A common and important process is the manufacture of gelatin for food, pharmaceuticals, photographic film, and various technical applications. The chemistry is the simple hydration of collagen from animal bones or skins:

Bones must be pretreated with steam to remove the grease, crushed into small particles, and then sent to a series of acidwash steps to remove calcium phosphate and other mineral matter.
The remaining collagen then goes to long storage (1 month or more) in lime to remove soluble proteins before finally going to the reactor and purification processes. An abbreviated process flow diagram appears below (Fig. P2.5).

For your interest, to produce 1 ton of gelatin requires approximately 3 tons of bones, 1 ton of hydrochloric acid, 3/4 tons of lime, and 400 lbm of steam.
For each of the following operations in this process, which of the first four chemical engineering phenomena (fluid mechanics, heat transfer, mass transfer, and reaction engineering) do you think are important parts of the operation?
a. Cooker: Steam is used to heat the bones and cause the grease to flow more easily. The stream of grease is caused to flow away from the bones.
b. Acid Wash: A stream of acid is brought in and mixed with the bone particles. The acid reacts with the solid material of the bones to break down that material and release the calcium phosphate and other minerals. The acid stream also carries away the minerals as it leaves the process.
c. Dryer: Steam is brought into the compartment where strips of gelatin are laying on trays. The steam heats the compartment until the gelatin is completely dry.

Transcribed Image Text:

C102 H149N31038 + HO C102H151 N31039 collagen water gelatin