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Abstract This study presents and evaluates the feasibility of a novel hybridization of modified Kalina cycle, reverse osmosis desalination, and low-temperature water electrolysis utilizing geothermal energy to yield power, distilled water, and hydrogen, respectively. The scientific impact of the current work has been improved considering the features of Sabalan flash-binary geothermal wells in Iran as a real model through a case study. In addition to designing a novel setup, the smart use of multi-heat recovery technique, modifying the base cycle, and utilizing a part of generated distilled water to produce hydrogen by the electrolyzer are the other structural originalities, distinguishing the current work from the previous studies. The suggested system is scrutinized via a parametric study and optimized based on a genetic algorithm. The parametric study demonstrated that the highest sensitivity of varying the performance criteria of the whole system is attributed to the change in flash tank pressure. Moreover, the multi-objective optimization led to achieving the exergy efficiency and trigeneration gain output ratio as 51.3% and 1.7 for the system, respectively. Furthermore, the system was able to produce 4795 kW of power, 5.3 kg/h of hydrogen, and 19.9 kg/s of distilled water.

Abstract In this study, parallel, bench-scale, mesophilic and thermophilic, dry, semi-continuous anaerobic digestion (DScAD) of Korea food waste (FW, containing 22% total solids (TS) and 20% volatile solids (VS)) was investigated thoroughly under varying operational conditions, including hydraulic retention times (HRTs) and organic loading rates (OLRs). The aim was to evaluate the start-up, stability, overall removal efficiency, and inhibitory effects of toxic compounds on process performance over a long-term operation lasting 100 days. The results from both digesters indicate that the simultaneous reduction of VS and the production of gas improved as the HRT decreased or the OLR increased. The highest average rates of VS reduction (79.67%) and biogas production (162.14 m 3 biogas/ton of FW, 61.89% CH 4 ), at an OLR of 8.62 ± 0.34 kg VS/m 3 day (25 days of HRT), were achieved under thermophilic DScAD. In addition, the average rates of reduction of VS and the production of biogas in thermophilic DScAD were higher by 6.88% and 16.4%, respectively, than were those in mesophilic DScAD. The inhibitory effects of ammonia, H 2 S, and volatile fatty acids (VFAs) on methane production was not clear from either of the digesters, although, apparently, their concentrations did fluctuate. This fluctuation could be attributed to the self-adaptation of the microbial well. However, digestion that was more stable and faster was observed under thermophilic conditions compared with that under mesophilic conditions. Based on our results, the optimum operational parameters to improve FW treatment and achieve higher energy yields could be determined, expanding the application of DScAD in treating organic wastes.

Alkaline pretreatment has been known as the most popular method to process lignocellulosic materials for bioethanol production due to its simplicity and high efficiency. However, the waste water of the process has a very high basicity, which requires neutralization with acids upon further disposal. In this study, rubber wood saw dust (Hevea brasiliensis) was employed as lignocellulosic material and its pretreatment was inspected with both diluted H2SO4 and NaOH in different combination ways. Hereby, acid was used not only for waste water neutralization but also to contribute to lignin removal. Analysis results showed that an aqueous solution of 2.0 - 2.5 wt.% H2SO4 can be used to treat the biomass followed by alkaline pretreatment. By this so-called combo-pretreatment technique, cellulose was well preserved without significant hydrolysis while the final pretreatment efficiency was up to 63.0%, compared to 48.2% of using only the alkaline solution and 13.7% of using only the acidic solution. Finally, alkaline waste water can be mixed to be neutralized with acidic waste water from the two previous steps. This innovated technique improved the pretreatment efficiency almost without increasing in chemical cost.

One of the principle concepts for understanding the hydrocarbon field is the heterogeneity scale; this becomes particularly challenging in supergiant oil fields with medium to low lateral connectivity in carbonate reservoir rocks. The main objective of this study is to quantify the value of the heterogeneity for any well, and propagate it to the full reservoir. This is quite useful specifically prior conducting detailed water flooding or full field development studies and work, in order to be prepared for a proper design and exploitation requirements, which fits with the level of heterogeneity of this formation. The main tool used for these purposes is the application of the famous Lorenz coefficient method, in conjunction with the Dykstra Parsons technique for calculating the degree of heterogeneity for any well.  The starting point for this kind of complicated studies needs to start from the basics. In order to understand the big picture and be able to plan properly for the scope to be delivered. Utilizing analytical tools like the ones mentioned above becomes quite necessary, if not crucial, to the success of full field modelling and choosing an optimum water flood pattern and design. This work covers the methodology for quantifying and calculating the level of heterogeneity in a given reservoir. The Dykstra-Parsons Coefficient or the variation of Dykstra Parsons (VDP) is commonly used in calculating permeability variation. The method of calculating begins by sorting the property of interest and make the other property fixed value (to calculate permeability you have to make porosity a fixed value for all calculations) and make permeability in order of decreasing magnitude. For each of the values calculate the percentage of values greater or the ‘cumulative probability’, so that the probability of X is P(x≤X). Then plot the original permeability values on a log probability graph with the cumulative probability values. The slope value and the intercept of the line of the best fit, for all data are used to calculate the 50th and 84th probability values or by variation layering system to calculate the variation of P10, P50 and P90, which are used to find VDP. This methodology has been tested successfully in the stated super giant oil field, in which the reservoir is a carbonate rock formation. The reservoir is areally extensive reservoir and not of a great thickness. The importance of this step is to conclude a utilizing heterogeneity calculation method before conducting any detailed reservoir simulation study. It can save a lot of time and effort by providing guidance to the path, which needs to be followed, and sheds light on the critical elements to be looked after. This also can help to uncover many insights on the reservoir itself, hence allowing the engineer to plan for the necessary voidage replacement and water injection rates to sustain the reservoir pressure and pattern development based on the magnitude of heterogeneity those results from this procedure. The suggested method, in combination with geological and petrophysical information available, can be applied to majority of the reservoirs. This combination is paramount to ensure optimum time and planning is followed for each reservoir development study that involves for example water flooding

A novel solar water-energy nexus technology is presented that combines the solar desalination of saline water and desalination-driven wastewater remediation coupled with the production of H2.

Abstract Reservoir wettability – the tendency of a rock surface to be in contact with one fluid more than other fluids – can vary substantially from strongly water-wet to strongly CO2-wet. However, the influence of such differences in wettability on the CO2 storage capacity has received little attention. Here, we studied the impact of reservoir wettability on CO2 plume behaviour and residual and solubility trapping capacities. We also compare the case of a homogeneous distribution of permeability and porosity values within the reservoir with that of a heterogeneous distribution. We found that CO2-wet reservoirs have the highest CO2 vertical migration, while water-wet reservoirs best retain CO2. In addition, less residual CO2 but more dissolved CO2 is obtained in a CO2-wet reservoir. Furthermore, we demonstrate that reservoir heterogeneity reduces the vertical CO2 migration and induces significant horizontal migration, while lower residual and solubility storage capacities are achieved. We thus conclude that both reservoir wettability and heterogeneity significantly impact CO2 migration and trapping capacities and need to be incorporated into reservoir simulations for accurate predictions of both CO2 plume behaviour and CO2 storage capacities. Overall, we conclude that strongly water-wet reservoirs are preferable CO2 sinks.

AbstractThis paper examines household responses to sustainability issues and adoption of energy saving technologies. Our example of solar hot water systems highlights the complexity and variability of responses to low-carbon technologies. While SHW systems have the potential to provide the majority of household hot water and to lower carbon emissions, little research has been done to investigate how SHW systems are integrated into everyday life. We draw on cultural understandings of the household to identify passive and active users of SHW systems and utilize a model that illustrates how technology use is dependent on inter-relations between cultural norms, systems of provision, the material elements of homes, and practice. A key finding is that households can be ill-prepared to make the most of their SHW systems and lack post-installation support to do so. Thus, informed and efficient use of SHW systems is hit and miss. Current policy is largely aimed at subsidizing purchase and installation on the assumption that this is sufficient for emission reduction goals. Our analysis provides evidence to the contrary. Areas we highlight for policy and practice improvement are independent pre-purchase advice, installation quality, and practical guidance on system operation and interaction with patterns of hot water use.

ABSTRACT Miniaturized growth systems for heterogeneous culture collections are not only attractive in reducing demands for incubation space and medium but also in making the parallel handling of large numbers of strains more practicable. We report here on the optimization of oxygen transfer rates in deep-well microtiter plates and the development of a replication system allowing the simultaneous and reproducible sampling of 96 frozen glycerol stock cultures while the remaining culture volume remains frozen. Oxygen transfer rates were derived from growth curves of Pseudomonas putida and from rates of oxygen disappearance due to the cobalt-catalyzed oxidation of sulfite. Maximum oxygen transfer rates (38 mmol liter −1 h −1 , corresponding to a mass transfer coefficient of 188 h −1 ) were measured during orbital shaking at 300 rpm at a shaking diameter of 5 cm and a culture volume of 0.5 ml. A shaking diameter of 2.5 cm resulted in threefold-lower values. These high oxygen transfer rates allowed P. putida to reach a cell density of approximately 9 g (dry weight) liter −1 during growth on a glucose mineral medium at culture volumes of up to 1 ml. The growth-and-replication system was evaluated for a culture collection consisting of aerobic strains, mainly from the genera Pseudomonas , Rhodococcus , and Alcaligenes , using mineral media and rich media. Cross-contamination and excessive evaporation during vigorous aeration were adequately prevented by the use of a sandwich cover of spongy silicone and cotton wool on top of the microtiter plates.

This study investigates the influence of alkali (Na, K), alkaline earth (Ca, Mg) and transition (Fe) metal nitrates on CO2 gasification reactivity of pistachio nut shell (PNS) char. The preliminary gasification experiments were performed in thermogravimetric analyzer (TGA) and the results showed considerable improvement in carbon conversion; Na-char>Ca-char>Fe-char>K-char>Mg-char>raw char. Based on TGA studies, NaNO3 (with loadings of 3-7 wt%) was selected as the superior catalyst for further gasification studies in bench-scale reactor; the highest reactivity was devoted to 5 wt% Na loaded char. The data acquired for gasification rate of catalyzed char were fitted with several kinetic models, among which, random pore model was adopted as the best model. Based on obtained gasification rate constant and using the Arrhenius plot, activation energy of 5 wt% Na loaded char was calculated as 151.46 kJ/mol which was 53 kJ/mol lower than that of un-catalyzed char.

Abstract Among various groundwater heat pump (GWHP) system configurations, the single-well circulation (SWC) groundwater heat pump system is totally different with other conventional GWHP systems. In recent years, the SWC system has gained increasing interest due to the fact that it is a cost-effective technology providing large quantities of heating and cooling to buildings. The performance of a SWC system is closely related to the hydrogeological and thermogeological properties. Also, the proper system design and installation are crucial to maintain long-term sustainability and efficiency. In this work, a series of scenarios were simulated to evaluate the influence of different parameters on the outlet temperature evolution and efficiency of a SWC system. It was found that the W-S mode with active cooling will be beneficial to the efficiency of the heat pump and the recovery of the subsurface. It is also demonstrated that the sealed section length plays the most influential role in the design of a SWC system. In addition, the present of groundwater flow will have positive effect on the system performance. In contrast to other factors, the thermal conductivity, volumetric heat capacity and porosity are considered to have a minor influence on the sustainability and efficiency of the system.