Ch. 22 - Industrial Chemistry Flashcards
What is a batch process?
A batch process is an industrial process in which an amount of the product is made in a vessel for a period of time, and is then removed from the vessel.
What is a continuous process?
A continuous process is an industrial process in which the reactants are continuously fed into the vessel and the products are continuously removed.
What is a semi-continuous process?
A semi-continuous process is an industrial process in which part of the process is a continuous process and part is batch process.
Give an example of a continuous process. Relate the reaction’s formula. Give a use for the product.
Haber process,
N2 + 3H2 =(reversible) 2NH3,
Used in manufacturing fertilisers.
What is feedstock?
The feedstock is the reactants in an industrial process.
What are co-products?
Co-products are other products formed along with the main products manufactured. They are disposed, used or sold.
Compare fixed and variable costs.
Fixed costs in an industrial process must be paid regardless of the rate of production, while variable costs depend directly on the level of plant output.
Fixed: labour, rent
Variable: heat, electricity
What is made in the Premier Periclase plant, and how?
MgO is made from seawater in a continuous process.
What feedstock is involved in the Premier Periclase plant?
Ca(OH)2 and purified sea water are the feedstock.
What are the raw materials involved in the Premier Periclase plant?
Limestone(calcium carbonate CaCO3) and fresh water are the raw materials.
How are the raw materials treated in the Premier Periclase plant?
Limestone is crushed, washed and heated.
CaCO3 = CaO + CO2
Fresh water is added
CaO + H2O = Ca(OH)2
What are the 2 main reactions in the Premier Periclase plant?
No catalysts used,
MgCl2 + Ca(OH)2 = CaCl2 + Mg(OH)2
In the furnace,
Mg(OH)2 = MgO +H2O
Pellets of MgO are formed, then periclase.
(yield= 2g of MgO for a L of seawater)
What is the main co-product in the Premier Periclase plant?
CaCl2
What are sources of pollution in the Premier Periclase plant and how are they mitigated?
Dust and sulfur dioxide. Dust is removed using electrostatic precipitators. Then, the gases are scrubbed with water, removing sulfur dioxide and grit.H
How is quality control conducted in the Premier Periclase plant?
Acid-base titrations are used to check the carbonate content of water and lime to ensure that CaCO3 isn’t precipitated out with MgO
