Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/5/2002
Publication Date: 2/1/2003
Citation: Wan, P.J., Zarins, Z.M. 2003. SPECIFIC HEATS OF COTTONSEED AND ITS CO-PRODUCTS. Journal of the American Oil Chemists' Society. 80(2):123-126. Interpretive Summary: Cottonseed is a by-product of cotton fiber production. The seed is largely stored after the cotton fiber is ginned. Due to its unique seed structure, with a layer of linters which remain on the seed surface after ginning, the seed quality is difficult to maintain. The stored seed temperature tends to rise with time and its crucial quality marker, free fatty acid content in the seed also rises with the storage temperature and time. To allow the engineer to estimate the proper air flow to keep the seed dry and cool or develop innovative means to cool the seed, a precise value for specific heat (Cp, calorie/g/oC) is very helpful. This article presents a set of experimental procedures which was designed to examine the specific heats of white cottonseed and cottonseed co-products derived from oil mills using a large scale differential scanning calorimeter (DSC) in a wide range of temperatures. The materials tested include cotton fiber, whole white cottonseed (white seed), linters, delinted seed (black seed), hulls, meats, crude oil and meal.
Technical Abstract: Most of the annual crops are harvested and stored for the entire crushing season until the new crop year begins. It is desirable to have the specific heat data of the agricultural materials for the engineer to manage the heat transfer problem associated with each crop during the storage. Thermal properties of agricultural products, such as cottonseed and its oil mill co-products are not commonly available. Partially because these materials are bulky and lack of uniformity, their thermal properties are difficult to assess precisely. The highly sensitive and large sample volume differential scanning calorimeter (DSC) has made the precise determination of specific heat of agricultural material possible. This report describes a procedure used to obtain the specific heat of white cottonseed and its co-products as a function of temperature. The materials tested included, cotton fiber, whole cottonseed, linters, hulls, meats and meal. Specific heat values of these materials ranged from 0.32 to 0.6 cal/g/ C at 30 C and 0.42 to 0.72 cal/g/ C at 90 C. When these materials were dried, the values converged to 0.24 to 0.33 cal/g/ C at 30 C.