Operating Parameters Of Process Research Articles

Process simulation and optimization for post-combustion CO2 capture pilot plant using high CO2 concentration flue gas as a source

This work mainly focuses on process simulation and optimization of a high-concentrated CO2 chemical absorption process using aqueous amine solutions based on both pilot plant data and process modeling. To optimize operating parameters for reducing energy consumptions, this study explores the influence of process structure and operational parameters on the product purity, capture rate, and energy consumption, which would provide theoretical and technical support for optimizing high-concentration CO2 capture. At first, the rate-based absorption/desorption models are established and well-verified by a total of 25 sets of pilot plant data, which shows high accuracy for reliable model predictions. Under an annual absorption capacity of 50 tons at a 90% capture rate and 95% product purity, the optimal case using Monoethanolamine (MEA) solution shows an increased CO2 capture rate of 12.37% and a decreased unit energy consumption of 22.5%. After flowsheet optimization, a new system of blended MEA, Methyl diethanolamine (MDEA), and 2-Amino-2-methyl-1-propanol (AMP) solution is designed to capturing high-concentrated CO2 under the same conditions. Compared with the MEA system, its specified energy consumption is reduced by 10.35% and its CO2 capture capacity increases by 11.6 tons annually.

Evaluation of hole quality in drilling process of GF/Aluminum wire mesh reinforced epoxy composites

The current work investigates the effects of drilling parameters on hole quality, including delamination and circularity, produced in hybrid composite materials consisting of neat glass fibre (NG) and hybrid glass fibre/Al-wire mesh in two distinct sequences, the first one being with Al-mesh in the outermost layers (AG) and the other with Al-mesh in the central layer (GA). The operation's process parameters are feed rate (F = 20, 40, and 60 mm/min), spindle speed (N = 1000, 2000, and 3000 rpm), and drill point angle (Ɵ = 90°, 120°, and 135°). Taguchi's L9 orthogonal array is used for the study. The optimal levels and effects of the process parameters were determined. Gray relational analysis (GRA) was employed to examine the complicated interactions influencing the results and ANOVA was used to evaluate the influence of process parameters. The results indicated that for all specimens, push-out delamination was more severe than peel-up. Circularity is minimized by using N = 3000 rpm, F = 20 mm/min, and Ɵ = 90°. At speed (N) of 3000 rpm circularity reduces by 83.5% and 76.5% compared to 1000 or 2000 rpm, respectively. Compared to other specimens, AG-specimen produced minimal delamination and circularity by an average of 6% and17.38%. The results of the confirmation test and regression model provide good agreement between the experimental and predicted results.

A hybrid electrocoagulation-biocomposite adsorption system for the decolourization of dye wastewater

Among the various methods for the removal of azo dye, electrocoagulation is recognized to be highly efficient. However, the process is associated with high operation and maintenance cost, which demands the need for reducing the electrolysis time without compromising the performance efficiency. This can be achieved by adopting hybrid electrocoagulation process with a low-cost but effective process, such as adsorption. The study investigated the performance of a hybrid electrocoagulation-biocomposite system (H-EC-BC) for removing methyl orange dye. Firstly, the operating parameters of electrocoagulation process were optimized and a removal efficiency of 99% has been attained using Fe-SS electrodes at a pH of 6 for a reaction time of 30 min. The performance of EC process was found to be decreasing with increase in dye concentration. Secondly, biocomposite was synthesized from Psidium guajava leaves and characterized using SEM, FTIR, EDAX, and XRD analyses. The results suggested that it is having a porous nature and cellulose crystal structure and confirmed the presence of chemical elements such as carbon (65.2%), oxygen (29.1%) as primary with Fe, Cl, Na and Ca as secondary elements. The performance of the biocomposite was evaluated for the dye adsorption using spectrophotometric methods. Various operating parameters were optimized using experimental methods and a maximum removal efficiency of 65% was achieved at a pH of 6, dosage of 5 g/L and an adsorption contact time of 120 min. The maximum efficiency (92.78%) was obtained with Fe-SS electrodes and KCl as a sustaining electrolyte under acidic circumstances (pH 6). The biocomposite was observed to be more efficient for higher dye concentration. Langmuir and Freundlich adsorption isotherms were fitted with the experimental results with R2 values as 0.926 and 0.980 respectively. The adsorption kinetics were described using Pseudo-first and Pseudo-second order models, wherein Pseudo-second order model fits the experimental results with R2 value of 0.999. The energy consumption of electrocoagulation (EC) process in the hybrid H-EC-BC system was compared to that of a standard EC process. The results demonstrated that the hybrid system is approximately 7 times more energy efficient than the conventional process, thereby implicating its adaptability for field application.

Prediction of SO2 emission concentration in industrial flue gas based on deep learning: The ammonia desulfurization system of the Yunnan aluminum carbon plant as the research object

The desulfurization efficiency of flue gas desulfurization (FGD) systems is affected by many operation parameters, and predicting SO2 emission concentration through mechanism models requires a significant number of resources, limiting the process optimization of the overall desulfurization efficiency. Taking the desulfurization system of Yunnan aluminum carbon plant as the research object, based on the inlet flue gas, process control parameters, and pollutants of the discharged flue gas, we constructed the NARX (nonlinear auto-regressive model with external inputs) neural network and TCN (temporal convolutional network) models. Predicted the concentration of SO2 in the discharged flue gas in the next moment from the above three types of historical data, optimized the industrial control parameters, and reduced the concentration of the discharged SO2. The results show that both TCN and NARX models have strong nonlinear dynamic descriptive ability, and both are capable of accurately predicting the SO2 concentration in the emitted flue gas. The TCN neural network model can control the mean absolute percentage error and root mean square error of the dataset within 1.46% and 1.86, respectively. The response relationship established by the model has an important role in guiding the regulation of SO2 emission and process operation parameters, such as reducing the flue gas pressure of the absorber tower inlet or increasing the pressure of the concentration section of the absorber tower, which can effectively improve the desulfurization rate.

Optimizing refuse-derived fuel production from scheduled wastes through Aspen plus simulation

This study aims to improve the quality of fuel with high calorific value namely Sfuel – a commercial high-quality refuse-derived fuel (RDF) from hazardous waste via modifying the process design and operating parameters of thermal conversion process. The study analyses key parameters of RDF quality, such as calorific value and heavy metal content, before and after process modifications based on the combination of experimental and simulation using Aspen Plus. In this study, the temperature and pressure of the simulation system are varied from 100 to 700 °C and from 1 to 5 bar, respectively. Findings indicate that there are a total of eleven heavy metals and 179 volatile compounds in the “Sfuels”. The quality of the targeted product is greatly improved by the metal evaporation at high temperatures and pressures. However, the calorific value of RDF significantly decreases at 700 °C due to a large amount of the carbon content being evaporated. Although the carbon content at high temperatures is significantly lost, the heat from the vapour stream reactor outlet, which is reused to preheat the nitrogen gas stream supplied to the system, reduces energy consumption while improving the thermal conversion efficiency of the system. Besides, low pressure along with high temperature are not the optimal conditions for quality Sfuels improvement by thermal conversion. Results also indicate that electric heating is more economically efficient than natural gas heating.

Sequential hydrotalcite precipitation, microbial sulfate reduction and in situ hydrogen sulfide removal for neutral mine drainage treatment

This study proposed and examined a new process flowsheet for treating neutral mine drainage (NMD) from an open-pit gold mine. The process consisted of three sequential stages: (1) in situ hydrotalcite (HT) precipitation; (2) low-cost carbon substrate driven microbial sulfate reduction; and (3) ferrosol reactive barrier for removing biogenic dissolved hydrogen sulfide (H2S). For concept validation, laboratory-scale columns were established and operated for a 140-days period with key process performance parameters regularly measured. At the end, solids recovered from various depths of the ferrosol column were analysed for elemental composition and mineral phases. Prokaryotic microbial communities in various process locations were characterised using 16S rRNA gene sequencing. Results showed that the Stage 1 HT-treatment substantially removed a range of elements (As, B, Ba, Ca, F, Zn, Si, and U) in the NMD, but not nitrate or sulfate. The Stage 2 sulfate reducing bioreactor (SRB) packed with 70 % (v/v) Eucalyptus woodchip, 1 % (w/v) ground (<1 mm) dried Typha biomass, and 10 % (w/v) NMD-pond sediment facilitated complete nitrate removal and stable sulfate removal of ca. 50 % (50 g-SO4 m−3 d−1), with an average H2S generation rate of 10 g-H2S m−3d−1. The H2S-removal performance of the Stage 3 ferrosol column was compared with a synthetic amorphous Fe-oxyhydroxide-amended sand control column. Although both columns facilitated excellent (95–100 %) H2S removal, the control column only enabled a further ca. 10 % sulfate reduction, giving an overall sulfate removal of 56 %. In contrast, the ferrosol enabled an extra 99.9 % sulfate reduction in the SRB effluent, leading to a near complete sulfate removal. Overall, the process successfully eliminated a range of metal/metalloid contaminants, nitrate, sulfate (2500 mg-SO4 L−1 in the NMD to <10 mg-SO4 L−1 in the final effluent) and H2S (>95 % removal). Further optimisation is required to minimise release of ferrous iron from the ferrosol barrier into the final effluent.

A Cleaning of Internal Surfaces of Bunkers Without the Presence of Operating Personnel Inside the Bunker

Abstract Bunkers are an integral part of the infrastructure of enterprises in various industries processing bulk materials. Corrosion processes and the formation of dust deposits on the internal surfaces of bunkers are irreversible and often lead to disruptions in the technological process and equipment performance parameters, and in some cases, to accidents. The stability and continuity of technological processes for processing bulk materials largely depend on the cleanliness of the internal surfaces of bunkers. Even the best technical characteristics of technological equipment only indicate the technical capabili-ties of the operation of technological lines. Their reliable and effective operation can be ensured by proper maintenance of the condition of internal surfaces and cleaning from corrosion and deposits. Increased dustiness, poor visibility, and confined spaces significantly complicate the conditions for performing work by service personnel inside bunkers. The enclosed space inside bunkers is a very dangerous place not intended for the work of service personnel. In order to avoid endangering ser-vice personnel and prevent people from entering the bunker, methods are proposed to easily, quickly, and, most importantly, safely clean the surfaces inside the bunkers.

Experimental study and model optimization of thermodynamic performance of a single screw water vapor compressor

Single screw water vapor compressor has greater advantages under conditions of low suction temperature and high compression ratio, however, the current study has the following limitations: (1) the volumetric and isentropic efficiency were substituted as a fixed value into the models of compressor, (2) The suction temperature is concentrated in the medium-high region, (3) The compression ratio is concentrated in the medium-low range, which failed to accurately describe the water vapor compression process. Therefore, the relationship between the volumetric efficiency, isentropic efficiency and key characteristic parameters of compressor is studied experimentally, the mathematical models of the volume flow and compression power are established and verified by experiments, the changes of the mass flow, compression power, COP and SMER with suction temperature, discharge pressure and compression ratio are analyzed, the operation process parameters of the single-screw water vapor compressor are optimized.

Optimizing processing parameters in electrical discharge milling of CFRP using metaheuristics

ABSTRACT The micro-channel fabrication in carbon fiber-reinforced polymer (CFRP) composite through electrical discharge machining (EDM) process followed by the comprehensive study of dimensional deviation in the conceived micro-channels are presented in this work. The factors namely, voltage (V), tool rotational speed (TRS), and feed rate (FR) were considered for assessing their impact on channel width deviation (CWD). In addition to the variance analysis,, two potential metaheuristic optimizers, the Butterfly optimization algorithm (BOA) and the Spotted Hyena optimization algorithm (SHO) were used to identify the optimal operating parameters of the aforementioned process. The BOA revealed that the optimal process variables were FR = 5.99 µm/s, V = 150 volt, and TRS = 577.08 rpm for a CWD = 74.96 µm. In contrary, SHO revealed that FR = 5.99 µm/s, V = 150 volt, TRS = 542.96 rpm, and CWD = 74.53 µm were the corresponding optimal values. Overcuts were observed in the fabricated micro-channels and a detailed illustration of the mechanism of overcut formation was provided.

Study of a Novel Fluidized Bed Flotation Column with Enhanced Bubble Dispersion

Flotation machines and flotation columns are widely used as separation equipment for coal sludge. In order to obtain better flotation results for different particle sizes, the bubble distribution and size in the flow field need to be studied. In this paper, a novel three-phase fluidized bed flotation column (TFC) was designed, and the shear effect of liquid velocity (0.198 m/s, 0.226 m/s, and 0.254 m/s) and static bed height (0.1 m, 0.2 m, and 0.3 m) on the bubbles in the mineralized flow field region was investigated and evaluated for the formation of bubbles by shear in laboratory and semi-industrial experiments. The results show that the increase in filling bed height has a very obvious strengthening effect on the reduction of bubble diameter, and after the filling bed height reaches a certain value, the filling bed height will weaken the effect of apparent gas velocity on bubble diameter. The apparent gas velocity has different influencing effects on bubble diameter, and under conditions of low water velocity, the increase in the apparent gas velocity contributes to the reduction of bubble diameter. The conclusions of this study are expected to optimize the operating parameters of the flotation mineralization process and enrich the study of TFC, which can provide a reference for the design of future TFC studies.

Anaerobic digestion of distillery wastewater and napier grass: Characterization and process performance parameters

The BOD/COD ratio of napier grass (NG) + distillery wastewater (DWW) was found to be 0.4982, which reflected that the biodegradability of organic material is high and can be degraded and treated efficiently via biological processes. Moreover, further reductions in total solids (TS) and volatile solids (VS) were observed after thermal pretreatment at temperatures of 60°C and 100°C. VS/TS ratio also increased from 0.8767 to 0.9508 indicating a more significant proportion of organic matter are favorable for biogas production. This was evidenced by the resulting removal efficiencies ranging from 15% to 32% and 23% to 42%, for TS and VS, respectively. Overall, the study reported relevant effects of the application of thermochemical pretreatment in the process performance parameters in anaerobic digestion.

Design and test of potato seeding apparatus based on double-layer seed picking scoop structure.

At present, potato seeders in China generally have poor uniformity of seed rows and high coefficients of variation in plant spacing during seed rows, causing difficulties for subsequent mechanized plant protection and harvesting. Based on the effect of seed discharge to analyze the sowing process, a potato seed discharger with a double-layer seed picking spoon structure was designed. By analyzing the seed discharging mechanism and its operation process, the shape and size structural parameters of the seed picking spoon were determined. Finite element simulation of the seed pickup process and seed carrying process of the seed discharging mechanism was carried out by EDEM software to determine the double-layer seed scoop scheme and the range of factors for subsequent tests. A two-factor test was conducted with seeding line speed and seed drop height as test factors, and plant spacing coefficient of variation and seed potato lateral offset dispersion as test indexes. The test results showed that the double-layer seeding spoon chain seeder reduced the coefficient of variation in plant spacing by 5.8%, and the dispersion in lateral offset by 5.5 mm, compared with the single seeding spoon seeder, when the seeding speed was 0.184 m/s and the height of falling seed was 9 cm.

Performance investigation of drying Ashwagandha roots in a forced convection-evacuated tube indirect solar dryer

In this research work, experiments are conducted on drying Ashwagandha using an evacuated tube solar collector (ETSC) in India. The drying process performance parameters are evaluated. Experiment results obtained in drying of Ashwagandha using ETSC are compared with results obtained in open sun drying (OSD). ETSC dryer consumes 16 hours to reduce initial moisture content of 61.2% (db) to final moisture content of 8% while OSD consumes 24 hours of drying time to reach the final and safe moisture content. The average drying rate in ETSC and OSD processes are 0.004 and 0.0023% d.b min−1, respectively. Average efficiencies of the air heater and drying cabinet are 52% and 35%, respectively. From thin-layer mathematical modelling, Page and Two-Term models are the best fit for ETSC and OSD, respectively. After drying, OSD samples have the highest colour change than OSD. Total phenolic contents are 32.35 ± 1.4 and 21 ± 2.1 of the solar and OSD samples, respectively.

Using the Fenton reactions to eliminate Total Organic Carbon (TOC) from industrial effluents

Industrial effluents are produced in large quantities in underdeveloped nations, where they cannot be handled using conventional treatment techniques. In this study, hydroxyl radicals (HO•) were successfully generated for the treatment of industrial wastewater represented in TOC removals by combining aferrouscatalystwithhydrogenperoxidein the Fenton reaction. The effects of operating conditions of pH, ferrous dose, H2O2 dose, time, and initial TOC concentration were studied for the Fenton process and different operating parameters were studied for the coagulation process to optimize and control the removal efficiency. The results showed that Fenton oxidation processes are able to reduce about 86 % for initial TOC level of 2000 and 95 % for initial TOC level of 400 after using 0.15 g/L ferrous dose, 10 mL/L of 30 % H2O2 for 30 min at acidic pH 4. Finally, this study recommends removing organic materials from industrial effluent using the Fenton oxidation method.

Occurrence and removal prediction of pharmaceuticals positively correlated with antibiotic resistance genes in wastewater treatment processes

Wastewater treatment plants (WWTPs) are important source of pharmaceuticals in the environment, identifying their relationship with antibiotic resistance genes (ARGs) and removal behavior is important for risk control. In this study, the correlations of common pharmaceuticals (including antibiotics and non-antibiotics) and ARGs both in wastewater and sludge were investigated, and machine learning was applied to predict the removal efficiencies of typical pharmaceuticals positively correlated with ARGs. Among the 23 kinds of target pharmaceuticals, both antibiotics and non-antibiotics were found to be positive with typical ARGs in wastewater (e.g. correlation coefficients between caffeine and blaTEM, aadD and qnrS were 0.738, 0.609, 0.936, p < 0.01) but negative in sludge (e.g. correlation coefficients between ofloxacin and tetO, tetW and qnrS were −0.922, −0.933 and −0.902, p < 0.01), indicating the high risk of pharmaceuticals in wastewater promoting ARG spread. Furthermore, based on pharmaceutical removal efficiencies in different wastewater treatment processes in this and previous studies, the removal efficiencies of typical pharmaceuticals highly correlated with ARGs were well predicted through process operation parameters and wastewater characteristics by Random Forest model. HRT and temperature were identified as the most important explanatory variables. This study could provide comprehensive references for controlling pharmaceuticals in WWTPs.

Analysis of the Effect of the Elongation Operation on the Welding of Internal Metallurgical Discontinuities.

This article discusses the results of our research into the effect of elongation on the welding of internal metallurgical discontinuities for two different geometrical shapes of a model feedstock of a selected magnesium alloy. Model discontinuities, specifically those of the metallurgical void type, were placed in various local zones of the modelled feedstock to check the influence of their location on their welding. The numerical modelling was carried out using the Forge®NxT2.1 application based on the finite element method. The results of the numerical tests were verified in laboratory conditions using the Gleeble simulator of metallurgical processes. Based on this research, it was found that the geometric shape of the feedstock material and the location of internal metallurgical discontinuities have a significant impact on the welding of discontinuities. The optimal values of the main process parameters of the elongation operation in flat dies were also determined for use in individual forging stages in order to eliminate internal metallurgical discontinuities. On the basis of the numerical studies carried out and their verification under laboratory conditions, it was concluded that a relative draft equal to 35% should be applied to weld the metallurgical discontinuities, which would result in a favorable hydrostatic pressure distribution within the discontinuities.

Effects of thermal pretreatment and biotin supplementation on the anaerobic digestion of pineapple (Ananas comosus) wastes, kinetics of methane production, and statistical analysis

The anaerobic digestion (AD) of pineapple wastes (PW) was employed to understand the effects of design parameters, namely thermal pretreatment (TP) temperature (X1) and reaction time (X2), and biotin concentration (X3), to methane production. Kinetic parameters were evaluated by utilizing sigmoidal growth functions, whereas modified Gompertz (MGM) and Logistic function (LF) best described the system among all batch assays. Principal components analysis (PCA) and Pearson correlation matrix were used to understand the correlation and relationship between the design parameters, evaluated kinetic parameters, methane yield (Y), and process performance parameters, wherein it was found that the significantly statistical correlations were Rm-A, λ-X1, A-Y, A-%VS reduction, A-%pH change, Rm-Y, Y-%VS reduction, Y-%pH change, and %VS reduction-%pH change. Furthermore, the cumulative methane production profile in all reactors showed an increase of 19.2–169.2 % in Y compared to the control, suggesting that TP and biotin supplementation were suitable for the optimization of Y from the AD of PW. The Y among all reactors followed the order of A0 <A1 <A2 <A4 <A7 <A3 <A5 <A8 <A6 wherein the lowest Y from pretreated PW was observed at A1 (77.6478 mL/gVS), while the highest was recorded at A6 (175.3053 mL/gVS). The ANOVA results demonstrated that the contribution of main and interaction parameters to Y (X3 >X1X3 >X2X3 >X1 >X2 >X1X2) were statistically significant (p < 0.05), and therefore relevant in the microbial syntrophies during the AD of PW. From the regression analysis, a surrogate mathematical model was constructed with a goodness of fit R2adj= 0.998. Herein, the optimum design conditions in the methane production from AD of PW were found to be X1 = 80ºC, X2 = 120 min, and X3 = 0.25 mg/L.

Comparative assessment of different grades of coal for methanol production: Simulation, optimization, environmental and economic analysis

The present study reports the modeling and simulation of methanol production through the gasification of freshly mined three coal samples having different wt.% of ash, viz., low-ash coal (LAC), medium-ash coal (MAC), and high-ash coal (HAC), collected from three different locations in India. The effect of the input parameters such as steam-to-coal mass ratio and gasification temperature on process performance parameters such as stoichiometric number, syngas yield, green house gas emissions from the process stream or net stream carbon dioxide equivalent, and methanol yield was studied through process sensitivity analysis and input parameters are optimized for the maximum methanol yield and minimum green house gas emission. Primary economic investigation at optimized conditions revealed that an internal rate of return of 5.93% is achieved for HAC at minimum plant scale and setting the methanol selling price of 400 USD/ton whereas IRR obtained as 3.20% and 5.87% for LAC and MAC, respectively, at this condition. The coal sample, HAC, performed better due to a high internal rate of return (i.e., 7.53% at base case) and subsequently low production cost. The present study's findings can be decisive for the countries with substantial low-grade high-ash coal reserves concerning coal diversification for its sustainable consumption in methanol production.

A laboratory-scale compression feed screw for characterizing continuous feeding of dense granular materials

Compression feed screws are commonly used in biorefineries for the continuous feeding of biomass feedstock into reactors. Developing methods to assess the feasibility of feeding granular materials in a compression feed screw is critical for reducing solids handling issues during operation. A laboratory-scale compression feed screw has been built to measure critical process parameters of the feeding operation, namely the driving torque and the mass flow rate. The process parameters of two granular materials, microcrystalline cellulose Avicel PH-200 and milled corn stover are measured using the laboratory-scale feeder. The results show that a larger torque is required to feed corn stover than Avicel PH-200, even though the former consists of more compressible particles. Further, the device can capture real-time fluctuations in the process parameters during operation. The laboratory-scale feeder can be used to compare the feeding of different granular materials and the measured parameters can be used to validate predictive models for a compression screw feeding process.

Operational process parameters of underground coal gasification technique and its control

Underground coal gasification (UCG) is a complex process as it depends on many factors such as geological and geo-hydrological analysis of strata, physical and chemical properties of coal, operational process parameters, seismic events, analysis of produced gases in real-time. This paper mainly identifies the process parameter variations due to underground coal gasification. This scientific study could help us to choose appropriate sensors, and design and develop suitable monitoring units for the control, monitoring and precaution during coal gasification. In this article, one experimental work is carried out in laboratory scale with the help of developed system. This paper also described individual control and monitoring techniques of different operational process parameters required for successful UCG operation. This is helpful for successful operation in the actual field and reducing its complexity.