Introduction to Direct Alcohol Fuel Cells

Abstract

Fuel cells are strongly linked to renewable energies, particularly to the so-called "Hydrogen Economy". For decades the development of fuel cells able to convert hydrogen and oxygen in electrical energy with water as unique byproduct has motivated huge activity in fundamental and applied electrochemistry.In this chapter we introduce the concept of methanol economy and discuss its status and perspectives. To be a reality the methanol and other alcohol economies depend on the development of alcohol feed fuel cells, whose components, operation modes and general performance are analyzed. World Energy Consumption: Current Status and TendenciesThe Stone Age did not end for lack of stone, and the oil age will end long before the world runs out of oil. Sheikh Ahmed Yamani (former Saudi Arabia's Oil Minister)The world energy consumption at the beginning of this decade was 12 billion tonnes of oil equivalent (toe), 1 and 87 % is generated by burning fossil fuels (oil 33.7 %, natural gas 23.6 % and coal 29.7 %) [1], which are non-renewable and increase the CO 2 content of the atmosphere, considered as the major man-made Around a half of the world energy demand corresponds to developed countries that originally signed the Convention on the Organisation for Economic Cooperation and Development (OECD), including United States, Canada, Japan and European Community. An important fraction of the other half is consumed by Russia and the fast-developing countries; particularly China and India, being coal, the worst fossil fuel in terms of CO 2 emissions, and the most vastly employed in these highly populated regions.An important fraction, close to 40 % of the fuel resources is used for power generation, while industry and transport demand around 30 % and 20 %, respectively [1,2]. Projections of energy demands for the next decades is a subject that concerns oil-related industries [2-4], governments and energy planners. British Petroleum projections till 2030 [2] are summarized in Fig. 1.1, where the growth in energy demand is basically modulated by the growth of the population and gross domestic product (GDP), mainly due to the contribution of the non-OECD countries. By 2030, 1.3 billion more people will need energy; and the world income is expected to roughly double the 2011 level.The raise of fossil fuel prices to record levels in real terms over the past decade inevitably lead to supply responses, by development and deployment of new technologies across a range of energy sources. Thus, the "shale revolution", first for gas and then for oil, will allow account for almost a fifth of the increase in global energy supply to 2030 [2]. Simultaneously, high prices for fossil fuels will also support the expansion of biomass renewable energy supply, accounting for 17 % of the increase in global energy supply by 2030. Hydro and nuclear together will

Anion exchange membranes based on carbazole-containing polyolefin for direct methanol fuel cells

“…An OCV of 0.93 V and a MPD of 125.8 mW cm À 2 are achieved when the current density is 272 mA cm À 2 . As a comparison, commercial A201 Tokuyama membranes exhibited a MPD in the range of 67-130 mW cm À 2 at temperature from 50 to 80°C [45]. The good fuel cell performance using the as-prepared membranes can be attributed to their high ion conductivity and low methanol permeability.…”

Fundamentals of Electrochemistry with Application to Direct Alcohol Fuel Cell Modeling

“…Water is the most used solvent due to its natural properties and because of its importance for the correct operation of the membrane. Alcohols are considered a promising source fuel to fuel cells [28]. Light alcohols, such as methanol or ethanol, are able to electrooxidate at relative low temperatures (less than 90 C).…”

Recent advances on Zeolite modification for direct alcohol fuel cells (DAFCs)

“…In a DAFC, the alcohol is oxidized at anode while the oxygen is reduced at cathode. [46][47][48] Between the anode and cathode, a membrane exists (Fig. 3).…”

“…Some strategies may be applied to overcome this problem including selection of the alcohol fuel, adjustment of temperature and membrane modification. 47,48,65 Based on the ionic species passed through it, the membrane in DAFC can be categorized into two types: proton exchange membrane (PEM) and anion exchange membrane (AEM). The original DAFC works with PEM where the alcohol oxidized in anode releasing H + .…”