Synthesis and application of polypyrrole/carrageenan nano-bio composite as a cathode catalyst in microbial fuel cells

A novel nano-bio composite polypyrrole (PPy)/kappa-carrageenan(KC) was fabricated and characterized for application as a cathode catalyst in a microbial fuel cell (MFC). High resolution SEM and TEM verified the bud-like shape and uniform distribution of the PPy in the KC matrix. X-ray diffraction (XRD) has approved the amorphous structure of the PPy/KC as well. The PPy/KC nano-bio composites were then studied as an electrode material, due to their oxygen reduction reaction (ORR) ability as the cathode catalyst in the MFC and the results were compared with platinum (Pt) as the most common cathode catalyst. The produced power density of the PPy/KC was 72.1 mW/m2 while it was 46.8 mW/m2 and 28.8 mW/m2 for KC and PPy individually. The efficiency of the PPy/KC electrode system is slightly lower than a Pt electrode (79.9 mW/m2) but due to the high cost of Pt electrodes, the PPy/KC electrode system has potential to be an alternative electrode system for MFCs

Electerochemical study of sulfonated poly ether ether ketone nanocomposite membrane for direct methanol fuel cell application

High methanol permeability and expensive price of current commercial Nafion® membrane for direct methanol fuel cell (DMFC) have encouraged researchers to modify proton exchange membrane (PEM). Sulfonted poly ether ether ketone (SPEEK) is a polymer which attracted a lot of attention recently. This study aimed to test the DMFC performance of nanocomposite SPEEK membrane filled with Cloisite 15A® clay by introducing 2,4,6 triaminopyrimidine (TAP) as a compatibilizer as electrolyte membrane at room temperature to 80oC and compare with Nafion 117. SPEEK polymer was made at 60oC in order to obtain the degree of sulfonation of 60%. According to the results, the SPEEK nanocomposite with the following composition SP60/CL2.5/TAP5.0 showed higher proton conductivity and methanol permeability than of Nafion 117 at various temperatures because of the presence of CL and TAP addition.Furthemore the highest overall performance( membrane selectivity) was allocated to the SP60/CL2.5/TAP5.0 at 60oC while the lowest one was for Nafion 117 at 80oC. In addition DMFC performance results showed the OCV for the nanocomposite membrane increase when the temperature increase. In addition voltage and power density increase with temperature incerement due to catalyst high activity on electrode surface,and higher proton conductivity , clearly the maximum power density at 60oC was 54.93 (mWcm-2)

Review on the development of fuel cells and its future prospects

Fossil fuels are unsustainable energy storage medium with pollution problems. With the limitation of fossil fuels, fuel cells, which are known as effective electrochemical converters, has attracted much attention. Present review paper provides a complete information on fuel cell technology and history which includes competing technologies, current status of research-and-development and its future direction. Fuel cell plays an important role in stationary applications from 1990s till now due to its efficiency upon reducing emissions

Influence of mesoporous phosphotungstic acid on the physicochemical properties and performance of sulfonated poly ether ether ketone in proton exchange membrane fuel cell

This study demonstrates the successful development of hybrid mesoporous siliceous phosphotungstic acid (mPTA-Si) and sulfonated poly ether ether ketone (SPEEK) as a proton exchange membrane with a high performance in hydrogen proton exchange membrane fuel cells (PEMFC). SPEEK acts as a polymeric membrane matrix and mPTA-Si acts as the mechanical reinforcer and proton conducting enhancer. Interestingly, incorporating mPTA-Si did not affect the morphological aspect of SPEEK as dense membrane upon loading the amount of mPTA-Si up to 2.5 wt%. The water uptake reduced to 14% from 21.5% when mPTA-Si content increases from 0.5 to 2.5 wt% respectively. Meanwhile, the proton conductivity increased to 0.01 Scm−1 with 1.0 wt% mPTA-Si and maximum power density of 180.87 mWcm−2 which is 200% improvement as compared to pristine SPEEK membrane. The systematic study of hybrid SP-mPTA-Si membrane proved a substantial enhancement in the performance together with further improvement on physicochemical properties of parent SPEEK membrane desirable for the PEMFC application

Sulfonated poly ether ether ketone with different degree of sulphonation in microbial fuel cell: Application study and economical analysis

A microbial fuel cell (MFC) is a device for the simultaneous treatment of wastewater and the generation of electricity with the aid of microorganisms as a biocatalyst. Membranes play an important role in the power generation of microbial fuel cells. Nafion 117, the most common proton exchange membrane (PEM), is expensive and this is the main obstacle for commercialization of MFC. In this study, four kinds of sulphonated poly ether ether ketone (SPEEK) with different degrees of sulphonation (DS) referred to hereafter as SPEEK 1 (DS = 20.8%), SPEEK 2 (DS = 41%), SPEEK 3 (DS = 63.6%), and SPEEK 4 (DS = 76%), were fabricated, characterized and applied in an MFC. The membranes were characterized by thermogravimetric analysis TGA) and differential scanning calorimetry (DSC) and their morphologies were observed by scanning electron microscopy (SEM). The degree of sulphonation was determined by nuclear magnetic resonance (NMR). Then the membranes were applied to the MFC system. The results indicated that the power produced by MFC with SPEEK 3 (68.64 mW/m) was higher than with the other SPEEK membranes while it was lower than with Nafion 117 (74.8 mW/m). SPEEK3 also had the highest chemical oxygen demand removal (91%) and coulombic efficiency (26%) compared to other SPEEK membranes. The cost evaluation suggests that application of SPEEK 3 is more cost effective than applications of the other types of SPEEK and Nafion 117, due to its high power density generation per cost

Treatment of two different water resources in desalination and microbial fuel cell processes by poly sulfone/sulfonated poly ether ether ketone hybrid membrane

The PS (Polysulfone)/SPEEK (sulfonated poly ether ether ketone) hybrid membranes were fabricated and modified with low and high DS (degrees of sulfonation) for the desalination of brackish water and proton exchange membrane in microbial fuel cell. The results illustrated that SPEEK has changed the morphology of membranes and increase their hydrophilicity. PS/SPEEK with lower DS (29%) had the rejection percentage of 62% for NaCl and 68% for MgSO4; while it was 67% and 81% for PS/SPEEK (76%) at 4 bars. Furthermore, the water flux for PS at 10 bar was 12.41 L m-2 h-1. It was four times higher for PS/SPEEK (29%) which means 49.5 L m-2 h-1 and 13 times higher for PS/SPEEK (76%) with means 157.76 L m-2 h-1. However, in MFC (microbial fuel cell), the highest power production was 97.47 mW/m2 by PS/SPEEK (29%) followed by 41.42 mW/m2 for PS/SPEEK (76%), and 9.4 mW/m2 for PS. This revealed that the sulfonation of PEEK (poly ether ether ketone) made it a better additive for PS for desalination, because it created a membrane with higher hydrophilicity, better pore size and better for salt rejection. Although for the separator, the degree of sulfonation was limited; otherwise it made a membrane to transfer some of the unwanted ions

Power generation and wastewater treatment using a novel SPEEK nanocomposite membrane in a dual chamber microbial fuel cell

In this paper, the performance of two common and two self-fabricated proton exchange membranes were compared. Nafion 112 and Nafion 117, which are two of the most common proton exchange membranes that can be used in all fuel cell systems, were compared to SPEEK and SP/CC/TAP. The results showed that at lower COD such as 2000 mg/l, Nafion 117 has the highest performance in terms of power production and COD removal, while once the COD of wastewater goes up to 5000 mg/l, SP/CC/TAP has approximately the same performance as Nafion 117. The membranes were characterized by FESEM, while the degree of sulfonation was measured by NMR. The oxidation activity of microorganisms was measure by cyclic voltammetry (CV). Also, the attachment of bacteria onto the anode electrode was observed by SEM, which showed that different bacteria from the media with a mixed culture inoculum had attached to the anode electrode