Chin-Tsan Wang

Novel bufferless photosynthetic microbial fuel cell (PMFCs) for enhanced electrochemical performance

Photosynthetic microbial fuel cells (PMFCs) are novel bioelectrochemical transducers that employ microalgae to generate oxygen, organic metabolites and electrons. Conventional PMFCs employ non-eco-friendly membranes, catalysts and phosphate buffer solution. Eliminating the membrane, buffer and catalyst can make the MFC a practical possibility. Therefore, single chambered (SPMFC) were constructed and operated at different recirculation flow rates (0, 40 and 240 ml/min) under bufferless conditions. Furthermore, maximum power density of 4.06 mW/m2, current density of 46.34 mA/m2 and open circuit potential of 0.43 V and low internal resistance of 611.8 Ω were obtained at 40 ml/min. Based on the results it was decided that SPMFC was better for operation at 40 ml/min. Therefore, these findings provided progressive insights for future pilot and industrial scale studies of PMFCs.

The development and testing of a novel cross axis wind turbine

A novel cross axis wind turbine (CAWT) which comprises of a cross axis blades arrangement was presented and investigated experimentally. The CAWT is a new type of wind turbine that extracts wind energy from airflow coming from the horizontal and vertical directions. The wind turbine consists of three vertical blades and six horizontal blades arranged in a cross axis orientation. Hubs in the middle of the CAWT link the horizontal and vertical blades through connectors to form the CAWT. The study used a 45° deflector to guide the oncoming airflow upward (vertical wind direction). The results from the study showed that the CAWT produced significant improvements in power output and rotational speed performance compared to a conventional straight-bladed vertical axis wind turbine (VAWT).

Effects of chaotic acclimation applied on performance of microbial fuel cells

ABSTRACT Microbial fuel cells (MFCs) are one of the bioreactors that produce electrons by metabolizing substrate from microorganisms, and have the ability to both degrade waste solution and produce electrons. Recently, the activity of microorganisms has limited the power performance of MFCs. Chaos has been used to stimulate activity of microorganisms, but it has not been used previously in MFCs. In this study, three types of acclimations – native acclimation (NA), MFC acclimation (MFCA), and MFC embedded with chaotic electric field acclimation (CMFCA) – are applied to realize their performance and chemical oxygen demand (COD) removal in MFCs, respectively. Results show that the current density and the power density of CMFCA were improved by 1.33 and 1.25 times than MFCA, and the COD removal of CMFCA reached 85% after five days. In addition, the acclimation stage at the condition of CMFCA appeared after 10 days, but was not found for the MFCA system. These observations would provide positive information for improving the performance of MCFs in the future.

Experimental Combined Numerical Approach for Evaluation of Battery Capacity Based on the Initial Applied Stress, the Real-Time Stress, Charging Open Circuit Voltage, and Discharging Open Circuit Voltage

With the intensification of energy crisis, considerable attention has been paid to the application and research of lithium-ion batteries. A significant progress has also been made in the research of lithium-ion battery capacity evaluation using electrochemical and electrical parameters. In this study, the effect of mechanical characteristic parameter (i.e., stack stress) on battery capacity is investigated using the experimental combined numerical approach. The objective of the proposed approach is to evaluate the capacity based on the initial applied stress, the real-time stress, charging open circuit voltage, and discharging open circuit voltage. Experiments were designed and the data is fed into evolutionary approach of genetic programming. Based on analysis, the accuracy of the proposed GP model is fairly high while the maximum percentage of error is about 5%. In addition, a negative correlation exists between the initial stress and battery capacity while the capacity increases with real-time stress.

Application of interface material and effects of oxygen gradient on the performance of single-chamber sediment microbial fuel cells (SSMFCs)

Single-chamber sediment microbial fuel cells (SSMFCs) have received considerable attention nowadays because of their unique dual-functionality of power generation and enhancement of wastewater treatment performance. Thus, scaling up or upgrading SSMFCs for enhanced and efficient performance is a highly crucial task. Therefore, in order to achieve this goal, an innovative physical technique of using interface layers with four different pore sizes embedded in the middle of SSMFCs was utilized in this study. Experimental results showed that the performance of SSMFCs employing an interface layer was improved regardless of the pore size of the interface material, compared to those without such layers. The use of an interface layer resulted in a positive and significant effect on the performance of SSMFCs because of the effective prevention of oxygen diffusion from the cathode to the anode. Nevertheless, when a smaller pore size interface was utilized, better power performance and COD degradation were observed. A maximum power density of 0.032mW/m2 and COD degradation of 47.3% were obtained in the case of an interface pore size of 0.28μm. The findings in this study are of significance to promote the future practical application of SSMFCs in wastewater treatment plants.

Implementation of surface modified carbon cloth electrodes with biochar particles in microbial fuel cells

ABSTRACT Microbial fuel cells (MFC) are bioelectrochemical reactors that convert chemical energy in organic substrates to electrical energy through catalytic reactions of microorganisms. The relationship between microorganisms and electrodes plays a vital role for effective functioning of an MFC. The physical and chemical properties of the electrodes are more crucial for a feasible MFC performance. Plain Carbon cloth (CC) and surface modified CC with four different sizes of Biochar (BC) particles such as 2 mm BC< 2, BC2-4, BC4-6, and BC6-10 were employed as anode electrodes in dual-chambered MFCs and their performance was compared. Results showed that the electrode with BC< 2 enhanced the MFC performance to with power density of 312 mWm−2 and BC6-10 facilitated the maximum COD degradation performance of 77% in the MFC both due to electrode properties like high porosity and large surface area. This study in general is a proof that BC has high feasibility for usage in MFC electrode modification studies.