The production bioethanol from Ceratophyllum demersum L . in Iraq

Biofuels have attracted a lot of attention due to the growing demand for energy resources and concerns about greenhouse gas emissions. Unlike other green energy resources, biofuels like bioethanol, can provide liquid fuels that is essential for transportation. Second-generation bioethanol can be produced from lignocellulosic biomass through acid hydrolysis and fermentation. Lignocellulosic biomass is widely available and does not affect on the nutritional needs of agricultural crops. In this study, the aquatic plant Ceratophyllum demersum was used. Ceratophyllum demersum is a type of invasive aquatic plant that can live in fresh and brackish waters, and it is abundant in most regions of southern Iraq. The bioethanol with the highest concentration was identified by high-performance liquid chromatography (HPLC). The results showed that 14% of bioethanol was produced in the absence of acid hydrolysis, while the concentration of it increased to 25% with the presence of acid hydrolysis. Acid hydrolysis aims to increase the breaking bonds of lignin and hemicellulose, increase the porosity of the material, and damage the crystalline structure of cellulose, and thus facilitates its conversion to glucose and increases the percentage of ethanol production

Biomass Based Materials in Electrochemical Supercapacitor Applications

Biomass is the general term for organic substances derived from living organisms (plants and animals). Since, biomass is a renewable, sustainable, innovative, low cost and carbon-neutral energy source, the applications of nano-micro particles produced from biomass in electrochemical applications have emerged. A large number of carbon-based materials, such as featured activated carbon, carbon nanotube, C-dots, biochar, hybrid carbon-metal/metal oxide … etc. can be produced from divergent types of biomass. With the growing energy need in the world, supercapacitors have also developed considerably besides the energy generation and storage methods. The supercapacitor is an energy storage system that can work reversibly to provide high energy in a short time. In these systems, electrode structure and surface properties are crucial for energy capacity enhancement. In this sense, electrode modifications with the above-mentioned biomass-based nano-micro structures are widely used in supercapacitor applications

Electricity generation by Pseudomonas aeruginosa ZH1 in microbial fuel cell using palm oil mill effluent

Microbial fuel cell (MFC) is a bioelectrochemical system that is recognised as a promising source of renewable energy. Electro-active bacteria are used to generate electricity in MFC, either as pure or mixed culture. Recent studies have shown that MFC is capable of utilising various types of wastewaters as the substrate for electricity generation. In view of this, the investigation on the feasibility of pure bacterial culture for electricity generation in a double-chambered MFC using final discharge palm oil mill effluent (POME) was carried out. The physical enhancement method was used to isolate electro-active bacteria from POME sludge grown on the anode of MFC. The isolate was identified and designated as Pseudomonas aeruginosa ZH1 using the 16S rRNA gene sequence analysis. The maximum power density and current density generated in MFC using P. aeruginosa ZH1 were 451.26 ± 22.97 mW/m2 and 654.90 ± 17.12 mA/m2, respectively. The high electricity generation was contributed from the self-produced pyocyanin which acted as the electron mediator. Analysis on the biochemical and physical factors affecting the MFC performance showed that P. aeruginosa ZH1 could not achieve high electricity generation and efficient treatment of POME simultaneously in MFC. Significant electricity generation was achieved at initial anode pH 9, external resistance of 500 Ω, 10% (v/v) inoculum size, under facultative anaerobic condition, undiluted POME as the substrate, using graphite felt as the electrodes with a surface area of 24.84 cm2 and the addition of pyruvate and yeast extract in the anode. Furthermore, the time-course characterisation method was conducted to analyse the performance of MFC at 4, 24, 72 and 120 hours, respectively under batch mode operation. The maximum power generation and polarisation curve indicated that the optimum MFC performance was achieved at 72 hours. This was in correlation with the optimum biofilm development at 72 hours as observed from the bacterial concentration, microscopic imaging and Fourier Transform Infra-Red spectroscopy (FTIR) analysis. The long term MFC performance was investigated under sequential batch mode for 25 days at five days/cycle. The addition of pyruvate and yeast extract increased the electricity generation in which the maximum power density and current density were achieved during the second cycle at 33.51 ± 30.35 mW/m2 and 153.40 ± 68.90 mA/m2, respectively. Microscopic and elemental analysis revealed that the developed biofilm consists of web-like structures which could represent bacterial nanowires for extracellular electron transfer. In conclusion, this study demonstrated that P. aeruginosa ZH1 is a suitable electro-active bacteria for the generation of electricity in MFC using final discharge POME

Supercapacitors for the Next Generation

Supercapacitors are presently applied in various devices and have the potential to be used in many fields in the future. For example, the use of supercapacitors is currently limited not only to automobiles, buses, and trucks, which have been electrified recently, but also to railways and aircraft. We believe that these devices are the most suitable physical batteries for absorbing regenerative energy produced during motor regeneration; thus, further research and development in this direction is expected in the future

Carbon-Based Nanomaterials in Biomass-Based Fuel-Fed Fuel Cells

Environmental and sustainable economical concerns are generating a growing interest in biofuels predominantly produced from biomass. It would be ideal if an energy conversion device could directly extract energy from a sustainable energy resource such as biomass. Unfortunately, up to now, such a direct conversion device produces insufficient power to meet the demand of practical applications. To realize the future of biofuel-fed fuel cells as a green energy conversion device, efforts have been devoted to the development of carbon-based nanomaterials with tunable electronic and surface characteristics to act as efficient metal-free electrocatalysts and/or as supporting matrix for metal-based electrocatalysts. We present here a mini review on the recent advances in carbon-based catalysts for each type of biofuel-fed/biofuel cells that directly/indirectly extract energy from biomass resources, and discuss the challenges and perspectives in this developing field