scholarly journals Spectroscopic Analysis of Heterogeneous Biocatalysts for Biodiesel Production from Expired Sunflower Cooking Oil

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Enoch Wembabazi ◽  
Patrick Joram Mugisha ◽  
Asumani Ratibu ◽  
Deborah Wendiro ◽  
Joseph Kyambadde ◽  
...  
Keyword(s):  
Calcium Oxide ◽  
Sunflower Oil ◽  
Active Form ◽  
Single Step ◽  
Biodiesel Production ◽  
Saw Dust ◽  
Heterogeneous Biocatalysts ◽  
Egg Shells ◽  
Heterogeneous Biocatalyst

The study characterized heterogeneous biocatalyst synthesized from sucrose, saw dust, and chicken egg shells using Fourier Transform Infrared (FTIR) spectroscopy coupled with Attenuated Total Reflectance (ATR) technique. Acidic sulphonate (–SO3H) groups were more visible in the spectrum generated for carbonized and sulphonated sucrose than in carbonized and sulphonated saw dust. This was highlighted further by the significantly higher conversion percentage achieved for sulphonated sucrose (62.5%) than sulphonated saw dust (46.6%) during esterification of expired sunflower oil (p=0.05). The spectra for calcinated egg shells also showed that the most active form of calcium oxide was produced at calcination temperature of 1000°C. This was confirmed in the single-step transesterification reaction in which calcium oxide generated at 1000°C yielded the highest biodiesel (87.8%) from expired sunflower oil. The study further demonstrated the versatility of the FTIR technique in qualitative analysis of biodiesel and regular diesel by confirming the presence of specific characteristic peaks of diagnostic importance. These findings therefore highlight the potential of FTIR-ATR as an inexpensive, fast, and accurate diagnostic means for easy identification and characterization of different materials and products.

Characterization of calcium oxide catalysts from natural sources and their application in the transesterification of sunflower oil

2014 ◽  
Vol 151 ◽  
pp. 207-213 ◽  
Author(s):  
Leandro Marques Correia ◽  
Rosana Maria Alves Saboya ◽  
Natália de Sousa Campelo ◽  
Juan Antonio Cecilia ◽  
Enrique Rodríguez-Castellón ◽  
...  
Keyword(s):  
Calcium Oxide ◽  
Sunflower Oil ◽  
Oxide Catalysts ◽  
Natural Sources

scholarly journals Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable Oil

2020 ◽  
Vol 10 (9) ◽  
pp. 3153 ◽  
Author(s):  
Samya Elias ◽  
Ademola M Rabiu ◽  
Benjamin I Okeleye ◽  
Vincent Okudoh ◽  
Oluwaseun Oyekola
Keyword(s):  
Heterogeneous Catalyst ◽  
Calcium Oxide ◽  
Vegetable Oil ◽  
Palm Oil ◽  
Sunflower Oil ◽  
Biodiesel Production ◽  
High Yield ◽  
Catalyst Characterization ◽  
High Concentration ◽  
Waste Vegetable Oil

Bifunctional solid catalysts facilitate the esterification of free fatty acids (FFA) into alkyl esters alongside the transesterification reaction, which allows for the use of waste vegetable oils with high water and FFA contents for biodiesel production. This makes the process economically viable and greener, as the waste fats and oils are readily available. The concurrent esterification and transesterification of waste palm oil (WPO) and waste sunflower oil (WSO) with methanol was investigated in the presence of calcium oxide on alumina catalyst in a conventional batch process. The catalyst characterization showed the existence of calcium oxide aluminates (calcined at 750 °C), which exhibited crystalline phases with porous/spongy-like particles. The high concentration of CaO in CaO/Al2O3 was a favorable support material in the heterogeneously-catalyzed transesterification reactions. The optimum catalyst parameters for the production of fatty acid methyl esters (FAMEs) were observed at 65 °C for 4 h with a methanol-to-oil ratio of 9:1, 60% (waste palm oil, or WPO) and 80% (waste sunflower oil, or WSO), CaO/Al2O3 (% wt/wt) catalyst ratio as well as 4% CaO/Al2O3 concentration (% wt.) for WSO and WPO. The simultaneous esterification/transesterification reactions at optimum conditions on WPO and WSO led to high yield of FAMEs of 89, 61 and 55% for WPO and 54, 75 and 98% for WSO at catalyst ratios (wt %) of 60, 70 and 80% respectively. The use of bifunctional heterogeneous catalyst (CaO/Al2O3) with waste vegetable oil can result in high performance and the upscaling of biodiesel production.

scholarly journals Immobilization Screening and Characterization of an Alcohol Dehydrogenase and its Application to the Multi-Enzymatic Selective Oxidation of 1,-Omega-Diols

2021 ◽  
Vol 1 ◽  
Author(s):  
Javier Santiago-Arcos ◽  
Susana Velasco-Lozano ◽  
Eleftheria Diamanti ◽  
Aitziber L. Cortajarena ◽  
Fernando López-Gallego
Keyword(s):  
Alcohol Dehydrogenase ◽  
Nadh Oxidase ◽  
Specific Activity ◽  
Enzyme Stability ◽  
Enzyme System ◽  
Life Time ◽  
Immobilized Enzymes ◽  
Heterogeneous Biocatalysts ◽  
Heterogeneous Biocatalyst

Alcohol dehydrogenase from Bacillus (Geobacillus) stearothermophilus (BsADH) is a NADH-dependent enzyme catalyzing the oxidation of alcohols, however its thermal and operational stabilities are too low for its long-term use under non-physiological conditions. Enzyme immobilizations emerges as an attractive tool to enhance the stability of this enzyme. In this work, we have screened a battery of porous carriers and immobilization chemistries to enhance the robustness of a His-tagged variant of BsADH. The selected carriers recovered close to 50% of the immobilized activity and increased enzyme stability from 3 to 9 times compared to the free enzyme. We found a trade-off between the half-life time and the specific activity as a function of the relative anisotropy values of the immobilized enzymes, suggesting that both properties are oppositely related to the enzyme mobility (rotational tumbling). The most thermally stable heterogeneous biocatalysts were coupled with a NADH oxidase/catalase pair co-immobilized on porous agarose beads to perform the batch oxidation of five different 1,ω-diols with in situ recycling of NAD+. Only when His-tagged BsADH was immobilized on porous glass functionalized with Fe3+, the heterogeneous biocatalyst oxidized 1, 5-pentanediol with a conversion higher than 50% after five batch cycles. This immobilized multi-enzyme system presented promising enzymatic productivities towards the oxidation of three different diols. Hence, this strategical study accompanied by a functional and structural characterization of the resulting immobilized enzymes, allowed us selecting an optimal heterogeneous biocatalyst and their integration into a fully heterogeneous multi-enzyme system.

Continuous flow reactive distillation process for biodiesel production using waste egg shells as heterogeneous catalysts

RSC Advances ◽  
2014 ◽  
Vol 4 (96) ◽  
pp. 54109-54114 ◽  
Author(s):  
S. Niju ◽  
K. M. Meera S. Begum ◽  
N. Anantharaman
Keyword(s):  
Heterogeneous Catalyst ◽  
Calcium Oxide ◽  
Continuous Flow ◽  
Heterogeneous Catalysts ◽  
Reactive Distillation ◽  
Frying Oil ◽  
Biodiesel Production ◽  
Distillation Process ◽  
Waste Frying Oil ◽  
Egg Shells

A laboratory scale continuous flow jacketed reactive distillation (RD) unit was developed to evaluate the performance of calcium oxide (CaO) derived from egg shells as a heterogeneous catalyst for transesterification of waste frying oil.

A p-Type PbS Quantum Dot Ink with Improved Stability for Solution Processable Optoelectronics

2021 ◽  
Author(s):  
Fiaz Ahmed ◽  
John Hardin Dunlap ◽  
Perry J. Pellechia ◽  
Andrew Greytak
Keyword(s):  
Quantum Dot ◽  
Ligand Exchange ◽  
Chemical Characterization ◽  
Single Step ◽  
Improved Stability ◽  
Solution Processable ◽  
P Type ◽  
Pbs Quantum Dot

A highly stable p-type PbS-QDs ink is prepared using a single-step biphasic ligand exchange route, overcoming instability encountered in previous reports. Chemical characterization of the ink reveals 3-mercaptopriopionic acid (MPA)...

Synthesis and characterization of coal fly ash supported zinc oxide catalyst for biodiesel production using used cooking oil as feed

2021 ◽  
Vol 170 ◽  
pp. 302-314
Author(s):  
Adeyinka S. Yusuff ◽  
Aman K. Bhonsle ◽  
Jayati Trivedi ◽  
Dinesh P. Bangwal ◽  
Lok P. Singh ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Fly Ash ◽  
Oxide Catalyst ◽  
Coal Fly Ash ◽  
Biodiesel Production ◽  
Synthesis And Characterization ◽  
Cooking Oil ◽  
Used Cooking Oil

scholarly journals Synthesis and Polymerization Kinetics of Rigid Tricyanate Ester

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1686
Author(s):  
Andrey Galukhin ◽  
Roman Nosov ◽  
Ilya Nikolaev ◽  
Elena Melnikova ◽  
Daut Islamov ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Single Step ◽  
Polymerization Kinetics ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Diffusion Controlled ◽  
Polymerization Product ◽  
The One ◽  
Kinetics Of

A new rigid tricyanate ester consisting of seven conjugated aromatic units is synthesized, and its structure is confirmed by X-ray analysis. This ester undergoes thermally stimulated polymerization in a liquid state. Conventional and temperature-modulated differential scanning calorimetry techniques are employed to study the polymerization kinetics. A transition of polymerization from a kinetic- to a diffusion-controlled regime is detected. Kinetic analysis is performed by combining isoconversional and model-based computations. It demonstrates that polymerization in the kinetically controlled regime of the present monomer can be described as a quasi-single-step, auto-catalytic, process. The diffusion contribution is parameterized by the Fournier model. Kinetic analysis is complemented by characterization of thermal properties of the corresponding polymerization product by means of thermogravimetric and thermomechanical analyses. Overall, the obtained experimental results are consistent with our hypothesis about the relation between the rigidity and functionality of the cyanate ester monomer, on the one hand, and its reactivity and glass transition temperature of the corresponding polymer, on the other hand.

A Single Step Synthesis By Mechanical Alloying and Characterization of Nanostructured Fe2B of High Magnetic Moment

2021 ◽  
Author(s):  
Telem Şimşek ◽  
Barış Avar ◽  
Tuncay Şimşek ◽  
Buğra Yıldız ◽  
Arun K. Chattopadhyay ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Magnetic Moment ◽  
Single Step ◽  
High Magnetic Moment

scholarly journals Single Step 2-Port Device De-Embedding Algorithm for Fixture-DUT-Fixture Network Assembly

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1275
Author(s):  
Simone Scafati ◽  
Enza Pellegrino ◽  
Francesco de Paulis ◽  
Carlo Olivieri ◽  
James Drewniak ◽  
...  
Keyword(s):  
Standard Technique ◽  
Single Step ◽  
Scattering Parameters ◽  
Linear Set ◽  
S Parameter ◽  
Parameter Conversion ◽  
Before And After ◽  
One Step ◽  
Typical Measurement

The de-embedding of measurement fixtures is relevant for an accurate experimental characterization of radio frequency and digital electronic devices. The standard technique consists in removing the effects of the measurement fixtures by the calculation of the transfer scattering parameters (T-parameters) from the available measured (or simulated) global scattering parameters (S-parameters). The standard de-embedding is achieved by a multiple steps process, involving the S-to-T and subsequent T-to-S parameter conversion. In a typical measurement setup, two fixtures are usually placed before and after the device under test (DUT) allowing the connection of the device to the calibrated vector network analyzer coaxial ports. An alternative method is proposed in this paper: it is based on the newly developed multi-network cascading algorithm. The matrices involved in the fixture-DUT-fixture cascading gives rise to a non-linear set of equations that is in one step analytically solved in closed form, obtaining a unique solution. The method is shown to be effective and at least as accurate as the standard multi-step de-embedding one.

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