Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

With crude oil reserves dwindling, the hunt for a sustainable alternative feedstock for fuels and materials for our society continues to expand. The biorefinery concept has enjoyed both a surge in popularity and also vocal opposition to the idea of diverting food-grade land and crops for this purpose. The idea of using the inevitable wastes arising from biomass processing, particularly farming and food production, is, therefore, gaining more attention as the feedstock for the biorefinery. For the three main components of biomass—carbohydrates, lipids, and proteins—there are long-established processes for using some of these by-products. However, the recent advances in chemical technologies are expanding both the feedstocks available for processing and the products that be obtained. Herein, this review presents some of the more recent developments in processing these molecules for green materials, as well as case studies that bring these technologies and materials together into final products for applied usage

A Different Flow Field Design Approach for Performance Improvement of a PEMFC

Flow fields influence the deployment of the reactant gases over the surface of catalyst layer and the removal of the produced water from the cell. An optimum flow field design should provide lowest energy loss, uniform mass distribution and minimize pressure drop between inlet and outlet of the gas stream. An even reactant distribution reduces the mass transport losses and thus allows higher power density. This study is focused on flow fields inspired by veins of the tree leaves, which have effective performance improvement by minimizing the pressure drop and even deploy reactant gases without water flooding. The branching of flow channels corresponds to the Murray's law, which is also applicable to plants. Additionally semi cylindrical obstacles were fabricated at the bottom of the daughter channels to increase the diffusion into the gas diffusion layer. Cylindrical obstacles were applied to reduce the concentration losses, especially at the high current densities. Cell performance and current density vs temperature distribution measurements show that the new innovative designs shows a better performance compared to standard serpentine design by 42.1% at 0.4 V operating voltage. Furthermore, homogenous current and temperature distributions and better water removal are achieved

Combustion and Performance Characteristics of CI Engine Running with Biodiesel

Biodiesel is one of the alternative fuels which is renewable and environmentally friendly and can be used in diesel engines with little or no modifications. In the present study, experimental investigations were carried out on the effects of biodiesel types, biodiesel fraction and physical properties on the combustion and performance characteristics of a compression ignition (CI) engine. The experimental work was conducted on a four-cylinder, four -stroke, direct injection (DI) and turbocharged diesel engine by using biodiesel of waste oil, rapeseed oil and corn oil and normal diesel. Based on the measured parameters, detailed analyses were carried out on cylinder pressure, heat release rate and brake specific fuel consumption (BSFC). It has been seen that the biodiesel types do not result in any significant differences in peak cylinder pressure and BSFC. The results also clearly indicate that the engine running with biodiesel have slightly higher in-cylinder pressure and heat release rate than the engine running with normal diesel. The BSFC for the engine running with neat biodiesel was higher than the engine running with normal diesel by up to 15%. It is also noticed that the physical properties of the biodiesel affects significantly the performance of the engine