Grasim Industries Limited

Introduction:

I did a 2-month remote internship at Grasim Industries Limited, Nagda which started on 1st May 2022 and ended on 30th June. The main purpose of this internship was to get some exposure into the industry. The interns were tasked to study the presentation provided by the company, and perform the mass and energy balance on the CS2 (carbon disulphide) manufacturing process (on an equipment level), and come up with some recommendations to improve the efficiency of the overall process.

My Work:

I performed mass balance on the calciner unit. A calciner is essentially a vessel in which calcination is done. Calcination refers to thermal treatment of a solid chemical compound whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen, generally for the purpose of removing impurities or volatile substances and/or to incur thermal decomposition.

Raw charcoal mainly consisted of carbon, VM (volatile matter), ash, & moisture. Composition of charcoal does vary depending on source and method of manufacture. Moisture and VM are required to be removed as they produce undesired gases like  COs & H2S during subsequent processes. Carryover/generated fines are also required to be removed through rotary screen.

(image of a calciner)

I also performed mass balance on the electric furnace. The furnace is where carbon (from charcoal) and sulfur combined to form CS2 in vapor form. Side products like H2S (hydrogen sulphide gas) also form, but sulfur is recovered from H2S and recycled.

For calculations and more details, click here for full report.

I was asked by the allotted college faculty to lead the group of interns and also represent them all. This involved coordinating with all the interns, tracking the progress of each task, and ensure that the tasks were done in an appropriate order.

Conclusion:

We came up with the following recommendations:

• frequent cleaning of the calciner to remove deposits to prevent heat loss; &
  
• utilization of heat from flue gas to preheat the feed.

I sincerely thank my manager Mr. Jaswant Singh for his guidance during the internship period.