Bed System Research Articles

Investigation of Hydrodynamics Characteristics of Fluidized Bed with back propagation Artificial Neural Network (BPANN)

Correlations have also been developed with system parameters by using dimensional analysis and an artificial neural network approach. The paper describes an investigation for the thermal design of a fluidized bed cooler and prediction of heat transfer rate among the media categories. It is devoted to the thermal design of such equipment and their application in the industrial fields. In the present work, an extensive ANN by using back propagation (BP) has been carried out to correlate the expansion ratio, fluctuation ratio in gas-solid fluidized bed. Back propagation network is the most well-known and widely used among the current types of neural network system, several applications of ANN for modeling of nonlinear process systems and subsequent control were reported. In back-propagation, different ANN structures (I×H×O) with varying number of neurons in the hidden layer were used as a tool for training input and output data for prediction value of hydrodynamic characteristics of the bed system. It was noted that ring models are the best ones in reducing bed expansion ratio and fluctuation ratio around (25%) and (23.22%).

Electrolysis-boosted substitute natural gas from biomass: Kinetic modeling of fluidized bed gasification and system integration

The present work deals with the modeling of electrolysis-boosted biomass gasification for the production of green synthetic methane (or substitute natural gas) with a composition that enables its potential injection into the natural gas distribution grid.A kinetic and hydrodynamic model has been built to simulate a bubbling fluidized bed reactor using a mixture of steam and oxygen as gasifying agent. The model was firstly validated by comparing it with experimental results available in the open literature. Outlet temperature spans from about 730 to 1060 °C depending on the used amount of oxygen and steam within the gasifying agent, expressed through parameters like equivalence ratio and steam-to-biomass ratio.Then, process modeling for the integration between biomass gasification and high-temperature steam electrolysis has been carried out. Electrolysis has been sized to enrich the hydrogen content of the syngas, enabling a stoichiometric composition in terms of hydrogen, carbon monoxide, and carbon dioxide for the subsequent catalytic methane synthesis via carbon oxides hydrogenation. Thermal integration has been carefully designed to improve the overall process efficiency up to about 71 % (based on lower heating value of both biomass and substitute natural gas).

Scaling up 3D printed hybrid sorbents towards (cost) effective post-combustion CO2 capture: A multiscale study

A 3D-printed sorbent containing polyethylene-imine and multi-walled carbon nanotubes (PEI-MWCNT) was studied for post-combustion carbon capture. In this work, the adsorbent was printed on a kg scale and characterized for CO2 adsorption through lab experiments. A 6-step VSA process was simulated using the lab data to capture CO2 from a representative 800 MW power plant. The adsorbent captured >70 % of the CO2 and 95 % CO2 purity was achieved. The levelized cost of electricity (LCOE) was 130.2 $/MWh and the costs of CO2 captured and avoided were 80 and 100.12 $/tonne. However, a zeolite 13X-activated carbon (13X-AC) monolith achieved a lower LCOE of 118.1 $/MWh, with the captured and avoided costs being 63 and 78.4 $/tonne, respectively. The LCOE value for the 13X-AC monolith was 5.1 % lower than a reference-packed bed system with Zeolite 13X pellets. The corresponding cost values were lower by 9.1 % and 13.9 %, respectively for the costs of CO2 captured and avoided. The lab experiments on the PEI-MWCNT sorbent revealed that further work is necessary to improve the thermal stability and stability with long-term storage of the precursor paste.

Development of a multifunctional nursing bed system for in-bed position recognition and automatic repositioning

Bedridden elderly need to be repositioned at regular intervals to prevent pressure ulcers. However, repositioning, being one of the most physically demanding tasks in nursing, faces many challenges, including work-related injuries and limited manpower. To address these problems, we have developed a multifunctional nursing bed system. This system not only assists in repositioning and transitioning positions but also features in-bed position recognition, enabling automatic repositioning based on recognition results. In this paper, the repositioning process was analysed, and the nursing bed mechanism and its control design were developed. An algorithmic framework for in-bed position recognition, including preprocessing and convolutional neural networks, is proposed. The experimental results demonstrate that the nursing bed system facilitates comfortable repositioning and position transition for subjects. In a short-term experiment, the system demonstrated an accuracy rate of 96.83% for in-bed position recognition. Meanwhile, in a long-term experiment, it achieved a success rate of 93.89% for automatic repositioning. These findings indicate that the proposed system demonstrates substantial potential in nursing care, particularly in pressure ulcer prevention.

Evaluation of a granular Cu-modified chitosan biocomposite for sustainable sulfate removal from aqueous media: A batch and fixed-bed column study

Adsorption-based treatment of sulfate contaminated water sources present challenges due to its favourable hydration characteristics. Herein, a copper-modified granular chitosan-based biocomposite (CHP-Cu) was prepared and characterized for its sulfate adsorption properties at neutral pH via batch equilibrium and fixed-bed column studies. The CHP-Cu adsorbent was characterized by complementary methods: spectroscopy (IR, Raman, X-ray photoelectron), thermal gravimetry analysis (TGA) and pH-based surface charge analysis. Sulfate adsorption at pH 7.2 with CHP-Cu follows the Sips isotherm model with a maximum adsorption capacity (407 mg/g) that exceeds most reported values of granular biosorbents at similar conditions. For the dynamic adsorption study, initial sulfate concentration, bed height, and flow rate were influential parameters governing sulfate adsorption. The Thomas and Yoon-Nelson models yield a sulfate adsorption capacity (146 mg/g) for the fixed bed system at optimized conditions. CHP-Cu was regenerated over 5 cycles (33 % to 31 %) with negligible Cu-leaching. The adsorbent also displays excellent sulfate uptake properties, regenerability, and sustainable adsorbent properties for effective point-of-use sulfate remediation in aqueous media near neutral pH (7.2). This sulfate remediation strategy is proposed for other oxyanion systems relevant to contaminated environmental surface and groundwater resources.

Integrated process for a new sequential valorization of corn ethanol production by-products: Production of fermented solid with lipase activity, ethyl esters, and animal feed

The use of co-products from corn ethanol production such as distillers’ dried grains with solubles (DDGS) and distillers’ corn oil (DCO) to produce a crude extract with lipolytic activity and fatty acid ethyl esters was studied in an integrated process. The dry fermented solid (DFS) with lipase activity was produced from the fermentation of the filamentous fungus Rhizomucor miehei in DDGS in tray-type reactors and column systems. The DFS was used to catalyze esterification reactions between oleic acid and ethanol, with conversions of 72% and 80% (within 4 h) for the biocatalyst produced in tray-type and fixed bed systems, respectively. The biocatalyst also converted glycerides from DCO into FAEE, with an ester yield higher than 70% after three consecutive reactions. By introducing 2 wt% of a commercial preparation (Novozym 435) in the system with the DFS, ester contents of 81% were obtained and, the yield was higher than 95% after three consecutive reactions. The biocatalyst could be reused 6 consecutive times in the esterification reactions, after washing with ethanol and 5 times after washing with hexane. In DCO transesterification reactions, reuse was less efficient with a loss of activity after the second reuse. Bromatological analysis showed that the fermented material maintained the main properties of the in natura DDGS, with a reduction in the oil and grease and an increase in protein content. The chemical composition was maintained after its use in the corn oil ethanolysis (used DFS). These findings show the potential for developing novel pathways to diversify the use and enhance the value of co-products derived from the large-scale corn ethanol industry, in a biorefinery concept.

Methods of processing recycled manure solids bedding on Midwest dairy farms II: Relationships between bedding characteristics and bedding bacterial count

The first objective of this study was to identify bedding characteristics associated with bedding bacterial count (BBC) in ready-to-use (RTU) recycled manure solids (RMS). The second objective was to explore the association between processing method and bedding characteristics in RTU solids. A third objective was to investigate factors associated with BBC in used solids (after placed in stalls). This observational study recruited 29 premises in Minnesota and Wisconsin. Farms were visited twice, once in August of 2019 and again in January of 2020. At each visit, the herd manager/owner completed a questionnaire describing facilities, bedding and manure management, and mastitis control practices. Additionally, pre-processed RTU and used bedding samples were collected for determination of BBC (coliforms, Klebsiella spp., Streptococcus or Streptococcus-like organisms and Staphylococcus spp.) and bedding characteristics (dry matter [DM]), organic matter [OM], water soluble carbohydrates, total nitrogen, soluble nitrogen and pH). Mixed linear regression showed that increased DM, decreased OM and RMS processing method were all associated with reduced BBC in RTU RMS samples. Processing method for RMS was associated with DM, total nitrogen and soluble nitrogen, but not other characteristics in RTU RMS samples. Low BBC in RTU solids, decreased OM in RTU solids, and use of deep bedding systems were associated with lower BBC in used RMS. Implications for these findings are that producers should strive to put clean and high DM fresh (RTU) bedding into stalls. Monitoring BBC and DM in RTU solids may be of value for producers using RMS bedding.

Effect of limited irrigation and planting systems on yield and water productivity of maize (Zea mays)

A field experiment was conducted during the rainy (kharif) seasons of 2019 and 2020 at the research farm opf ICAR-Indian Agricultural Research Institute, New Delhi to study the effect of limited irrigation application and planting systems on yield and water productivity of maize (Zea mays L.). The experiment was laid out in factorial randomized complete block design with 3 replications. The experiment consisted of two crop establishment methods as one factor, viz. Narrow bed planting and broad bad planting and 5 irrigation levels, viz. 25% DASM (Depletion of available soil moisture); 25% DASM at tasselling, silking, grain filling and 50% during rest of time; 50% DASM at all growth stages; 50% DASM + KCl spray at 40 DAS and at pre-tasselling; and 50% DASM+2% Urea spray at 40 DAS and at pre-tasselling. Experimental results revealed that the broad bed system of planting during 2019 and 2020 recoded significantly higher grain yields (4.37 and 4.57 t/ha) compared to the narrow bed system (4.23 and 4.38 t/ha), respectively. Regarding different irrigation levels, the highest water productivity (91.26 and 199.76 kg/ ha-cm) was observed with irrigation at 50% DASM along with two sprays of urea at 40 DAS during both the years, respectively. It was concluded that broad bed along with irrigation at 50% DASM with two sprays of urea proved to be most effective approach to enhance water productivity and yield of maize crop.

Simulation of the L-valve in the circulating fluidized bed with a coarse-grained discrete particle method

Stable and controllable solid flow is essential in circulating fluidized bed (CFB) systems. The L-valve is a typical non-mechanical valve that can provide flexible solid feeding. The investigation of the solid circulation rate and the hydrodynamic characteristics of the L-valve is crucial to its design and operation. The gas-solid flow in the L-valve of a full-loop CFB is studied with the coarse-grained discrete particle method (EMMS-DPM). Good agreements on the solid circulation rate and the pressure drop through the L-valve are achieved between the simulated and experimental data. The solid circulation rate increases linearly with the aeration velocity until the stable particle circulation of the CFB is destroyed. The flow patterns in the horizontal section of L-valve are gas-solid slug flow above the stationary solid layer and the moving solid layer, respectively. The effects of L-valve geometric parameters on the solid flow characteristics are also investigated. The results indicate that reducing the diameter and length of the horizontal section of L-valve can improve the solid transport efficiency, especially at low aeration velocity. Besides, the solid conveying capacity and flow stability are improved when the sharp bend of L-valve is modified to be a gradual bend.

Measurement and Control of Body Pressure Towards Smart Bed System

This research paper introduces a novel methodology for optimizing pressure dispersion in interactive bed systems, aiming to enhance sleep comfort while considering variegated body shapes and sleeping positions. By controlling the spring constant with precision, which is further optimized by a secondary differential filter, the proposed methodology assures ideal pressure distribution across the bed surface. At the heart of the proposed methodology lies the design of an interactive bed system that effectively responds to the unconscious postural shifts of the user during sleep. The implementation of a secondary differential filter in modulating the spring constant is an integral part of this approach, facilitating the crafting of a responsive bedding surface that promptly adapts to pressure alterations. The effectiveness of this novel method is verified through finite element method (FEM) analysis, which confirms successful pressure dispersion across the bed surface, an essential factor in enhancing sleep comfort. The research also proposes potential enhancements to this methodology, such as incorporating air-pressure control mechanisms, thereby introducing additional pressure control axes akin to those present in existing technologies. This study represents a significant stride forward in the advancement of interactive bed systems by presenting a new method for optimizing pressure dispersion, and hence, enhancing sleep comfort. The employment of FEM analysis not only validates the effectiveness of the proposed methodology but also highlights the potential for the future development of personalized and adaptive bedding solutions.

Energy and exergy analysis of drying of potash particles in a pulsation-assisted fluidized bed

Potash particles exhibit cohesiveness and hygroscopic behavior in the presence of moisture. During the drying of wet potash particles, solid bridges form, and the agglomeration behavior of such particles reduces the efficiency of drying. In this work, pulsed airflow was employed to break agglomeration and eliminate channeling in a fluidized bed with wet potash particles. The effect of different operating conditions including inlet drying gas temperature (40 °C, 50 °C, and 60 °C) and pulsation frequency (1.0 Hz and 2.0 Hz) on the energy and exergy efficiency of fluidized bed drying of potash particles was investigated. A drying model based on the thin-layer theory was employed to correlate the experimental data of drying of potash particles. The results showed that the highest energy and exergy efficiency of potash drying, 28.6% and 27.8%, respectively, was achieved when the fluidized drying of potash particles was operated at lower temperatures and close to the natural frequency of the fluidized bed system.

Tillage and Cover Crop Systems Alter Soil Particle Size Distribution in Raised-Bed-and-Furrow Row-Crop Agroecosystems

Conservation alternatives that include no-tillage (NT) and cover crops (CCs) reduce soil erosion in row-crop agroecosystems. However, little information is available about how these alternatives affect soil textural properties responsible for soil fertility. This study evaluated the soil particle size distribution and volumetric water content after three years of consistent management in a raised bed system. There were four treatment systems in a dryland maize/soybean rotation on a silt loam soil (Oxyaquic Fraglossudalfs) that included: NT + CCs, conventional tillage (CT) + CCs, CT + winter weeds, and CT + bare soil in winter in northwest Mississippi. The NT + CC system retained 62% more coarse sand in the furrow than the other systems (2.1% compared to 1.3%; p = 0.02). Regardless of the location, the NT + CC system (2.5%) retained 39% more fine sand than the CT + CC system (1.8%; p = 0.01), suggesting that coarse and fine sands were being trapped in furrows combining NT + CC systems, minimizing their off-site transport. In furrows, CCs increased soil volumetric water content by 47% compared to other winter covers. In beds, NT + CCs increased bed water contents by 20% compared to CT + CCs (17.1 to 14.3%; p < 0.01). Implementing conservation alternatives may promote the retention of sand fractions in silty loam soils that are important in supporting soil fertility and crop sustainability.

Nano-Iron Oxide Coating for Enhanced Heat Transfer in Gas–Solid Fluidized Bed Systems

This study explores using iron oxide coatings on glass beads to improve heat transfer efficiency in fluidized bed reactors. Techniques such as BET surface area analysis, SEM imaging, and X-ray diffraction were used to characterize the coated beads. Results showed the successful creation of a crystalline iron layer on the beads’ surface and increased thermal conductivity, especially at elevated temperatures. The study also quantified the impact of air surface velocity and heating power on the heat transfer coefficient, revealing substantial improvements, especially at higher velocities. It was found that the heat transfer coefficient for 600 µm glass beads increases significantly from 336.4 W/m2·K to 390.3 W/m2·K when the velocity is 0.27 m/s and the heating flux is 125 W. This demonstrates the effectiveness of the iron oxide coating in improving heat transfer. The results of this study emphasize the efficacy of iron oxide coatings in augmenting heat transmission characteristics, particularly in fluidized bed reactor.

Rearing of broiler chickens when using an anti-stressor

Many scientists believe that stress and the consequences of stressful situations are an inevitable outcome due to the fact that poultry farming has reached a broad industrial basis. The intensive growth of this industry is associated with high demand for poultry meat products. Condensed planting of poultry and its regrouping lead to stress, and specialists are faced with the task of minimizing the consequences of stressful situations throughout the entire life cycle of the poultry and increasing its productivity. The purpose of the work was to study the rearing of broiler chickens when using the anti-stress additive Feed-Food Magic Antistress Mix in their diets under conditions of bed system. The chickens of the control group received standard compound feed, while the broilers of the 1st experimental group were given the anti-stress additive Feed-Food Magic Antistress Mix in the diet in the amount of 500 g/t of compound feed, and the 2nd experimental group 200 g/t of compound feed. The duration of the scientifi c and farm experiment lasted 37 days. Despite the higher cost of compound feed in the experimental groups (due to additional costs for the anti-stress additive), in these groups an additional profi t was received in the 1st experimental group in the amount of 1138,70 rubles and in the 2nd experimental group 898,08 rubles, which allows us to draw a conclusion about the economic feasibility of using additive Feed-Food Magic Antistress Mix when rearing broiler chickens. It has been established that the use of the anti-stress additive Feed-Food Magic Antistress Mix in the diets of broiler chickens when using bed system helps to increase the level of profi tability. This economic eff ect allows us to recommend the use of the tested anti-stress additive in the industrial production of broiler chicken meat.

Degradation of fluoride in groundwater by electrochemical fixed bed system with bauxite: performance and synergistic catalytic mechanism.

Fluoride pollution in water has garnered significant attention worldwide. The issue of fluoride removal remains challenging in areas not covered by municipal water systems. The industrial aluminum electrode and natural bauxite coordinated defluorination system (IE-BA) have been employed for fluoride removal. The experiment investigated the effects of pH, current density, and inter-electrode mineral layer thickness on the defluorination process of IE-BA. Additionally, the study examined the treatment efficiency of IE-BA for simulated water with varying F- concentrations and assessed its long-term performance. The results demonstrate that the defluorination efficiency can reach 98.4% after optimization. Moreover, irrespective of different fluoride concentrations, the defluorination rate exceeds 95.2%. After 72 hours of continuous operation, the defluorination rate reached 91.9%. The effluent exhibited weak alkalinity with a pH of around 8.0, and the voltage increased by 2.0 V compared to the initial moment. By analyzing the characterization properties of minerals and flocs, this study puts forward the possible defluorination mechanism of the IE-BA system. The efficacy of the IE-BA system in fluoride removal from water was ultimately confirmed, demonstrating its advantages in terms of defluorination ability under different initial conditions and resistance to complex interference. This study demonstrates that the IE-BA technology is a promising approach for defluorination.

CO2 conversion to CO via plasma and electrolysis: a techno-economic and energy cost analysis.

Electrification and carbon capture technologies are essential for achieving net-zero emissions in the chemical sector. A crucial strategy involves converting captured CO2 into CO, a valuable chemical feedstock. This study evaluates the feasibility of two innovative methods: plasma activation and electrolysis, using clean electricity and captured CO2. Specifically, it compares a gliding arc plasma reactor with an embedded novel carbon bed system to a modern zero-gap type low-temperature electrolyser. The plasma method stood out with an energy cost of 19.5 GJ per tonne CO, marking a 43% reduction compared to electrolysis and conventional methods. CO production costs for plasma- and electrolysis-based plants were $671 and $962 per tonne, respectively. However, due to high uncertainty regarding electrolyser costs, the CO production costs in electrolysis-based plants may actually range from $570 to $1392 per tonne. The carbon bed system in the plasma method was a key factor in facilitating additional CO generation from O2 and enhancing CO2 conversion, contributing to its cost-effectiveness. Challenges for electrolysis included high costs of equipment and low current densities. Addressing these limitations could significantly decrease production costs, but challenges arise from the mutual relationship between intrinsic parameters, such as CO2 conversion, CO2 input flow, or energy cost. In a future scenario with affordable feedstocks and equipment, costs could drop below $500 per tonne for both methods. While this may be more challenging for electrolysis due to complexity and expensive catalysts, plasma-based CO production appears more viable and competitive.

Effect of torrefaction pretreatment on combustion behaviour of different agricultural wastes

In this study, which was carried out to investigate the effect of the torrefaction process on the combustion behaviour of agricultural wastes, almond hulls and shells, olive seeds and corn stalks were used. The samples, dried in a laboratory atmosphere, were torrified at 300 5ºC for 41 minutes. The change in fuel properties was determined by making proximate analyses of the solid product obtained after the process and compared with the raw sample. The effects of the torrefaction process on the combustion behaviour of agricultural wastes of different structures were investigated by burning the 1 0.15 g weighted raw and torrefied samples at 700ºC furnace initial temperature in a fixed bed system. Biochars containing higher fixed carbon were obtained with the torrefaction process applied to agricultural waste, and it was determined that this caused biochars to burn more efficiently and for a longer time than raw biomass. As a result, it was determined that biochar with better properties was produced by the torrefaction process applied to agricultural wastes and it was suitable for burning in solid fuel combustion systems. Thus, biochar obtained will both contribute to the country's economy and add value to agricultural wastes that cause problems during storage, transportation, loading into the burning system, and combustion.

A Colourful Way to Unravel the Important Fluidization-Related Granule Size Effect on Semi-Continuous Drying.

Continuous twin screw wet granulation (TSWG) systems are possible pathways for oral solid dosage manufacturing in the pharmaceutical industry. TSWG requires a drying step after granulation before the tableting process. Typically, semi-continuous fluidized bed dryers (FBDs) are used for this purpose. At the same time, the pharmaceutical sector is interested in mathematical prediction models to save resources during the early drug product development (DPD) stage or to control manufacturing. Several authors have already developed prediction models for semi-continuous drying processes. However, these model structures reported systematic prediction offsets, which could be related to the incomplete implementation of fluidization and granule segregation phenomena. This study evaluates the complex fluidization behavior of wet granules in industrially relevant semi-continuous FBDs. A transparent perspex version of the dryer was used for the analysis of bed height, pressure drop, porosity, segregation, and spatial heating patterns at varying process settings. The investigated behaviors of the fluidizing bed will be helpful to derive phenomenological (sub)models for the detailed description of segregation in the semi-continuous fluidized bed system. In this study, it was found that semi-continuous FBDs are characterized by a change in fluidization regime from plug flow to a bubbling bed at the moment that the granule bed slumps. Secondly, the presence of size-based vertical segregation phenomena as well as spatial temperature differences were proven. The experimental results suggest that larger granules are dried under more intense drying conditions than smaller granules.

Productivity and Profitability of Tomato under Organic Nutrition in Wicking Bed System

Tomato (Solanum lycopersicum L.), one of the most popular vegetables globally and rich in bio active compounds is an excellent model for studying under organic nutrition. There is need to evaluate the organic nutrition in wicking bed irrigation for the homestead cultivation of vegetables with tomato as a test crop using the liquid organic manures which are easy to prepare and affordable. A pot culture experiment was laid out in completely randomized design with three replications during summer season 2022. The treatments were soil application of cow’s urine and vermiwash at weekly intervals along with foliar application of panchagavya at 3%, vermiwash at 3%, moringa leaf extract at 4% and water spray at 20, 40 and 60 DAT. Irrigation was provided by sub irrigation to tomato through wicking bed. The experiment results revealed that organic nutrition had a significant effect on growth, yield attributes and yield of tomato. Basal application of enriched farmyard manure supplemented with soil application of vermiwash or cow’s urine at weekly intervals along with foliar application of panchagavya at 3% at 20, 40 and 60 DAT could be recommended for enhanced productivity and profitability of tomato under wicking bed system.

Response of gerbera under soil and soil-less production systems

Response of gerbera var. Arka Nesara was studied under different soil-less production systems with the aim to improve quality, productivity and water use efficiency, in completely randomized design with eight treatments viz., deep flow technique (DFT), nutrient film technique (NFT), aggregate wick system (AWS) with pots on NFT bench, AWS with pots on ground, AWS with grow bags on ground, AWS on soil bed, aeroponics and conventional soil-based drip system, which were replicated five times. Results revealed that AWS with pots on ground recorded maximum plant height (31.66 cm), leaf length (21.31 cm), leaf breadth (9.96 cm) and stalk diameter near neck (4.75 mm), minimum stem deviation (1.27 cm) and stem deflection (2.2o), prolonged vase life (9.2 days), greater water use efficiency (92 mL/plant/day) and water saving (83.46%). Hence, cultivation of gerbera var. Arka Nesara under aggregate wick system with pots on ground could be the superior alternative for traditional soil cultivation.