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The materials used for fuel cell membrane must have a high proton conductivity, a strong enough wall to block the reactant flow rate and be chemically or mechanically stable in the environment around the fuel cell. To improve the effectiveness of fuel cell membranes and reduce production costs, several synthetic polymer membranes have been developed, including polyethersulfone, polysulfone, polyvinyl alcohol, and polystyrene. Membranes from this polymer have the advantage of being cheap, commercially available, and allowing its structure to store moisture so it can operate at higher temperatures, yet it has low hydrophilic property. Chitosan, as a biopolymer that has strong hydrophilicity property resulted from numerous hydrophilic groups (e.g. –OH, –NH2 and –NR3 þ), can be used for various chemical modifications including to increase mechanical and chemical stability and modification to the possibility of producing ion exchange and increasing ionic conductivity which is a requirement for fuel cell membrane. The purpose of this study is to review the use of chitosan as synthetic polymer-based membrane modification from its structure and properties. Recent achievements and prospect of its applications have also been included.

Polylactic Acid (PLA) is a natural polymer that can be used as a raw material for making plastics. PLA plastic manufacturing has developed rapidly since the crude oil supply is getting lower, besides PLA plastic is environmentally friendly. In this research, the development of PLA from starch and wheat bran was developed by using glycerol as a plasticizer. PLA film is made by lactic acid fermentation. After fermentation, PLA mixed with wheat bran with a ratio of 20:80 (w/w) and a variety of glycerol concentration of 0%; 1%; 3%; 5%; and 7%, then heating at 200 °C for 5 minutes. The film later printed in plastic size dimension of 15cm × 20cm and incubated at 50 °C for 5 hours, then dried in room temperature of ± 27 °C. The effect of glycerol addition as a plasticizer on PLA is analyzed using mechanical tests, swelling, solubility, and chemical resistance. Film with 1 wt% of glycerol composition is optimal composition of tensile strength value of 1.22 MPa, 0.014% elongation, swelling of 0.4, solubility of 0.0207%.

Microbial fuel cells (MFCs) are devices that utilize the work of microorganisms to oxidize organic substrate involving biochemical pathways. Several studies have been done based on experiments while simulation and modelling remain unexplored. Basically, MFCs have a lot of similarities to chemical fuel cell systems, which modelling and simulation have been widely developed. Hence, a study should be done to develop the model in order to widen the implementation of MFCs. In order to evaluate MFCs performance with less cost and time, numerical modelling might be an effective approach. Models could also be easily developed or modified for various operation conditions and configurations to generate experimental data on MFCs. A number of papers on simulation and modelling focused on cell voltage as function of both cell current density and chemicals concentration. In this paper, a double chamber acetate MFCs under continuous operation and unsteady state condition would be investigated. MFCs model based are developed by calculating biochemical reactions, Butler-Volmer equation, and electrochemical equations using MATLAB 2018a software. The parameters and constants data reported from recent literature are used. Results show that periodic flow rate of fuel could improve the power production. This result also gives the prediction of cell voltage and current density. Nevertheless, models with various conditions or configurations could be developed to scale-up or create more efficient MFCs using simple methods.

The energy crisis has become a global issue that has plagued almost all parts of the world. MFCs (Microbial Fuel Cells) is an alternative technology because of its ability to convert waste into electrical energy. The bacterio-algal fuel cell (BAFCs) is kind of an effort for increasing the economic value and carbon capture capability of MFCs. In this case, algae used as a catholyte and organic substrate containing anode-reducing exoelectrogenic bacteria acted as anolyte. This research will examine the potential of algae in BAFCs as an alternative energy for Indonesia's future. By photosynthesis reaction, bacterio-algal fuel cells are operated in a self-sustaining cycle. It can be configured in single, dual chambers, and triple chambers. The performance of bacterio-algal fuel cells is strongly influenced by the bacterial and algae species in each compartment. Factors involved in bacterial-algal fuel cells are also analyzed and assessed: electrode materials, membrane, carbon sources, and algae pretreatment, including the operational parameter, such as pH and temperature. Bacterio-algal fuel cells are recommended to be used to convert algae into electricity by scaling-up and integrating the devices. Organic substrate could be obtained from municipal wastewater. Algae as by-product could be harvested and converted into certain products. Algal Fuel Cell is the solution to produce electricity and reduce CO2 pollution at the same time. Also, an algal fuel cell is potential for sustainable use in the future. By integrating the algal fuel cell in the factory that produces high-concentrated wastewater, the fuel cell can purify the wastewater so that it is safe to be drained to the environment and also can make an integrated electricity production for the whole factory. Some ways to improve the power production are proposed to improve the power generation from BAFCs since this technology offers clean, affordable, sustainable energy, and in-line with SDGs.