Influence of process variables on granulation of microcrystalline cellulose in vibrofluidized bed

Abstract

Wet granulation of microcrystalline cellulose (MCC) has the objective of minimizing particle losses caused by elutriation in compression and coating processes. The MCC physical properties suggest the conventional fluidized bed as adequate for the granulation process; however, literature reports the occurrence of poor fluidization dynamic (preferential channels and dead zones) during this particle fluidization. This work reports the granulation of MCC in vibrofluidized bed, using aqueous solution of maltodextrin (35%) as binder. A fractional experimental design (2 5 − 1 ) was developed to assess the influence of process variables: amplitude and frequency of vibration, atomization pressure, inlet air temperature, and granulating solution flow rate on the responses: particle growth, angle of repose, lump index and mass of elutriated particles. The results showed an increase of the Sauter mean diameter related to the original value from 3.17 to 33.11%, confirming the granulation of the material. The granules obtained revealed good flowability and low lumps index. The levels of independent variables that resulted in a higher reduction of elutriation were the same ones that provided the highest growth of the particles.

Statistical Optimization for Acid Hydrolysis of Microcrystalline Cellulose and Its Physiochemical Characterization by Using Metal Ion Catalyst

“…Indian bamboo [ 16 ] and Luffa cylindrica [ 17 ] have been identified as prospective sources of MCC. During the acid hydrolysis of cellulosic materials, amorphous regions are disintegrated, resulting in a highly crystalline substrate with different degrees of the crystallinity index [ 18 ]. The amorphous regions are selectively hydrolyzed by strong mineral acids, such as hydrochloric, nitric and sulfuric acids [ 19 , 20 ].…”

http://www.asianjournalofchemistry.co.in/user/ViewFreeArticle.aspx?ArticleID=30_5_23

“…The percentage of crystallinity MCC from sugar palm fibers (97.5 %) was considerably high than other nonwoods (52-53 %) [21]. High crystallinity related to acid hydrolysis process for preparing MCC [22] At the time of acid hydrolysis, cellulose chains apart rapidly at 1.4 glycosidic bond so produce short-chain cellulose. Amorphous part of the glycosidic bond partially degraded to form an acid insoluble nature of the final product, while the crystalline leaves a residue and only a change slightly due to acid hydrolysis.…”

Estudo Do Comportamento Fluidodinâmico De Um Leito Vibrofluidizado Para Diferentes Amplitudes E Frequências

“…Este tipo de equipamento pode ser aplicado em vários setores e indústrias, podendo ser utilizado na secagem de materiais granulares (Silva-Moris e Costa 2006), na secagem de materiais pastosos (Meili et al 2010), no recobrimento de partículas (Nunes et al 2012) e na granulação (Costa et al 2011). Para a secagem de pastas com o auxílio do material inerte, existentes vários tipos de equipamentos que podem ser promissores para o desenvolvimento desta operação.…”