• Energy Research
• engineering and technology close
• 2. Zero hunger close
• EG close

In this study two tasks were accomplished. First, a modified simple purification and collection lab system is described for CO2-free bio-hydrogen production. Second, the efficiency of hydrogen production was investigated by mixed dark and photo-fermentative hydrogen producing bacteria Escherichia coli, Clostridium acetobutylicum, Rhodobacter capsulatus and Rhodobacter sphaeroides from sorghum grains crude starch. The crude starch of white sorghum grains showed a higher potency as a carbon source for fermentative hydrogen production than that of red sorghum grains although both varieties are quite applicable for industrial scale hydrogen production. Using mixed R. capsulatus and R. sphaeroides showed a higher efficiency for hydrogen production than using each alone in the combined dark and photo-fermentation due to their varying efficiencies of converting various volatile fatty acids produced by dark fermentation into hydrogen gas. For enhanced hydrogen production, this study suggests using mixed strains of non-oxygenic photosynthetic purple non-sulfur bacteria in the combined dark and photo-fermentation. The high efficiency of hydrogen production from sorghum starch suggests that using this cheap crop in future industrial application of biological H2 production would increase its economic feasibility in developing countries of arid climate where sorghum is no longer widely used as human food.

Abstract In rural Egypt, communities face multiple challenges such as insufficient infrastructures for waste treatment, limited access to cheap energy and poor soils fertility. A decentralized, low-tech biogas technology for combined waste treatment and energy production, anaerobic digestion can achieve many sustainable development goals and resolve many issues faced by rural communities, treating and stabilizing organic waste into high-quality biofertilizer. Household biogas units for rural communities, however, should be subjected to techno-economic assessment to confirm their feasibility and technical efficiency. Therefore, this paper conducted: (1) survey of household biogas units and agricultural crop residues in rural communities in Egypt, (2) technical study of household biogas units, and (3) financial economic study. The results can be summarized as follows: (1) complete set of technical data on biogas units were documented, (2) crop residues were mapped using GIS software, (3) financial feasibility results were discussed. The total revenues were 1716.01, 2574.02, 3432.02, and 5148.04 EUR for the household biogas unit with the capacity of 2, 3, 4, and 6 m3, respectively. It was concluded that the units available in rural Egypt are considered as profitable projects from the profitability perspectives, and the values of the profitability indicators increased as the unit size increased.

Abstract The conventional cell of the indented cylinder separator gives poor length grading of agricultural grains. A systematic study was conducted to establish the optimum parameters of the cell design. A new cell was developed which showed a better separation effectiveness in the case of beans, when compared with the conventional cell.

Abstract Hernad Valley is one of the most underdeveloped areas of Hungary in social, infrastructural and economic aspects. At the same time, there are significant reserves regarding the bio-energy sector, energy investments and local raw material production. The biomass potential of the underdeveloped areas is tremendous (125,000 t/year, its energy value 25–28 M EUR/year), but quite difficult to exploit since the implementation of efficient energetic procedures is made very difficult by the indifference or resistance of the local population or the lack of capital (either on the part of the local authorities or the investors) which would be necessary to finance the improvements. During our three-year-long research, we collected the most significant social, economic and fitomass production data of the examined settlements based on statistical resources and our own personal research. Based on the size and location of biomass data, we recommended sample projects which most probably could be operated economically, could produce the highest added value and could retain most of the produced value in the area. Based on a statistically reliable amount of data, we present the awareness and acceptance of the biomass energetic procedures and how much these factors would affect the implementation of the recommended projects.

Monthly rainfall data for Blue Nile Basin (BNB) were obtained from the Ethiopian Meteorological Authority (1950–2018). Long-term trends in the BNB annual and monthly rainfall are investigated in this study. The challenges of the paper were to explore the impact of climate change on the study area using sound practical methods. The paper used the widely used statistical methods to find precisely the significance of the impact of climate change rainfall variability and distribution both spatially and temporally in the BNB. The statistical significance of the trend in the study is calculated by the Mann-Kendall (MK) test. Data were analyzed using the coefficient of variation, anomaly index, and precipitation concentration index. The coefficient of variation is high in Kiremt rainfall which implies more inter-annual variability of Bega rainfall than Kiremt (Coefficient of Variation (CV): Bega˃ Belg˃ Kiremt season). Based on Precipitation Concentration Index (PCI) value, the number of moderate concentration years (89.9%) has been increasing through time and the study area has encountered successive years of drought. The results showed that the annual, Bega, Belg, and Kiremt precipitation over the whole of BNB is significantly decreasing except Bega season with a magnitude of 36.38, 3.8, 7.8, and 24.7 mm per decade respectively. The rainfall in the study area is characterized by a high CV. Moreover, prolonged droughts have become common which adversely affects the agricultural system. It was also found that very low values of rainfall anomalies that correspond to severe droughts were associated with El Niño Southern Oscillation (ENSO) events.

Abstract Electrical conductivity has a vital role in food industries through heating operations. So, this paper focused on the temperature-dependent electrical conductivity and Joule heating effects on the boundary layer flow of micropolar fluid. Activation energy, microstructural/multiple slips, and thermal radiation effects are considered. Appropriate similarity variables convert the resulting system of partial differential equations (PDEs) to a model of highly non-linear ordinary differential equations (ODEs). Semi-analytical results are obtained using a highly accurate/trusted technique called the Shooting technique. Accuracy of obtained results is approved/confirmed semi-analytically with recently published results by Dawar 2021 using the generalized differential transform method GDTM by Mathematica 13.1.1. Results show that the temperature-dependent electrical conductivity parameter raises the fluid temperature, and more energy is gained in the heating operation system, which is significant in the design of Ohmic heaters (food industry processes).

A novel technology for co-production of xylooligosaccharides (XOS) and glucose from Monterey pine sawdust and wheat straw was introduced using dilute acid (DA)/pentanol pretreatment. Effects of pretreatment severity (PS), lignin removal, and inhibitors with byproduct concentrations on XOS production were investigated. Optimal identified conditions (PS: 3.71; 170 °C, 45 min) resulted in maximum XOS of 48.65 % (pine sawdust) and 46.85 % (wheat straw), due to appropriate lignin removal (pine sawdust, 88.5 %; wheat straw, 89.7 %) and formation of small amounts of inhibitors and byproducts. Enzymatic hydrolysis of optimal pretreated solid residues yielded 88.65 % and 93.34 % glucose in pine sawdust and wheat straw, respectively. Biomass characterization revealed that DA/pentanol pretreatment enhanced porosity and pore size along with removal of amorphous fractions in both samples, thereby increasing cellulose accessibility and glucose yield. This study demonstrated lignin removal and low formation of inhibitors and byproducts, effectively enhancing XOS and glucose production from lignocellulosic biomass.

AbstractFreshwater resources in the arid Arabian Peninsula, especially transboundary aquifers shared by Saudi Arabia, Jordan, and Iraq, are of critical environmental and geopolitical significance. Monthly Gravity Recovery and Climate Experiment (GRACE) satellite‐derived gravity field solutions acquired over the expansive Saq transboundary aquifer system were analysed and spatiotemporally correlated with relevant land surface model outputs, remote sensing observations, and field data to quantify temporal variations in regional water resources and to identify the controlling factors affecting these resources. Our results show substantial GRACE‐derived terrestrial water storage (TWS) and groundwater storage (GWS) depletion rates of −9.05 ± 0.25 mm/year (−4.84 ± 0.13 km3/year) and −6.52 ± 0.29 mm/year (−3.49 ± 0.15 km3/year), respectively. The rapid decline is attributed to both climatic and anthropogenic factors; observed TWS depletion is partially related to a decline in regional rainfall, while GWS depletions are highly correlated with increasing groundwater extraction for irrigation and observed water level declines in regional supply wells.

The increasing demand for freshwater supplies and the effects of climate change in arid and hyper-arid regions are pushing governments to explore new water resources for food security assurance. Groundwater is one of the most valuable water resources in these regions, which are facing water scarcity due to climatic conditions and limited rainfall. In this manuscript, we provide an integrated approach of remote sensing, geographic information systems, and analytical hierarchical process (AHP) to identify the groundwater potential zone in the central Eastern Desert, Egypt. A knowledge-driven GIS-technique-based method for distinguishing groundwater potential zones used multi-criteria decision analysis and AHP. Ten factors influencing groundwater were considered in this study, including elevation, slope steepness, rainfall, drainage density, lineament density, the distance from major fractures, land use/land cover, lithology, soil type, and the distance from the channel network. Three classes of groundwater prospective zones were identified, namely good potential (3.5%), moderate potential (7.8%), and poor potential (88.6%) zones. Well data from the study area were used to cross-validate the results with 82.5% accuracy. During the last 8 years, the static water level of the Quaternary alluvium aquifer greatly decreased (14 m) due to excessive over pumping in the El-Dir area, with no recorded recharges reaching this site. Since 1997, there has been a noticeable decline in major rainfall storms as a result of climate change. The current study introduces a cost-effective multidisciplinary approach to exploring groundwater resources, especially in arid environments. Moreover, a significant modern recharge for shallow groundwater aquifers is taking place, even in hyper-arid conditions.