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Presented By,Prem BabooSr. Manager(Prod)National Fertilizers Ltd. Vijaipur, India

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To understand how to utilize feed stock

efficiently

To reduce plant down time

To improve man & machine safety

To reduce pollution level

To reduce capital cost

To optimize the process

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Various Hydrogen and SyngasProduction Technologies

Gaseous andLight Liquid

HydrocarbonsHeavy Oil Methanol Coal Water

Steam &Autothermal

Reforming

PartialOxidation

Reforming Gasification Electrolysis

Hydrogenand Syngas

Oil RefiningHydrocrackingHydrotreating

AmmoniaMethanol

Fischer Tropsch

Fine ChemicalsOxo alcoholsAcetic Acid

SNGOre ReductionMiscellaneous

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Main types of production process for ammonia synthesis gas currently in operation -

– Steam reforming of natural gas or other light hydrocarbons (Natural Gas Liquids, Liquefied Petroleum Gas, Naphtha)

– Partial oxidation of heavy fuel oil or vacuum residue

Coal gasification and water electrolysis are no longer in use in ammonia industry.

About 85% of world ammonia production is based on steam reforming concepts.

Heavy oil may be attractive under special environmental concerns, when natural gas is not available and the partial oxidation process could solve a waste problem (heavy residues, plastics recycle).

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Principal Reaction of HydrocarbonsReforming and Partial Oxidation

Reforming (strongly endothermic)

CnHm + n H2O n CO + (m/2 + n) H2

CnHm + n CO22n CO + m/2 H2

Combustion (strongly exothermic)

CnHm + (n + m/4) O2 n CO2 + m/2 H2O

CnHm + n/2 O2 n CO + m/2 H2

Shift Conversion (mildly exothermic)

CO + H2O CO2 + H2

Carbon Formation

CnHmn C + m/2 H2 (Cracking)

2CO CO2 + C (Bouduard)

6Steam/ Air Reforming Process Partial Oxidation Process

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Relative consumption figures of natural gas reforming, heavy oil

and coal gasification process.

Natural Heavy Coal

gas oil

Energy consumption 1.0 1.3 1.7

Investment cost 1.0 1.4 2.4

Production cost 1.0 1.2 1.7

Drawbacks:

Steam Reforming: Large loss of energy because of endothermic

reaction.

Partial oxidation: Reaction is exothermic and that the optimum

H2/CO ratio of FT reaction, etc. is 2 or less.

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Block Diagram Of Ammonia Plant

Gas

Purification

ReformingShift

Conversion

Methanation

Ammonia

Synthesis

Steam

Process Air

NG/PN

Ammonia

9

0

100200

300400

500

600700

800900

1000

B/L HDS ZnO Pre-

Ref

Pri-

Ref

Sec-

Ref

HT LT GV Syn

Units (Converters)

Tem

per

atu

re (

°C)

0

2040

6080

100

120140

160180

200

Pre

ssu

re (

kg/c

m²)

10

11

Natural Gas+

Recycle H2

HDS

(Co-Mo / Ni-Mo) ZnO-A ZnO-B

S + H2 = H2SH2S + ZnO = ZnS

Co-Mo for Naphtha

Ni-Mo for

Natural Gas

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Natural Gas contains both Inorganic and

Organic sulphur.

Sulfur is poisonous to Reforming Catalyst

Ni + S = NiS

Leads to:

Low catalyst activity (More CH4 Slip)

High tube skin temperature

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Organic Sulfur can not be removed.

Difficult to analyze.

Both HDS and The ZnO catalysts are

not fully utilized

Sulfur slip can only be detected with

lab. Analysis

Life of catalyst can not be determined

unless lab. tests

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New catalysts are available for Organic

sulfur removal

ST-101 of Haldor Topsoe

Synetix(Katalco)-Puraspec-2084

Sulfur level in ZnO catalyst bed

TRACERCO, it is probe used from out side to

determine the level of sulfur absorption. (Synetix)

Sulfur testing coupons inserted at the down stream

of ZnO beds. Analyzed after every 4-8 weeks

(Synetix)

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Syngas Production Technologies

Reforming and Partial Oxidation

Pre-Reforming Operating temperatures 390 °C - 500

°C

Catalyst

Adiabatic

Low steam/carbon ratio

Feed: Hydrocarbons up to final boiling point of 200 °C

No carbon formation

Steam Reforming Operating temperatures 650 °C - 900

°C

Catalyst

Heat by external combustion with air

High steam/carbon ratio

No carbon formation

Autothermal Reforming Operating temperatures 850 °C - 1000

°C

Catalyst

Heat by internal combustion with oxygen

High steam/carbon ratio

No carbon formation

Partial Oxidation Operating temperatures 1300 °C -

1500 °C

Non catalytic

Heat by internal combustion with oxygen

Low steam / carbon ratio

Carbon formation

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(Computation Fluid Dynamic)

Heat integration and metallurgy

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To reduce High Capital Cost

To reduce High Stack Losses and Pollution

To reduce High surface heat loss

To reduce Large Structure

To reduce Pressure drop

To reduce Costly catalyst tubes

To reduce startup time

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To Simplify the process

To reduce S/C ratio

To reduce Maintenance cost

To simplify system heat integration

To reduce energy for ID & FD

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Catalyst

Catalyst tube material

Air pre-heater (Modification)

Pre-Reformer

Reforming Process (heat integration)

Design

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High activity

More surface area

Low pressure drop

High physical strength

More stable for poisons

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Reforming Catalysts

RING WAGON WHEEL

5-HOLE

DD-RING

Monolithic10-HOLELatest by

Synetix

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Reformer Tubes

Concept

To Increase heat transfer

Facilitate more catalyst packing

Increase life and skin temperature

Thickness reduced, increasing ID, OD kept

Constant.

Material of construction changed

HK-40 ►IN519 ►Micro alloy (Manu rite)

What has

been

changed?

Latest &

best metal?

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Grade C Cr Ni Others

HK-40 (1970’s) 0.40 25 20

HP-45Nb 0.45 25 35 1.5Nb

HP-45Nb MA 0.45 25 35 1.5Nb,Ti,Zr

HP-15Nb 0.15 25 35 1.5Nb

IN-519 (1980’s) 0.30 24 24 1.5Nb

IN-657 0.08 50 48 1.5Nb,N

20Cr-32Ni+Nb 0.10 20 32 Nb

35Cr-45Ni,MA(1990’s) 0.45 35 45 1.5Nb,Ti,Zr

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Basic reason is to reduce heat loss

through Primary Reformer stack

To save Fuel and proper combustion.

ID fan load is reduced.

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Process

Air

Hydrocarbons

+

Steam

Adiabatic

Pre-Reformer

Primary

Reformer

Secondary

Reformer

Heat Integration (Tri-Reforming)

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Feed Stock flexibility (Higher hydrocarbons)

Reduced Load on Primary Reformer

Improvement of Primary Reformer catalyst

life

Lower tube skin temperature

As guard for Primary Reformer Catalyst

Easy replacement of catalyst (without

complete plant shut down)

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Feed 5.4 to 5.6 Gcal/MT NH3

Fuel 1.7 to 2.5 Gcal/MT NH3

Power 0.05 to 0.09 Gcal/MT NH3

Steam + or - Gcal/MT NH3

Total 7.15 to 8.2 Gcal/MT NH3

Steam energy depends on the internal generation & consumption

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Can Energy be reduced?

Feed Energy

Fuel Energy

Steam Energy

Electrical Power

Yes

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Steam-Methane-Reforming (SMR)

Auto thermal Reforming (ATR)

Non-Catalytic Partial Oxidation (NCPOX)

Catalytic Partial Oxidation (CPOX)

Combined Reforming (CR)

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CONVENTIONAL STEAM REFORMING

Process Air

Natural Gas

+

Steam

Reformed Gas

Fuel

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STEAM REFORMER TOP

FIRED

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Steam-Methane Reforming

Advancements

Reduction in numbers of catalyst tubes

Primary Reformer size reduction

Elimination of FD fan

Dual fuel firing system

To improve combustion, improved burner designs

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Combustion Air

Suction duct

Reformer furnace height is large

Normally ID fan is at the top

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Auto Thermal Reformer

Auto thermal reformer is a pressure vessel similar to

that of Secondary Reformer.

Catalyst is advanced, resistance to high temperature.

It can be operated up to a pressure of 50kg/cm²G.

Start up time is minimum as compared to

conventional reforming.

It is economic if used in large capacity

plants(1800MTPD & above)

CH4 conversion is more than 99%

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Auto Thermal Reforming Route

ATR technology is offered by three Process Licensors

M/s Lurgi, Germany

M/s KBR, USA

M/s HTAS, Denmark

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KBR ATR/ KRES (KBR Reforming Exchange System)

Purifier Technology

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Kellogg’s Advanced Auto Thermal Reformer

1. Being vertical in shape can be

accommodated in small area

2.Capacity is very high

3. Reduced NOx and Sox

4. Carbon conversion more than 99%

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Lurgi G-POX Low cost non-catalytic partial oxidation

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Lurgi C-PoXCatalytic partial oxidation

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Lurgi’s Auto Thermal Reformer (ATR)

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HTASThe key elements of the technology are the design

of the burner, the catalyst formulation, and

refinement of the operating conditions.

Topsøe’s proprietary burner design has been

developed on the basis of computational fluid

dynamics, hydraulic simulation, pilot plant

testing, and feedback from industrial operation.

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Secondary Reformer

Critical parts

Burner (gun)

Catalyst and top bricks

Insulation material

Material of construction

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Combined Reforming

In this process the heat generated in

Secondary Reformer has been used in

Primary Reformer

Type of Combined Reformers

Gas Heater Reforming (GHR)

Heat Exchange Reforming (HER)

Heat Integrated Reforming (HIR)

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ICI – Heat Exchange Reformer

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Some Facts & Figures

Process Feed

Gcal

Fuel

Gcal

Total

Gcal

Steam Reforming 5.29 1.72 to 2.15 7.01 to 7.44

Excess air

Reforming

5.60 1.08 to 1.72 6.68 to 7.32

Auto thermal

Reforming

5.93 0.86 to 1.72 6.79 to 7.65

Partial Oxidation 6.89 1.29 to 2.15 8.18 to 9.04

Energy = Gcal/MT Ammonia

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Brand

Name

GREENCAST 94

TRL

KAST-O-LITE 97

L TRL

SiO2 0.1 0.16

Al2O3 94.6 95.2

Fe2O3 0.1 0.1

CaO 4.9 4.16

MgO Traces Traces

TiO2 Traces Traces

Na2O+K2O 0.2 0.3

Trange 1850°C 1900°C

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Advanced Burner for Secondary Reformer

ICI Burner Haldor Topsoe Burner

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MPG - LURGI MULTI PURPOSE GASIFCATION

•Multi Purpose Gasification "MPG" is a process for the

partial oxidation of hydrocarbons delivering a synthesis gas

composed mainly of carbon monoxide and hydrogen.

•Different -even unmixable- hydrocarbon-containing feeds

can be gasified: ranging from

•Natural gas,

•Tars,

•Other coal gasification residues,

•Refinery residues,

•Asphalts

•Slurries and chemical wastes

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Waste Utilization Centre at SVZ (Sekundärrohstoff Verwertungs Zentrum

Schwarze Pumpe)

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Gasifiers operated at SVZ (Sekundärrohstoff Verwertungs

Zentrum Schwarze Pumpe)

•Fixed bed gasifiers (FBG)

•British Gas/Lurgi gasifier (BGL)

•Multi Purpose gasifier (MPG)

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MPG Gas-gasification

Gasification occurs in the empty, refractory-lined reactor at temperatures between 1200°C

and 1400°C

A water-scrubbing tower removes traces of soot, HCN and NH3

Soot formation in the process is extremely low, so that no special filtration is necessary

with the wastewater passing to a sour-water stripper and final treatment

A desulfurization unit can be located either upstream or downstream of the gasification,

depending again on the heat utilization and on the material selection for the equipment in

areas prone to metal dusting.

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ATR Gas-MPG

pressure [bar] 35 70

temperature inlet [°C] 750 500

temperature outlet [°C] 950 1400

O2 / natural gas [mol/mol] 0.4 0.7

steam / natural gas [mol/mol] 1.5 … 1.7 0.05…0.2

Comparison of Lurgi´s catalytic and non-catalytic partial

oxidation processes

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0 1 2 3 4 5 6 7 8

MPG

Autothermal

Reforming

Steam

Reforming

H2/CO Molar Ratio

Process

Syngas Production Process Comparison

H2 / CO Ratios

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The reaction

CO + H2O CO2 + H2 (exothermic) Water Shift reaction.

HT Shift Reaction : Iron Oxide Cromia Catalyst

300 – 450 oC

CO Conversion : 90 – 95 %

LT Shift Reaction : CuO – ZnO Catalyst

200 - 300 oC

Present process is highly stable and well proven.

The drawbacks of the process are:

High pressure drop

Degree of conversion

Bottom most catalyst remains half utilized

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Isothermal reactors were tested to improve the

CO conversion but failed.

Reasons

High pressure drop

Mechanical failure of inter bed exchangers

What is successful ?

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Radial flow converter

Advantages:

Low pressure drop

Low CO slip

More than 80% of the

catalyst utilization

Casale Radial-Axial Flow

Shift Converter

69Axial-Radial distribution concept

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Process Chemical absorption

Benfield, GV, Glycine, Catacarb, MEA.

Physical absorption

Methanol (Rectisol), Sulfolane (Sulfinol),

Dimethyl ether of propylene Glycol (Selexol)

Adsorptive Purification

Zeolites (PSA)

Membrane Seperation

CMS (Carbon molecular Sieves): hydrogen

permeation

Nanoporous Carbon membranes: Carbon

dioxide permeation

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Advancements Why?

High loop pressure

Low conversion per path

Compressor Recycle stage Efficiency Low

High pressure drop across the loop

High Compression power

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Advancements What?

Improved catalyst activity

Reduce pressure +drop

Increase conversion per path

Reduce synthesis gas compressor size and

increase efficiency.

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Synthesis gas purification (eliminate CH4, Ar)/Reduction in gas volume

Latest Ruthenium catalyst (Reduced loop pressure)

Using catalyst in multi-beds with inter-stage cooler.

Drying and cooling synthesis gas

Eliminate inter cooler separators (or make compact)

Improved design

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Haldor Topsoe

Kellogg (KRES)

Kellogg-Braun-Root (KAAP, KBR)

Foster Wheeler

Krupp-Uhde

ICI, Leading Concept Ammonia (LCA)

Most widly used Technologies

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Iron Catalyst

Ruthenium

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Ammonia Casale Axial Radial

Converter:

Annular top bed is left open at the top to permit a

part of the gas flow radially through the catalyst

bed.

The Brown & Root Braun Adiabatic

Converter:

Two adiabatic converters in series each

containing a single catalyst bed.

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19.14-21.53

G C al/ MT

11.24-12.68

07.89-10.05

06.46-07.89

05.74-6.22

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