This poster was presented in GPA (Gas Processors Association) 23rd technical conference in November 2015. It is the outcome of an individual research that was done voluntarily by me during my internship in Tatweer Petroleum.
Processing of Hydrogen Sulfide & Carbon Dioxide From Natural Gas Streams
1. Sweetening Processes: Recovery & Reforming
Natural Gas Dehydration Process
• Khuff Gas is directed to Gas Dehydration Units to reduce
water content only.
• Triethylene Glycol (TEG)
is used to absorb water
molecules.
Natural Gas Composition
• Carbon Dioxide Reforming:
• Carbon Dioxide can be processed by reacting it with
methane (CH4) in order to produce synthesis gas
(a mixture of H2 and CO):
CO2 + CH4 >>> 2CO + 2H2
• At high temperatures (700 – 1100 °C) and in the
presence of a metal-based catalyst (nickel), carbon
dioxide reacts with methane to yield carbon monoxide
and hydrogen.
• Synthesis Gases are a crucial intermediate resource for
production of hydrogen, ammonia, methanol, and
synthetic hydrocarbon fuels. They are often used in
internal combustion engines since they are combustible.
• Can be used to produce useful gases (syngas) from an
acidic, corrosive gas.
• Positive impact on the environment.
Sweetening Process: Removal
• Amine Based Process:
• Reaction in the absorber is at constant pressure and a temperature range between
80 °F to 120 °F:
2RNH2 + H2S >>> (RNH2)2S
2RNH2 + CO2 + H2O >>> (RNH2)2H2CO3
• Regeneration reaction in the reboiler and stripper is at a constant lower pressure
and a temperature range between 240 °F and 300 °F:
(RNH3)2S + heat >>> 2RNH2 + H2S
(RNH3)2CO3 + heat >>> 2RNH2 + CO2 + H2O
PROCESSING OF HYDROGEN SULFIDE & CARBON DIOXIDE
From Natural Gas Streams
Done By: Mohammed Almoalem
• Claus Sulphur Recovery:
• Most common technology for recovering elemental
Sulphur from H2S.
• Involves thermally converting some of the H2S with air in
a reactor furnace to form sulphur dioxide (SO2) and
water:
2H2S + 3O2 >>> 2SO2 + 2H2O
• The remaining H2S is then reacted with the thermally
produced SO2 to form elemental sulphur in the thermal
stage and the subsequent catalytic stages:
2H2S + 3O2 >>> 2SO2 + 2H2O
• Can be used to produce a marketable element (Sulphur)
from a corrosive, hazardous gas (H2S).
• Will have a positive impact on the company’s income.
• Other Sulphur Recovery method: Liquid Redox Sulphur
recovery, which is used only in relatively small or dilute
H2S streams.
Component Abbreviation Percentage Description
Methane CH4 70-90% Main components. Useful as a fuel source, but also considered as greenhouse gases. Calorific
value: 38 MJ/m3Ethane C2H6 0-20%
Propane C3H8 0-20%
Liquefied Petroleum Gases. Useful as source of fuel. Higher calorific value than CH4: 94 MJ/m3
Butane C4H10 0-20%
Heavier Hydrocarbons CxHy 0-20% Crude Oil. Source of fuel, Alkenes, lubricants, wax, asphalt, etc.
Carbon Dioxide CO2 0-8% Acidic and greenhouse gas. Corrosive and undesired in pipelines
Oxygen O2 0-0.2%
Useful elements that can be used to form other compounds
Nitrogen N2 0-5%
Hydrogen Sulphide H2S 0-5% Acidic, Corrosive and Poisonous gas
Rare Gases A, He, Ne, Xe Trace -
Amine Based Solutions:
• MEA: Used in low pressure
natural gas treatment
applications requiring
inflexible outlet gas
specifications
• MDEA: Has a higher affinity
for H2S than CO2 which
allows some CO2 emission
while retaining H2S removal
capabilities.
• DEA: Used in medium to
high pressure treating. Does
not require reclaiming, as do
MEA.