Pulse Feeding Research Articles

Experimental Investigation of Taylor bubbles in a gas-liquid column with pulsed gas feed

Experimental Investigation of Taylor bubbles in a gas-liquid column with pulsed gas feed

ELECTRODE WIRE FEEDER FOR MIG/MAG AND TIG WELDING PROCESSES

The electrode wire feeding mechanisms of welding machines are designed to transport the electrode wire from the spool to the welding zone at a constant, predetermined speed or at a speed that varies according to a given law. One of the most promising areas for improving arc welding and surfacing equipment is to control the transfer of electrode metal by pulsing the electrode wire. Therefore, the feeding mechanisms of welding machines must ensure compliance with the conditions of continuous feeding at a constant speed or pulsed feeding with an intermittent movement. The problem of forming pulses with the required parameters can be solved by feeding mechanisms with a vibration drive. The main advantage of such a technical solution is the ability to produce pulsed motion with controllable frequency and amplitude parameters. Due to the high resolution of movement and high dynamic properties in transient motion modes, vibration-driven feeding mechanisms are able to provide high accuracy of bar material feeding into the working area of technological equipment. The principle of operation of such a mechanism is based on the transformation of spatial vibrations into linear displacements. The analytical dependencies obtained in this work allow us to determine the parameters of electrode wire movement by the vibratory feeding mechanism. The proposed technical solution makes it possible to provide different movements of the wire along its axis, and changing the pulsation mode is made possible by adjusting the oscillation frequency of the drive.

Biological Removal of Zinc (II) by Fusarium solani under Different Modes of Operational Strategies: A Comparative Study

The goal of the current batch biosorption experiment was to determine how well Fusarium solani (isolated from soil) resting cells could remove zinc (II) from aqueous solution. With an increase in pH (up to pH 5.0) and an increase in initial zinc (II) concentration of up to 500 mg/L, the specific zinc (II) removal increases. By increasing biomass content from 2.5 to 5.5 g/L, the specific zinc (II) removal remained nearly constant. The investigations also utilised resting cells from various growth stages and at an initial zinc (II) concentration of 500 mg/L, the maximum specific zinc (II) uptake (51.7 mg/g) was accomplished (36 h old). The comparison of the results revealed that cells in a growing state (63.9 mg/g) can achieve the highest selective uptake. Hence, the uptake of zinc(II) under various operational strategies was only done with growing cells. The biological uptake of zinc (II) was then done in a fed batch mode of operation using Fusarium solani growing cells. Increased volume pulse feeding (IVPF) and constant volume pulse feeding (CVPF) were used to study the fed batch process and the impacts of these operational methods on biological performance were contrasted with those of a traditional batch process. According to batch experiments, at pH 5.0 and an initial zinc (II) ion concentration of 500 mg/l, the maximum specific zinc (II) removal was 63.9 mg/g. The maximal specific zinc (II) removal in the IVPF process was determined to be 45.47 mg/g and 33.58 mg/g, but the values in the CVPF process were 33.12 mg/g and 22.59 mg/g respectively for the first and second pulse feedings in both cases. The zinc (II) uptake found in prior investigations carried out by the current authors employing the continuous mode of operation was then compared with these results. The process could be run for a longer period of time with a maximum specific zinc (II) removal of 52.8 mg/g when operating in a continuous mode which was shown to be the optimal operational strategy.

Применение вертикальных вибрационных смесителей в технологии получения мучных смесей

The food industry is currently demonstrating a tendency to substitute traditional high-humidity raw materials with their dry analogues. This research introduces new designs of vertical vibrating mixers that could preprogram flour mix quality. The vertical continuous vibration mixers designed for granular materials showed a good potential for a wider scope of application.
 The experiment involved high-quality wheat flour, sugar, salt, egg powder, and powdered milk, as well as three vertical mixers, i.e., a lifting mixer, a flow mixer, and a cascade mixer.
 Wheat flour entered the working body of the mixer and came into a stable vibration-boiling state in layers of ≤ 35 mm with a vibration amplitude of 4.5 mm and a frequency of ≥ 20 Hz. The speed rate of the flour increased together with the oscillation frequency of the working body and the size of the perforation area but went down as the layer grew wider. The efficiency increased following the increase in the perforation area on the spiral surface and depended on the maximal thickness of the dough layer. The flow vibrating mixer proved to be the most effective one. The frequency of pulse feeding of ingredients into the mixer was ≤ 50% (Vc ≤ 14.5%) to obtain flour mixes of satisfactory quality while good-quality mixes required 25% average time the particles spent in the mixer (Vc ≤ 6%).
 The results obtained can be used to design technological lines for flour mix production.

Effect of flow area ratio of scrolls to turbine on matching of exhaust pulse energy distribution of an asymmetric twin-scroll turbocharging heavy-duty diesel engine

The operation mode of an asymmetric twin-scroll turbine is significantly different from that of a steady state under exhaust pulse feeding conditions, which leads to a more complex matching between a turbine with an engine. In this paper, It was first studied that the matching effect of the flow area ratio of asymmetric twin-scroll to turbine wheel on the pulse energy distribution of asymmetric twin-scroll turbocharged engines. Firstly, It was compared that the deviation between turbine average efficiency on time average testing results and turbine cycle average efficiency based high frequency test results under the background of pulse energy distribution in the scheduling of asymmetric twin-scroll turbocharged engines, as well as a matching method based on pulse energy weight distribution was proposed. Furthermore, the impact of the flow area ratio of scrolls to turbine on matching was studied to further optimize turbine matching. Finally, the optimal and original turbines were tested on the engine to further demonstrate the accuracy and rationality of the results. The results showed that the turbine cycle-average efficiency and the engine fuel economy were improved by about 2%–4% and 0.8%, respectively at the middle and high speeds region of the engine with maintaining equivalent NOx emissions.

Pulse feeding and pulse growth: a highly adaptive strategy of heterotrophic dinoflagellates Oxyrrhis marina

Pulse feeding and growth of the Black Sea strain of dinof lagellates Oxyrrhis marina (Dujardin, 1841) (OXY–IBSS), equivalent spherical diameter (ESD) (23.5 ± 3.1 mm) have been studied under experimental conditions simulating phytoplankton blooms. Microalgae Phaeodactylum tricornutum (P, ESD 3.4 ±0.3 mm), Isochrysis galbana (I, ESD 3.7 ± 0.4 mm), Tetraselmis suecica (T, ESD 6.1 ± 0.9 mm), and Rhodomonas salina (R, 7.4 ± 0.7 µm) were used as food objects in a one-component and three-component suspensions. Microalgae concentrations (~106 cells/mL for T and R; up to ~4 × 106 cells/mL for P and I) were chosen to ensure their equal total carbon biomass ~0.02 mg C/mL in the food mixtures at the beginning of the experiment. Under ad libitum conditions, the maximum clearance rates of the OXY–IBSS reached 0.1–0.5 mL ind./day, and the grazing rate of microalgae was 34–44 cells/(ind h) for P and I, and 2–11 cells/(ind. h) for R and T, respectively. The grazing rate of microalgae in carbon units was significantly higher when feeding on I (3.9 ng C/(ind. day)) and significantly less when fed with a mixture of microalgae TRP (1.5 ng C/(ind. day)). Maximum abundance of OXY–IBSS, achieved within 3 or 4 days (by the time the microalgae concentration decreased below threshold), varied from 19 × 103 ind./mL (P) to 43 × 103 ind./mL (I). In the absence of food, dinof lagellates O. marina turned to cannibalism, and within 4 days the oscillating f luctuations (within 50%) in their number took place. Although the specific population growth rate (m, day-1) of OXY–IBSS was higher when feeding on small cells (~2 days–1 on I), the gross growth efficiency (GGE) of OXY–IBSS was significantly higher when fed on large (T and R) microalgae (26–29% vs. 14–15%). At lower daily rations (DRs) when fed with the mixture TRP, the GGE of OXY–IBSS was significantly higher (41%) when compared to other nutritional conditions. The feeding strategy of opportunistic predator O. marina on diverse (in terms of size and chemotaxonomic characteristics) mixtures of prey lay in a f lexible choice between high specific population growth rate, or high gross growth efficiency, that obviously gives the populations of this species the advantages over other protists under conditions of the pulsed phytoplankton blooms.

Poly-γ-glutamic acid overproduction of Bacillus licheniformis ATCC 9945a by developing a novel optimum culture medium and glutamate pulse feeding using different experimental design approaches.

The commercial production of multifunctional, biocompatible, and biodegradable biopolymers such as poly-γ-glutamic acid via microbial fermentation requires the development of simple and cheap methods for mass production. This study optimized the poly-γ-glutamic acid production of Bacillus licheniformis ATCC 9945a in several steps. At first, the most critical components of the culture medium, including l-glutamic acid, citric acid, and glycerol, were selected by screening nine factors through the Plackett-Burman experimental design and then were optimized using the response surface method and the central composite design algorithm. Under optimal conditions, the production of poly-γ-glutamic acid increased by more than 4.2 times from 11.2 to 47.2g/L. This is one of the highest production rates of this strain in submerged batch fermentation reported so far using the optimized medium compared to the conventional base medium. A novel and efficient sudden pulse feeding strategy (achieved by a novel one-factorial statistical technique) of l-glutamic acid to the optimized medium increased biopolymer production from 47.2 to 66.1g/L, the highest value reported in published literature with this strain. This simple, reproducible, and cheap fermentation process can considerably enhance the commercial applications of the poly-γ-glutamic acid synthesized by B. licheniformis ATCC 9945a .

Automated Pet Feeder with RFID Technology using Design Thinking Approach

Abstract: With the increasing demand for technological solutions in the pet care industry, this paper presents the development of an automated pet feeder that integrates RFID technology and Arduino as the microcontroller. The proposed system aims to streamline and enhance the feeding process for domestic pets by enabling pulsed feeding schedules and portion control based on RFID-tagged collars. The system uses an RFID reader to identify individual pets, triggering a simple motor mechanism to deliver the designated portion of pet food. The Arduino microcontroller facilitates the coordination of RFID tag recognition and food delivery, providing a user-friendly and customizable interface for pet owners. The design and implementation considerations, including hardware integration, software development, and fuzzy control logic, were thoroughly discussed. Experimental results demonstrate the feasibility and efficacy of the proposed automated pet feeder in maintaining a consistent feeding schedule and portion management, ensuring the well-being and health of pets. The study not only contributes to the advancement of pet care technology but also highlights the potential for further enhancements and applications in the realm of smart pet management systems.

Adapted feeding strategies in fed-batch fermentation improve sugar delivery and ethanol productivity

ABSTRACTBioethanol is a renewable fuel widely used in road transportation and is generally regarded as a clean energy source. Although fermentation is one of the major processes in bioethanol production, studies on improving its efficiency through operational design are limited, especially compared to other steps (pretreatment and hydrolysis/saccharification). In this study, two adapted feeding strategies, in which feed medium addition (sugar delivery) was adjusted to increase the supply of fermentable sugar, were developed to improve ethanol productivity in 5-L fed-batch fermentation by Saccharomyces cerevisiae. Specifically, a linear adapted feeding strategy was established based on changes in cell biomass, and an exponential adapted feeding strategy was developed based on cell biomass accumulation. By implementing these two feeding strategies, the overall ethanol productivity reached 0.88±0.04 and 0.87±0.06 g/L/h, respectively. This corresponded to ~20% increases in ethanol productivity compared to fixed pulsed feeding operations. Additionally, there was no residual glucose at the end of fermentation, and final ethanol content reached 95±3 g/L under the linear adapted operation and 104±3 g/L under the exponential adapted feeding strategy. No statistical difference was observed in the overall ethanol yield (ethanol-to-sugar ratio) between fixed and adapted feeding strategies (~91%). These results demonstrate that sugar delivery controlled by adapted feeding strategies was more efficient than fixed feeding operations, leading to higher ethanol productivity. Overall, this study provides novel adapted feeding strategies to improve sugar delivery and ethanol productivity. Integration into the current practices of the ethanol industry could improve productivity and reduce production costs of fermentation processes.

Lactic Acid Fermentation of Carrageenan Hydrolysates from the Macroalga Kappaphycus alvarezii: Evaluating Different Bioreactor Operation Modes

Lactic acid is a molecule used abundantly in the food, cosmetic, and pharmaceutical industries. It is also the building block for polylactic acid, a biodegradable polymer which has gained interest over the last decade. Seaweeds are fast growing, environmentally friendly, and economically beneficial. The Rhodophyta, Kappaphycus alvarezii, is a carrageenan-rich alga, which can be successfully fermented into lactic acid using lactic acid bacteria. Lactobacillus pentosus is a versatile and robust bacterium and an efficient producer of lactic acid from many different raw materials. Bioreactor strategies for lactic acid fermentation of K. alvarezii hydrolysate were tested in 2-L stirred-tank bioreactor fermentations, operating at 37 °C, pH 6, and 150 rpm. Productivity and yields were 1.37 g/(L.h) and 1.17 g/g for the pulse fed-batch, and 1.10 g/(L.h) and 1.04 g/g for extended fed-batch systems. A 3.57 g/(L.h) production rate and a 1.37 g/g yield for batch fermentation operating with an inoculum size of 0.6 g/L was recorded. When applying fed-batch strategies, fermentation products reached 91 g/L with pulse feed and 133 g/L with constant continuous feed. For control and comparison, a simple batch of synthetic galactose-rich Man-Sharpe-Rugosa (MRS) media was fermented at the same conditions. A short study of charcoal regenerability is shown. A scheme for a third-generation lactic acid biorefinery is proposed, envisioning a future sustainable large-scale production of this important organic acid.

Pulsed CO2 feeding promotes methane yield in anaerobic digester by diverting acidogenic pathways

CO2 injection or biogas recirculation can affect the process of anaerobic digestion, but there is a lack of systematic study on the injection strategy in the continuously operated reactors. In this study, the performance of a continuous stirred anaerobic digester treating food waste were evaluated under different injection rates (RC1-1.32 L/L/d v.s. RC2-0.66 L/L/d) and different CO2 injection modes (pulsed feeding v.s. continuous feeding). Under the pulsed CO2 feeding mode, the methane yields of RC1 and RC2 were increased by 19.3% and 27.1%, respectively as compared to the control reactor, correspondingly 34.5% and 59.0% of injected CO2 was reduced. When transferred to continuous feeding CO2 mode, only 12.4% increment of methane yield was found in RC1 as compared to RB. The intermediate metabolites analyses indicated that CO2 enrichment reinforced acetic acid and lactic acid production pathway and weakened the propionic acid pathway, which is favorable for elevating methane yield. Microbial community analysis revealed that the relative abundance of hydrogenotrophic methanogens increased accompanied with some acidogenic consortia and CO2 fixation associating consortia. This work provides a new approach to promote methane generation from organic wastes with sequestered more CO2 thus contributing to a circular economy.

Forced periodic operation via pulsing and feed switching to address methane dehydroaromatization catalyst deactivation challenge

Methane Dehydroaromatization is a one-step catalytic reaction that converts methane into aromatics and hydrogen with zero CO2 emission from the reaction stoichiometry. This work represents an engineering approach to address the rapid catalyst deactivation challenge by implementing forced periodic operation with shorter times at the scale of minutes. A systematic study was carried out by investigating pulse and periodic feed switching on a typical Mo/HZSM-5 catalyst. A fixed operating temperature and space velocity was maintained in both reaction and regeneration, while the operational time and type of regenerating molecules using reductive (H2) and oxidative (CO2) were investigated. For both modes of regeneration, CO2 was not an efficient oxidative molecule. Pulse feeding with hydrogen improved the catalyst stability, but it minimized the rate of aromatics production. The best performance was observed for the periodic switch with H2. Even a very short regenerating during 1 min H2 after 15 min reaction, was sufficient to achieve stable operation in the tested range. The global benzene production doubled compared to the base case which is a significant improvement reached by optimizing the mode of regeneration and conditions. A mathematical model was constructed and successfully used to simulate and explain the repeated reaction-regeneration cycles for different conditions. The result here is aiming to shed light on the opportunity of the forced periodic operation as an engineering strategy to mitigate the catalyst deactivation challenge and develop a reliable and stable MDA reactor operation.

Effect of Pulsed Feeding of GIFT Strain of Tilapia in Biofloc System Using Inland Saline Water

Feed is one of the major inputs in aquaculture system and constitutes 60%–80% of total production costs of tilapia. Inappropriate selection of feed quality and the feeding strategy affects the feed utilization resulting in high food conversion ratio (FCR). A 60 days experiment was conducted to evaluate the growth performance and immuno-physiological responses of GIFT tilapia, (Oreochromis niloticus) by pulsed feeding under biofloc culture system in inland saline water. For the experiment, feeding pattern in pulsed was followed viz., in situ biofloc with daily feeding (T1), in situ biofloc with alternate day feeding (T2), in situ biofloc with every third day feeding (T3), in situ biofloc with no feeding (T4), and clear water control with daily feeding (C) each in triplicates. Biofloc based treatment receiving daily feeding (T1) resulted in significantly (P<0.05) higher average body weight, weight gain, and specific growth rate (SGR) compared to control. T1 and C showed a significantly similar feed conversion ratio (FCR) and protein efficiency ratio (PER). Fish maintained in T4 grew the least and survival was lowest (85%). The immunological parameters showed a significant difference (P<0.05) for nitroblue tetrazolium (NBT) and myeloperoxidase content whereas no significant difference (P>0.05) for lysozyme activity was observed. Higher NBT activity was observed in biofloc based treatments compared to control. Activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity were considerably higher (P<0.05) in biofloc based treatments than control. Among biofloc based treatments the antioxidant activities were lower in T1. The carbohydrate metabolism enzymes lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) were lower in T1, T2, and T3 compared to control and T4. In conclusion, in-situ biofloc with daily feeding is found to be effective in growth improvement and to elicit immune-physiological responses in GIFT tilapia under pulsed feeding using biofloc based system.

Effects of selected herbal diets on performance of Trypanosome-challenged West African Dwarf Sheep

Herbal remedies play a major role in animal production with many of these herbs serving as treatment for some ailments and also allowing animals become more resistant to deleterious effects of disease. This study was conducted to evaluate the effect of herbal based diet on physiological parameters (temperature and pulse rate), feed intake, weight gain and feed conversion ratio respectively in West African Dwarf sheep infected with trypanosomes. Fifteen (15) West African Dwarf sheep separated into 5 groups fed various herbal diets in sole or mixed formulations thentemperature and pulse rate, feed intake, weight gain and feed conversion ratio were measured on a daily basis.Animals placed on Diet E (Occimum gratissimum + Vernonia amygdalina) had a significantly higher average daily weight gain (24.32g, p<0.05) when compared across all treatments whileanimals placed on Diet D (Vernonia amygdalina+ Citrus aurantifolia) had a significantly higher (p<0.05) average daily feed conversion ratio (35.02). A combination of Occimum gratissimum + Vernonia amygdalina and Vernonia amygdalina + Citrus aurantifolia aided in ameliorating the deleterious effects of trypanosomosis on production in sheep.

Scale-down of oxygen and glucose fluctuations in a tubular photobioreactor operated under oxygen-balanced mixotrophy.

Oxygen-balanced mixotrophy (OBM) is a novel type of microalgal cultivation that improves autotrophic productivity while reducing aeration costs and achieving high biomass yields on substrate. The scale-up of this process is not straightforward, as non-ideal mixing in large photobioreactors might have unwanted effects in cell physiology. We simulated at lab scale dissolved oxygen and glucose fluctuations in a tubular photobioreactor operated under OBM where glucose is injected at the beginning of the tubular section. We ran repeated batch experiments with the strain Galdieria sulphuraria ACUF 064 under glucose pulse feeding of different lengths, representing different retention times: 112, 71 and 21 minutes. During the long and medium tube retention time simulations, dissolved oxygen was depleted 15 to 25 minutes after every glucose pulse. These periods of oxygen limitation resulted in the accumulation of coproporphyrin III in the supernatant, an indication of disruption in the chlorophyll synthesis pathway. Accordingly, the absorption cross section of the cultures decreased steeply, going from values of 150 - 180 m2 ·kg-1 at the end of the first batch down to 50 - 70 m2 ·kg-1 in the last batches of both conditions. In the short tube retention time simulation, dissolved oxygen always stayed above 10% air saturation and no pigment reduction nor coproporphyrin III accumulation were observed. Concerning glucose utilization efficiency, glucose pulse feeding caused a reduction of biomass yield on substrate in the range of 4 to 22% compared to the maximum levels previously obtained with continuous glucose feeding (0.9 C-g·C-g-1 ). The missing carbon was excreted to the supernatant as extracellular polymeric substances constituted by carbohydrates and proteins. Overall, the results point out the importance of studying large-scale conditions in a controlled environment and the need for a highly controlled glucose feeding strategy in the scale-up of mixotrophic cultivation. This article is protected by copyright. All rights reserved.

Scale-up of 2,3-butanediol production by Paenibacillus peoriae NRRL BD-62 using constant oxygen transfer rate-based strategy

Bio-based 2,3-butanediol (2,3-BDO) production is still limited to the lab scale, although its advantages over the chemical route include optically pure isomer production and lower energy demand. Few previous studies have investigated bio-based 2,3-BDO scale-up using well-defined criteria and safe microorganisms. This study aimed to produce 2,3-BDO by a newly Paenibacillus peoriae NRRL BD-62 in a pilot bioreactor with 70 L, keeping the oxygen transfer rate (OTR) constant and below 1.68 mmolO2/L/h to ensure the microaerobic conditions. A surface aeration system was adopted, and an energy dissipation of 270.5 W/m3 and an impeller tip speed of 2.04 m/s were required. A 2,3-BDO productivity and yield of 0.90 g/L/h and 0.40 g/g, comparable to unsafe or genetically engineered microbial producers, were observed in the batch assay, respectively. No acetoin accumulation and a levo-2,3-BDO optical purity of about 98 % were achieved in 26 h. A delay in pulse feeding resulted in an ethanol coproduction (1:1 ratio) in the fed-batch assay, although the global productivity and yield were similar to the batch assay. To the best of our knowledge, this is the first time that 2,3-BDO has been produced by wild-type and safe P. peoriae strain in a pilot bioreactor keeping OTR constant.

Haematococcus pluvialis cultivation and astaxanthin production using different nitrogen sources with pulse feeding strategy

Haematococcus pluvialis cultivation and astaxanthin production using different nitrogen sources with pulse feeding strategy

Twice daily feeding of canola oil steeped with Asparagopsis armata reduced methane emissions of lactating dairy cows

Red seaweeds have emerged as a potent methane-mitigating feed additive in ruminant diets. However, to date they have only been applied to production systems where total mixed rations (TMR) are given. New formulations are being developed to increase the application of red seaweeds, mainly Asparagopsis spp., across different production systems including those without TMR such as grazing-based systems. One product of interest is Asparagopsis armata steeped in edible oil (ASP-Oil) to extract and stabilise the primary antimethanogenic compound, bromoform. The aim of this study was to determine the effect of feeding two formulations of ASP-Oil, with (ASP-Oil 1) and without (ASP-Oil 2) the seaweed biomass removed, on enteric methane emissions, dry matter intake (DMI), milk yield and milk composition of dairy cows over 32 d. Thirty-nine lactating, multiparous, Holstein-Friesian (75 ± 20.6 days in milk) were randomly allocated to one of the three treatments; control (CON; basal diet + 134 g canola oil), ASP-Oil with the seaweed biomass removed (ASP1; basal diet + 134 g ASP-Oil 1), and ASP-Oil without the seaweed biomass removed (ASP2; basal diet + 145 g ASP-Oil 2 + 12 g canola oil). The treatments were given twice daily, using a pulse feeding technique, as a concentrate/oil supplement during each milking. The basal diet consisted of vetch hay ad libitum and 7.0 kg DM/d of a grain mix. Individual forage intakes were measured daily via electronic monitoring of individual cows at the feed bins. Methane emissions were measured using the modified sulphur hexafluoride tracer technique on days 27–32. At the rate of 136 g/d, there was no significant effect of treatment on DMI or milk yield, however during the transition period a rate of 268 g/d decreased hay intake. The supplementation of ASP1 and ASP2 decreased energy corrected milk (ECM; P = 0.029) compared to those cows offered the CON diet. Methane production (g/d) of cows given the ASP1 diet was 44 % lower than cows on the CON diet, methane yield (g/kg DMI) was 44 % lower, and methane intensity (g/kg ECM) was 38 % lower. For the ASP2 cows, the reductions were 39 % for methane production, 33 % for methane yield, and 31 % for methane intensity. Feeding the ASP-Oil increased bromoform concentrations in milk. However, the concentrations detected were demonstrated to be considerably lower than published safe concentrations in milk for human consumption (100 μg/L). These results show that the ASP-Oil has potential to be used as a methane mitigating feed additive when fed in a pulse feeding system.

Multi-angle evaluation of the anaerobic digestion of Molasses vinasse using two different feeding patterns

Molasses vinasse (MV) is a waste burden in alcohol production due to its high organic matter content. However, it represents a potential source of energy recovery if adequately treated. In this study, two feeding patterns (pulse feeding: 8 ​L/4 ​h and semi-continuous feeding: 8 ​L/23 ​h) were evaluated for their effects on MV anaerobic digestion from multiple perspectives in a laboratory-scale reactor. The results demonstrated that semi-continuous feeding not only achieved a higher soluble chemical oxygen demand (sCOD) removal rate of 78.48% but also increased the production of biogas and methane by 20.04% and 51.48%, respectively. In addition, the chemical composition analysis suggested that the semi-continuous feeding pattern degraded the majority of lignin/CRAM and aromatic substances more effectively than the pulse feeding pattern. Moreover, the microbial analysis revealed that semi-continuous feeding increased the number of dominant bacteria, including Chloroflexi, Synergistetes, and Cloacimonetea, and methanogenic archaea, including Methanosaeta and Methanosarcina. The findings of this study, therefore, confirm that the semi-continuous feeding model is more effective and has good application potential, laying the groundwork for the MV anaerobic industrial processes.

Velocity measurement of pneumatically conveyed particles via a simple current signal technique and the influence of electrostatic charge

Particle velocity in pulse feeding pneumatic conveying was measured utilizing current signal analysis and video imaging. Glass beads and silica particles were conveyed in a conductive tube (ID of 4.57 × 10 −3 m) at gas velocities of 7, 15, and 30 m/s. To measure particle velocity, electrical current signal method was used with a new approach that uses raw current data and eliminates signal conditioning and cross-correlation analysis. This technique was successful and results were comparable to video imaging results. The conveyed particles' charge was measured to determine its influence on particle velocity. 30 m/s gas velocity resulted in a turbulent flow and greater charge generation causing more deviations between particle and gas velocity due to the enhancement of particles' radial motion. Finally, the comparison of results with predictions of existing models revealed that further research is necessary to better understand the effect of particles' motion and charge on their conveying velocity. Video imaging and current signal measurement techniques and the acquired electrostatic charge during pneumatic conveying. • Particle velocity in pneumatic conveying was measured based on particles charge. • A simplified technique based on electrical current signal method was proposed. • Influence of particles electrostatic charge on their velocity was investigated. • Existing models overestimated particle velocity in the presence of electrostatics. • Existing models predictions were not in agreement to the measurements at high gas velocities.