Question

Chemical processing industries are now become essential and it is contributing the needs of our day-to-day life. There are vast number of industries which can be broadly classified into organic and inorganic, these industries include; petrochemicals, pharmaceuticals, paint, polymers, textiles and biomedical to name a few. Along with other specialties such as economic, engineering and scientific personnel, chemical engineers play pivotal role in these industries. In view of the current importance of chemical processing industries, address each of the following tasks with detailed justification.

1. Identify any one domestic industry and provide its details such as name, location, raw materials used/finished products and discuss the role of chemical engineers in this industry.

2. Choose any suitable chemical processing industry and explain the unit process and unit operations that are taking place in the above selected industry.

3. Discuss the importance of packing used in the packed bed columns and evaluate the different types of packing materials.

4. A synthetic oil was developed by Research and development section of a petrochemical industry as an automobile engine lubricant. However, under test conditions it was observed that viscosity of newly developed lubricant oil drastically decreases with rise in the temperature of engine. Give the detailed justification for this observed phenomenon

Answer 1

1). The identified domestic industry is Gujarat Alkalies and chemicals ltd.

Location - Vadodara, Gujarat, India

Process - H2O2 production

Raw materials - Hydrogen (H2), Air , Working solution comprising of ethylanthraquinone, 2- methyl cyclohexyl acetate and SC-150 ( an organic chemical) as carrier solution and 2% Pd on zeolite as a catalyst.

Finished product - Hydrogen peroxide (H2O2).

The role of chemical engineers in this industry is to monitor and control the plant process over DCS and to coordinate with operators and maintainance department for field operations.

2). Chemical processing industry chosen is Hydrogen manufacturing process by Auto oxidation process.

Unit processes involved:

i). Hydrogenation - The working solution is reduced in hydrogenator by feeding hydrogen.

ii). Oxidation - The reduced working solution is oxidised to produce hydrogen peroxide.

Unit operations involved are:

i). Extraction

ii). Filtration

iii). Distillation

iv). Centrifugation

v). Evaporation

vi). Gravity separation

3). Importance of packing are :

i). Increase the surface area for Gas- liquid contact.

ii). Helps to increase mass transfer.

iii). In comparison to tray columns, packing offers lower pressure drop, better resistance to corrosion, better handling of foaming liquids.

Different types of packing materials:

I). Random packing - Differently shaped hollow packing materials are dumped in a column in a random manner. For eg- the different types of random packings used are Raschig rings, intalox saddle, pall rings, berl saddle etc.

II). Structured or grid packing - This type of packing consists of thin corrugated metal plates or gauzes to force liquids on complicated parts throughout the column. They are either woven or mesh like and have a definite structure. Examples include - flexipac, mellapac, genpac etc.

4). With the increase in temperature, the energy level of liquid molecules (kinetic energy) increases leading to increase in distance between the molecules. This reduces the cohesive forces between the molecules and as viscosity in liquids is mainly due to cohesive forces, so a decrease in cohesive forces will decrease the viscosity.