Composite chitosan and quaternary ammonium modified nanofibrillar cellulose anion exchange membranes for direct ethanol fuel cell applications

Fuel cells are a promising technology for energy production, but their commercialization is hindered mainly due to high costs. Direct alkaline ethanol fuel cells (DAFC) are receiving increasing attention as they can utilize cheaper, non-precious metal catalysts. A vital component of a DAFC is the anion exchange membrane (AEM). Currently, the commercially available AEMs don’t possess satisfactory properties. This indicates a need for the development of new highly efficient, environmentally friendly, and economically viable AEMs. Synthesis of synthetic polymer AEMs is usually complex and time-consuming, as well as environmentally unfriendly. Therefore, it is highly desired that the membrane material is bio-renewable, non-toxic and environmentally benign. In this work, a series of biopolymer membranes were designed by a simple, cost-effective, dispersion-casting procedure, fully complying with green-chemistry principles. Design of experiments was used as a methodology for identifying optimal combinations of influencing factors and their relations within selected responses. The obtained chitosan-Mg(OH)2 composite membranes containing modified nanofibrillar cellulose (CNF) fillers with quaternary ammonium groups were investigated for their mechanical properties, swelling ratio, ethanol permeability and ion exchange properties. Obtained data suggest the applicability of newly prepared, biopolymeric composites as eco-friendly AEMs in DAFC technologies.

Biofuel Resources Plan: Theoretical Case Assessment of Automotive Industries

Crude oil exhaustion and greenhouse emissions have remained a global concern till date. Domestic production of biofuel blends and micro-emulsion as substitutes for conventional fuel in tackling greenhouse gas emission has challenges like feedstock inadequacy, fuel-energy content, compatibility, oxidation stability and other automotive fuel property issues. Strategies to address these issues are discussed in this study. Case study of Nigeria shows that an annual conversion rate of 6.9/3.3% (2.1: 1) of cassava wastes will meet its E10/E5 blend from local production capacity. An effort has been made to correlate existing ethanol and biodiesel yields, ƐѱE and ƐѱB with expected oil yield as a function of gasoline and diesel shares, αE and αB per hectare of cultivation, to generate total oil yield per desired short and medium term biofuel targets utilizing selected feedstock at applicable yield bounds. A typical E10 gasohol from cassava will need 16,133 and 28,543 hectares from cassava plantation to meet its annual short and medium term biofuel targets. The r2-square value of 0.6402 for CF/SPeel and 0.9044 for CF/SPulp is an indication that more litre/tonne volume of ethanol could be produced from CF/SPeel except for in consistency when ammonia extract and urea are used as nitrogen source. Specific energy for direct ethanol fuel cell (DEFC) from daily production capacity equivalence of E10 per annum is estimated at 2.34GWh/Kg. Biofuel and fuel cells are good alternatives to explore as replacement of fossil fuel in automotive application.

Influence of Solvents on the Electroactivity of PtAl/rGO Catalyst Inks and Anode in Direct Ethanol Fuel Cell

This paper presents research on the effects of common solvents such as n-butyl acetate, isopropanol, and ethanol on the properties and electroactivity of catalyst ink based on PtAl/rGO. The inks prepared by mixing PtAl/rGO catalyst, Nafion solution (5 wt%), and solvent were coated on carbon cloth by the spin coating method. The results obtained showed that ethanol was the most suitable solvent for the preparation of catalyst ink with a volume ratio between catalyst slurry and solvent of 1 : 1 (CI-EtOH (1/1) ink). The surface of the CI-EtOH (1/1) coated electrode was smooth, flat, and even and had no cracks due to the increase of Nafion mobility, resulting in significant improvement in the interaction between Pt particles and ionomer. Moreover, the electrochemical activity of the CI-EtOH (1/1) ink in ethanol electrooxidation reaction, in both acidic and alkaline media, has the highest value, with the forward current density, IF, reaching 1793 mA mgPt−1 and 4751 mA mgPt−1, respectively. In the application in direct ethanol fuel cell (DEFC), the CI-EtOH ink-coated anode also exhibited the highest power density in both PEM-DEFC (with a proton exchange membrane) and AEM-DEFC (with an anion exchange membrane) at 19.10 mW cm−2 and 27.07 mW cm−2, respectively.