7/28/2019 Gas to Liquids.doc

1/8

Gas to Liquids

Intro

the reactions(exothermic, heterogeneous/homogeneous) Syngas Thermo-Intro

reactor designs (history, current, future)

catalysts (physical, chemical, attrition)

Reaction:

Overview

The Reactant- synthesis gas

o coal gasification, natural gas (methane) reformation, wood gasificaiton

o CO/H2 ratio

H2/CO preferred range between 1.7:1 and 3:1

-options for increasing hydrogen concentration: (1)water/gas shift or (2) burn methane (CH4)

from FT process.

Contaminates (deactivation/recovery), dilutants

o sulfur

o cyanide

o amonia

o metallic carbonyls

o soot

o CO2

o other acidic and basic components

o nitrogen

o nitrous oxides

The Product- liquid fuel

http://wiki.gekgasifier.com/Syngas+Thermo-Introhttp://wiki.gekgasifier.com/Syngas+Thermo-Introhttp://wiki.gekgasifier.com/Syngas+Thermo-Intro

7/28/2019 Gas to Liquids.doc

2/8

o liquid list

Fischer-Tropsch (hydrocarbons)

The Fischer-Tropsch reaction is the recombination of CO and H2 into hydrocarbon chains -CH2-

over nickel, cobalt, iron and ruthenium catalysts. The temperature, pressure, and catalyst type

determines the chain polymerization versus chain termination ratio. This ratio governs theaverage molecular weight of the 'syn crude' produced.

Chain Growth:

The Fischer-Tropsch reaction has the capability of producing a large range of hydrocarbons,

which have to be separated using fractional distillation. The environment of the reactor can becontrolled so that a smaller range of hydrocarbons can be selected. In a fancy equation that will

be posted later, the Probability of Chain Growth (alpha) can be calculated for a given reactor

environment and the product distribution are as follows:

Affecting alpha: Temperature, catalyst activity, pressure, etc.

Temperature:

http://wiki.gekgasifier.com/Fischer-Tropschhttp://wiki.gekgasifier.com/Fischer-Tropsch

7/28/2019 Gas to Liquids.doc

3/8

There is either a low temperature Fischer-Tropsch process (LTFT) or high temperature Fischer-

Tropsch process (HTFT).

LTFT: 200-240C (typically iron or cobalt catalyst)

HTFT: 300-350C (typically iron catalyst)

An increase in temperature leads to shorter chains (ex: at 330 C mostly gasoline and olefins are

produced; at 180-250C mostly diesel and waxes are produced)

methanol

Methane

mixed alcohols Alcohols

Dimethyl Ether

overview of routes

o Methanol to Gasoline

o etc

kj/mol for individual reactions and average

Exothermic Reaction:

This is a highly exothermic reaction and cooling the reactor is usually combined with steamproduction and electrical generation. This excess heat can also be used towards fractional

distillation.

Typical hydrocarbon recombination reactions of Fischer-Tropsch:

Reaction Reaction Enthalpy: deltaH(300K) kJ/mol

CO + 2H2 --> -CH2- + H2O -165.0

2CO + H2 --> -CH2- + CO2 -204.7

CO + H2O --> H2 + CO2 -39.8

3CO + H2 --> -CH2- + 2CO2 -244.5

CO2 + 3H2 --> -CH2- +2H2O -125.2

http://wiki.gekgasifier.com/Methanehttp://wiki.gekgasifier.com/Alcoholshttp://wiki.gekgasifier.com/Dimethyl-Ether-(DME)http://wiki.gekgasifier.com/Gasoline-from-Methanolhttp://wiki.gekgasifier.com/Methanehttp://wiki.gekgasifier.com/Alcoholshttp://wiki.gekgasifier.com/Dimethyl-Ether-(DME)http://wiki.gekgasifier.com/Gasoline-from-Methanol

7/28/2019 Gas to Liquids.doc

4/8

table of properties

Reactors

overview of possible physical characteristics and demands of catalysts

reactor designs (fixed, fluidized, slurry, recycling, microtube)

o Microchannel and the OMX method:ptq_2q_microchannel_reactors.pdf

-Slurry-Phase Reactor: This reactor uses a wax support that is liquid at reaction temperatures(higher boiling point than FT product) which supports the metal oxide catalyst particles of which

the syn gas is bubbled through the bottom. Because of the high exothermic reaction, the slurry

acts as a heat sink which stabilizes the temperatures in the reactor. Because of the interface ofmineral oil slurry with the metal oxide catalyst, the hydrocarbon is soluble in the slurry phase,

pulling it away from the catalyst which increases catalyst activity, decreases oxidation of the

catalyst, increases catalyst activity, and decreases/stabilizes chain-growth. Slurry-phase cobalt

catalyst reactors are the most common theme for most companies, and they are typically the leastexpensive. (LTFT)

-Fixed-bed reactor: Typically these reactors have been made of many small tubes with the

catalyst fixed in the inside of the tube where the syn gas flows through. On the outside, water isflushed over to stabilize the temperature of reaction. (LTFT)

(1)

http://wiki.gekgasifier.com/f/ptq_2q_microchannel_reactors.pdfhttp://www.zero.no/transport/bio/fischer-tropsch-reactor-fed-by-syngashttp://wiki.gekgasifier.com/f/ptq_2q_microchannel_reactors.pdfhttp://www.zero.no/transport/bio/fischer-tropsch-reactor-fed-by-syngas

7/28/2019 Gas to Liquids.doc

5/8

heat transfer calculations

scaling (process heat loss or use)

handling of heterogeneous media

o separation of catalyst from liquid product

o downstream upgrade of product

Catalysts

elemental notes and mechanisms

o transition metal oxides

-Iron oxide- less expensive! (*)

-Product Distribution charts:

Iron catalyst: 30 bars, 280C (x-axis: chain length; y-axis: percentage on weight)

High selectivity of C10-C18 (high yield of diesel fuel)

(Source: Technical University of Vienna)

-Nickel oxide- high activity, more selective towards shorter chains, will tend to the production of

methane, does not do well at higher pressures.

-Cobalt oxide- much more resistant to oxidation by oxygen and water giving it a higher activity

and longer life than iron.

7/28/2019 Gas to Liquids.doc

6/8

Cobalt catalyst: 30 bars, 240C (x-axis: chain length, y-axis: percentage on weight)

Wider distribution with a higher growth probability and heavier products produced,(1)

(Source: Technical University of Vienna)

Cobalt does not promote the water gas shift as much as iron catalysts typically, therefore less

oxygenates, other than alcohols are created in the resulting liquid product.

-Ruthenium catalysts: The availability of Ru is limited, forcing high prices. Ru based catalystshave been more recently studied in their selectivity of the gasoline and jet fuel- C9-C16

hydrocarbons using a supported zeolite matrix.

o aluminum and silicon oxides (promoters, supports)

o K and Na promotor (bicarbonates)

o carbies

o raw

o other

catalyst macro physical characteristics (solid, liquid, slurry, embedded, microtube,

zeolite)

micro characeristics (surface area, active sites)

procedural methods to make catalysts

o OMX, co-precipitate, fused, etc.

activation/deactivation/re-activation

http://www.zero.no/transport/bio/fischer-tropsch-reactor-fed-by-syngashttp://www.zero.no/transport/bio/fischer-tropsch-reactor-fed-by-syngas

7/28/2019 Gas to Liquids.doc

7/8

recycle catalyst/haz mat concerns/economical impact

References:

Review of Biomass Gasification Technologies.NNFCC.Jun09.pdf great basic over view

of current technologies and requirements of gas to liquid catalysts/processors.

Attrition Resistant Iron Based Fischer Tropsch Catalysts:

AttritionResistantIronBasedFischerTropschCatalysts.pdf

Development of Precipitated Fischer Tropsch CatalystsDevelopment of Precipitated

Fischer Tropsch Catalysts.pdf

Technology Development for Iron and Cobalt Fischer-Tropsch Catalysts: 40308r01.pdf

Supported Iron Catalysts in Fischer Tropsch Synthesis: Influence of preparation method:http://pubs.acs.org/doi/abs/10.1021/ie00090a002

Strengthening Iron Fischer-Tropsch Catalyst by Co-Feeding Nitrate and Precipitating

Agent or Separately Precipitating From Ferrous Nitrate and Ferric Nitrate Solutions.

http://www.faqs.org/patents/app/20090298678#ixzz0xZWQxCVO

"Slurry Phase Fischer TropschReactor"http://www.rodisyngas.com/rodi_syngas_inc/technology.html

-comparison of slurry and fixed bed reactors. equation references for effective reaction rate

constants and syngas space time yield figures.

"The Fischer Trposch (FT) Process" http://knol.google.com/k/the-fischer-tropsch-ft-process#

-very broad simple overview of FT

"Recent Research on the Fischer Tropsch synthesis" http://www.fischer-tropsch.org/primary_documents/presentations/recent_research/recent_report.htm

-brief summery of FT temperature and gas throughput relationships to space velocity yield.

Catalyst Manufacturers:

Catalyst manufacturerhttp://www.topsoe.com/

http://www.topsoe.com/Business_areas/Methanol/Processes/MethanolSynthesis.aspx/

Catalyst Manufacture: bookmark: http://books.google.com/books?

id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magneti

http://wiki.gekgasifier.com/f/Review+of+Biomass+Gasification+Technologies.NNFCC.Jun09.pdfhttp://wiki.gekgasifier.com/f/AttritionResistantIronBasedFischerTropschCatalysts.pdfhttp://wiki.gekgasifier.com/f/AttritionResistantIronBasedFischerTropschCatalysts.pdfhttp://wiki.gekgasifier.com/f/Development+of+Precipitated+Fischer+Tropsch+Catalysts.pdfhttp://wiki.gekgasifier.com/f/Development+of+Precipitated+Fischer+Tropsch+Catalysts.pdfhttp://wiki.gekgasifier.com/f/Development+of+Precipitated+Fischer+Tropsch+Catalysts.pdfhttp://wiki.gekgasifier.com/f/40308r01.pdfhttp://pubs.acs.org/doi/abs/10.1021/ie00090a002http://www.faqs.org/patents/app/20090298678#ixzz0xZWQxCVOhttp://wiki.gekgasifier.com/f/SlurryPhaseFischerTropscReactor.pdfhttp://knol.google.com/k/the-fischer-tropsch-ft-processhttp://www.fischer-tropsch.org/primary_documents/presentations/recent_research/recent_report.htmhttp://www.fischer-tropsch.org/primary_documents/presentations/recent_research/recent_report.htmhttp://www.topsoe.com/http://www.topsoe.com/Business_areas/Methanol/Processes/MethanolSynthesis.aspx/http://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://wiki.gekgasifier.com/f/Review+of+Biomass+Gasification+Technologies.NNFCC.Jun09.pdfhttp://wiki.gekgasifier.com/f/AttritionResistantIronBasedFischerTropschCatalysts.pdfhttp://wiki.gekgasifier.com/f/Development+of+Precipitated+Fischer+Tropsch+Catalysts.pdfhttp://wiki.gekgasifier.com/f/Development+of+Precipitated+Fischer+Tropsch+Catalysts.pdfhttp://wiki.gekgasifier.com/f/40308r01.pdfhttp://pubs.acs.org/doi/abs/10.1021/ie00090a002http://www.faqs.org/patents/app/20090298678#ixzz0xZWQxCVOhttp://wiki.gekgasifier.com/f/SlurryPhaseFischerTropscReactor.pdfhttp://knol.google.com/k/the-fischer-tropsch-ft-processhttp://www.fischer-tropsch.org/primary_documents/presentations/recent_research/recent_report.htmhttp://www.fischer-tropsch.org/primary_documents/presentations/recent_research/recent_report.htmhttp://www.topsoe.com/http://www.topsoe.com/Business_areas/Methanol/Processes/MethanolSynthesis.aspx/http://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=false

7/28/2019 Gas to Liquids.doc

8/8

te&source=bl&ots=i07PHKhLjU&sig=TV-

m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi

=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=false

Catalyst Notes

More articles to sift through:

More articles

http://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://wiki.gekgasifier.com/Catalyst-Noteshttp://wiki.gekgasifier.com/More-articels-to-sift-through%3Ahttp://www.highbeam.com/http://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://books.google.com/books?id=MWmAPq4ZFyUC&pg=PA169&lpg=PA169&dq=fischer+tropsch+sintered+magnetite&source=bl&ots=i07PHKhLjU&sig=TV-m6SvRYhKp24JvFjcKhshLjYw&hl=en&ei=ar64TMmBKIr4sAOXzbmZDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAg#v=onepage&q=fischer%20tropsch%20sintered%20magnetite&f=falsehttp://wiki.gekgasifier.com/Catalyst-Noteshttp://wiki.gekgasifier.com/More-articels-to-sift-through%3Ahttp://www.highbeam.com/