The enhancement in methane production under cold climates is one of the essential prerequisites to enable year-round performance improvement of any biogas plant. In Egypt, the winter is reasonably cold which offers a good opportunity to study the enhancement in the methane yield and corresponding performance improvement of a family-scale biogas digester using the co-digestion technique. This work reports the field performance of floating-dome type biogas digester using anaerobic co-digestion (AcoD) of cattle manure (CM) with a milled corn stover (CS). The performance of AcoD is compared with the performance of anaerobic mono-digestion (AmoD) of CM under winter conditions. Moreover, a numerical method for preparing the digested slurry is def

Thermal energy storage devices are vital for reducing the inconsistency between energy supply and demand as well as for enhancing the performance of solar thermal systems. The present study investigates the melting process in metallic honeycombed heat exchangers filled with n-octadacane as phase change material (PCM). Further, a parametric study is conducted for four different honeycomb cell sizes, fin thicknesses, and angles of inclinations of the computational domain. The findings are described in the form of heated surface average temperature variation, melt fraction of the PCM, and thermal energy stored. Results show that the honeycomb fin structure considerably improves the heat transfer in the PCM. Further, it was observed that the ho

There are increasing concerns and growing regulations over contamination and environmental pollution. One of the major concerns is the pollution caused by mineral oils. As the world oil reserves are dwindling the pressures for finding alternative replacements are increasing. Vegetable oils are a biodegradable and renewable source of lubricants. Thus, they seem to be attractive candidates for the replacement of mineral oils. In this study, chemical modification of sunflower waste cooking oil through epoxidation reaction was used to improve its physicochemical properties to be used as biolubricant. Then, using the response surface method (RSM), the reaction yield was statistically modeled as a quadratic regression equation and optimal points

The performance of a developed brackish water reverse osmosis (BWRO) desalination unit integrated with a stand-alone hybrid photovoltaic-thermal (PVT) module was evaluated under the climatic conditions of Tehran (35.68? N latitude 51.42? E longitude). From the experimental results, the maximum surface temperature of the PV module and thermal efficiency of the PVT module were recorded as 60.38 ?C and 83.7%, respectively at the set-point temperature of 50.00 ?C for the thermostat, and under the average solar radiation of 971.34 W/m2. During the evaluation, the maximum average productivity of the BWRO unit was obtained as 13.98 L/h when temperature values of the PV module, soft water, and brackish feed water (BFW) were recorded as 52.94 ?C, 28