Commercialization of Nitrogen-Rich Natural Reservoirs

Albert Bradley CurtisS. Monique Wess

Miguel Bagajewicz

OverviewBackground

Goals

Superstructure of Process

Process Descriptions

Mathematical Model

Results

Conclusions

2

Background

Background

• Natural gas is one of the most vital sources of energy in U.S.

• It is made up of primarily of methane and significant quantities of heavier hydrocarbons

• Several contaminants are common (CO2, N2, H2S)

• Advantages over other fuel types: Lower capital cost, higher efficiency, lower air pollutant emissions

4

Background

• Low quality natural gas (LQNG) has one or more impurities that prevent it from being put into a pipeline without going through a pretreatment process

• Approximately 30% of known reserves contain LQNG– Lower heating value– Corrodes pipe lines– Lower Wobbe index – interchangeability of fuel types

5

Background

• Most popular contaminants– Carbon Dioxide > 2%– Nitrogen > 4%– Hydrogen Sulfide > 4ppm– Water

• Minor contaminants include– Helium– Argon– Hydrogen– oxygen

57%33%

10%

Top Contaminants of LQNG Reserves

Nitrogen Content Carbon Diox-ide ContentOther Con-tamininants

6

This Work Objective

Perform an economic analysis on the feasibility of production and commercialization of LQNG

7

Superstructure of Processes

9

Low Quality Natural Gas Reservoir

Boiler

Steam Turbine

Central Utility Plant Usage

Sold in Market

Low Quality Natural Gas

Steam

Electricity

Electricity

Power Generation Process Flow

----- Steam----- Electricity LQNG

*All intermediates can be used in other processes or sold in market

Low Quality Natural Gas Reservoir

Boiler

Steam Turbine

Central Utility Plant Usage

Sold in Market

Steam Reforming

Water Gas Shift

Haber-Bosch

Bosch-Meiser

Methanol Synthesis

Methanol Oxidation

Carbonylation

Dehydration

Fischer-Tropsch

Power Generation and Synthesis Gas Process Flow

----- Steam----- Electricity----- Hydrogen Ammonia Nitrogen Product Streams

*All intermediates can be used in other processes or sold in market

Low Quality Natural Gas

Low Quality Natural Gas

Steam

Electricity

Electricity

Synthesis Gas

Synthesis Gas

Synthesis Gas

Hydrogen

Methanol

Ammonia Urea

Formaldehyde

Acetic Acid

Dimethly Ether

Diesel and Naphtha

Nitrogen Plant

Oxygen

Molecular Gate Pressure Swing Adsorption

Bosch-Meiser

Bosch-Meiser

Methanol Oxidation

Boiler

Central Utility Plant Usage

Steam Reforming

Diesel and Naphtha

Low Quality Natural Gas

Low Quality Natural Gas

Low Quality Natural Gas

Methanol

Steam

Pipeline Quality Natural Gas

Synthesis Gas

Hydrogen

Ammonia

Ammonia

Synthesis Gas

Synthesis Gas

Electricity

Electricity

Synthesis Gas

Synthesis Gas

Synthesis Gas

Ammonia

Methanol

Urea

Urea

Urea

Formaldehyde

Formaldehyde

Acetic Acid

Acetic Acid

Dimethly Ether

Dimethly Ether

Diesel and Naphtha

Methane/Nitrogen Stream mixture

Power Generation and Synthesis Gas Process Flow

----- Steam----- Electricity----- Hydrogen Ammonia Nitrogen ----- Nitrogen rich

stream Product streams*All intermediates can be used in other processes or sold in market

Nitrogen Plant

Oxygen

CostsProcess Method of

SeparationApplication Total Capital Cost

($/Mscfd)*Operating Cost ($/Mscf)*

Cryogenic Distillation

Distillation at cryogenic

temperaturesHigh flow

rates $1184 $ 1.30

Pressure Swing

AdsorptionAdsorption of

methane

Small to Medium flow

rates$1320 $1.65

Lean Oil Absorption

Absorption of methane in chilled

hydrocarbon oilHigh Nitrogen

Content N/A $3.35

MembranesMethane moves

faster though barrier

Low flow rates $277 $.30

Molecular Gate PSA

Adsorption of nitrogen in solvent

High Nitrogen Content $226 $.16

12

PSA

• Engelhard Corporation’s Molecular Gate PSA– Traps nitrogen while letting methane flow through

at high pressure– Capable of reducing nitrogen content from 30% to

4%.– Adsorbent material is titanium silicate (CTS-1)

designed with a pore size of 3.7 Ao

13

Molecular Gate Adsorber

• Operates at pressure levels between 100 – 800 psia• Uses a series of 3-9 fixed bed adsorber vessels• Methane rich steam that is recycled to increase the

methane recovery• Spent vessel is depressurized to produce a nitrogen

rich low pressure fuel stream.

14

Synthesis Gas Production

• Syngas consists primarily of carbon monoxide, carbon dioxide, and hydrogen

• Synthesis gas can be generated by steam reforming of methane.

• We considered steam reforming with and without nitrogen removal to investigate the impact of additional processing and reactor size

• Used as fuel source or intermediate for production of other chemicals

15

Molecular Gate Pressure Swing Adsorption

Bosch-Meiser

Bosch-Meiser

Methanol Oxidation

Boiler

Central Utility Plant Usage

Steam Reforming

Diesel and Naphtha

Low Quality Natural Gas

Low Quality Natural Gas

Low Quality Natural Gas

Methanol

Steam

Pipeline Quality Natural Gas

Synthesis Gas

Hydrogen

Ammonia

Ammonia

Synthesis Gas

Synthesis Gas

Electricity

Electricity

Synthesis Gas

Synthesis Gas

Synthesis Gas

Ammonia

Methanol

Urea

Urea

Urea

Formaldehyde

Formaldehyde

Acetic Acid

Acetic Acid

Dimethly Ether

Dimethly Ether

Diesel and Naphtha

Methane/Nitrogen Stream mixture

Power Generation and Synthesis Gas Process Flow

----- Steam----- Electricity----- Hydrogen Ammonia Nitrogen ----- Nitrogen rich

stream Product streams*All intermediates can be used in other processes or sold in market

Nitrogen Plant

Oxygen

Synthesis Gas Conversion

Product General Production Formula Uses

Methanol Simplest alcohol, light, volatile

steam-methane reforming

2H2 +CO →CH3OH antifreeze, solvent, fuel, intermediate in the production of other products

Acetic Acid weak carboxylic acid methanol carbonylation

CO + CH3OH → CH3COOH

vinyl acetate monomer and aceticanhydride

Formaldehyde simplest aldehyde oxidation and dehydrogenation ofmethanol

CH3OH → H2CO + H2 polymers and a widevariety of specialty chemicals

Dimethly Ether Gaseous ether methanol dehydration 2CH3OH → CH3OCH3 + H2O

aerosol spray propellant ora refrigerant

17

Synthesis Gas ConversionProduct General Production Formula Uses

Ammonia colorless alkaline gas with penetrating odor

Haber-Boschprocess

3H2 + N2 → 2NH3 nitrogen source in fertilizer and the manufacture of urea

Urea solid produced as prills or granules

Bosch- Meiser 2NH3 + CO2 → NH2CONH2 + H2O

fertilizers, plastics, and protein supplement in animal feed

Hydrogen Colorless, odorless gas

Steam reforming / Water gas shift reaction

CH4 +H2O → 3H2 + CO processing of fossil fuelsand to produce ammonia or methanol

Synthetic Fuel liquid hydrocarbons Fischer-Tropsch process

3H2 + CO → CH4 +H2O diesel and naptha

18

Utility Integration

• Use a fire-tubed boiler to create steam, which is used in Steam Methane Reforming.

• This produces NOx emissions, which are regulated from the EPA.

19

Control Technology Typical Emission Levels

SCONOxTM 2-5 ppm

XONON flameless combustion 3-5 ppm

Selective catalytic reduction (SCR) 5-9 ppm

Selective non-catalytic reduction (SNCR) 9-25 ppm

Non-selective catalytic reduction (NSCR) 9-25 ppm

Dry low NOx combustor 9-25 ppm

Water or steam injection 25-40 ppm

Utility Integration

• Using a turbine to convert steam to electricity, which is used inside the plant to fuel other processes and can be sold to outside markets.

• Combustion Turbine Operation– Ambient air is drawn in and compressed– Fuel is introduced, ignited, and burned– Hot exhaust gas is recovered in the form of shaft

horsepower

20

Mathematical Model

Mathematical Model

• Mathematical model was coded and run using the Generic Algebraic Modeling System (GAMS) as interface

• Based on Mixed Integer Linear Programming (MILP) (Cplex is the solver used)

• The objective function maximized is the Net Present Value (NPV) of the project

22

Mathematical Model

• Specifications– 23 processes were considered– 20 years of production was assumed– Reaction stoichometry, raw materials, demand,

operating costs, and product flow were included in the model

– Began with a total available investment of $100,000,000

23

Mathematical Model

• Why use a mathematical model instead of using Microsoft Excel?

• Combinations:– 176,640,000

24

Mathematical Model

25

Bring in clear copy and highlight equation for explanation

Mathematical Model

• An Example:FCI(i,t) .. FC(i,t) =e= (Y(i,t)*alpha(i) + beta(i)*initialcapacity(i,t));

– i = Process– t = year– Y = binary expansion variable– alpha = Additional capital cost per mole – beta = Initial capital cost per mole– initialcapacity = variable

26

Results

Steam R efo rm in g

W ater G as Sh ift

H ab er-B o sch

H ab er-B o sch

C arb o n ylati o n

D eh yd rati o n

Fisch er-Tro p sch

Steam Tu rb in e

So ld in M arket

Steam R efo rm in g

W ater G as Sh ift

H ab er-B o sch

B o sch -M eiser

M eth an o l Syn th esis

C arb o n ylati o n

D eh yd rati o n

Fisch er-Tro p sch

Diesel and Naphtha

Low Quality Natural Gas

Low Quality Natural Gas

Low Quality Natural Gas

Methanol

Steam

Pipeline Quality Natural Gas

Synthesis Gas

Hydrogen

Ammonia

Ammonia

Synthesis Gas

Synthesis Gas

Electricity

Electricity

Synthesis Gas

Synthesis Gas

Synthesis Gas

Ammonia

Methanol

Urea

Urea

Urea

Formaldehyde

Formaldehyde

Acetic Acid

Acetic Acid

Dimethly Ether

Dimethly Ether

Diesel and Naphtha

Methane/Nitrogen Stream mixture

Nitrogen PlantOxygen

Below 5 MMscf/day < 30% N2

Low Quality Natural Gas Reservoir

Molecular Gate Pressure Swing Adsorption

Sold as pipeline quality gas

At 3 MM SCF/D 15% N2

NPV = $20,425,000Investment = $475,000

Steam R efo rm in g

W ater G as Sh ift

H ab er-B o sch

H ab er-B o sch

C arb o n ylati o n

D eh yd rati o n

Fisch er-Tro p sch

Steam Tu rb in e

So ld in M arket

Steam R efo rm in g

W ater G as Sh ift

H ab er-B o sch

B o sch -M eiser

M eth an o l Syn th esis

C arb o n ylati o n

D eh yd rati o n

Fisch er-Tro p sch

Diesel and Naphtha

Low Quality Natural Gas

Low Quality Natural Gas

Low Quality Natural Gas

Methanol

Steam

Pipeline Quality Natural Gas

Synthesis Gas

Hydrogen

Ammonia

Ammonia

Synthesis Gas

Synthesis Gas

Electricity

Electricity

Synthesis Gas

Synthesis Gas

Synthesis Gas

Ammonia

Methanol

Urea

Urea

Urea

Formaldehyde

Formaldehyde

Acetic Acid

Acetic Acid

Dimethly Ether

Dimethly Ether

Diesel and Naphtha

Methane/Nitrogen Stream mixture

Nitrogen PlantOxygen

Above 5 MMscf/day 15% - 30%

Low Quality Natural Gas Reservoir

Molecular Gate Pressure Swing Adsorption

Steam Reforming

Water Gas Shift

Haber-Bosch

Bosch-Meiser

Boiler

Steam Turbine

Central Utility Plant Usage

Nitrogen Plant

Low Quality Natural Gas

Low Quality Natural Gas

Steam

Hydrogen AmmoniaSynthesis Gas

Electricity

Urea

Oxygen

Ammonia Nitrogen

At 10 MM SCF/D 25% N2

NPV = $138,600,000Investment = $9,250,000

Steam R efo rm in g

W ater G as Sh ift

H ab er-B o sch

H ab er-B o sch

C arb o n ylati o n

D eh yd rati o n

Fisch er-Tro p sch

Steam Tu rb in e

So ld in M arket

Steam R efo rm in g

W ater G as Sh ift

H ab er-B o sch

B o sch -M eiser

M eth an o l Syn th esis

C arb o n ylati o n

D eh yd rati o n

Fisch er-Tro p sch

Diesel and Naphtha

Low Quality Natural Gas

Low Quality Natural Gas

Low Quality Natural Gas

Methanol

Steam

Pipeline Quality Natural Gas

Synthesis Gas

Hydrogen

Ammonia

Ammonia

Synthesis Gas

Synthesis Gas

Electricity

Electricity

Synthesis Gas

Synthesis Gas

Synthesis Gas

Ammonia

Methanol

Urea

Urea

Urea

Formaldehyde

Formaldehyde

Acetic Acid

Acetic Acid

Dimethly Ether

Dimethly Ether

Diesel and Naphtha

Methane/Nitrogen Stream mixture

Nitrogen PlantOxygen

Above 5 MMscf/day 4% - 15%

At 10 MM SCF/D 10% N2

NPV = $169,350,000Investment = $6,200,000

Low Quality Natural Gas Reservoir

Boiler

Steam Turbine

Central Utility Plant Usage

Steam Reforming

Water Gas Shift

Haber-Bosch

Bosch-Meiser

Nitrogen plant

Oxygen

Urea

Steam

Steam

Electricity

Syn Gas Hydrogen Ammonia

Ammonia Nitrogen

Results Summary

31

Option # Reserve Size % N2 Content Initial Investment NPV

1 Less than5 MMSCF/D

Less than30% $475,000 $ 20,425,000

2 Greater than5 MMSCF/D

Between15 – 30 % $9,250,000 $ 138,600,000

3Greater than5 MMSCF/D Less than

15% $6,200,000 $169,350,000

Urea

• Major markets:– ≈90% of urea goes into fertilizers– ≈10% in other commodity markets such as

cigarettes, toothpaste, pretzels ect…• Price is quite volatile and is largely dependent

on the price of nitrogen and natural gas.• Since nitrogen is included in utility integration,

nitrogen price is no longer a variable.

32

Urea

• The demand, however, is fairly constant and seems like a good business decision:

33

Future Prices

• The current Urea Price: $390/ton

• If future prices decrease more than 20%, compared to other products, another option should be considered.

• The next highest process rout was the combination of formaldehyde and acetic acid.

34

Conclusions

• Molecular gate pressure swing adsorption is the most cost effective way of separating oxygen.

• After compiling the superstructure of processes in the mathematical model, the model gave three separate results dependent on the reserve size and nitrogen concentration.

35

Acknowledgements

• Dr. Miguel Bagajewicz• Quang Nguyen• Liu Shi• Roman Voronov

36

References

• http://www.naturalgas.org/naturalgas/processing_ng.asp#water

• http://www.lowimpactliving.com/pages/your-impacts/electricity1

• “Green is Seen in Fertilizers” - A New Approach to Municipal Solid Waste Management - Carrie Farberow and Kevin Bailey

• Upgrading low BTU gas of high nitrogen content to power or pipeline - Javier Lavaja, Bryce Lawson, Andres J. Lucas

• http://www.moleculargate.com/37