Layer by Layer Composite Membranes of Alginate-Chitosan Crosslinked by Glutaraldehyde in Pervaporation Dehydration of Ethanol

Hydrophilicity of membrane causing only water can pass through membrane. Pervaporation process using organophilic membrane has been offered as alternative for ethanol dehydration. This paper investigate pervaporation based biopolymer composite membrane from alginate-chitosan using layer by layer method prepared by glutaraldehyde as crosslinking agent and polyethersulfone (PES) as supported membrane. Characterization of crosslinked of composite membrane by FTIR helped in identification of sites for interaction between layers of membrane and support layer (PES). The SEM showed a multilayer structure and a distinct interface between the chitosan layer, the sodium alginate layer and the support layer. The coating sequence of membranes had an obvious influence on the pervaporation dehydration performance of membranes. For the dehydration of 95 wt% ethanol-water mixtures, a good performance of PES-chitosan-alginate-chitosan (PES/Chi/Alg/Chi) composite membrane was found in the pervaporation dehydration of ethanol. Article History: Received April 12nd , 2016; Received in revised form June 25th , 2016; Accepted July 1st , 2016; Available online How to Cite This Article: Rokhati, N., Istirokhatun, T. and Samsudin, A.M. (2016) Layer by Layer Composite Membranes of Alginate-Chitosan Crosslinked by Glutaraldehyde in Pervaporation Dehydration of Ethanol. Int. Journal of Renewable Energy Development, 5(2), 101-106. http://dx.doi.org/10.14710/ijred.5.2.101-10

Hidrolisis Kitosan Menggunakan Katalis Asam Klorida (Hcl)

The molecular weight is an important factor in the application of chitosan. High molecular weight will restrict the use of chitosan. This research uses a chemical process with acid hydrolysis. Hydrolysis is de-polymerization to lower molecular weight that occur because of the termination of glycoside bond by reaction with water (H2O). De-polymerization of chitosan is different from other polysaccharide compounds, because its have a difficult decomposed β-bond and a cationic amine groups. Therefore, it required operating conditions and type of catalyst to produce chitosan in accordance with specifications. The purpose of this research is to obtain optimum conditions of chitosan hydrolysis process and determine the type of acid catalyst is best to produce chitosan with low molecular weight (LMWCs). Results showed that temperature, catalyst concentration, and type of catalyst greatly affect on the depolymerization of chitosan. Depolymerization effect increases with increasing temperature and catalyst concentration, characterized by reduced viscosity and molecular weight of chitosan. To produce chitosan with a molecular weight between 50-100 kDa, optimum conditions : temperature of 70 0C, hydrolysis time 120 minutes, and the concentration of Hidrochloric Acid (HCl )was 0.6 to 0.8 N

Pengaruh Konsentrasi Kitosan Terhadap Proses Flokulasi Pada Pemanenan Mikroalga

The common method used for harvesting microalgae is filtration. But, it has disadvantages such as particle size of microalgae are generally small causing the harvesting process uneffecient. It can be measure using chitosan as bioflocculant. The first procedure of research is making a stock solution of chitosan was prepared by dissolving chitosan flakes in 1% (v/v) acetic acid until the flakes was totally dissolved, then it is introduced into 500 ml of microalgae culture (Spirulina sp). The flocculation process is experimental designed by the variation of the concentration of chitosan (5 mg/L ; 10 mg/L ; 15 mg/L ; 40 mg/L ; 70 mg/L ; 100 mg/L) at pH 8 and slow mixing speed 40 rpm. The result shows that increasing concentration of chitosan causes increasing flocculation efficiency but at the concentration that is too high, it will make flocculation efficiency decrease