Environmental Progress & Sustainable Energy最新文献

Activated carbon can be used as a catalyst for the reduction of Co(III)TETA to Co(II)TETA so as to maintain the ability of removing NO from gas stream with Co(II)TETA solution. Calcium nitrate has been utilized to treat activated carbon to improve its catalytic ability in the regeneration of Co(II)TETA. The biggest Co(III)TETA conversion is gained by the carbon being soaked in 0.3 mol/L calcium nitrate solution at 65°C for 12 h with a solid/liquid ratio of 1 g/50 mL followed being carbonized at 400°C for 2 h in nitrogen. The characterization with Fourier transform infrared spectroscopy, XPS, BET (Brunauer-Emmett-Teller) and Boehm titration indicates that the modification with calcium nitrate increases the specific surface area and acidic groups on activated carbon. The continuous experiments reveal that the NO removal efficiency obtained by the modified carbon is over 12% up to that by the original one.

The control of heliostat is crucial for the development of solar tower power plant. Currently, most power plants use open-loop control, which has low cost but low efficiency, closed-loop control has high concentrating efficiency, but each heliostat requires sensors and has high cost, and Proportional-Integral-Derivative (PID) controller has good control effect, but the parameter adjustment is difficult and overshooting problem occurs. In this paper, we propose a DDPG-based heliostat cluster control aimed at improving the heliostat control effect and reducing the control cost. A leader-follower strategy is used to control the heliostat, where the whole heliostat field is divided into several groups, each group is assigned a leader heliostat, and the rest of the heliostats follow the leader heliostat to rotate. The leader acquires the control error by means of a photoelectric sensor or a camera device. The following heliographs rotate with the leader to obtain the control signal, so there is no need for sensors, which reduces the number of sensors and lowers the cost. To address the shortcomings of traditional PID, we propose a DDPG-based PID control algorithm. The algorithm is trained to find out the optimal value at each moment, which ensures that the controller parameters are optimal at each moment. The results show that the tracking error is below 0.0001 rad for both cluster control and individual control. This ensures effective tracking performance while reducing the sensor cost. The controller based on the DDPG algorithm eliminates overshoots, reduces errors, and shortens the stabilization time by 0.5 seconds.

This review shows an outlook about several works which have used the factorial design methodology for synthesizing zeolites and mesoporous materials, included the use of wastes as sources of silicon and aluminum. In the bibliography several interesting works were identified with a complete development of the factorial design methodology. However, there are other works that showed a limited statistical analysis of the results. In spite of these issues, their contribution in the advance of synthesis of zeolites is important. Moreover, different ways to measure the crystallinity were detected being the X-ray diffraction (XRD) the most used technique. This work also gives a proposal of the complete factorial design methodology as a guide in future works for synthesizing zeolites or zeo-types materials. This work presents a detailed review of the methodology of designing experiments for the synthesis of zeolite or zeo-type materials, where it has been shown and analyzed the type of design used, because the choice of a design involves a large number of experiments or few experiments thus facilitating the production of zeolite, in addition to the factors that influence the synthesis give information of the type to obtained zeolites, also includes a guide for applying this methodology. Experiment design methodology can help to produce high quality zeolites from virgin raw material or waste that impact the economy of the zeolite industry.

The present study investigated the performance of dual function reverse flow solar collector (RFSC). The impact of the mass flow rate of air and water on outlet temperature, thermal performance, and overall performance of dual-function solar air heater (SAH) has also been investigated. An experimental investigation of three different working models namely, Model-A: SAH, Model-B: solar water heater (SWH), and Model-C: integrated solar air-water heater (SAWH) for dual heating applications was performed to analyze the actual performance of these models. The investigation of the impact of time intervals on the water inlet and outlet temperatures at various mass flow rates of water is conducted to analyze the time-varying efficiency of SWH systems. Furthermore, the effect of solar intensity on the performance of the dual-function heating system has also been explained. The result reveals that the maximum thermal efficiency of Models: A and B can be achieved at about 78.8% and 67.9%, at a mass flow rate of 0.0644 and 0.10 kg/s, respectively, according to the experimental findings. The maximum temperature rise of air and water reaches about 52.4 and 55.58°C for Models A and B, respectively. The total efficiency of Model C reaches 81.69%, exceeding that obtained in Models A and B individually. The efficiency, outlet temperature of the fluid, and heat transfer effectiveness of the system strongly depend on the mass flow rate. The increase in heat removal factor is negligible for a higher flow rate (more than 0.10 kg/s).

The study of radionuclide concentrations is significant for the exposure of the radiation on the livings from these radionuclides and they are transferred from plants, animals to livings, and this is important for the health of livings. In this paper, ⁴⁰K concentration and elements content of wheat, barley, corn, and chick feeds, which are used as animal feed using gamma-ray spectrometry and inductively coupled plasma-optical emission spectrometry (ICP-OES) were examined. The animal feeds were obtained from two different sellers for representative and to be able to compare the obtained results from studied animal feeds. The mean value of ⁴⁰K radionuclide concentration for wheat, barley, and corn is smaller than the world mean value whereas it is higher for chick feeds than the world mean value. The H_in, H_ex, and I_γ of studied animal feeds are lower than limit value reported in the scientific report. There are positive and significant correlations between K, Ca, Fe, Mg, Na, P, and ⁴⁰K at the 0.01 level and between Cu, Mn, Ni, Zn, and ⁴⁰K at 0.05 level.

The present research employed ethylenediaminetetraacetic (EDTA) modified cellulose to remove basic violet 10 (BV10) and reactive orange 16 (RO16) dyes. The cellulose was obtained from sago bark which was solid waste of sago starch industries. Sago bark contains 56.86% cellulose so that it can provide significant amount of active site. The optimum condition was examined using batch method investigating some parameters including pH, initial dye concentration, contact time, and thermodynamics. The adsorption capacity of cellulose (Cell) itself was also investigated for the comparison. The characterization of adsorbent showed the presence of ester bond, amine groups and escalating of surface area and pores after EDTA modification. The adsorption capacity of EDTA-modified cellulose (Cell-EDTA) was 73.53 mg/g for BV10 and 22.42 mg/g for RO16. The adsorption of both dyes onto Cell-EDTA followed Langmuir isotherm model and pseudo-second-order kinetic model. Thermodynamic parameters indicated that the adsorption process was spontaneous, endothermic and feasible. Desorption studies proved that NaOH was an effective desorbing agent of BV10 and RO16. Based on research, Cell-EDTA was more favorable in cationic dye, basic violet 10 than anionic dye, reactive orange 16.

Thermal energy storage devices are gaining importance and momentum in the building space cooling and renewable energy applications. Retaining the stored energy for long hours through proper insulation is crucial in achieving economic benefits. In the present research, a novel composite material (FRP) is introduced for the development of cool storage tank along with two different methods of insulation (nitrile rubber foam insulation and vacuum insulation) to assess the performance of cool energy retention. The results show that the effect of vacuum insulation is lower compared with nitrile rubber foam insulation. This is due to the low specific heat capacity of the FRP material compared with air that increases the surface temperature of the tank than the ambient air during the day time in the case of vacuum insulation. Hence the study concludes that the additional layer of insulation material with high specific heat capacity than the ambient air to be added on the surface to avoid the overheating of the wall surface. The results are useful in designing the insulation for thermal storage tanks and managing the heat loss.

This article investigates the integration of circular economy methodologies and biorefinery concepts for the sustainable recovery of bio-based products from industrial effluents, addressing the critical need for resource efficiency and environmental sustainability in the face of climate change and resource depletion. Emphasizing the valorization of industrial by-products, the study explores innovative, eco-friendly recovery processes within a biorefinery framework to transform waste into valuable resources such as biofuels, biochemicals, and biomaterials. Through a systematic search in various bibliographic databases and a comprehensive literature review, the study critically analyzes existing studies, identifies research gaps, and offers new perspectives on the integration of biorefinery and circular economy principles. The findings reveal that strategic integration of biorefinery processes and circular economy principles can significantly reduce environmental footprints and foster sustainable industrial practices. Key challenges such as feedstock variability, technological barriers, and economic scalability are identified, along with recommendations for overcoming these obstacles through interdisciplinary collaboration, technological innovation, and supportive policy interventions. The main contribution of this research lies in its comprehensive approach, integrating cutting-edge technologies and circular economy principles to offer viable strategies for sustainable bio-based product recovery, thus significantly advancing the field of industrial sustainability. The article contributes to the advancement of sustainable technologies, policies, and strategies, advocating for a transition towards a more circular, resource-efficient industrial sector. Continued innovation and research are emphasized to optimize recovery processes and explore new applications, supporting a sustainable and thriving future for our planet.

Solar drying systems have proven to be cost-effective and environmentally friendly for drying various products. An extensive investigation of solar dryers with different designs, applications, and operating principles is conducted. Compared to direct drying, solar drying improves product quality by lowering moisture content without compromising the original product's qualities. Solar dryers are of two types: passive solar dryers and active solar dryers. Passive-mode solar dryers circulate air through natural convection, whereas active ones circulate air through forced convection. Crop-affected design characteristics include crop sensitivity, cost and time available to dry the crop, crop moisture content, the level of drying required, and so on. A wide range of research has been carried out on the thermal modeling of the dryer, using different designs. This article also discussed and compared the drying performance of three basic solar dryers: direct solar dryer, dryer with PVT air collection, and phase change materials (PCM). Even though PCM dryers are more expensive and uncommon, their ability to speed up drying at night makes them impactful.