A. Hamdy

The Optimization of Biodiesel Production from Waste Frying Corn Oil Using Snails Shells as a Catalyst

In this study, calcium oxide as a heterogeneous catalyst for biodiesel production was prepared by a simple calcination process at 800°C for snails shells collected from Egyptian shorelines. D-optimal design of experiments and response surface methodology was applied to analyze the influence of four process variables; methanol:oil (M:O) molar ratio, catalyst concentration (wt%), reaction time (min), and mixing rate (rpm) on biodiesel production through transesterification of waste frying corn oil at 60°C using the prepared biocatalyst. A second order quadratic model was obtained to predict the % biodiesel yield and it adequately described the studied experimental range. Based on the experimental analysis and response surface methodology study, the most suitable operational conditions for this process were: M:O, 6:1 molar ratio; catalyst concentration, 3 wt%; reaction time, 60 min; and mixing rate, 200 rpm. The corresponding predicted % yield of biodiesel was 96.76% and the experimental one was 96%. The activity of the produced green catalyst was comparable to that of chemical CaO and immobilized enzyme Novozym 435.

Application of D-optimal Design and RSM to Optimize the Transesterification of Waste Cooking Oil Using a Biocatalyst Derived from Waste Animal Bones and Novozym 435

This study was performed to investigate the applicability of the basic heterogeneous fluorapatite catalyst prepared from waste animal bones in the transesterification of waste cooking oil with methanol for production of biodiesel. Response surface methodology based on D-optimal design of experiments was employed to study the significance and interactive effect of methanol to oil (M:O) molar ratio, catalyst concentration, reaction time, and mixing rate on biodiesel yield using the prepared fluorapatite and Novozym 435. Quadratic model equations were obtained describing the interrelationships between dependent and independent variables to maximize the response variable (biodiesel yield) and the validity of the predicted models were confirmed. The optimum combination for transesterification were determined to be 7.35:1 and 6:1 M:O, 4.35 and 8.8 catalyst wt%, 91 and 96 min, and 331 and 394 rpm at 60°C, for prepared fluorapatite and Novozym 435, respectively, with maximum biodiesel yield of ≈ 96 and 62%, respectively. Fuel properties of the produced biodiesel and its blends with petro-diesel were measured and compared with those of Egyptian petro-diesel and international biodiesel standards. Acceptable agreement was observed, encouraging application of fluorapatite prepared from waste animal bones for production of biodiesel as an alternative or complementary to petro-diesel.

Recycling of some domestic wastes to produce green corrosion inhibitors and biocides for sulfate reducing bacteria

ABSTRACT Egypt suffers from a huge amount of domestic wastes which causes a lot of economic and environmental problems. This work investigated the possibility of recycling of some of these wastes into green corrosion inhibitors and biocides. The studied aqueous extracts of outer brown peels of onion (A), outer peels of garlic (B), orange (C), and mandarin (D) peels reduced markedly the corrosion rate of carbon steel alloy in 1.0 M HCl and behaved as mixed inhibitors. The inhibition efficiency decreased in the following order: C > B > A > D and generally increased with the increase of the extract concentration. The inhibition mechanism and adsorption isotherms were discussed to describe the adsorption characteristics of the extracts on the carbon steel surface. The extracts of orange and mandarin peels expressed biocidal effect on sulfate reducing bacteria (SRB). However, those of onion and garlic peels did not express any biocidal activity against SRB.

An Investigation of Biodiesel Production from Wastes of Seafood Restaurants

This work illustrates a comparative study on the applicability of the basic heterogeneous calcium oxide catalyst prepared from waste mollusks and crabs shells (MS and CS, resp.) in the transesterification of waste cooking oil collected from seafood restaurants with methanol for production of biodiesel. Response surface methodology RSM based on D-optimal deign of experiments was employed to study the significance and interactive effect of methanol to oil M : O molar ratio, catalyst concentration, reaction time, and mixing rate on biodiesel yield. Second-order quadratic model equations were obtained describing the interrelationships between dependent and independent variables to maximize the response variable (biodiesel yield) and the validity of the predicted models were confirmed. The activity of the produced green catalysts was better than that of chemical CaO and immobilized enzyme Novozym 435. Fuel properties of the produced biodiesel were measured and compared with those of Egyptian petro-diesel and international biodiesel standards. The biodiesel produced using MS-CaO recorded higher quality than that produced using CS-CaO. The overall biodiesel characteristics were acceptable, encouraging application of CaO prepared from waste MS and CS for production of biodiesel as an efficient, environmentally friendly, sustainable, and low cost heterogeneous catalyst.

Characterization and antimicrobial activity of silver nanoparticles mycosynthesized by Aspergillus brasiliensis

Since mycosynthesis of metal nanoparticles (NPs) is advertised as a promising and ecofriendly approach. Thus, this study aims to investigate the capability of Aspergillus brasiliensis ATCC 16404 for mycosynthesis of silver NPs (AgNPs).

Physiochemical properties of Trichoderma longibrachiatumDSMZ 16517-synthesized silver nanoparticles for the mitigation of halotolerant sulphate-reducing bacteria

In order to efficiently control the corrosive sulphate‐reducing bacteria (SRB), the main precursor of the microbial influenced corrosion (MIC) in oil industry, the ability of Trichoderma longibrachiatumDSMZ 16517 to synthesize silver nanoparticles (AgNPs) was investigated and their biocidal activity against halotolerant SRB was tested.

Waste upcycling of Citrus sinensis peels as a green route for the synthesis of silver nanoparticles

ABSTRACT The present study reports a rapid one-step green synthesis of silver nanoparticles (AgNPs) using hot water extract of Citrus sinensis (sweet orange) peels. A visible color change was observed from faint yellow to brown, upon the bioreduction of silver nitrate with peels’ extract and then the stabilization of the synthesized AgNPs. The UV–Vis spectrophotometric analysis proved the characteristic absorption peak λmax 422 nm of AgNPs. The one-factor-at-a-time-optimization technique was used to study the effect of the key factors governing the synthesis of AgNPs, including temperature, illumination, pH, different concentrations of peels’ extract and silver nitrate, mixing rates, and reaction time. The average particles size was measured by dynamic light scattering (DLS) and revealed 23.81 nm. The zeta potential value of −20.3 mV proved the stability of the synthesized AgNPs. Energy-dispersive X-ray (EDX) confirmed the strong signals for elemental silver. The X-ray diffraction confirmed the crystalline nature of the biosynthesized AgNPs with an average size of 15 nm. Fourier transform infrared (FTIR) spectroscopy identified the possible functional groups involved in capping and efficient stabilization of the synthesized AgNPs. Field emission scanning electron microscope (FESEM) and high-resolution transmission electron microscope (HRTEM) revealed the spherical-shaped AgNPs with an average size of 3–12 nm.

Thermal and surface studies on the corrosion inhibition of petroleum pipeline by aqueous extract of Allium cepa skin under acidic condition

ABSTRACT In this study, the temperature effect on the inhibitory action of the cheap, eco-friendly and sustainable hot water extract of onion skin (HWEOS) on the corrosion of C-steel petroleum pipeline in 1 M hydrochloric acid solution was investigated using weight loss technique. Generally, the inhibition was found to increase with inhibitor concentration but decreased with the increase in temperature. The presence of protective inhibitor film on metal surface was confirmed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The thermodynamic activation parameters were evaluated, suggesting a physical adsorption, the corrosion process was suggested to be a unimolecular reaction, the enthalpies reflected the endothermic nature of the steel dissolution process. Large and negative values of entropies showed that the activated complex in the rate determining step represented an association rather than a dissociation step. HWEOS adsorbed on the metal surface according to the Langmuir isotherm at all the studied temperatures. The compounds responsible for the inhibitory action of HWEOS were proved to be flavonoids including quercetin and a suggested mechanism of corrosion inhibition was elucidated.