LQ3 Industrial Chemicals Flashcards
Ancient Egpyt and Mesopotamia used alkali
(sodium carbonate) and limestone (calcium
carbonate) to make glass
4000-7000 B.C.
China used saltpeter (potassium nitrate), sulfur, and
charcoal to produce. Sources say that they used 15% by weight of carbon, 10% sulfur dioxide, and 75% potassium
nitrate.
800-900 A.D.
this started the chemical industry to the high
demand of chemicals for their products. This the
main purpose of the chemical industry: to convert
raw materials such as oil, air, water, metals, and
minerals into commodity chemicals.
Industrial Revolution
Top 5 In-demand Chemicals
- Sulfuric acid
- Sodium hydroxide
- Nitrogen
- Propylene
- Ethylene
What are the raw materials for industrial chemicals
Sulfur, air, and water
Main source of sulfur is from
Petroleum or natural gas
Hydrogen is used as an agent for the reduction of sulfur content
Hydrodesulfurization
It can also be mined from volcanic areas, hot springs, hydrothermal vents, or their emissions
Sulfur, air, water
It is most commonly mined in countries inside the pacific ring of fire
Sulfur, air, and water
Has low yield, very exothermic, and not environmentally-friendly
Lead chamber process
Has high yield, less exothermic, reversible, and more environmentally frienly
Contact process
What is the method 1 of sulfur dioxide
Direct combustion of elemental sulfur
S(s) + O2 (g) —> SO2 (g)
What is the method 2 of sulfur dioxide
Roasting of sulfide ores (e.g. pyrite)
4FeS2(S) + 11O2(g) —> 2Fe2O3(s) + 8 SO2 (g)
Removal of Solid Particulates
Electrostatic Precipitators
Dusting tower
Removal of soluble contaminants
Washing tower
Removal of moisture
Drying tower
Removal of arsenic oxides (catalyst poisons)
Arsenic purifier
This is the initial process of generating sulfur dioxide (SO₂). It involves burning elemental sulfur in a sulfur furnace or roasting sulfide ores, reacting sulfur with oxygen at high temperatures to create SO₂ gas, the feedstock for the rest of
the process.
Combustion
This is the core chemical transformation of the process, converting sulfur dioxide (SO₂) into sulfur trioxide (SO₃). It is achieved by passing the purified SO₂ and oxygen mixture over a vanadium(V) oxide (V₂O₅) catalyst bed at elevated temperatures, accelerating the reaction to form SO₃.
Catalytic oxidation
This process involves dissolving sulfur trioxide (SO₃) into concentrated sulfuric acid (H₂SO₄) to produce oleum (H₂S₂O₇). It’s favored over direct absorption into water to avoid creating corrosive sulfuric acid mists and to achieve a higher concentration of sulfur oxides.
Absorption
This is the final process step where oleum (H₂S₂O₇) is mixed
with water (H₂O) to produce concentrated sulfuric acid
(H₂SO₄) of the desired strength. The dilution is carefully
controlled to manage the heat generated and to achieve the
target sulfuric acid concentration.
Dilution
Unit process are
Combustion, catalytic oxidation, absorption, dilution
Unit operations are
Dusting, washing, drying, arsenic removal, heat exchange, mixing
This operation removes dust
particles and other solid
impurities from the sulfur dioxide
(SO₂) gas stream using a dusting
tower. It is crucial for protecting
downstream equipment and
preventing catalyst poisoning by
removing particulate matter from
the gas stream
Dusting
This operation removes soluble
contaminants from the sulfur dioxide
(SO₂) gas stream by washing it with
water in a washing tower. It targets
contaminants like halides and other
acidic gases, ensuring a cleaner SO₂
stream for the catalytic oxidation
stage
Washing
This operation removes moisture
from the gas stream by contacting
it with concentrated sulfuric acid
in a drying tower. It is essential
for protecting the catalyst in the
converter because water vapor
can deactivate the catalyst,
reducing its efficiency
Drying
This operation specifically targets
and removes arsenic oxide
impurities from the gas stream. It
is essential in plants where the
sulfur source contains arsenic
because arsenic compounds are
potent catalyst poisons,
significantly reducing the
catalyst’s effectiveness.
Arsenic removal
This operation is critical for
managing the temperature of the
gas stream before absorption.
Cooling the sulfur trioxide in a heat
exchanger prior to absorption helps
to increase the absorption efficiency
and recover heat that can be used
elsewhere in the process.
Heat exchange
Mixing and agitation are
important within some of the
towers to promote contact
between phases. This ensures
uniform distribution of reactants
and efficient mass transfer in the
washing, drying, and absorption
towers, optimizing the efficiency
of each operation.
Mixing
