Specific Consumption Research Articles

Operation optimization of cement clinker production line based on neural network and genetic algorithm

The operation control plays a great role in the running performance of an industrial process. To achieve a successful control, the key point is searching for the target value of the control parameters. The relationship between operation parameters and performance parameters is usually nonlinear and complex, so it is hard to control an industrial process excellently with workers' experience. Based on a large amount of actual operation data, a bridge between control parameters and performance parameters might be built by the neural network. Prediction model is established by using neural network, genetic algorithm was then used to refine these parameters, the optimal condition can be further achieved by combining the relation bridge and genetic algorithm (GA). Paying attention to a cement clinker production process, this article established an optimizing approach based on the neural network and genetic algorithm and one-year operation data (615 sets). The feeding mass rate of raw meal and coal at the precalciner and the feeding coal mass rate at the rotary kiln are selected as the main independent variable and control parameters, and the specific standard coal consumption is determined as the key performance parameter and the optimization objective function. The mean square error and the correlation coefficient of the established neural network model are 12.84 and 0.89, respectively. The relative errors of approximately all prediction data (92.52 %) are within ±5 %. The optimal values for the raw meal feeding rate, the coal feeding rate into precalciner, and the coal feeding rate into rotary kiln are 259.57 t/h, 7.84 t/h, and 7.40 t/h, respectively. In that optimal condition, the specific standard coal consumption reaches 80.00 kgstandard coal/tclinker (This is a relative value, as there is a slight drift in zero point of the factory's instruments). A highly accurate neural network model is developed, which can significantly reduce standard coal consumption and improve industrial energy efficiency.

The influence of acetylene black microparticles as a fuel additive in pure palm oil and its performance characteristic on diesel engine

Fuel additives are recognized for their potential to make diesel engines cleaner and more efficient. However, the use of Pure Palm Oil (PPaO) as a fuel faces challenges due to its inherent combustion inefficiencies. This study explores how Acetylene Black (AB), as an additive, affects the combustion performance and spray characteristics of a diesel engine. Observations of spray phenomena were conducted using a High-Speed Camera Phantom C110. The addition of AB to PPaO resulted in an increase in engine power and torque by 11.43 % at a 60 % load, averaging a 2.97 % improvement over diesel fuel (DF). PPaO demonstrated the most significant improvement in Specific Fuel Consumption (SFC) by 17.2 % at a 40 % load, averaging an 8.2 % increase. For PPaO with AB (PPaOAB), the greatest enhancement in SFC occurred at a 10 % load, showing a 9.2 % improvement over DF, with an average increase of 2.1 %. The study also found that thermal efficiency was optimally enhanced with PPaOAB at a 20 % load, achieving a remarkable 17.7 % improvement compared to DF. Notably, the inclusion of PPaOAB significantly reduced the thickness of carbon deposits on the pistons and cylinder head by 51.8 % and 3.9 %, respectively, and improved spray angle and penetration compared to PPaO. These findings suggest that AB could be a promising additive for PPaO, sparking further research interest in the application of AB in other fuels.

Heat recovery of multistage circulated permeate gap membrane distillation for energy-efficient water production

Addressing the challenges of energy efficiency in the desalination industry, this study proposed an energy-efficient water desalination system, focusing on the novel innovative approach of gap water circulation in permeate gap membrane distillation (PGMD) systems. A counterflow multistage is considered and analyzed using combined heat-mass transfer modeling. In comparison to conventional PGMD configurations, the introduction of gap water circulation has visibly emerged to increase water productivity while decreasing energy consumption. This research systematically explored the impact of this innovation, employing a comprehensive methodology that includes modifying flow chamber configurations and analyzing operational parameters. The study was performed at different seawater intake flow rates, intake temperature, feed injection temperature, and different number of stages. It was found that increasing the number of stages in the counterflow configuration presented better energy efficiency and higher feed recovery ratios at different conditions. A remarkable reduction in Specific Thermal Energy Consumption (STEC) to 92 kWh/m3, coupled with a notable increase in flux values reaching 28 kg/m2.hr for the alternative modules due to the intensified turbulence and mixing. The study demonstrated the potential of gap water circulation in significantly enhancing the energy efficiency and productivity of MD systems compared to conventional PGMD systems.

High ethane content enables efficient CO2 capture from natural gas by cryogenic distillation

Cryogenic CO2 capture technique is superior to other CO2 capture methods in terms of potential environmental protection, because it uses no chemical solvent or membrane materials that need regular replacement. However, the freezing problem of CO2 makes it difficult to achieve CO2 capture through simple gas–liquid separation, and the existing cryogenic CO2 capture techniques often require a specially designed separation equipment. In addition, cryogenic CO2 capture is generally considered a method with high energy consumption due to the need for refrigeration. This study proposes a cryogenic distillation-based CO2 capture method for natural gas with high ethane content, such as shale gas and oilfield associated gas. This method utilizes the azeotropic characteristics of CO2 and ethane to avoid CO2 freeze-out and the energy consumption for CO2 capture is minimized through process integration with natural gas liquefaction and ethane recovery. The proposed system uses the propane precooled mixed refrigerant process to provide the required refrigeration, and it is simulated in Aspen HYSYS and optimized by a combined method of a genetic algorithm and sequential optimization. The results show that the proposed process can remove up to 17 mol% of CO2 to less than 50 ppm. With extractive distillation, 99.50 % of the ethane in the feed gas is recovered with a purity of 99.50 mol%. The optimal results corresponding to the maximum allowable CO2 content to avoid its freeze-out (with a solubility margin of 500 ppm) show that when ethane content is 2–20 mol%, the specific power consumption of the system is about 0.43 kWh/Nm3(NG) with an exergy efficiency higher than 50 %. The proposed process achieves energy-saving and efficient CO2 capture method for natural gas with high ethane content.

Predicting combustion, performance, and emission characteristics of a compression ignition engine utilising coconut oil methyl ester and MoO3 nanoparticles

The present study used a blend of biofuel and nanoparticles to examine the effectiveness and emission properties of a four-stroke, single-cylinder, direct-injection diesel engine with an injection pressure of 250 bar. The use of MoO3 in biodiesel enhances its environmental sustainability and dependability, making it a promising substitute for traditional diesel fuel. The study emphasises the ecological advantages of using a combination of coconut oil and MoO3 to accomplish the production of renewable energy. MoO3 nanoparticles ultimately function as an oxidation catalyst, enhancing combustion. A study with MoO3 nanoparticles at 50 and 100 ppm concentrations was carried out. Utilising a photo spectrometer, stability was determined. The CI engine demonstrated improved thermal efficiency and reduced Fuel Consumption compared to diesel, both at full load conditions and at 64.5 bar pressure. The performance, combustion, and emission parameters were precisely forecasted using Design Expert, exhibiting a robust connection with the testing results. The Rb values for Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTE), Peak Cylinder Pressure (P-CA), Net Heat Release Rate (NHRR), Crankcase Heat Release Rate (CHRR), Carbon Monoxide (CO), Unburned Hydrocarbons (UHC), Nitrogen Oxides (NOX), and Smoke Opacity are 0.997, 0.9998, 0.8898, 0.979, 0.9838, 0.9815, 0.9917, 0.9958, and 0.9261 respectively.

Investigations of a turbine pre-swirl system with high temperature drop efficiency through the design of a novel vane-shaped receiver hole

The pre-swirl system, a vital system responsible for supplying cooling gas to the turbine blades. However, the pre-swirl system involves rotor-stator matching and intricate power-heat conversion challenges, which has led to a bottleneck in the development of its temperature drop potential. This study investigates the traditional pre-swirl system structure to identify factors limiting its temperature drop performance. A novel design idea is proposed to enhance the temperature drop performance by reducing the power consumption in the pre-swirl system. Subsequently, the structure optimization and performance improvement for pre-swirl system are conducted through the design of four vane-shaped receiver hole models. To assess the effectiveness of these enhancements, the thermodynamic and aerodynamic characteristics of the pre-swirl system before and after optimizations are evaluated using numerical simulations. Finally, the system temperature drop characteristics equipped with optimal receiver holes are thoroughly evaluated by experimental test analysis. The findings reveal that the new type of pre-swirl system, featuring a leading-edge vane-shaped receiver hole design and the removal of the cover-plate cavity, surpasses traditional designs. It exhibits a remarkable 35.3 % improvement in the receiver hole discharge coefficient, a 39.7 % reduction in system entropy increase, and a 6.36 kW/(kg/s) decrease in specific power consumption. Significantly, experimental verification demonstrates a 10 % increase in the nozzle pressure ratio, the temperature drop of pre-swirl system increased by 53.6 % from 23.5K to 36.1K, and the temperature drop efficiency of pre-swirl system increased from 0.567 to 0.872. Therefore, this study offers valuable insights for the design of high-performance pre-swirl systems, contributing to the overall improvement of turbine efficiency.

Neural network for predicting operating modes and calculating energy characteristics of steam turbine plants

The article describes the results of work on the creation of neural networks calculating the technical and economic parameters of all possible modes of operation of a thermal turbine unit with a steam turbine of type PT-60-130/13. In accordance with the objectives set, recommendations for the preparation of training data samples are formulated. The input and output parameters of the condensing and heating modes of operation of the steam turbine are determined. The results of research on determining the most optimal architecture of neural networks for calculating the energy characteristics of steam turbine plants of the heating type are presented. The results of calculations of the mean squared errors of neural network predictions from the results of calculations performed using a verified object-oriented model of a PT-60-130/13 turbine unit are tabulated.Graphs of the dependence of the specific heat consumption for the generation of electrical energy on the power of a PT-60-130/13 turbine unit for condensation and heating modes of operation using neural networks are plotted. The conclusion is formulated about the possibility of using neural networks for the development of energy characteristics and regulatory documentation on fuel use of equipment of thermal power plants.

Effect of process parameters on the extraction kinetics of Leptocarpha rivularis DC. in a packed bed extractor using supercritical carbon dioxide

The kinetics of supercritical extraction from L. rivularis stalks using CO2 were studied in terms of temperature (40−60ºC), pressure (18–30 MPa), specific CO2 consumption (30−50 kg/kg d.s.), and particle diameter (0.5−1.1 mm). The extraction yield was found to range from 17.30 to 27.23 g/kg d.s. The highest extraction yield was obtained at 40°C, 30 MPa, 30 kg CO2/kg d.s., and mean particle size of 0.5 mm. The yield increased with pressure and decreased with temperature and particle size (p≤0.05). The diffusion model based on Fick's 2nd law adequately described the cumulative extraction curves, using the effective diffusion coefficient (De) as the adjusted parameter, which ranged between 3.50 and 19.26×10−12 m2/s. The Biot number was estimated, indicating a prevalence of internal control to mass transfer resistance. Additionally, the “apparent solubility” was obtained from the initial slope of the cumulative extraction curves. The extraction yield correlated positively with apparent solubility (p≤0.05) and De coefficient (p≤0.05).

Analysis and development of criteria for the operational efficiency of urban electric buses

Problem. Currently, manufacturers and research specialists primarily utilize the amount of autonomous mileage and/or the specific electricity consumption of autonomous DEEs per unit of mileage to describe the general characteristics of urban electric buses. However, the structural mass and the key operational parameter, the nominal passenger capacity, are often disregarded. Therefore, comparing electric buses of the same type with identical dimensional parameters based solely on these criteria is illogical and incorrect. Goal. This study aims to establish criteria for the operational efficiency of urban low-floor electric buses of various types, considering autonomous DEE and their charging or replacement systems. These criteria should account for structural mass and nominal passenger capacity, facilitating a proper comparative assessment and the selection of the most optimal options for use in urban passenger transportation systems. Methodology. Criteria for the operational efficiency of city electric buses of various types are proposed based on an analysis of electricity consumption required for both movement and the operation of heating, ventilation, and air conditioning systems. The criteria consider the mass in the equipped state and the main parameter - nominal passenger capacity. Results. Several operational efficiency criteria for urban electric buses, incorporating mass parameters and passenger capacity, are suggested. The feasibility of their application is demonstrated through a comparison of five sketch projects of electric buses of various types with modern models. Originality. The proposed criteria for the operational efficiency of urban electric buses offer a method for adequately comparing any selected models, regardless of their types and technical specifications. Practical value. The proposed criteria for the operational efficiency of urban electric buses of various types can be beneficial for transport company specialists in selecting suitable rolling stock for specific routes. Additionally, design bureau and scientific and technical center specialists can utilize these criteria during the design process of new urban electric transport models.

Encouraging Invasive Acacia Control Strategies by Repurposing Their Wood Biomass Waste for Pulp and Paper Production

Concerns on the expanding infestation of several Acacia species in the southern Mediterranean European countries have triggered an ever-growing requirement for costly targeted control actions. Valorizing biomass waste produced could help promote and better finance these actions. For that purpose, wood wastes from invasive control actions were tested regarding their pulp and paper potential, aiming to entice cellulose industries to partake in future conservation actions. Wood waste from the five most pervasive Acacia species was studied (Acacia dealbata Link, Acacia longifolia Willd, Acacia mearnsii De Wild, Acacia melanoxylon R.Br, and Acacia saligna Labill) regarding physical and chemical characteristics, and a central composite design was used to optimize alkali charge and reaction temperature on pulping yield and delignification. Bleached kraft pulps were produced with each species’ optimized conditions and for an equitable mixture of all species. Optimized pulp yields (52.6%–53.5%) and pulp polymerization degree (2867–3690) of Acacia species were higher than those of Eucalyptus globulus Labill (used as reference). Optimized bleached pulps were refined and fiber, pulp, and handsheet properties determined. Acacia dealbata and A. longifolia presented high specific wood consumption and lower handsheet strength properties, pointing to overall lower pulping potential, while A. melanoxylon and A. mearnsii characteristics were equal to or higher than those of E. globulus. A. saligna pulp and handsheet characteristics appear more suited for tissue paper. The Acacia mixture achieved acceptable characteristics, enabling the indiscriminate use of Acacia wood regardless of the species. As a shortcoming, the Acacia pulps showed the worst optical characteristics, with brightness dropping substantially with beating (64%–76%) when compared to E. globulus (81%).

Influence of loading on the heat transfer rate and specific water consumption of detached loosed fresh palm fruits during vertical mini-batch sterilization

This study presents the effect of loading on the heat transfer rate and specific water consumption of detached loosed fresh palm fruits during sterilization. Sterilization is an integral process of palm oil extraction that consumes a lot of water. However, most industrial research in the past focused on fresh fruit bunch (FFB) sterilization dynamics. At the same time, the medium- and small-scale industries sterilize already detached loosed fresh palm fruits (LFPF) that have been removed from the spikelet as purchased from aggregators. Therefore, the process data generated from the sterilization of FFB might not be optimal for sterilizing LFPF. This study, therefore, investigates the transient response of variation in LFPF loading of the sterilization chamber to steam injection during steam sterilization of LFPF at 3 ± 0.5 bars using a vertical, single-peak LFPF sterilizer that combines the boiler and sterilizer in a single unit. The LFPF were loaded at mass intervals of 0.2 kg ranging from 0.2 kg to 2 kg. The vapour temperature dynamics, heat transfer rate, steam energy utilization efficiency and specific water consumption parameters were studied. The average vapour temperature varied from 100 °C to 130 °C for the LFPF mass range of 0.2 to 2 kg at steam injection temperature of 140 °C and pressure of 3 ± 0.5 bars. This temperature range matched the saturated vapour temperature of pure water at 1.0––2.8 bars absolute pressure but slightly lower than the saturated vapour temperature of 133.54 °C for pure steam at 3 bars. The percentage of steam energy utilization effectiveness is inversely related to the steam mass flow rate. While energy effectiveness increased with loading mass, the steam mass flow rate decreased with increased LFPF mass. The value of the heat transfer rate ranged between 1.7––55.4 W, while the specific heat transfer rate ranged between 8.5–––41.8 W/kg. The average specific water consumption ranged from 0.014 to 0.09 kg-water/kg-LFPF, with an average value of 0.031 kg-water/kg-LFPF. This value is lower than 0.112–––0.5 kg-water/kg-FFB, with an average value of 0.256 kg-water/kg-FFB for conventional FFB steam sterilization. This represents an 87.9 % reduction in water consumption in conventional FFB steam sterilization. An empirical model deduced for specific heat transfer rate and water consumption for steam sterilization of LFPF at 3 ± 0.5 bars and vapour temperature range of 100––130 °C showed a high coefficient of determination above 99 %.

The effects of user- and marketer-generated content on customer satisfaction: A textual analysis approach

Online reviews and management responses are important user-generated content (UGC) and marketer-generated content (MGC) in social media platforms, which directly reflect the customer’s and merchant’s feedback on a specific consumption and may further affect customer satisfaction. However, as the targeted feedback to UGC, the impact of MGC and the total impact between UGC and MGC are still understudied. In this work, we proposed a systematic analysis procedure for unravelling the impacts of online catering UGC and MGC on customer satisfaction in-depth. By studying the collected 130,412 review data from a leading online catering review website in China, we empirically extracted several new UGC topics using a topic model, thereby expanding the customer value factor set from previous literature; we also quantitatively analyzed their effectiveness in explaining customer satisfaction. We further integrated the UGC and MGC, and causally elaborated upon the usefulness of targeted responses in customer relationship management through difference-in-difference (DID) analysis. The findings validated that the effectiveness of management response on customer future satisfaction is relatively limited compared to the impact brought by the rating variables in UGC, but targeted management responses can perform more effectively in improving customer satisfaction. In addition, moderation roles based on the consumption price and the subjective emotional tendency of customers revealed in the textual comments were also investigated. Thus, this study helped to form a comprehensive understanding of customer satisfaction by contributing to a better quantification of customer value factors and understanding of the influence mechanism for customer satisfaction through the integration of UGC and MGC. Several managerial implications for optimizing customer relationship management in online catering markets were also provided.

Study of rock fracture patterns for obtaining the basis for energy-efficient ore ball milling

The study is conducted using methods of analysis (in proving the possibility of assessing the disintegration of rocks by energy consumption), methods of free vibration theory (to determine the motion of a falling ball over an elastic connection), methods of energy balance, methods of theoretical mechanics and material resistance (to study amplitude characteristics of mechanical systems), methods of rock fracture theory (to determine fracture work), physical modeling (to design test benches) and experimental methods (to find relationships between parameters). The strength of bulk crushed material in the first stages of ore preparation is practically independent of its coarseness and solid form, which allows the estimated volume of disintegrated ore (particle concentration) to be determined by the energy expended, translated into other physical quantities. Results of experimental studies support the theoretical dependences. The proposed approach of automatic stabilisation of solid concentration in the ball mill pulp at the optimum level allows to increase the productivity of ore preparation on the finished grade in the first stages by 10% at reduction of specific power consumption for ore grinding.

Investigation on Synergism and Its Influence Parameters between Coal and Biomass during Co-Gasification Based on Aspen Plus

The co-gasification of coal and biomass offers numerous benefits, including improved gasification efficiency, reduced pollution emissions, and the utilization of renewable resources. However, there is a lack of comprehensive research on the synergistic effects of, and influence parameters on, coal–biomass co-gasification. This study employs Aspen Plus simulations to investigate the co-gasification behavior of coal and corn straw, focusing on the synergistic effects and the impact of various operating conditions. A synergistic coefficient is defined to quantify the interactions between the feedstocks. Sensitivity analyses explore the effects of gasification temperature (800–1300 °C), coal rank (lignite, bituminous, anthracite), biomass mass fraction (0–50%), oxygen-to-carbon ratio, and steam-to-carbon ratio on the synergistic coefficients of effective syngas content (CO + H2), specific oxygen consumption, specific fuel consumption, and cold gas efficiency. The results reveal an optimal biomass mass fraction of 10% for maximizing cold gas efficiency, with the syngas primarily consisting of H2 (36.8%) and CO (61.6%). Higher gasification temperatures (up to 1200 °C) improve syngas quality and process efficiency, while higher-rank coals exhibit better gasification performance compared to lignite. Optimal oxygen-to-carbon and steam-to-carbon ratios are identified for maximizing syngas yield and quality. These findings provide valuable guidance for the design and optimization of industrial coal–biomass co-gasification processes, enabling the maximization of syngas quality, process efficiency, and resource utilization.

Experimental Evaluation of Methanol/Jet-A Blends as Sustainable Aviation Fuels for Turbo-Engines: Performance and Environmental Impact Analysis

This study offers a comprehensive examination, both theoretically and experimentally, of the potential of methanol (M) as a sustainable aviation fuel (SAF) assessed in combination with kerosene (Ke—Jet-A aviation fuel + 5% Aeroshell oil). Different blends of methanol and kerosene (10%, 20%, and 30% vol. of (M) was added to Ke) were tested in an aviation micro turbo-engine under various operating regimes, such as idle, cruise, and maximum. Key engine parameters, including combustion temperature, fuel consumption, and thrust, were closely monitored during these trials. Essential performance indicators such as combustion efficiency, thermal efficiency, and specific consumption for all fuel blends under maximum operating conditions are also presented. Physical and chemical characteristics, such as viscosity, density, calorific value and flash point, were determined for each blend. Moreover, elemental analysis and FTIR spectroscopy were utilized to evaluate the chemical composition of the fuels. This study further investigated the air requirements for stoichiometric combustion and computed the resulting CO2 and H2O emissions. Experimental tests were conducted on the Jet Cat P80® micro turbo-engine, covering assessments of starting procedures, acceleration, deceleration, and pollutant emissions (CO and SO2) during various engine operating conditions. The results suggest that the examined fuel blends demonstrate stable engine performance at concentrations of 10% and 20% methanol. However, observations indicate that with an increase in methanol concentration, particularly at 30%, the stability of the engine at idle and, notably, at maximum speed decreases significantly. Specifically, at a 30% methanol concentration, the engine no longer operates stably, exhibiting significant rpm fluctuations, leading to the decision not to explore higher concentrations.

Power consumption of electric centrifugal pumping plants under extraction of highly watered oil

Relevance. Currently, oil fields in Russia are mainly developed using the method of artificial maintenance of reservoir pressure to achieve high oil recovery. The use of artificial impact on productive formations by the method of water injection contributes to the premature irrigation of production wells. Water content of productive layers in oil fields significantly complicates the technology of oil production. With the increase in water content of the surface fluid, the power consumed by the engine increases. Minimization of energy consumption is quite relevant, as oil is produced with significant expenditures of electrical energy. It is important to investigate the dependences of the electric energy consumption on the well water cut. Aim. To study the dependence of energy consumption of submersible electric centrifugal units operated in oil production wells on water cut. Methods. Submersible electric centrifugal installations for oil production. Results. In order to study the effects of formation water cut on electrical energy specific consumption, wells with a water cut of more than 90% were selected. Using the formula, the authors have calculated the electrical energy specific consumption for oil production. The analysis of the results of the calculated data showed that in producing wells with a water cut of up to 90 %, the average specific electric power consumption for oil production is within the recommended standards. In wells with the water cut more than 90%, the average specific electric power consumption for oil production exceeds recommended specific norms of electric energy consumption during operation of oil producing wells equipped with electric centrifugal installations. Based on calculated data, the dependence of the specific electrical energy consumption for oil production on the water cut of reservoir products was plotted, and wells with a water cut of more than 90% were selected. The analysis of the graphical dependence showed that in wells with an oil water cut of more than 90%, the specific energy consumption reaches maximum values ​​(the specific energy consumption increases by 40%).

Process design and adsorbent screening of VSA and exchanger type VTSA for flue gas CO2 capture

Carbon capture, as a core technology for mitigating greenhouse gas emissions, the greatest challenge is the balance between separation performance and energy consumption. This study seeks to evaluate and screen the separation performance and energy consumption of four typical adsorbents (13X, Mg-MOF-74, activated carbon, and Lewatit VP OV 1065) in vacuum temperature swing adsorption (VTSA) and vacuum swing adsorption (VSA) through optimization approach, which will support in-depth research and decision-making on adsorption processes. A non-isothermal non-adiabatic numerical model was carried out to describe a novel 4-bed 10-step VTSA cycle developed on an exchange type adsorption unit (ETAU), and the model was validated by binary breakthrough and temperature swing experiments. A 4-bed 10-step VSA cycle was in turn established and investigated. Parametric analysis of the two cycles was performed by varying the operating variables including feed gas flow rate, recycle time, and purge-to-feed ratio. Process optimization of the multiplicative fraction evaluation function, simultaneously considering purity, recovery, and productivity, was achieved using a dual convergence algorithm. Results showed that all four adsorbents could achieve more than 90 % purity and recovery on the VTSA process employing the ETAU for post-combustion carbon capture, and the separation performance was substantially superior to that of the VSA cycle. Mg-MOF-74 obtained a CO2 product with 97.90 % purity, 98.48 % recovery, and 5.48 mol/kgads/hr productivity at a desorption temperature of 383.15 K; it has a specific heat consumption of 1.45 GJth/ton and a specific power consumption of 0.55 GJel/ton. The total energy consumption of 13X was slightly lower than that of amine adsorbents, giving 95.00 % purity, 97.60 % recovery, and 1.91 mol/kgads/hr productivity. Relatively low desorption temperature is expected to introduce ultra-low-grade waste heat for partial heat source substitution, contributing to the energy sustainability of adsorption carbon capture technology.

A Life Cycle Assessment of Methane Slip in Biogas Upgrading Based on Permeable Membrane Technology with Variable Methane Concentration in Raw Biogas

While energy-related sectors remain significant contributors to greenhouse gas (GHG) emissions, biogas production from waste through anaerobic digestion (AD) helps to increase renewable energy production. The biogas production players focus efforts on optimising the AD process to maximise the methane content in biogas, improving known technologies for biogas production and applying newly invented ones: H2 addition technology, high-pressure anaerobic digestion technology, bioelectrochemical technology, the addition of additives, and others. Though increased methane concentration in biogas gives benefits, biogas upgrading still needs to reach a much higher methane concentration to replace natural gas. There are many biogas upgrading technologies, but almost any has methane slip. This research conducted a life cycle assessment (LCA) on membrane-based biogas upgrading technology, evaluating biomethane production from biogas with variable methane concentrations. The results showed that the increase in methane concentration in the biogas slightly increases the specific electricity consumption for biogas treatment, but heightens methane slip with off-gas in the biogas upgrading unit. However, the LCA analysis showed a positive environmental impact for treating biogas with increasing methane concentrations. This way, the LCA analysis gave a broader comprehension of the environmental impact of biogas upgrading technology on GHG emissions and offered valuable insights into the environmental implications of biomethane production.

Analysis of the Operating Energy Variables Involved in Mechanized Khoa Production

Significant portion of the total milk production of India has been utilized for the manufacture of the Traditional Indian Dairy Products (TIDP). Khoa based products were traditionally produced in the Indian sub-continent since ancient times. Khoa produced by the mechanized methods can overcome the demerits of traditional manufacturing methods like insufficient use of energy, poor hygiene and sanitation, non-uniform product quality, etc. In the present study, steam jacketed open type hemispherical kettle equipped with spring loaded Teflon edged scraper blade assembly was utilized for the mechanized production of khoa. A standardized mixed milk having (6.0±0.1%) fat and (9.0±0.2%) SNF, was evaporated to the different level of concentration using a batch type vacuum pan. The performance of the mechanized manufacture of khoa was evaluated at different steam pressures (P1= 98.06 kPa, P2=147.1 kPa, P3=171.61 kPa), scraper speed (R1=0.67rps), and different level of milk concentration (C1=35 %TS, C2=40 %TS, C3=45 %TS) for first stage. During the second stage, effect of operating variables on process mechanization were evaluated at different steam pressures (S1= 49.03 kPa and S2= 78.45 kPa) and scraper speed (R2=0.33rps). The primary objective of present study is to carry out thermal and electrical energy analysis associated with mechanized khoa production, which has a significant role in process optimization, scale-up of the operation and to design and fabricate the mechanized system. The overall heat transfer coefficients (U-values) of the mechanized system obtained at various processing parameters ranged from 156.87 to 234.16 W/m2K during khoa manufacturing. The treatment C1 P1 S2 gave the highest U-values for sensible and latent heating. The mean U-values of sensible heating and latent heating were increased with an increase in steam pressure during khoa making in the mechanized system. The mean value of specific steam consumption (kg steam/kg water evaporated) for the optimized operating conditions was 1.950 (kg steam/kg water evaporated) for manufacture of khoa in mechanized system. The total heat losses of mechanized system during manufacture of khoa was 17.15 to 28.02 % at different operating conditions studied. The mean values of electrical power consumption ranged from 141 to 203 Wh under different operating conditions. Considering the energy consumption data, we can narrate that existing system is energy efficient with lower electrical energy consumption and can reduce the labour cost due to mechanization.

Small-scale perfusion mimic cultures in the ambr250 HT bioreactor system

Perfusion cell cultures generate higher viable cell densities (VCD) and volumetric productivity compared to fed-batch cultures. However, due to the limited availability of small-scale perfusion models, perfusion systems are seldom used to produce licensed biotherapeutics. This study evaluated two small-scale perfusion mimic protocols to bridge the research-to-production gap. Shake flasks and the ambr250 HT were used to compare centrifugation and in situ gravity settling protocols. The centrifugation protocol achieved a peak VCD >50 million cells/mL and is well-suited to media formulation and feeding strategy comparisons. The in situ gravity settling protocol achieved ∼20 million cells/mL and is well-suited to cell productivity and stability studies. The cell retention steps resulted in temporary DO and pH changes but did not affect the overall culture's health. Further, both protocols were able to recover from an imposed long-duration DO stress, although the centrifugation protocol cultures had higher cell specific oxygen consumption rates indicative of higher culture stress. Both protocols sustained the cultures for 39 days with stable cell specific productivities (∼27 pg/cell·day). Overall, this study demonstrated the feasibility of two economic small-scale perfusion mimic protocols in a standard small-scale bioreactor system, which could be translated to other multi-unit small-scale bioreactor systems.