cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.27329246.v1
title: Experimental research and reaction process analysis of degradation of strong greenhouse gas SF<sub>6</sub> using 304 stainless steel

description: Emission reduction and substitution of sulfur hexafluoride (SF<sub>6</sub>) is an important way to build a new type of green and low-carbon power platform system and to achieve the goal of “net-zero.” As a strong greenhouse gas widely used in the power industry, it is especially necessary to carry out harmless degradation treatment for SF<sub>6</sub> exhaust gas that cannot meet the reuse conditions. In this paper, based on thermal degradation treatment technology, 304 stainless steel was utilized to degrade SF<sub>6</sub>. The study revealed that 304 stainless steel had a significant effect on the degradation of SF<sub>6</sub> gas. Particularly under low initial concentration (1700 ppm), low space velocity (1200–2400 mL/g<sub>304</sub>·h), and high temperature (800 ℃) conditions, the currently designed SF<sub>6</sub> degradation platform could achieve a 100% degradation efficiency and maintain it for a long time. Simultaneously, the main gas phase products of the degradation reaction were detected as SO<sub>2</sub> and SiF<sub>4</sub>, while the solid phase products were related to the initial concentration of SF<sub>6</sub>. Under low concentration conditions, the solid phase products of the degradation reaction were FeF<sub>2</sub> and FeS, while under high concentration conditions, the degradation products were FeF<sub>3</sub> and S, the byproducts of Ni and Cr in 304 stainless steel were NiF<sub>2</sub> and CrF<sub>3</sub> respectively. Finally, the possible reaction pathways for 304 stainless steel to degrade SF<sub>6</sub> were determined, and the feasibility of the reaction was confirmed through thermodynamic calculations. This research provides valuable reference for the harmless degradation of SF<sub>6</sub> gas in the domestic and international power industry.
DOI: 10.6084/m9.figshare.26425520
title: Numerical investigation of the laminar burning velocity and adiabatic flame temperature phenomenon for NH<sub>3</sub>/Hydrogen rich coal gases (HRCGs)/air flames

description: This paper deals with improving the combustion performance of NH<sub>3</sub> by mixing it with hydrogen-rich coal gases (HRCG). To this aim, temperature and NO emission profiles of NH<sub>3</sub>/Coke Oven Gas (COG) and NH<sub>3</sub>/Water Gas (WG) fuel mixtures were investigated. In addition, adiabatic flame temperature and laminar burning velocity (LBV) characteristics of the mixtures were also predicted, and all results obtained were compared with the predictions of the NH<sub>3</sub>/air blend. Adding COG or WG increased LBV and adiabatic flame temperature values consistent with the increasing amounts of HRCG in the fuel mixtures. For 45% mixing ratios of HRCG, the maximum LBV value of NH<sub>3</sub>/air increased by 216% and 149% whereas its’ maximum adiabatic flame temperature value increased by 5% and 4% when mixed with COG or WG, respectively. In addition, blending the NH<sub>3</sub>/air mixture with HRCG increased temperature distributions within the combustor. However, this promoted the NO formation of NH<sub>3</sub>/air flame. The main reason for the increase in NO emissions is that adding HRCG into the NH<sub>3</sub>/air mixture triggered the decomposition of NH<sub>3</sub> in the fuels and caused higher flame temperatures. This finding was confirmed by estimating the concentrations of O, OH, and HNO radicals in the flame zone. Effects of coal gases addition into NH3/air mixture have been investigated.A better combustion performance of NH3/air mixture has been achieved.
Addition of coke oven gas provided more favorable results.Blending with coal gases promoted the NO emissions of NH3/air flame. Effects of coal gases addition into NH3/air mixture have been investigated. A better combustion performance of NH3/air mixture has been achieved. 
Addition of coke oven gas provided more favorable results. Blending with coal gases promoted the NO emissions of NH3/air flame.
DOI: 10.6084/m9.figshare.27019568
title: Exploratory investigation on conversion behaviors and coking tendency during coal-based asphaltene hydrogenation processes

description: Coking is an urgent problem to be solved in direct coal liquefaction（DCL）industry, and coal-based asphaltene is considered as the main source of coking. Therefore，in this manuscript, the effects of solvent/asphaltene ratio, temperature and hydrogen pressure on conversion behaviors of asphaltene were investigated, and coking propensity of asphaltene in relatively high temperature and hydrogen-deficient systems was focused. The results show that in the hydrogen-deficient system, temperature significantly affects asphaltene conversion and coke yield, which reaches 82.91% and 6.31% at 470°C. And moreover, with hydrogen pressure increases from 2MPa to 4MPa, oil yield increases from 65.28% to 71.16% while coke yield decreases significantly from 8.85% to 2.90%, which indicates that relatively increase hydrogen pressure can effectively stabilize the free radicals to produce oil and restrict the generation of coke at 470°C. With increasing temperature or decreasing hydrogen pressure, H/C atom ratio of hydrogenated asphaltene decreases to 0.54–0.82 at the temperatures of 430–470°C and 0.45–0.66 at hydrogen pressures of 2.0–6.0MPa, while the H/C atom ratio of asphaltene is 1.02. Besides, methyl and methylene carbons are easily cleaved, and protonated aromatic carbons are converted to bridgehead aromatic carbons during hydrogenation process, which increases the aromaticity of asphaltene from 61.43% to 83.90% at 470°C.
DOI: 10.6084/m9.figshare.27019568.v1
title: Exploratory investigation on conversion behaviors and coking tendency during coal-based asphaltene hydrogenation processes

description: Coking is an urgent problem to be solved in direct coal liquefaction（DCL）industry, and coal-based asphaltene is considered as the main source of coking. Therefore，in this manuscript, the effects of solvent/asphaltene ratio, temperature and hydrogen pressure on conversion behaviors of asphaltene were investigated, and coking propensity of asphaltene in relatively high temperature and hydrogen-deficient systems was focused. The results show that in the hydrogen-deficient system, temperature significantly affects asphaltene conversion and coke yield, which reaches 82.91% and 6.31% at 470°C. And moreover, with hydrogen pressure increases from 2MPa to 4MPa, oil yield increases from 65.28% to 71.16% while coke yield decreases significantly from 8.85% to 2.90%, which indicates that relatively increase hydrogen pressure can effectively stabilize the free radicals to produce oil and restrict the generation of coke at 470°C. With increasing temperature or decreasing hydrogen pressure, H/C atom ratio of hydrogenated asphaltene decreases to 0.54–0.82 at the temperatures of 430–470°C and 0.45–0.66 at hydrogen pressures of 2.0–6.0MPa, while the H/C atom ratio of asphaltene is 1.02. Besides, methyl and methylene carbons are easily cleaved, and protonated aromatic carbons are converted to bridgehead aromatic carbons during hydrogenation process, which increases the aromaticity of asphaltene from 61.43% to 83.90% at 470°C.
DOI: 10.6084/m9.figshare.25046560.v1
title: Energy efficiency analysis and optimization of heat exchange network under the goal of “double carbon”: a case for production process of isopropyl acetate

description: In order to response to the “double carbon” strategy for reducing emissions, chemical production processes were optimized to lower the amount of utility work and equipment investment expenses with increasing the system’s capacity for heat recovery. A sensitivity analysis and the energy efficiency analysis with pinch technique were performed on the distillation and purification of the 30 kt/a isopropyl acetate (IPAC) production process by using process simulation software of Aspen Plus. The IPAC refining tower optimization results show that the purity of the refined IPAC could be reached 99.9% at circumstances of 44 theoretical plates, 19 feed plates, and 0.755 reflux ratio. According to the optimized energy consumption data from Aspen Energy Analyzer (AEA), the cold and heat logistics matching was performed. It can be seen that the heat exchange network was tuned to maximize energy recovery by reducing the amount of utility work. The optimized cold and heat utility usage were 734.69 and 727.81 kW, which meaning that compared with original process, the cold and heat utility usage energy can be save with 10.0%, respectively. The optimized results provide a certain theoretical basis and solution for improving energy saving and reducing investment costs.
DOI: 10.6084/m9.figshare.26425520.v1
title: Numerical investigation of the laminar burning velocity and adiabatic flame temperature phenomenon for NH<sub>3</sub>/Hydrogen rich coal gases (HRCGs)/air flames

description: This paper deals with improving the combustion performance of NH<sub>3</sub> by mixing it with hydrogen-rich coal gases (HRCG). To this aim, temperature and NO emission profiles of NH<sub>3</sub>/Coke Oven Gas (COG) and NH<sub>3</sub>/Water Gas (WG) fuel mixtures were investigated. In addition, adiabatic flame temperature and laminar burning velocity (LBV) characteristics of the mixtures were also predicted, and all results obtained were compared with the predictions of the NH<sub>3</sub>/air blend. Adding COG or WG increased LBV and adiabatic flame temperature values consistent with the increasing amounts of HRCG in the fuel mixtures. For 45% mixing ratios of HRCG, the maximum LBV value of NH<sub>3</sub>/air increased by 216% and 149% whereas its’ maximum adiabatic flame temperature value increased by 5% and 4% when mixed with COG or WG, respectively. In addition, blending the NH<sub>3</sub>/air mixture with HRCG increased temperature distributions within the combustor. However, this promoted the NO formation of NH<sub>3</sub>/air flame. The main reason for the increase in NO emissions is that adding HRCG into the NH<sub>3</sub>/air mixture triggered the decomposition of NH<sub>3</sub> in the fuels and caused higher flame temperatures. This finding was confirmed by estimating the concentrations of O, OH, and HNO radicals in the flame zone. Effects of coal gases addition into NH3/air mixture have been investigated.A better combustion performance of NH3/air mixture has been achieved.
Addition of coke oven gas provided more favorable results.Blending with coal gases promoted the NO emissions of NH3/air flame. Effects of coal gases addition into NH3/air mixture have been investigated. A better combustion performance of NH3/air mixture has been achieved. 
Addition of coke oven gas provided more favorable results. Blending with coal gases promoted the NO emissions of NH3/air flame.
DOI: 10.6084/m9.figshare.25412499
title: Feasibility of co-disposal of lignite and eucalyptus wood in coal-fired power plants: thermogravimetric characterization, typical gaseous pollutant emission characteristics, and economic analysis

description: Energy issues are becoming increasingly prominent, and biomass blending in coal-fired power plants can improve combustion performance and reduce gaseous pollutant emissions, thereby improving economic efficiency. In this study, a thermogravimetric analyzer, a horizontal tube furnace, and an infrared flue gas analyzer were used to investigate the combustion behavior and gaseous pollutant emissions of the co-combustion of LC and EW. The results show that blending EW into LC cofiring can inhibit the release of volatile matter and promote the decomposition of fixed carbon and lignin simultaneously. The HHV of EW (15.88 MJ/kg) reaches 63.7% of LC’s (24.90 MJ/kg), indicating EW has a high energy utilization value. With increasing combustion temperature, the average value of <i>CR</i><sub><i>S</i></sub> increased from 47.09% to 59.94%, and the average value of <i>CR</i><sub><i>Cl</i></sub> increased from 26.15% to 52.15%, leading to a significant increase in SO<sub>2</sub> and HCl emissions. The decrease in combustion temperature slightly promoted the release of N (<i>CR</i><sub><i>N</i></sub> increased from 11.76% to 14.45%). The results of the economic analysis show that the cost of CaO and NH<sub>3</sub>·H<sub>2</sub>O used for removing gaseous pollutants decreased the most, and the economic efficiency increased the fastest to 14,000 RMB/day when the EW blending ratio increased from 10% to 20%.
DOI: 10.6084/m9.figshare.26520553
title: Optimal and reliable design of stand-alone hybrid renewable energy systems: A multi-objective approach

description: This study presents solutions for multi-objective, multi-constraint optimization for both photovoltaic (PV) and photovoltaic/thermal (PV/T) stand-alone hybrid renewable energy systems (SA-HRES). The main objective is to optimize the size and improve the reliability of SA-HRES, which relies exclusively on renewable resources for hydrogen production. To solve the problem, an optimization algorithm based on Non-Dominated Sorting Genetic Algorithm-II (NSGA-II) was proposed and a new power management strategy (PMS) was developed. The reliability index, known as Power Loss Probability Percentage (LPSP), serves as both an objective function and a constraint. The waste energy percentage (PEW) is evaluated as a constraint to ensure that system efficiency remains within specified limits. Among the Pareto optimal solutions that satisfying the constraints of 10% LPSP and 5% PEW, the lowest PEW solutions for PV SA-HRES are $9388.5 with a PEW of 4.32% and LPSP of 6.0%. For PV/T SA-HRES, these values are $9211.6, 3.85%, and 6.9%, respectively. Despite similar annualized cost of system (ACS) values, the PV/T solution, which uses fewer PV/T, has an LPSP with a negligible difference and a lower PEW compared to the PV solution. This suggests the potential benefits of using PV/T instead of PV in HRES, offering improved efficiency and reliability.
DOI: 10.6084/m9.figshare.26520553.v1
title: Optimal and reliable design of stand-alone hybrid renewable energy systems: A multi-objective approach

description: This study presents solutions for multi-objective, multi-constraint optimization for both photovoltaic (PV) and photovoltaic/thermal (PV/T) stand-alone hybrid renewable energy systems (SA-HRES). The main objective is to optimize the size and improve the reliability of SA-HRES, which relies exclusively on renewable resources for hydrogen production. To solve the problem, an optimization algorithm based on Non-Dominated Sorting Genetic Algorithm-II (NSGA-II) was proposed and a new power management strategy (PMS) was developed. The reliability index, known as Power Loss Probability Percentage (LPSP), serves as both an objective function and a constraint. The waste energy percentage (PEW) is evaluated as a constraint to ensure that system efficiency remains within specified limits. Among the Pareto optimal solutions that satisfying the constraints of 10% LPSP and 5% PEW, the lowest PEW solutions for PV SA-HRES are $9388.5 with a PEW of 4.32% and LPSP of 6.0%. For PV/T SA-HRES, these values are $9211.6, 3.85%, and 6.9%, respectively. Despite similar annualized cost of system (ACS) values, the PV/T solution, which uses fewer PV/T, has an LPSP with a negligible difference and a lower PEW compared to the PV solution. This suggests the potential benefits of using PV/T instead of PV in HRES, offering improved efficiency and reliability.
DOI: 10.6084/m9.figshare.31306658.v1
title: Effect of long–term storage on the fatty-acid profile of biodiesel and its impact on key ultrasonic properties of biodiesels and blends

description: Biodiesel is a good alternative to Petroleum Diesel (PD). The storage of fuel is unavoidable for its future use. The objective of the study was to investigate ultrasonic parameters: viscosity, relaxation time, ultrasonic absorption and Gibb’s free energy for 2-year long-term stored biodiesels and blends with PD. The two biodiesels were Cotton Seed Oil Methyl Esters (CSOME) and Palm Stearin Methyl Esters (PSME). Five biodiesel blends with PD in 10, 20, 30, 40 and 50 volume per cent were studied at the room temperature of 301 K. The fatty-acid profiles were also investigated using GC–MS chromatographic analytical tool and the viscosity was determined using an Ostwald viscometer. Ultrasonic velocity was measured with an ultrasonic interferometer of fixed frequency 2 MHz. The results show that CSOME biodiesel contains 13.47 and 86.53 weight per cent of low molecular weight nonpolar and high molecular weight polar compounds, respectively, and PSME biodiesel with 38.66% and 61.33%, respectively. The measured parameters increased for both the biodiesel blends due to storage. The increase in CSOME blends is more than that in PSME blends. For CSOME blends, highest and lowest changes are 64.28% and 4.48% for 10% volume blend of viscosity and pure CSOME biodiesel of Gibb’s free energy, respectively. In PSME blends, they are 31.25% for 10% volume blend of viscosity and zero for 50% volume blend of Gibb’s free energy. The highest difference occurred for 50% volume blends between old CSOME and PSME blends. From the overall results, it is concluded that variations of the measured parameters strongly depend on the fatty-acid profile of biodiesels due to storage.
DOI: 10.6084/m9.figshare.27255857.v2
title: Mathematical modeling for the efficiency function of the Retiro small hydroelectric power plant turbine-generator set

description: Many authors use an efficiency constant for the turbine-generator set to calculate energy generation in hydroelectric projects. This often does not reflect reality because the efficiency of this system is relative and is related to the potential of the net head height and the flow of turbine discharge. The present work aims to perform a mathematical modeling for an analysis of the efficiency of the Turbine-Generator Small Hydroelectric Power Plant (SHPP) Retiro. To perform this analysis, a model based on a second-degree polynomial function was employed. A multivariate regression technique was applied by the Least Square Method (LSM) to obtain the coefficients of the function. To verify the behavior of the measured and adjusted data, the Determination Coefficient (R<sup>2</sup>) of Root Mean Square Error (RMSE) algorithm was applied. The RMSE Mean of 0.022 and the RMSE Std of 0.029 suggest that the second-degree polynomial function is more consistent and stable across different training and validation datasets. The R<sup>2</sup> value of 0.993 indicates that 99.3% of the variability in the data is explained by the model. The Omnibus, Durbin-Watson, and Jarque-Bera tests were applied to diagnose potential issues related to normality, autocorrelation, and adequacy, thereby validating the accuracy and significance of the model. The Hessian matrix technique was also used to verify the critical points of the function. The critical point corresponding to a water head of 11.47 meters and a turbine flow of 145.1 m<sup>3</sup>/s presented the highest operational efficiency. This study allows presenting a turbine efficiency function, its Hill Curve and a generator efficiency function with its corresponding Efficiency Curve. For efficiency analysis in several flow, height and power settings. The technique has proved efficient and can be an applicable tool in energy parameter studies for other hydroelectric projects with the same characteristics as SHPP Retiro.
DOI: 10.6084/m9.figshare.27149571
title: Deactivation mechanism of catalyst in long-period experiment of 1,1,2-TCE dehydrochlorination

description: VDC, as an important raw material for high barrier material PVDC and lithium-ion battery binder PVDF, had an increasing demand. The catalytic dehydrochlorination of 1,1,2-TCE to generate VDC was a green process route that was expected to replace the heavily polluting sodium hydroxide saponification process in industry. There was a certain research foundation for the catalytic dehydrochlorination of 1,1,2-TCE, among which the core problem was that the catalyst was prone to deactivation. Previous studies had calculated the average molecular structure of the spent catalyst surface species when coconut shell activated carbon was used as the support. In subsequent studies, alumina support had been proven to be a better carrier for dehydrochlorination of 1,1,2-TCE, and the selected catalyst had been used in long-period laboratory experiments. The results indicated that the catalyst life had been significantly improved. In the early stage of the reaction, the activity of the catalyst decreased rapidly. In the first 20 h, the conversion of 1,1,2-TCE decreased from 49.35% to 40.36%. From 21 h to 120 h, the conversion of 1,1,2-TCE decreased from 39.96% to 36.18%, tending to stabilize. After 120 h of reaction, the catalyst was extracted and elemental analysis, FTIR, and GPC characterization were performed on the spent catalyst surface species. The average molecular formula of the carbon deposits was obtained as C<sub>96.08</sub>H<sub>50.29</sub>Cl<sub>36.53</sub>. Compared with coconut shell activated carbon support, under the action of activated alumina support, the route of catalyst carbon deposition had changed, and the sediment was more composed of polyvinylidene chloride components. Under certain conditions, sediment formed a dynamic equilibrium, which explained why the activity of the catalyst gradually stabilized. This study revealed the catalytic mechanism of active alumina supported catalyst and the pathway of carbon deposits generation, which was of great significance for improving the lifespan of improved catalyst.
DOI: 10.6084/m9.figshare.27149571.v1
title: Deactivation mechanism of catalyst in long-period experiment of 1,1,2-TCE dehydrochlorination

description: VDC, as an important raw material for high barrier material PVDC and lithium-ion battery binder PVDF, had an increasing demand. The catalytic dehydrochlorination of 1,1,2-TCE to generate VDC was a green process route that was expected to replace the heavily polluting sodium hydroxide saponification process in industry. There was a certain research foundation for the catalytic dehydrochlorination of 1,1,2-TCE, among which the core problem was that the catalyst was prone to deactivation. Previous studies had calculated the average molecular structure of the spent catalyst surface species when coconut shell activated carbon was used as the support. In subsequent studies, alumina support had been proven to be a better carrier for dehydrochlorination of 1,1,2-TCE, and the selected catalyst had been used in long-period laboratory experiments. The results indicated that the catalyst life had been significantly improved. In the early stage of the reaction, the activity of the catalyst decreased rapidly. In the first 20 h, the conversion of 1,1,2-TCE decreased from 49.35% to 40.36%. From 21 h to 120 h, the conversion of 1,1,2-TCE decreased from 39.96% to 36.18%, tending to stabilize. After 120 h of reaction, the catalyst was extracted and elemental analysis, FTIR, and GPC characterization were performed on the spent catalyst surface species. The average molecular formula of the carbon deposits was obtained as C<sub>96.08</sub>H<sub>50.29</sub>Cl<sub>36.53</sub>. Compared with coconut shell activated carbon support, under the action of activated alumina support, the route of catalyst carbon deposition had changed, and the sediment was more composed of polyvinylidene chloride components. Under certain conditions, sediment formed a dynamic equilibrium, which explained why the activity of the catalyst gradually stabilized. This study revealed the catalytic mechanism of active alumina supported catalyst and the pathway of carbon deposits generation, which was of great significance for improving the lifespan of improved catalyst.