This study aimed to investigate the role of nano graphene dispersion on the rate of evaporation of saline water to save energy consumption during thermal desalination. The effect of various operating conditions including: current density, sulfuric acid concentration, electrolysis time and temperature were studied to optimize graphite dissolution. The produced nano graphene particles were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-Ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The TEM-photographs proved that; the particles of nano graphene are spherical with diameter ranged from 10 to 41 nm. Increasing current density from 100 to 150 mA/cm2 at cell voltage 0.3 V and 60min. electrolysis time, increases graphite dissolution by 32%. From the results, it is clear that the selected dose for saving maximum energy was 10 g/l. This study indicates that graphene is one of the best nano material that can maximize the heat transfer efficiency.

Graphene derivatives revolutionize a lot of industries since its discovery. In this investigation nano graphene oxide (NGOCB) was synthesized via sulfuric acid dehydration by mixing of sugar (as source of carbon) with bentonite clay as substrate. NGOCB was characterized by using scaning electron microscope, transmission electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy and scattered area electronic diffraction analysis. The experimental results showed that the particles of graphene oxide are spherical in shape and the diameter ranged from 6 to 33 nm. The data indicated the presence of graphene oxide mono-layers with hexagonal pattern over the bentonite substrate surfaces. On applying the obtained NGOCB in thermal desalination process, several findings were observed such as saving the energy required for reaching the boiling temperature from room temperature by 11% (NGOCB 4 g/l). While on using 10 g/l of NGOCB more than 50% of the energy consumption for evaporation was saved. Also the generated desalinated water quantity obtained using nano graphene oxide was more than double the quantity that obtained by the traditional thermal desalination method. The generated steam was applied for electricity generation by mini steam turbine, which leads to 22% energy saving.

Background The nano-adsorbents present considerable decontamination potential due to their unique characteristics. This study aimed to investigate the adsorption efficiency and capacity of synthesized nano graphene oxide coated layer over Egyptian clays (bentonite, kaolinite and feldspar) as substrate. The experimental work involves nano graphene oxide coating using acid dehydration via sulfuric acid in presence of different percentage of sugar (fine powder from 1 to 7%), followed by thermal activation to improve the adsorption capacity of natural clay that is locally available in Egypt. Several operating parameters were studied to prepare the superior adsorbent (type of substrate, sulfuric acid concentration, sugar concentration and contact time). Results The optimum preparation conditions of nano graphene oxide coated bentonite (NGOCB) adsorbent were bentonite substrate 1 kg, sulfuric acid concentration 1.5 kg/kg clay, sugar fine powder 50 g/kg clay, water 3000 ml/kg clay, and stirring time of 30 min at 100 °C. The morphology characterization showed that the deposited graphene oxide layer is in the nano form (6 to 33 nm). Sets of experiments were conducted to evaluate the adsorption performance of synthesized NGOCB for removal of methylene blue (MB) dye from aqueous solutions. Effect of initial dye concentration, contact time, pH and temperature on the adsorption capacity of the modified adsorbent were studied. The capacity of the prepared nano graphene oxide coated bentonite adsorbent was 1000 mg/g. Conclusions The removal efficiency of nano graphene coated clay reached to 99.9% that indicates the Egyptian bentonite could be employed as a low-cost absorbent for dye removal.

Today, a huge volume of jet fuel is consumed through air transportation. Petroleum-based jet fuels, including Jet A-1, produce considerable amount of particulate and gaseous pollutions which affect the world climate change. To overcome these pollutions, portion of jet fuel should be replaced by jet biofuels. This can be achieved by blending Jet A with efficient energy source with lowest emission such as biofuels from vegetable oils. Biodiesel from palm, Jatropha curcas, and waste cooking oils show promising potential in producing aviation biofuels when blending with Jet A. Various volumetric ratios of biodiesel (5–25%) were blended with high-grade kerosene. The binary blends of jet biofuels were characterized and compared with Jet A fuels. The comparison indicated that biofuels with 5% ester content have almost similar characteristics with Jet A aviation. The physicochemical properties of 5% binary blends of palm, Jatropha curcas, and waste cooking oils were kinematic viscosity (at −20 °C) of 8.6, 5.1, and 5.1; high heating value (HHV) around 43 Mj/kg and freezing point of −14.5, −15.5, and −25.5 °C for binary blends of the biodiesel from the three types of oils with Jet A, respectively. Additives may be added to binary blends to reach exact Jet A physicochemical characteristics. The yield %│C8–C15 were determined for the 5% ester content for each binary blends using GC-mass spectrometry.

In the production of biodiesel from vegetable oils, separation and purification of biodiesel and glycerol as a by-product are critical processes. Conventional methods used for this separation are gravitational settling, decantation and filtration. Biodiesel and glycerol were produced through transesterification of jatropha curcas oil (JCO) using; KOH as a liquid base catalyst and CaO as a solid super base catalyst respectively with methanol. Reducing free fatty acids for (JCO) by esterification was studied. Biodiesel purification is performed by washing using water and acids. Fuel properties of produced fatty acids methyl esters (biodiesel) including; density, viscosity, flash point, cetane number, acid value and iodine value were qualified. The results showed that; the produced biodiesel can safely be used as an alternative diesel fuel. The use of solid base catalyst (CaO) showed a great improvement in produced glycerol purity up to 99.46%. A comparison between homogeneous and heterogeneous reaction conditions and products' purity are presented. Key words— Biodiesel, Jatropha curcas, homogeneous, Vegetable oils pretreatment, Glycerol separation,Decalcification, Glycerol purification. ——————————  ——————————

This investigation reports the reduction of silver ions to silver nano-particles as a rapid single step green process using Jatropha seeds extract, which is successfully reducing and stabilizing agent. In this study, silver nano-particles were synthesized from silver nitrate solution using locally prepared aqueous extract from crushed dry jatropha seeds. Effect of various operating conditions including pH, heating and the ratio between AgNO3 and aqueous extract Jatropha-curcas seeds were examined and confirmed by the ultra violet-visible spectra (UV-VIS) which gave surface plasma resonance for silver nano-particles at 430 nm. The produced nano silver was characterized by transmission electron microscope (TEM) and Scattered area electronic diffraction (SAED) which revealed that the produced nano-particles are of spherical shape within size range (20-50) nm. Higher conversion of nano silver particles was achieved at pH approximate to 10.6 and in absence of heat which was confirmed by UV-VIS spectra.

Bio–oil from spirulina sp. is complicated mixture with valued chemicals. The hydrothermal liquefaction (HTL) converts directly the spirulina microalgae into liquid oil at reaction temperature 300°C with heating rate 10°C /min,100 bars pressure and 30 min. reaction time eight different organic solvents with different polarities were applied to extract the bio – oil from these chemicals. The order of bio–oil extraction yield of the eight solvents from high to low were as follow tetrahydrofuran (THF) ˃ dichloromethane (DCM) ˃ acetone (ACE) ˃ chloroform (CHL) ˃ methanol (MeOH)˃ ethyl-acetate (EAC) ˃ hexane (HEX) ˃toluene (TOL).The results obtained from single stage extraction process showed that maximum percentage oil yield was (26.55%). with rather high heating value (HHV ≈ 30 MJ/kg). The combination of THF, EAC and n-hexane was selected to extract and separate the bio – oil into three fraction heavy oil (48.9%) mid weight oil (37.8%) and light oil (62.2%). These three oils were characterized using gas chromatography mass spectrum (GC – mass). Keywords:- Bio–oil , extractives, hydrothermal , liquefaction, micro- algae.

In this study biocrude oil with H/C ratio resembling that of petroleum crude oil was produced via hydrothermal liquefaction of wet Spirulina platensis under subcritical water conditions. Factorial design and response surface methodology were used in synthesis of bio-crude oil. The experimental design was performed to study the effect of the variables (time &temperature) on the process and interaction among variables, while the response was the % yield by weight of produced bio-fuel. It was found that the model agreed well with the experimental data. The higher heating value of the bio -crude oil was estimated to be about 35.77MJ kg-1.The elemental composition of the liquefied Spirulina platensis was comparable to that of petroleum crude oil with the exception of the oxygen and nitrogen content being higher in the bio-oil. Thus upgrading of the liquefied micro algae especially deoxygenating and denitrogenating is necessary.

This paper presents a statistical technique to characterize the biodiesel production process from Jatropha seeds and predict the conversion efficiency of the oil into biodiesel. A multivariate regression model is proposed herein to simultaneously capture the joint effect of the variable operating conditions. It is a general technique and can be used with different production methods, but this paper uses experimental results of the in-situ heterogeneous extraction and transesterification process. The results imply the success of the introduced technique to assess how much the operating variables affect the conversion. Also, the joint effect of the time, catalyst dose, methanol to oil ratio, and hexane to oil ratio has been defined. Experimental measurements have been used to perform this analysis. A linear multiple regression model with coefficient of determination (R-2) of 0.999 has been developed whereby the four investigated operation variables are related with the conversion into biodiesel has been developed. Hence, utilizing the coefficients of the developed model have been used to rank their significance, which is the most important variable and to what extent. Accordingly the most important factors are the time and the hexane ratio.

Integrated extraction and transesterification process for biodiesel production from Jatropha Curcas (JCL) seeds using hexane and methanol via base catalyzed transesterification is reported in this paper. The effects of reaction time, catalyst dose, liquid to solid ratio, type of solvent and grain size of JCL seeds on biodiesel production were investigated. It was found that hexane played the role of both co - solvent and co - extractant which enhanced the efficiency of oil extraction and facilitated mass transfer. The highest biodiesel yield (90.8%) was obtained at hexane to seed ratio of 5:1 (vol / wt), methanol to seed ratio 1:1 (vol /wt), activated Ca O of 1% by wt of seeds, stirring speed 700 rpm, temperature of 70 degrees C at reaction time 6 hours.

Transesterification of jatropha curcas oil (JCO) with high acidity (8.4%),using methanol over sulfated zirconia as heterogeneous acid catalyst was investigated. Sulfated zirconia was directly synthesized by solvent – free method (S-ZrO2) at 600°C for 5 h, and characterized by various physicochemical techniques. The surface areas and pore volume were 9.71716 m 2 /g and 5.20631x 10 -3 cm 3 /g respectively. This catalyst exhibits excellent activity in esterification / transesterification of (JCO). The alcoholysis conversion of JCO under optimized conditions (65°C,16 h , 1:40 MR oil to methanol and 12.5% wt of catalyst) was 92 .33%.While under subcritical methanolysis (200°C, 21 bars) was 95.6% after 1h. Generally oils containing high level of FFA cannot be directly esterified using base catalysts currently employed. Kinetic data on the transesterification reaction were achieved by conducting the reaction at various reaction times, catalyst dose and molar ratio. The experimental data was interpreted with a 1 st order reaction. The reaction was represented fairly well by pseudo homogeneous 1 st order reaction and the kinetic parameters were obtained. A good agreement between the experimental data and the model were observed.

Fatty acid methyl ester (biodiesel) has been identified as biodiesel alternative fuel obtained from renewable sources. Efforts in Egypt are directed toward the development of new non-edible sources. At the forefront of these non-edible sources comes Jatropha curcas oil (JCO) because it has been grown successfully in Egypt using primary treated municipal wastewater for irrigation. Based on previous research findings for the production of biodiesel from (JCO) using heterogeneous catalyst, some kinetic data on the transesterification reaction were provided. This was achieved by conducting the reaction at various temperatures, reaction time, and dose of catalyst and reactant molar ratios. The transesterification reaction was observed with regard to the percent biodiesel yield versus time and the reaction order was found to be a first order reaction rate equation. Techno-economic indicators revealed that the price of biodiesel produced by heterogeneous base catalyzed method was $0.665/L with a gross profit per year of $37,403,643.

Transesterification of Jatropha curcas oil (JCO) to biodiesel using Ca O as a solid base catalyst is studied. Effect of molar ratio of methanol to oil, water content, reaction time and mass ratio of catalyst to oil are investigated on bench scale. Experimental results revealed that a 12:1 molar ratio of methanol to oil, addition of 1.5% (w/v) Ca O catalyst , 70oC reaction temperature, 2% water content in the oil produced more than 95% biodiesel yield after 3 hours reaction time. Calcium oxide activated with ammonium carbonate was an efficient super base catalyst for a high yield transesterification reaction and the base strength of Ca O was more than 26.5 after dipping in ammonium carbonate solution followed by calcinations. Transesterification of Jatropha oil using supercritical methanol has been studied under different conditions of temperature (from 120oC to 250oC), pressures (from 5- 37 bars) using superbase catalyst Ca O and acid catalyst. The reaction products were analyzed for their content of glycerol by high performance liquid chromatography (HPLC)which indicated that the process of supercritical transesterification achieved a yield of more than 95% after 1 hour.