scholarly journals Comparison of Water-Removal Efficiency of Molecular Sieves Vibrating by Rotary Shaking and Electromagnetic Stirring from Feedstock Oil for Biofuel Production

Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 132
Author(s):  
Cherng-Yuan Lin ◽  
Lei Ma

Adequate water-removal techniques are requisite to remain superior biofuel quality. The effects of vibrating types and operating time on the water-removal efficiency of molecular sieves were experimentally studied. Molecular sieves of 3 Å pore size own excellent hydrophilic characteristics and hardly absorb molecules other than water. Molecular sieves of 3 Å accompanied by two different vibrating types, rotary shaking and electromagnetic stirring, were used to remove initial water from the reactant mixture of feedstock oil in order to prevent excessive growth or breeding of microorganisms in the biofuel product. The physical structure of about 66% molecular sieves was significantly damaged due to shattered collision between the magnetic bar and molecular sieves during electromagnetic stirring for 1 h. The molecular sieves vibrated by the rotary shaker appeared to have relatively higher water-removal efficiency than those by the electromagnetic stirrer and by keeping the reactant mixture motionless by 6 and 5 wt.%, respectively. The structure of the molecular sieves vibrated by an electromagnetic stirrer and thereafter being dehydrated appeared much more irregular and damaged, and the weight loss accounted for as high as 19 wt.%. In contrast, the structure of the molecular sieves vibrated by a rotary shaker almost remained original ball-shaped, and the weight loss was much less after regenerative treatment for those molecular sieves. As a consequence, the water-removal process using molecular sieves vibrated by the rotary shaker is considered a competitive method during the biofuel production reaction to achieve a superior quality of biofuels.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Madan Lal Verma ◽  
Wamik Azmi ◽  
Shamsher Singh Kanwar

Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM), concentration of biocatalyst (25–125 mg/mL), reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55°C in n-heptane under continuous shaking (160 rpm) using bound lipase (25 mg). Addition of molecular sieves (3 Å  × 1.5 mm) resulted in a marked increase in ester synthesis (73.0 mM). Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse.



2017 ◽  
Vol 60 (4) ◽  
pp. 1359-1367 ◽  
Author(s):  
Nicholas Rhea ◽  
John Groppo ◽  
Czarena Crofcheck

Abstract. Algae can be used as a feedstock for agricultural fertilizers, livestock and poultry feeds, anaerobic digestion, and biofuel production. For each end product, the requirements for moisture content (or solids content) vary, such that a desirable water removal strategy needs to be adaptable to varying levels of water removal. Flocculation, sedimentation, and filtration were evaluated as possible strategies for thickening and dewatering of algae. The goal of this study was to validate that algae cells treated by such means could be processed by vacuum belt filters and to determine the conditions under which the solids content could be increased to 5 to 25 wt%. The flocculation and sedimentation studies focused on conditions needed to thicken algae from a culture concentration range of 0.4 to 1 g L-1 to an end-product concentration range of 15 to 50 g L-1. Sedimentation rates of were measured with varying flocculant dosages (0 to 25 ppm) for various flocculants. The highest level of compaction was achieved with a synthetic cationic polymeric flocculant with higher molecular weight at a dosage of 15 ppm, which provided 16.3 mL of compacted solids (3.3 wt% solids). Subsequently, solids were successfully separated as a cake via gravity and vacuum filtration. The filtration studies focused on the conditions needed to filter flocculated algae slurry from a concentration range of 15 to 50 g L-1 to a product at a concentration range of 50 to 250 g L-1. Filtration rates of were measured on algae slurry treated with 10 to 15 ppm of a synthetic cationic polymeric flocculant. Processing parameters such as cake formation time, filtration rate, and mass throughput were evaluated against variables such as cake thickness, feed concentration, and processing time. Keywords: Algae, Dewatering, Filtration, Flocculation, Scenedesmus sp., Sedimentation, Thickening.



2005 ◽  
Vol 44 (17) ◽  
pp. 6751-6759 ◽  
Author(s):  
Jun Li ◽  
Miguel Rodrigues ◽  
Henrique A. Matos ◽  
Edmundo Gomes de Azevedo


2020 ◽  
Vol 26 (9) ◽  
pp. 11-23
Author(s):  
Rand Shakir Mahmood ◽  
Nawar O.A. Al-Musawi

The electrocoagulation process became one of the most important technologies used for water treatment processes in the last few years. It’s the preferred method to remove suspended solids and heavy metals from water for treating drinking water and wastewater from textile, diary, and electroplating factories. This research aims to study the effect of using the electrocoagulation process with aluminum electrodes on the removal efficiency of suspended solids and turbidity presented in raw water and optimizing by the response surface methodology (RSM). The most important variables studied in this research included electrode spacing, the applied voltage, and the operating time of the electrocoagulation process. The samples were taken from the Al Qadisiyiah water treatment plant. The treatment set up was in a batch mode; two parallel plates of aluminum were used as electrodes. Experimental results showed that the maximum removal efficiency of 96% for turbidity and 97% for TSS were obtained at operating time 60 minutes, voltage 30 V, and electrode spacing 1.7cm. Two models for predicting removal efficiency obtained, the first model was for turbidity with a correction factor of 94.7%, and the second one was for the TSS with a correction factor of 94.85%.



2019 ◽  
Vol 25 (3) ◽  
pp. 11-22
Author(s):  
Luma Hussein Mahmood

The present work is to investigate the feasibility of removal vanadium (V) and nickel (Ni) from Iraqi heavy gas oil using activated bentonite. Different operating parameters such as the degree of bentonite activation, activated bentonite loading, and operating time was investigated on the effect of heavy metal removal efficiency. Experimental results of adsorption test show that Langmuir isotherm predicts well the experimental data and the maximum bentonite uptake of vanadium was 30 mg/g. The bentonite activated with 50 wt% H2SO4 shows a (75%) removal for both Ni and V. Results indicated that within approximately 5 hrs, the vanadium removal efficiencies were 33, 45, and 60% at vanadium loadings of 10, 30, and 40 ppm respectively. Further processing of heavy gas oil with 10 ppm vanadium shows a continuous slight increase in metal removal with operating time. At 10, 20, 40, and 50 hrs the removal efficiency was 68, 75, 78 and 78% respectively. Results indicated that an equilibrium concentration of the 10 ppm of vanadium was attained after 30 hrs while for Nickel at a loading of 4 and 7 ppm the equilibrium achieved after 40 hrs. Results depicted that activated bentonite has higher selectivity towards Vanadium. Results depict that activated bentonite (ACB) has a remarkable capacity for removal of (V) and (Ni) from heavy gas oil.        



Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 203
Author(s):  
Xiawen Yi ◽  
Meng Zhang ◽  
Weilong Song ◽  
Xinhua Wang

Anaerobic membrane bioreactors (AnMBRs) have aroused growing interest in wastewater treatment and energy recovery. However, serious membrane fouling remains a critical hindrance to AnMBRs. Here, a novel membrane fouling mitigation via optimizing initial water flux is proposed, and its feasibility was evaluated by comparing the membrane performance in AnMBRs between constant flux and varying flux modes. Results indicated that, compared with the constant flux mode, varying flux mode significantly prolonged the membrane operating time by mitigating membrane fouling. Through the analyses of fouled membranes under two operating modes, the mechanism of membrane fouling mitigation was revealed as follows: A low water flux was applied in stage 1 which slowed down the interaction between foulants and membrane surface, especially reduced the deposition of proteins on the membrane surface and formed a thin and loose fouling layer. Correspondingly, the interaction between foulants was weakened in the following stage 2 with a high water flux and, subsequently, the foulants absorbed on the membrane surface was further reduced. In addition, flux operating mode had no impact on the contaminant removal in an AnMBR. This study provides a new way of improving membrane performance in AnMBRs via a varying flux operating mode.



2017 ◽  
Vol 75 (8) ◽  
pp. 1830-1838 ◽  
Author(s):  
Xiansheng Wang ◽  
Jiaheng Ni ◽  
Shuo Pang ◽  
Ying Li

A electrocoagulation (EC)/peanut shell (PS) adsorption coupling technique was studied for the removal of malachite green (MG) in our present work. The addition of an appropriate PS dosage (5 g/L) resulted in remarkable increase in the removal efficiency of MG at lower current density and shorter operating time compared with the conventional EC process. The effect of current density, pH of MG solution, dosage of PS and initial concentration of MG were also investigated. The maximum removal efficiency of MG was 98% under optimum conditions in 5 min. And it was 23% higher than that in EC process. Furthermore, the unit energy demand (UED) and the unit electrode material demand (UEMD) were calculated and discussed. The results demonstrated that the EC/PS adsorption coupling method achieved a reduction of 94% UED and UEMD compared with EC process.



2015 ◽  
Vol 640 ◽  
pp. 13-20
Author(s):  
Rachid Djeridi ◽  
Mohand Ould Ouali

The wear behaviour of a filled styrene butadiene rubber (SBR) is investigated in this paper. The material contact used is plan /plan with a hard steel XC38. The influence of tribological parameters such as type contact (contact plan/plan under dry friction), relative motion between the contact surfaces (rotational disc/fixed elastomer sample), topography of the surface contact (roughness), loading (normal load or contact pressure), sliding friction and operating time or number of cycles is investigated. The highlighting of these parameters influence and analysis results permits us to formulate a wear model for the filled elastomer SBR. The model is based on the Archard law developed for metallic materials. The modification concerns the introduction of material parameters to take accounts the hyperelastic behaviour of elastomer due to the presence of amorphous phase. Particular interest is given to the influence of the surface state of the indenter given by the counterface arithmetic roughnessRaon the weight loss of the elastomer due to the wear phenomena. For a lower value (little to 6.3μm) of the arithmetic roughness, the weight loss is insignificant for different contact pressure and various sliding speeds. This effect is more noticeable at higher values of roughness and dependent on other tribological parameters. This results comfort other conclusion on the literature that express the influence of roughness by the geometric parameters of the micro-waves in the surface. The effects of the roughness can be explained by the ratio between the amplitude and wavelength of the corrugation. Indeed, we relate the roughness influence at the strain energy restored by material hyperelastic which also is, necessarily, a function of the velocity sliding and pressure contact.



2012 ◽  
Vol 461 ◽  
pp. 453-456 ◽  
Author(s):  
Deng Ling Jiang ◽  
Yan Hua Chen ◽  
Guo Wei Ni

Chemical forms of phosphorus in source and treated drinking water were studied in this paper. Removal of total phosphorus (TP) and microbially available phosphorus (MAP) by conventional treatment process of drinking water was examined. The results showed that particulate phosphorus constituted of most TP in source water. Content of total soluble phosphate (TSP) was about 30% of TP. Soluble reactive phosphate (SRP) can be measured in a few months during a year and its content was very low. Content of MAP was higher than content of TSP in source water, which showed that microbe can also use particle phosphorus. Ratio of TSP to TP increased evidently in treated water. This demonstrated that removal of TSP was more difficult than particulate phosphorus in conventional treatment process for drinking water. Removal of TP and MAP in conventional treatment process of drinking water was effective, with averaged removal efficiency of 66% and 69%, respectively. Coagulation-sedimentation and filtration removed TP efficiently. Enhanced coagulation may increases removal efficiency of MAP. Lower content of MAP can control biostability of drinking water.



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