• Energy Research

AbstractThe main emphasis of this work is to create a new perovskite material with three different compositions (La0.75Sr0.25Mn0.5Cr0.5−xAlxO3,x = 0.1, 0.2, 0.3) applied in both Intermediate‐ and High‐temperature Solid Oxide Fuel Cells (IT‐ and HT‐SOFCs). Perovskite‐type polycrystalline La0.75Sr0.25Mn0.5Cr0.5−xAlxO3−δ(x = 0.1, 0.2, 0.3) powders were synthesized and formed in a single phase structure by a dry chemistry route (standard solid‐state reaction method). The effect of Al doping on physicochemical and surface properties has been discovered. The compounds were crystallized in single phase rhombohedral symmetry (R‐3CSpace. Group). Total conductivity of Al doping in wet 5% H2was higher than both dry 5% H2and air. The obtained results enhance the electro‐catalytic performance and the material conductivity as well, which will be good for anode materials in IT‐ and HT‐SOFCs and the optimum doping is 10%.

The depletion of fossil fuels in the current world has been a major concern due to their role as a primary source of energy for many countries. As non-renewable sources continue to deplete, there is a need for more research and initiatives to reduce reliance on these sources and explore better alternatives, such as renewable energy. Hydrogen is one of the most intriguing energy sources for producing power from fuel cells and heat engines without releasing carbon dioxide or other pollutants. The production of hydrogen via the electrolysis of water using renewable energy sources, such as solar energy, is one of the possible uses for solid oxide electrolysis cells (SOECs). SOECs can be classified as either oxygen-ion conducting or proton-conducting, depending on the electrolyte materials used. This article aims to highlight broad and important aspects of the hybrid SOEC-based solar hydrogen-generating technology, which utilizes a mixed-ion conductor capable of transporting both oxygen ions and protons simultaneously. In addition to providing useful information on the technological efficiency of hydrogen production in SOEC, this review aims to make hydrogen production more efficient than any other water electrolysis system.

The use of lignocellulosic biomass in the production of bioenergy is escalating with time due to the increase in energy demand and ecological pollution. The purpose of this study is to examine the opportunities of biofuel production from Pennisetum purpureum which is an invasive perennial grass in Brunei Darussalam. The proximate analysis of the study showed that the proportions of moisture content (MC), volatile matter (VM), fixed carbon (FC), and ash content (AC) were 5.93%, 69.44%, 16.81%, and 7.82%, respectively. Moreover, the ratios of carbon (C), hydrogen (H), nitrogen (N), sulfur (S), and oxygen (O) provided by the ultimate analysis were 43.23%, 5.80%, 1.17%, 0.11%, and 41.76%, respectively. The low moisture content and the higher heating value (18.55 MJ/kg) marked this grass as a potential source of biomass. Fourier transform infrared spectroscopy revealed the strong bonds between O–H, C–H, C–O, C=O, and C=C in the biomass. The thermogravimetric and their derivative results depicted that the highest weight losses occurred at a temperature of 334 °C with a degradation rate of 6.56 °C/min for pyrolysis condition and at a temperature of 312 °C with a degradation rate of 7.66 °C/min in combustion conditions.

Abstract Two biological methods for treatment of cheese whey and concentrated cheese whey were investigated in this research. As the first method, fermentation of cheese whey for production of lactic acid, in an immobilized cell reactor (ICR) was successfully carried out. The immobilisation of Lactobacillus bulgaricus was performed by the enriched cells cultured media harvested at exponential growth phase. Furthermore, the FTIR analysis has been done to prove the production of lactic acid. The COD removal during the continuous process for both whey and concentrated whey was above 70% which showed the capability of reaction for wastewater treatment. The cells were immobilised by sodium alginate as a perfect polymer in this regard. The maximum produced lactic acid from whey was 10.7 g l−1 at 0.125 h−1 and 19.5 g l−1 from concentrated whey at 0.063 h−1. Finally it can be concluded that the process is efficient for lactic acid production and COD removal simultaneously. As the second studied method, whey and concentrated cheese whey were used as the sources of carbon in a microbial fuel cell. The power densities of 188.8 and 288.12 mW m−2 were recorded for whey-fed and concentrated whey-fed MFCs while the COD removal were 95% and 86% respectively. Biological wastewater treatment can be a very efficient alternative for traditional wastewater treatment which selecting any and or integrating of them depends on specific applications needed to be achieved.

Energy consumption is rising dramatically at the price of depleting fossil fuel supplies and rising greenhouse gas emissions. To resolve this crisis, barley waste, which is hazardous for the environment and landfill, was studied through thermochemical characterization and pyrolysis to use it as a feedstock as a source of renewable energy. According to proximate analysis, the concentrations of ash, volatile matter, fixed carbon, and moisture were 5.43%, 73.41%, 18.15%, and 3.01%, consecutively. The ultimate analysis revealed that the composition included an acceptable H/C, O/C, and (N+O)/C atomic ratio, with the carbon, hydrogen, nitrogen, sulfur, and oxygen amounts being 46.04%, 6.84%, 3.895%, and 0.91%, respectively. The higher and lower heating values of 20.06 MJ/kg and 18.44 MJ/kg correspondingly demonstrate the appropriateness and promise for the generation of biofuel effectively. The results of the morphological study of biomass are promising for renewable energy sources. Using Fourier transform infrared spectroscopy, the main link between carbon, hydrogen, and oxygen was discovered, which is also important for bioenergy production. The maximum degradation rate was found by thermogravimetric analysis and derivative thermogravimetry to be 4.27% per minute for pyrolysis conditions at a temperature of 366 °C and 5.41% per minute for combustion conditions at a temperature of 298 °C. The maximum yields of biochar (38.57%), bio-oil (36.79%), and syngas (40.14%) in the pyrolysis procedure were obtained at 400, 500, and 600 °C, respectively. With the basic characterization and pyrolysis yields of the raw materials, it can be concluded that barley waste can be a valuable source of renewable energy. Further analysis of the pyrolyzed products is recommended to apply in the specific energy fields.

CSZM compounds were synthesized by dry chemistry route with 5, 10, and 15% dopant of Mg dopants in the Ce 0.8−2x Sm 0.2 Zrx Mgx O2−d, {x = 0.05, 0.1 & 0.15}. The newly investigated materials were physically, chemically, and electrochemically studied and have shown promising results. The CSZM was crystalized in a fluorite structure with a pure cubic phase in a space group Fm3m and cell parameter a = 5.401742 °A and theoretical density from 7.6 to 8.9 after firing in the air with a final temperature of 1400 °C. Characterization of the structure and indexing of electrolyte materials were made after X-ray diffraction (XRD) testing. A Scanning electron microscope (SEM) morphological analysis was used to examine the microstructure details. Electrochemical impedance spectroscopy (EIS) measurements were performed from 400 °C to 700 °C which show the highest conductivity value of 1.0461 × 10+1 S/cm at 700 °C. In comparison, the minimum value was 2.7329 × 10−2 S/cm at 400 °C, and the total activation energy (Ea°A) was found to be 0.6865 eV under 5% H2/Ar.

Conventional solid oxide fuel cells (SOFCs) are operable at high temperatures (700–1000 °C) with the most commonly used electrolyte, yttria‐stabilized zirconia (YSZ). SOFC research and development activities have thus been carried out to reduce the SOFC operating temperature. At intermediate temperatures (400–700 °C), barium cerate (BaCeO3) and barium zirconate (BaZrO3) are good candidates for use as proton‐conducting electrolytes due to their promising electrochemical characteristics. Herein, two widely studied proton‐conducting materials with two dopants are combined and an attractive composition for the investigation of electrochemical behaviors is discovered. Ba0.9Sr0.1Ce0.5Zr0.35Y0.1Sm0.05O3−δ (BSCZYSm), a perovskite‐type polycrystalline material, has shown very promising properties to be used as proton‐conducting electrolyte at intermediate temperature range. BSCZYSm shows a high proton conductivity of 4.167 × 10−3 S cm−1 in a wet argon atmosphere and peak power density of 581.7 mW cm−2 in Ni–BSCZYSm | BSCZYSm | BSCF cell arrangement at 700 °C, which is one of the highest in comparison with proton‐conducting electrolyte‐based fuel cells reported until now.

To evaluate the possibilities for biofuel and bioenergy production Acacia Holosericea, which is an invasive plant available in Brunei Darussalam, was investigated. Proximate analysis of Acacia Holosericea shows that the moisture content, volatile matters, fixed carbon, and ash contents were 9.56%, 65.12%, 21.21%, and 3.91%, respectively. Ultimate analysis shows carbon, hydrogen, and nitrogen as 44.03%, 5.67%, and 0.25%, respectively. The thermogravimetric analysis (TGA) results have shown that maximum weight loss occurred for this biomass at 357 °C for pyrolysis and 287 °C for combustion conditions. Low moisture content (<10%), high hydrogen content, and higher heating value (about 18.13 MJ/kg) makes this species a potential biomass. The production of bio-char, bio-oil, and biogas from Acacia Holosericea was found 34.45%, 32.56%, 33.09% for 500 °C with a heating rate 5 °C/min and 25.81%, 37.61%, 36.58% with a heating rate 10 °C/min, respectively, in this research. From Fourier transform infrared (FTIR) spectroscopy it was shown that a strong C–H, C–O, and C=C bond exists in the bio-char of the sample.