THE PROCESSES OF GASIFICATION IN DETAIL
Gasification itself can be broken down into separate elements, which all take place within the gasifier and relate to temperature
levels within the overall process.
SERVOMEX SUPPLIES GAS ANALYSIS SYSTEMS FOR PROCESS AND QUALITY CONTROL TO
MANY GASIFICATION CUSTOMERS ACROSS THE WORLD. THE MAIN ANALYZERS USED IN
THESE SYSTEMS ARE:
• SERVOTOUGH SpectraExact 2500 on the feed hopper to measure 0-1% CO
• Redundant SERVOTOUGH Oxy 1900 and OxyExact 2200 SIL 2 analyzers on the taphole extraction line
• SERVOTOUGH Laser 3 Plus Ammonia on the scrubber vent line
DRYING (100-150 O C) COMBUSTION (800-1200 O C) REDUCTION (650-900 O C)
Water within the feedstock is driven off
with heat, by vaporization. This can be fueled by either the tar
gases or char from pyrolysis. All of the
heat for drying, pyrolysis and reduction
(depending on the gasifier type) comes
from combustion, or is recovered
indirectly by heat exchange processes. Reduction is the reverse process of
combustion. It strips oxygen atoms
from hydrocarbon molecules to return
the molecules to a combustible form. It
usually operates in equilibrium with the
combustion process, and is responsible
for transforming the carbon from the
char into syngas.
PYROLYSIS (200-500 O C)
This is the application of heat to the
dried feedstock, in the absence of air. It
breaks down the feedstock into char (a
charcoal-like substance), tar gases
and liquids.
Author: David Fahle - Market Sector Manager, Hydrocarbon Processing. Email: [email protected]
GASIFICATION
REACTIONS BY-PRODUCT
USAGE
PARTICULATE
REMOVAL
The feedstock reacts with oxygen to form
hydrogen and carbon monoxide. Keeping
the temperature high ensures complete
conversion of all feedstock materials. Inorganic materials from the coal are
trapped in a glassy matrix resembling
coarse sand. This inert material is referred
to as slag, and has various uses in the
construction industry. There is no ash
waste from the gasification process.
A scrubbing system removes all
particulates from the gas.
GAS
ENHANCEMENT
As the sour syngas is cooled, steam is
injected into the gas stream. Then, a
catalytic reaction enhances the oxygen
content of the syngas.
CRACKING (800-1200 O C)
The heat breaks down large complex
molecules such as tar into lighter gases. This
process is crucial in producing a clean gas.
SYNGAS
CLEAN-UP
In a series of gas clean-up process steps,
chloride, mercury, sulfur contaminants
and carbon dioxide are removed from the
syngas stream.
SYNGAS
USAGE
The clean, hydrogen-rich syngas can
be used in a combustion turbine to
generate electrical power, or can undergo
methanation to be converted to useful
manufacturing intermediates.
FEEDSTOCK
O 2 /
STEAM
SERVOTOUGH
SpectraExact 2500
INTERMEDIATES
CLEAN
SYNGAS
SERVOTOUGH
OxyExact 2200
SERVOTOUGH
Oxy 1900
METHANATION
CO
H 2
H 2 S
CO 2
ELECTRIC
POWER
SERVOTOUGH
Laser 3 Plus Ammonia
CO-GEN TURBINE
GAS CLEAN
UP PROCESS
SLAG FOR USE IN
CONSTRUCTION
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CONTAMINANTS
Find out more at servomex.com or contact your nearest business center
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