Transcript Production of Syngas and Ethanol

Production of Syngas
and Ethanol
Group II
Definition of Syngas
Syngas is the abbreviated name for synthesis
gas. It is a gas mixture that comprises of
hydrogen and carbon monoxide.
Η2 : CO  2 : 1
components of syngas
Importance of Synthesis Gas
The rising cost of petroleum has motivated the
examination of alternative feedstocks for chemical
production. One such feedstock is synthesis gas.
The major components of syngas, hydrogen and
carbon monoxide, are the basic building blocks of a
number of other products.
In the future, syngas will become increasingly
important for the production of cleaner fuels. The
huge potential market for syngas is illustrated by
the fact that almost 20% of the present world
primary energy consumption is for transportation
fuels only. If the chemical sector is included, the
total syngas potential increases to approximately
30%.
Routes to Syngas
There are three main routes to the production of
synthesis gas:
• steam reforming of natural gas
• partial oxidation of natural gas
• partial oxidation of vacuum residuum
Methods of Production
Steam Reforming of Natural Gas
Raw Materials
Natural Gas - methane, CO2, nitrogen, ethane, C3
Air - nitrogen, oxygen
Water - H2O
Reactions
CH4+H2O → CO+3H2
3CH4+2H2O+CO2 → 4CO+8H2
Product
Syngas - methane, CO2, CO, hydrogen, nitrogen, water
Methods of Production
Steam Reforming of Natural Gas
steam
244°C
38°C
SULFUR
REMOVAL
315 psia
natural gas
310 psia
885°C
STEAM
REFORMING
295psia
283 psia
49°C
raw syngas
49°C
CO2
SEPARATION
280psia
HEAT
RECOVERY
54°C
HYDROGEN
SKIMMING
253 psia
syngas product
Methods of Production
Steam Reforming of Natural Gas
Methods of Production
Partial Oxidation of Natural Gas
Raw Materials
Natural Gas - methane, CO2, nitrogen, ethane, C3
Oxygen - nitrogen, oxygen
Steam - H2O
Reactions
CH4+0.5O2 → CO+2H2
Product
Syngas - methane, CO2, CO, hydrogen, nitrogen, water
Methods of Production
Partial Oxidation of Natural Gas
steam
waste water
oxygen
371°C
965 psia
natural gas
OXIDIZER
REACTOR
49°C
1000 psia
149°C
1350°C
raw syngas
HEAT
RECOVERY
980 psia
49°C
CO2
SEPARATION
962 psia
syngas product
CO2
WATER
SCRUBBER
Methods of Production
Partial Oxidation of Natural Gas
Methods of Production
Partial Oxidation of Vacuum Residuum
Raw Materials
Vacuum Residuum - carbon, hydrogen, nitrogen, sulfur,
ash
Oxygen - oxygen, nitrogen
Steam - H2O
Reaction
Products
Syngas - methane, CO2, CO, hydrogen, nitrogen, water
Methods of Production
Partial Oxidation of Vacuum Residuum
steam
457°C
natural gas
1000psia
oxygen
OXIDIZER
REACTOR
1320°C
raw syngas
HEAT
RECOVERY
WATER
SCRUBBER
CO2-rich gas
ACID GAS
REMOVAL
49°C
CO SHIFT
REACTOR
425°C
SULFUR
RECOVERY
945 psia
sulfur by-product
915 psia
tail gas
49°C
945 psia
49°C
soot + inorganic matter
syngas product
Methods of Production
Partial Oxidation of Vacuum Residuum
Additional Methods for Syngas
Production
• Auto
thermal reforming (ATR)
• Combined reforming
Additional Methods for Syngas
Production
Auto thermal Reforming ATR
• This process combines partial oxidation and
adiabatic steam reforming.
• A process consist of desulphurization , preheater, reactor , heat recovery and separation
unit.
• A mixture of natural gas, oxygen and steam is
fed to the reactor.
• The partial oxidation occur in a combustion
area ,then the product pass through catalyst
bed where reforming reaction occur.
• The temperature of the produced syngas is less
than one of the partial reactor cause the
catalyst does not support high T values.
Additional Methods for Syngas
Production
Auto thermal Reforming ATR
Additional Methods for Syngas
Production
Combined Reforming
• Combined reforming includes steam reformer and
auto-thermic reactor .
•
The combined reforming reactor advantages are:
Control the H2/CO ratio in the synthesis.
• Oxygen used less than auto-thermic reforming
and partial oxidation in the case of nitrogen free
syngas.
• Pressure can be increased with lower exit
temperature of the reformer to reduce the size
of the reactor 50% compared with steam
reforming.
• Increase the pressure with saving oxygen.
• Hydrogen removed which leads less NOx
emission compared with steam reforming .
Ethanol from Synthesis Gas
Currently all commercial synthetic ethanol is
made by the hydration of ethylene. The rising
price of petroleum-based ethylene has
motivated the examination of routes to
ethanol from syngas.
One such route is the direct synthesis of
ethanol from syngas.
Production of Ethanol
Direct Synthesis of Syngas
Raw materials
Hydrogen, carbon monoxide, carbon dioxide, nitrogen
Reactions
4H2 + 2CO → CH3CH2OH + H2O
6H2 + 2CO2 → CH3CH2OH + 3H2O
Products
methanol, ethanol (main product), propanols,
butanols, pentanols, hexanols, heptanols, methane
Production of Ethanol
Direct Synthesis of Syngas
60°F
COMPRESSOR
COMPRESSOR
127°F
870 psia
syngas
3 PARALLEL
REACTOR
LOOPS
608°F
3 STEAM
GENERATORS
METHANOL
PRODUCT
COLUMN
250°F
AZEOTROPIC
DISTILLATION
COLUMN
recycled syngas
140°F
azeotrope
mixture
COOLING
DISENGAGEMENT
VESSEL
aqueous
alcohols
ethanol product
140°F
ALCOHOL
DRYING
COLUMN
dried
alcohols
ETHANOL
PRODUCT
COLUMN
n-propanol
Iso-propamol
Production of Ethanol
Direct Synthesis of Syngas
Uses of Syngas
• generation of industrial gases, fertilizers, chemicals
• production of transportation fuels
• used as an intermediary building block for the final production
of various fuels such as:
• synthetic natural gas
• methanol
• synthetic petroleum fuels (dimethyl ether –
synthesized gasoline and diesel fuel)
• hydrogen component of syngas can be used to directly power
hydrogen fuel cells for electricity generation
Uses of Ethanol
• used
extensively as a solvent in the
manufacture of varnishes and perfumes
• used as a cooking and lighting fuel
• used in an antiseptic
• manufacture of acetaldehyde and acetic
acid
• as the fluid in thermometers
•a
primary
constituent
in
alcoholic
beverages