale-up &

performance optimization• Intensified reactor configurations

Gas clean-up R&D• Catalytic reduction of trace metals• Process development for H2S

removal• Development, validation and

upgradation of process models

Catalysis R&D• Development of novel catalyst

and process design• Performance evaluation &

optimization• Effect of operating parameters,

kinetics

Flow scheme for 100 TPD Coal to Methanol plant

H2S,COS, CO2,NH3 removal

Gas coolerGasifierParticulate

removal

Gasification island

Shift reactor

350 TPD of coal input

Topping column

Refining column

Methanol reactor

Methanol

Water

60-80 bar

100 TPD

Gas cleanup Methanol synthesis

Methanol Purification

100 TPD is equivalent to typical 15 MWe coal power plant. Thermax has experience of establishing upto 300 MWe power plant

Char Combustor

Ash

steam

Flow Scheme for Methanol to DME

CatalystAl2O3OrZSM-5 zeolite

•Cetane number of DME :55-60 (Diesel: 40-55)•LHV: 6800 kcal/kg

2 CH3OH CH3OCH3 + H2O

Δ H°327° C. = −5.6 kcal/mol

AA Grade methanol

Pilot Plant : Coal to Methanol

56

• Being a leader in both AFBC (atmospheric fluid bed combustion) and its derivative CFBC (circulating fluid bed combustion) with units from 5 MW -300 MW in its technology basket, Thermax started working on Coal gasification using fluid bed concept.

• Over last four years, we have now four different fluid bed units from 250 kW to 4.5 MW on coal (India’s high ash coal) & biomass

• The design developed by Thermax is configured to take care of all the issues known in India’s high ash coal gasification in terms of carbon conversion, cold/hot gas efficiency, controls and more importantly failure of many sub components.

57

Thermax’s Experience in Gasification

58

500 kW coal Gasification facility EIL Gurgaon 1 MW coal Gasification facility Thermax Pune

Gasification Plant Installations

Turbulent fluidized bed with solid circulation Circulating fluidized bed

(Proposed to integrate with

methanol plant)

59

Gasification Plant Installations

250 kW coal Gasification facility Thermax Pune 4.5 MW Biomass gasification plant at RSIL

Washim, MH

Plant has completed ~2000 hours of operation

Bubbling fluidized bed Indirect /Twin bed design

60

Experience and Knowledge gained by Thermax from Pilot Scale plants

1. We have demonstrated that India’s high ash coal can be gasified, and maintained the gasifier under stable operating conditions

2. Pressure / scale / heat release pattern are three important parameters which if taken care, plant can be operated in a stable manner.

3. The design and operation of all the sub systems like coal feeding, ash withdrawal, cyclone and gas coolers, refractories got fine tuned in terms of their specification and operating conditions.

Conclusions: A 4-10 bar pressure of operation with capacity (diameter 1-1.5 m) at 5-25 Mw (input) and proper control of coal : air(oxygen):steam & usage of in bed heating system and an external circulating bed combustion is considered as the most optimum design for India’s high ash coal

Clean blue flame

61

R&D elements in Thermax’s developments

Cold flow model of CFBG

HPTGA facility

GC facility for syngas and tar analysis

62

Proposed Flowsheet

Gasifier

Acid gas removal

system

Methanol

reactor

Syngas

purification

Methanol

purification

Catalysis & Reaction Engineering

63

Objectives

• To synthesize a novel catalyst for direct conversion of syn-gas toMethanol

• Establishment of evaluation methodology and selection of optimalcatalyst for syn-gas conversion to methanol in a lab scale slurryreactor

• Optimization of the operating parameters

• Developing phenomenological kinetic models based on theproduct distribution and estimating the kinetic parameters thatcan be used for scale-up

• Characterization of Indian coal (with high ash content and otherimpurities), biomass followed by bench scale gasification

Methodology: Synthesis of Novel Catalysts and Screening

65

Catalyst Synthesis: Procedure and Facilities

To fixed bed reactor for initial screening of catalysts activityTo slurry bed reactor for performance evaluation

• Preparation ofsuitableprecursor andsupport

• Suitabletransition metalor a combinationof metals (withinput from Sub-D)

Calcination and

Catalyst

Activation

X-RD, TPX, BET Surface Area Analyzer etc.• Determination of catalyst crystal structure• TPR, weak and strong acidity, surface area , Pore

volume

Other issues that need attention :

• Feed sulfur tolerance

• Interphase and intraphase heat and mass transfer resistances in

the catalyst and reactor

• Metal particle size and phase composition, support and support

texture as well as promoters are important

• Parameters that control catalyst structure and catalyst

performance in DME synthesis. For example the selectivity of

this catalyst strongly depends on nature of promoter, metal

crystallite size and pore structure as metal easily forms metal

oxides with support.

• Adjusting the parameters of catalyst synthesis, pre-treatment

and reaction conditions could minimize catalyst deactivation

and production of undesired mixed compounds.

➢The exact reaction mechanism for syngas conversion to various possible products is still not completely

understood. The catalytic structure required for sites to be active for hydrocarbon such as oxygenate formation is

not known. Both are needed in order to understand and design better catalysts for selective synthesis.

➢Development of active, selective, stable and attrition resistant catalyst formulations and a fundamental

understanding of reaction kinetics could lead to enhance reaction yield and desirable product distribution and

improved reactor design and operation. This area is still active and open for new innovation.

➢Deactivation of catalyst can be significant due to pore plugging by waxes, carbon deposition, partial oxidation,

poison and attrition. Catalyst deactivation and regeneration issues need to be addressed.

➢While much is known regarding FTS catalyst design and performance, there are nevertheless significant

improvements that could be made though a more detailed understanding of the nano-scale structure of the

catalyst, reaction mechanism and kinetics. Metal particle size and phase composition, support and support texture

as well as promoters are important parameters that control catalyst structure and catalyst performance in FT

synthesis. All these parameters need to be controlled competently in the design of efficient FT catalyst.

➢For example a higher concentration of metal active sites usually favoured the chain growth. However, the

selectivity of this catalyst strongly depends on nature of promoter, metal crystallite size and pore structure as

metal easily forms metal oxides with support.

CO + 2H2 CH3OH

CO2 + 2H2 CH3OH + H2O

2CH3OH CH3OCH3 + H2O

2CO + 4H2 CH3OCH3 + H2O

3CO2 + 6H2 CH3OCH3 + 3H2O

CO + H2O CO2 + H2

Metal

Metal + Bronsted Acidity

Bronsted Acidity



Metal

Selection of Metal & Support is Crucial as Syn

Gas to DME Process follows

different Reaction Pathways

Dominant

Scope of Work

Coal

Biomass

Syn gas CO+H

2

Feedstock

+

CO H2

CH3

OH

Cu based catalyst

Methanol

Potential ApplicationsStage-1Stage-2

Scope of Work: Catalysis, Kinetics & Reactor Design

Feed Characterization

Ref: US Department of Energy

Other Products

Catalyst selection and Synthesis of Novel Catalysts

In order to achieve maximum methanol yield catalyst should possess:• Good hydrogen activation ability• Ability to activate C-O bond of CO/CO2 molecule without breaking it• Stability against reduction and sintering under reaction conditions• Reasonably low stability of intermediate metal methoxide to avoid surface poisoning• Absence of active alumina, iron, nickel and alkali metals all resulting in side reactions

and/or decreased activity

Catalyst Synthesis: Procedure and Facilities

Preparation of suitable precursor and support via wet-impregnation or co-precipitation

Suitable addition of promoter (transition metal) or a combination of metals

Catalyst Calcination and in –situ Catalyst Activation

Selection of Metal & Support is Crucial as Syn Gas to methanol

Process follows different Reaction Pathways

Classification of methanolsynthesis catalysts

Type of active metal- Cu based- Pd based- intermetallic

Type of support- ZnO or ZnO/Al2O3

- MgO- SiO- ZrO2

Type of promoter- Alkali metals- Non-alkali metals- Non-metals- Transition metals

*Studt F. et al.,Nature chemistry,2014

Catalyst performance evaluation in Fixed and Slurry bed reactors

Catalyst Performance Studies▪ Syngas conversion and Methanol

yield maximization will be targeted▪ Effect of pressure and temperature

will be studied▪ Effect of varying feed ratio will be

analyzed▪ Comparative study between fixed

reactor vs. slurry bed reactor will be performed.

Issues that need attention :

▪ Feed sulfur tolerance and CO2 utilisation by RWGS

▪ Interphase and intraphase heat and mass transfer resistances in the catalyst and reactor

▪ Metal particle size, phase composition, support and support texture, crystallite size, pore structure

as well as promoters

▪ Adjusting the parameters of catalyst synthesis, pre-treatment and reaction conditions could

minimize catalyst deactivation and production of undesired mixed compounds

Methodology: Performance Evaluation of Synthesized Catalysts

Slurry Bed Reactor• Smaller size and improved heat transfer• Higher Conversion• Lower Feed to Recycle Ratio• Low pressure drop & Low operating cost• Make up catalysts feed provision• Lower cooling surface requirement• Process intensification via steam generation

or boiler feed water heating

Catalyst Development• Development and performance evaluation

of novel catalysts in high pressure fixedbed reactor

• Based on results, minor modificationssuch as addition of promoters can be doneto improve the catalyst activity

Why do we need a slurry bed reactor?

Catalyst Performance Studies Effect of pressure and

temperature and varying feed ratio

Comparative study between fixed reactor vs slurry bed reactor

Conversion and Methanol yield maximization will be targeted

• Characterization of Indian coal,Effect of process variables on coalgasification performance throughHPTGA

• Optimization of product selectivity inreaction through catalystmodification

• Metals /support for Methanolsynthesis reaction handling highCO/H2 Coal (Indian) based Syngascontaining impurities

• Catalyst characterization andstructure-activity relationships

• Catalyst stability and deactivationkinetics on the basis of intrinsickinetic data based on time-on-stream product distribution and cokeformation

• Investigation of kinetics of Methanol Synthesis with novel catalyst formulations

• Detailed kinetic modelling of the complex reactions occurring in the Methanol synthesis

• Catalyst stability assessment using time-on-stream investigations

Prepr. Pap.Am. Chem. Soc., Div. Fuel Chem. 2003, 48(2), 921

Hydrodynamics & Reactor Engineering (H&RE)

70

(1) Process design & scale-up– Pilot-scale gasifier and methanol reactor(s) designed using lower

order/semi-empirical models available in the literature (for kinetics, heat & mass transfer coefficients, flow approximations, etc).

– Assessment using the pilot plant measurements

– Uncertainties associated with lower order/semi-empirical process models: kinetics, flow non-idealities, heat and mass transfer coefficients for specific reactor(s), change of these parameters with respect to reactor design and operating conditions

– Trouble shooting, design modifications, development of new/intensified reactor configurations

71

H&RE: Goals

• Pilot-scale measurements • Advanced measurements on mockup unit• Development of models for trouble shooting,

performance optimization & scale-up

(2) Pilot plant measurements– Radiotracing and gamma scanning to assess flow non-idealities, RTD,

phase distributions

– To be carried on pilot units (under hot conditions) with help of BARC Mumbai

– Real life data: critical to assess the performance of pilot units and trouble shooting

(3) Advanced flow characterization– Cold flow mock-up test loop units at IIT Delhi

– Measurement of solids / liquid phase velocity distribution using Radio-active Particle Tracking (RPT)

– Local gas volume fraction and bubble size distribution measurements using conductivity/optic fiber probes, time-averaged void fraction distributions, and dynamic gas/solids/liquid holdup using Electrical Resistance Tomography (ERT) / Electrical Capacitance Tomography (ERT)

72

H&RE: Goals

– Effect of gas/liquid flow rates and solid loading on liquid phase flow field/back mixing, local gas volume fraction and bubble size distribution

– Segregation/mixing in the polydisperse fluidized beds;

– Effect of reactor internals on hydrodynamics in the case of slurry bubble column

(4) Development of experimentally validated detailed models for scale-up and performance optimization– CFD models to simulate gas-solid flows in gasifier fluidized beds, as

well as the methanol reactor (multi-fixed bed and slurry reactors)

– For scale-up of the process, to explore "what if" scenarios

– Crucial inputs for the lower order/phenomenological reactor models

73

H&RE: Goals

(5) Development of intensified reactors– Intensification of reactor performance through novel design

configurations.

– Process intensification studies on laboratory-scale through use of structured reactors/monoliths, etc.

– Promising options can be considered for scale-up of process in future, New IP

74

H&RE: Goals

Expertise & FacilitiesAdvanced Experimental facilities available @ IITD

Electrical Resistance Tomography (ERT)

g-ray densitometry/ tomography

Voidage probes

Gas volume fraction distribution using ERT and g-ray tomography

Liquid flow field using RPT

Bubble size distribution using probes

State-of-the-art invasive and non-invasive measurements facilities established & benchmarked in last 10+ years

Start-of-the-art modeling & simulation capabilities

Critical for the proposed project

Simultaneous ERT and g-ray measurements for solid volume fraction distribution

Radioactive Particle Tracking

Intensified reactors

Methodology: Performance Evaluation of Synthesized Catalysts

76

Slurry Bed Reactor• Smaller size and improved heat transfer• Higher Conversion• Lower Feed to Recycle Ratio• Low pressure drop & Low operating cost• Make up catalysts feed provision• Lower cooling surface requirement• Process intensification via steam generation

or boiler feed water heating

Catalyst Development• Development and performance evaluation

of novel catalysts in high pressure fixed bed reactor

• Based on results, minor modifications such as addition of promoters can be done to improve the catalyst activity

Performance evaluation in Slurry Bed Reactor

Catalyst Performance Studies Effect of pressure and

temperature and varying feed ratio

Comparative study between fixed reactor vs slurry bed reactor

Conversion and DME yield maximization will be targeted

• Characterization of Indian coal ,biomass and MSW

• Effect of process variables on coal/biomass/MSW gasification performance through HPTGA

• Optimization of product selectivity in reaction through catalyst modification (effect of promoter addition)

– Metals /support for DME synthesis reaction handling high CO/H2 Coal (Indian) based Syngas containing impurities

– Catalyst characterization and structure-activity relationships

– Catalyst stability and deactivation kinetics on the basis of intrinsic kinetic data based on time-on-stream product distribution and coke formation

• Investigation of kinetics of Methanol and DMESynthesis with novel catalyst formulations

• Detailed kinetic modeling of the complexreactions occurring in the Methanol and DMSsynthesis

• Catalyst stability assessment using time-on-stream investigations

Methodology: Hydrodynamic Measurements and Development of CFD Model

Advanced Experimental facilities available @ IITD

Electrical Resistance Tomography (ERT)

g-ray densitometry/ tomography

Voidage probes

Gas volume fraction distribution using ERT and g-ray tomography

Liquid flow field using RPT Bubble size distribution using

probes

Slurry Bubble Column Reactor (SBCR) Most preferred reactor configuration for

“large-scale” DME production Conversions governed ability to manage the

heat of reaction-SBCR offer better heat management

Complex hydrodynamics Extensive hydrodynamic measurements Development of CFD models

Effect of reactor internals (baffles, heat transfer tubes, typically in vertical U-tube patterns) on hydrodynamics

Experimental data for validation of CFD models

Simultaneous ERT and g-ray measurements for solid volume fraction distribution

Radioactive Particle Tracking

77

Performance evolutions of intensified reactors Unit cell/volume approach Evaluation of alternative reactors configurations

involving monoliths and structures packings through CFD simulations

New configurations?

Methodology: Performance Evaluation of Different Reactor Configurations

Performance evaluation of conventional reactors through CFD simulations Slurry bubble columns vs. multi-tubular fixed beds Effects of feed flow rates and composition, particle size,

catalyst loading on reactor performance Local distribution of reactants/products and temperature

distribution Effect of reactor configuration and internals (multi-tubular

configurations for fixed beds and internals (baffles, heat transfer tubes) for slurry reactors

Development of experimentally validated CFD models Extensive experimental validation of hydrodynamics

under “cold flow conditions”, specifically for SBCRs Incorporation of chemistry and kinetics developed

through Sub-project B

Next phase (Pilot scale evaluations of promising reactor configurations)

78

Gas Cleanup R&D

79

• Multiple gas phase species other than H2 and CO – CO2, H2S, COS

• Particulates consist of ammonium compounds, hydrogen chloride in addition to trace metals such as Hg, Cd

• Multiple processes required for removal of contaminants– Candle filters / cyclone separators / scrubbers for particulates

– Solvent extraction / catalytic process for acid gases

– Adsorbents / catalytic processes for trace metals

• Widely different operating conditions for multiple processes

• Composition of coal will have a strong impact on the optimized process

• Desired H2:CO ratio to be obtained for optimum operation of the CH3OH production plant

80

Challenges of gas cleanup

Gas Cleanup Specification

Gas Composition Requirement for End Applications

83

Development and optimization of new technologies

• Selectivity towards various metals

• Activity at high temperatures

Reduction of trace metals using catalytically active

materials

• ZnO based catalysts

• Long term exposure studies under acidic conditions

Catalyst development for H2S removal

• Preparation of water gas shift catalysts

• Effect of sulphur

Optimization of process conditions for water gas

shift reaction

• Development of unit operation models

• Model upgradation using in-house data

Development, validation and upgradation of

process models

Process intensification studies

IN CONCLUSION

Enormous work is underway on managing Energy – Climate

change challenge. Solar + Wind alone can not meet the

energy needs of the globe. Fossil will continue to play a

major role and de carbonization of the fossil is the best way

forward.

We must learn to happily progress together or miserably perish together.

Man can live individually but can survive only collectively Atharva Veda

decarbonization of fossil: pathway to hydrogen economy · decarbonization of fossil: pathway to...

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