Urea Production Research Articles

Simulation of a reactor considering the Stamicarbon, Snamprogetti, and Toyo patents for obtaining urea

Abstract In the present work, the plug flow reactor of a urea production plant from ammonia produced from natural gas of the Camisea fields (Peru) was designed, comparatively analyzing three commercial processes currently in operation: Stamicarbon, Snamprogetti, and Toyo. ASPEN PLUS software was used as a simulation tool. To carry out the simulation and subsequent comparison of the three urea production patents, it will start from the same feed of ammonia (37,851 kmol/day) and carbon dioxide (18,989 kmol/day) for the three cases. For the design of urea synthesis reactors, reactors of the same size (2.3 m diameter and 29 m length) were designed. The results are graphs that illustrate the variation of the length of the reactor with the reaction temperature, the variation of the length of the reactor with the residence time, and the variation of the conversion with the time for each patent.

Production and Properties of Native Potato Starch-Coated Urea

This work is dedicated to researching the possibilities of using starch coating for slow-release fertilizers. Urea was used as nitrogen containing component, because it is the most suitable for the production of slow-release nitrogen fertilizers and has the highest concentration of nitrogen – 46.6 %. During the studies, native potato starch film was prepared and its stability was evaluated, subsequently, urea was coated with starch film/coating and the influence on properties of fertilizer granules (hygroscopicity and strength) was evaluated. Single and/or multiple layered films were formed during the coating process and the influence of coating thickness on urea solubility was researched. It was found that the mechanical properties of urea with double coating change quite insignificantly while coating reduces the solubility of urea by more than 20 %.

Surface engineering of Au nanostructures for plasmon-enhanced electrochemical reduction of N2 and CO2 into urea in the visible-NIR region

The photoelectrochemical reduction of CO2 and N2 (N2CO2RR) is a promising method of producing urea under ambient conditions since highly active and stable electrocatalysts are desired. Plasmonic metals have attracted considerable attention due to their enhanced electrochemical activity at visible and near-infrared wavelengths (NIR). Herein, the morphology of Au was tuned to spherical nanoparticles, nanorods, and nanosheets by utilizing a variety of structure-directing agents. Among them, Au nanosheets (Au NSs) can absorb a broad spectrum of NIR wavelengths, enabling electrochemical reduction of N2 into NH3, with high yield rates and higher Faradic efficiency (FE) than most of the N2RR results reported. In addition, a distal associative pathway for N2RR into NH3 has been established over Au NSs. Additionally, the Au NSs photocathode demonstrates high stability over a period of 10 consecutive runs. In addition, this work provides a guide to fabricating highly stable photocathodes that convert N2 and CO2 into urea. Au NSs photocathode achieves a maximum urea yield rate of 98.5 µgureamgcat-1h−1 and FE of 22.7% at −0.7 V vs. RHE. Results show that the N2 and CO2 is the primary factor for urea production, whereas reducing NO3– and HCO3– contributes significantly to the total urea yield rate. Density functional theory calculations (DFT) reveal that Au NSs play a crucial role in promoting N2 and CO2 adsorption, activation, and stimulating the coupling reaction between C-N to form urea by the distal mechanism. As a result, this work opens up the possibility of developing hybrid catalytic systems for simultaneously reducing nitrate-containing wastewater and CO2, thus producing urea-rich treated water for agricultural use and achieving carbon neutrality.

Effect of commercial slow-release urea product on in vitro rumen fermentation and ruminal microbial community using RUSITEC technique

BackgroundThe objectives of this study were to determine the effect of commercial slow-release urea (SRU) on in vitro fermentation characteristics, nutrient digestibility, gas production, microbial protein synthesis and bacterial community using a rumen simulation technique (RUSITEC). The experiment was a completely randomized design with four treatments and four replications of each treatment. Treatments were: control diet (no SRU addition), control diet plus 0.28% SRU (U28), or plus 0.56% SRU (U56), and control diet that was modified substituting a part of soybean meal equivalent to 0.35% SRU (MU35; dry matter [DM] basis). The experiment consisted of 8 d of adaptation and 7 d of data and sample collection. Rumen inoculum was obtained from three ruminally fistulated Angus cows fed the same diet to the substrate incubated.ResultsDigestibility of DM, organic matter (OM), crude protein (CP), fibre and starch was not affected, but daily production of gas (P < 0.07) and methane (P < 0.05) was quadratically increased with increasing SRU supplementation. The increase of SRU addition did not affect fermentation pH and total volatile fatty acid (VFA) production, whereas linearly (P < 0.01) decreased proportion of propionate, and linearly (P < 0.01) increased acetate to propionate ratio and ammonia nitrogen (N) concentration. The microbial N efficiency was also linearly (P < 0.03) improved with increasing supplementation of SRU. In comparison with control diet, the dietary substitution of SRU for part of soybean meal increased (P < 0.05) the digestibility of DM, OM and CP and decreased (P < 0.02) the total gas production. The total VFA production and acetate to propionate ratio did not differ between control and MU35, whereas the proportion of butyrate was lower (P < 0.05) and that of branched-chain VFA was greater (P < 0.05) with MU35 than control diet. Total and liquid-associated microbial N production as well as ammonia N concentration were greater (P < 0.03) with MU35 than control diet. Observed operational taxonomic units (OTUs), Shannon diversity index, and beta diversity of the microbial community did not differ among treatments. Taxonomic analysis revealed no effect of adding SRU on the relative abundance of bacteria at the phylum level, while at the genus level, the beneficial impact of SRU on relative abundance of Rikenellaceae and Prevotellaceae in feed particle-associated bacteria, and the abundance of Roseburia in liquid associate bacteria was greater (P < 0.05) with MU35.ConclusionsSupplementation of a dairy cow diet with SRU showed potential of increase in ammonia N concentration and microbial protein production, and change fermentation pattern to more acetate production. Adding SRU in dairy cow diet also showed beneficial effect on improving digestibility of OM and fibre. The results suggest that SRU can partially substitute soybean meal in dairy cow diet to increase microbial protein production without impairing rumen fermentation.

Energy efficiency intervention in urea processes by recovering the excess pressure through hydraulic power recovery Turbines (HPRTs)

Different energy efficiency interventions have been developed so far by different companies to reduce the energy consumption in urea processes, but none of them are related to the pressure energy recovery from liquids. In this paper, a power recovery solution is proposed for urea plants, namely Hydraulic Power Recovery Turbines (HPRTs). The ASPEN PLUS® software is used to simulate different scenarios where one or more HPRTs can be installed. Precisely, three different layouts having one, two, and three HPRTs, as well as different urea plants capacities (approximately 1,600, 2,300, 3,000, and 3,700 t/day), have been investigated. Focusing on the use of only one HPRT, the maximum yearly power recovery of almost 4,000 MWh/year has been obtained; then, the avoided Carbon Dioxide (CO2) has been also calculated by inspecting four different countries, achieving the highest value of 2,400 tCO2 in Italy. Considering the highest energy recovery value previously mentioned, a net economic saving of 806 k€/year and a PayBack Period (PBP) of 3 years can be achieved, showing the potential of this kind of intervention in existing plants and how it could further boost the urea production worldwide considering the urea itself as an efficient carbon capture technique.

Moringa oleifera extract protects against rhabdomyolysis‐induced acute kidney injury

Acute kidney injury (AKI) is a life‐threatening abrupt disruption in kidney function. The pathophysiological mechanisms of AKI are poorly understood. Also, there are currently no effective drugs to treat AKI. Phytochemicals from Moringa oleifera plants exhibit antihypertensive, cholesterol‐lowering, diuretic, and hepatoprotective properties. This study aims to determine if Moringa oleifera extract can ameliorate rhabdomyolysis‐induced AKI and its possible mechanisms of action.Experimental rats were randomly divided into five groups. Rhabdomyolysis was induced by intramuscular glycerol injection. Group A received distilled water only. Group B received distilled water, followed by 50% glycerol on the 8th day. Group C and D received 50 and 100 mg/kg methanol stem extract of Moringa oleifera (orally) for seven days and glycerol on the 8th day. Group E received 100 mg/kg of methanol stem extract of Moringa oleifera alone for seven days and normal saline on the 8th day. Necropsy was performed 24 h after glycerol treatment. Blood and kidneys samples were collected for biochemical, histopathological, and immunohistochemical analyses.Significant decreases in superoxide dismutase, glutathione peroxidase, glutathione S‐transferase, glutathione, protein thiols, and non‐protein thiols were observed in animals treated with only glycerol when compared with the control groups. Glycerol treatment also caused a significant increase in markers of AKI and inflammation, including creatinine, nitric oxide, urea, hydrogen peroxide, malondialdehyde, protein carbonyl, and advanced oxidative protein products. Immunohistochemical staining of renal NF‐ƙβ and KIM‐1 was also elevated in glycerol‐treated rats. Treatment with methanol stem bark extract of Moringa oleifera ameliorated glycerol‐induced oxidative stress, kidney damage, and inflammation.The methanol stem extract of Moringa oleifera alleviated rhabdomyolysis‐induced AKI in rats through its antioxidant and anti‐inflammatory properties.

Identification of a Novel Candidate to Promote Hepatic Maturation in HepG2 Cells In Vitro

Drug‐induced cholestasis (DIC) is characterized by impaired bile flow caused by exogenous compounds and remains a major culprit of attrition of drug candidates, as illustrated by liver toxicity representing 40% of all clinical trial terminations. Strategies for earlier (preclinical) detection of DIC‐inducing drug candidates has thus been an area of extensive research. Nevertheless, the currently available in vitro models for DIC suffer from major knowledge gaps in terms of underlying mechanisms. The crux is the inability to fully mature hepatic phenotypes. Previous studies show a different transcriptome, proteome and epigenetic profile between iPSC‐derived hepatocyte‐like cells (HLCs) and primary human hepatocytes (PHHs), with low levels of hepatic transcription factors (TFs) and biotransformation CYP450 enzymes in HLCs.A recent mechanistic study revealed that maintenance of mature phenotypes of PHHs and their (glucose) metabolism in vitro, at least partially, depends on blocking epithelial‐mesenchymal transition (EMT) and subsequently identified TGF‐β, Wnt, BMP, Notch, and cAMP signaling as master regulators of this process. However, 5 different chemical compounds, each corresponding to a specific pathway, had to be administered into the culture medium for sufficient EMT inhibition. Building further on the previous knowledge that AKT/mTORC1 signaling is a strong inducer of gluconeogenesis and CYP450 activity, we hypothesized that an upstream pathway and/or common protein(s) could simultaneously activate AKT/mTORC1 and inhibit EMT. Not only would it lead to more mature hepatic phenotypes (and thus better models) in vitro, but it would also broaden the mechanistic understanding underlying hepatic maturation.Preliminary data suggests that this goal may be accomplished. After targeted inhibition with a small molecule in HepG2 cells, expression patterns were consistent with (i) an upregulation of AKT/mTORC1 as well as estrogen biosynthesis (indicative for strong CYP450 activation), and (ii) a shift in cell metabolism from glucose fueling to β‐oxidation and amino acid consumption with induction of gluconeogenesis (indicative for strong EMT inhibition). Furthermore, the epithelial marker CDH1 (encoding for E‐cadherin) was sharply increased and AKT/cAMP signaling together with typical hepatic TFs that serve as maturation biosensor (HNF4A, FOXO1 and FOXO3) were predicted to be significantly activated. Consistent with this expression data, mitochondrial functionality was confirmed to be improved by quantifying urea production and measuring mitochondrial membrane potentials.Taken together, gathered preliminary data points towards a novel link between (loss of) the identified target, inhibition of EMT and the enhancement of hepatic maturation TFs as well as CYP450 expression and activation. Generation of knock‐out cells and elaborate bile acid profiling is on‐going and will be applied in further mechanistic studies of DIC.

Analysis of Key Genes Responsible for Low Urea Production in Saccharomyces cerevisiae JH301.

There is a potential safety risk with ethyl carbamate (EC) in Hongqu Huangjiu production; 90% of the EC in rice wine is produced by the reaction of the urea with the alcohol of Saccharomyces cerevisiae. In our previous experiments, we screened and obtained a S. cerevisiae strain JH301 that offered low urea production. However, the key genes responsible for low urea production of strain JH301 remain unclear. Here, the whole genome sequencing of S. cerevisiae strain JH301 was accomplished via a next-generation high-throughput sequencing and long-read sequencing technology. There are six main pathways related to the urea metabolism of strain JH301 based on KEGG pathway mapping. Three species-specific genes are related to the urea metabolism pathways and were found in comparative genome analysis between strains JH301 and S288c during Hongqu Huangjiu production for the first time. Finally, the ARG80 gene was found to be likely a key gene responsible for low urea production of S. cerevisiae strain JH301, as determined by PCR and qRT-PCR check analyses from DNA and RNA levers. In conclusion, the results are useful for a scientific understanding of the mechanism of low urea production by Saccharomyces cerevisiae during Hongqu Huangjiu fermentation. It also is important to control the urea and EC contents in Hongqu Huangjiu production.

Effect of feeding slow release non protein nitrogen sources on milk productionand milk quality parameters in Cross bred dairy cows

A study of 90 days duration was conducted on 18 multiparous crossbred cows (363±14kg, body weight; in II or III lactation; 3,000-4,500kg milk yield per lactation) randomly allotted to 3 dietary treatments with 6 animals in each group in a completely randomized design to investigate the effect of two slow release non protein nitrogen (SRNPN) products on feed intake, milk yield, milk composition, blood biochemical parameters and cost economics. The concentrate mixture for control group was formulated with maize, gram husk, ground nut cake, wheat bran, deoiled rice bran, salt and mineral mixture. The other two experimental concentrate mixtures were prepared by totally replacing ground nut cake with calcium salts of fatty acid coated urea (CFCU) and Hydroxypropyl methylcellulose coated urea (HMCCU) at 2.42%. The cows were offered fixed quantity of Napier green fodder (10kg/cow/day) and ad libitum paddy straw. The daily allowance of respective concentrate mixture offered to each cow was calculated based on body weight, previous week milk yield and roughage intake to meet the nutrient requirements of as per ICAR (2013). Incorporation of either of the coated urea products in concentrate mixtures did not affect the total DM intake, milk yield (13.94 to 14.11kg/d), milk composition (Milk fat, Protein, SNF and Lactose) and blood biochemical (Blood urea nitrogen, Glucose and total protein). Though non significant, the average daily cost of feeding (Rs/d) was lowered in CFCU (228.14) and HMCCU (215.98) diet fed cows compared to control group cows (237.08) by 3.77 and 8.89% respectively. Whereas, the cost of feeding (Rs) per kg milk production differed significantly (P&lt;0.01) with highest in control diet fed group (16.80) while in CFCU (15.43) and HMCCU (15.49) fed group it was lower. CFCU and HMCCU can be included at 1% of dry matter or 2.42% in the concentrate replacing the conventional protein sources, without affecting the milk yield and its composition in cross bred cows and reducing the feed cost per kg milk production.

Protective Effect of Selenium against Methotrexate Induced Hepatotoxicity

Introduction: The liver is the largest internal organ by percent weight in the human body and has crucial functions, including cholesterol production, intermediary metabolism, hormone synthesis, bile and urea production and drug detoxification. Objectives: The main objective of the study is to analyse the Protective effect of selenium against methotrexate induced hepatotoxicity in mice. Material and methods: This descriptive study was conducted in Jinnah Hospital Lahore during 2020. Selenium and all chemical reagents of analytical grades were purchased from Sigma Chemical Co. (St. Louis, Mo, USA). The dose of MTX diluted in water (50% 1ml/kg of body weight of Mice were applied twice a week for six weeks to induced hepatocellular injury determined by liver function tests. The mice were maintained under pathogen-free conditions with air conditioning, a 12-hr light/12-hr dark cycle, and %55 humidity. Results: Results shows that a significant increase in serum enzymes (ALT, AST, ALP) and significant decrease in total protein was observed in all groups receiving MTX for the induction of hepatic injury. Mice receiving combination therapy of selenium along with MTX shows a time course recovery towards normalcy. The highest value of ALT (94.83 IU/L), AST (73.21 IU/L) and ALP (157 IU/L) were recorded in Mice receiving MTX for hepatic injury. The lowest values (63.67, 51.49 and 139.95 IU/L) was recorded in group treated with MTX+ Se (200mg/kg b.w) but both the groups differed non significantly and shows the same trend but a decreasing trend in serum enzymes (ALT 32.85%), (AST 29.67%) and (ALP 11.40%). Conclusion: It is concluded that selenium supplementation in MTX treated rats elicited a reduction in the toxic effects of the pesticide by improving the studied parameters, which was confirmed by the biochemical analysis of serum.

Amine-Modified Biochar for the Efficient Adsorption of Carbon Dioxide in Flue Gas

Biochar-based carbonaceous adsorbents are gaining interest due to their high availability, ease of modification, and low cost; however, they show limited adsorption of CO2 in flue gas due to common textural properties. In this study, TEPA-modified biochar was used to prepare a solid amine adsorbent for the efficient capture of CO2 in flue gas. First, the porous biochar was prepared with FeCl3, Mg(NO3)2, and H2O (g) as activators and walnut shells as carbon sources. Next, the biochar was modified with TEPA to obtain a solid amine adsorbent. Porous texture properties and sample surface functional groups were characterized, and we measured the adsorption CO2 of the amine-modified biochar in a breakthrough adsorption device. Results showed that biochar has a large specific surface area (744.38 m2 g−1), a total pore volume of 1.41 cm3 g−1, and a high mesoporous volume ratio (82.7%). The high pore volume provided a more efficient support space for loading tetraethylenepentamine (TEPA). The adsorbent had an excellent CO2 adsorption capacity, corresponding to 2.82 mmol g−1, which increased to 3.31 mmol g−1 and kept water resistance at 10% H2O (g) simulated flue gas (SFG). The FTIR analysis showed that H2O (g) inhibited urea production after cyclic adsorption. Therefore, solid amine adsorbent created by amine-modified biochar has potential advantages in its application for capturing CO2 in SFG.

Utilization of carbon-based energy as raw material instead of fuel with low CO2 emissions: Energy analyses and process integration of chemical looping ammonia generation

Ammonia (NH3) has attracted much attention as both a fuel and an energy carrier due to its transportability and cleanliness. At present, most of NH3 is synthesized by the catalytic Haber-Bosch reaction (N2+3H2⇌2NH3). Due to its energy-intensive processes for hydrogen production, high carbon dioxide (CO2) emissions as well as high pressure required for NH3 synthesis, an alternative highly efficient system is needed. In this study, an integrated system based on chemical looping ammonia generation (CLAG), which combines air separation, N-sorption/desorption (ammonia synthesis), steam generation and urea production is proposed. The system employs a novel ammonia production loop and produces steam, carbon monoxide (CO) and urea as by-products. System modelling is conducted using Aspen Plus V11 (Aspen Technology, Inc.). The results showed the energy consumption can reach 6.88 GJ/tNH3. The total CO2 emission of the ammonia synthesis system was 2.05 kg/kg NH3 in which direct CO2 emission dropped to 0.43 kg/kg NH3, and with urea production, the direct CO2 emission can reduce to −0.86 kg/kg NH3, leading to negative CO2 emissions.

Exergoenvironmental analysis and thermoeconomic optimization of an industrial post-combustion CO2 capture and utilization installation

CO2 utilization is one of several tools available to us to mitigate climate change. This paper aims to study and optimize the urea production in the largest CO2 utilization plant in Iran. The location, magnitude, and source of thermodynamic inefficiencies of the plant are evaluated using exergy, exergoeconomic and exergoenvironmental analyses. The optimization process uses as decision variables the temperature of the lean monoethanolamine solution and loading, along with the height of the absorber and the stripper of the plant. The decision variables and objective functions are trained with a hybrid combination of an artificial neural network with a genetic algorithm. The multi-objective genetic algorithm results in a pareto front of solutions. The exergy efficiency of the overall system is found to be 30.89% and 3.57, 2.86, 2.21% of the exergy of the fuel provided to the plant is destroyed in the soda ash wash direct contact, the stripper, and the absorber columns (424.07, 339.71 and 258.61 kW), respectively. The exergoeconomic analysis shows that the heat exchangers E-7 and E-8 result in relatively low exergoeconomic factor; therefore, an enhancement in the thermodynamic performance of the heat exchangers should be considered. The absorber column is found to have the largest environmental impact, equal to approximately 0.1205 mPt/s. The highest environmental impact of exergy destruction, equal to 33,256.3 mPts/hr is found in the stripper.

Urea transporter B downregulates polyamines levels in melanoma B16 cells via p53 activation

Urea transporter B (UT-B, encoded by the SLC14A1 gene) is a membrane channel protein involved in urea transmembrane transport. Compared with normal tissues, UT-B expression is significantly decreased in most tumours, especially melanoma. However, the UT-B role in tumorigenesis and development is still unclear. Herein, we investigated the effects of UT-B overexpression on polyamine metabolism and the urea cycle in murine melanoma B16 cells, to explore the roles of mitochondrial dysfunction and p53 activation in cell growth and polyamines metabolism. UT-B overexpression in B16 cells decreased cell growth, increased apoptosis, and significantly altered metabolic pathways related to the urea cycle, which were characterized by reduced production of urea and polyamines and increased production of nitric oxide. Subsequently, we observed that activation of the p53 pathway may be the main cause of the above phenomena. The p53 inhibitor pifithrin-α partially restored the production of polyamines, but the mitochondrial morphology and function were still impaired. Further treatment of UT-B-overexpressing B16 cells with reactive oxygen species scavenging agent N-acetyl-l-cysteine and coenzyme Q10 restored cell viability and mitochondrial function and increased polyamine production. In conclusion, UT-B overexpression caused mitochondrial dysfunction and increased oxidative stress in B16 cells, and then activated p53 expression, which may be one of the mechanisms leading to the decrease in intracellular polyamines.

Coupling mechanism of N2 and CO2 to urea over artificial frustrated Lewis pairs

The simultaneous electrocatalytic conversion of N2 and CO2 into value-added urea is a top-challenging reaction. In this issue of Chem Catalysis, Zhang’s group reported a rice-like InOOH nanocrystal with the well-defined frustrated Lewis pairs (FLPs, i.e., In⋯In–OH), which promoting electrochemical C-N coupling reactions in urea production. This work provides an in-depth understanding of urea synthesis by achieving the integration of the active site.

Establishing the Principal Descriptor for Electrochemical Urea Production via the Dispersed Dual-Metals Anchored on the N-Decorated Graphene.

Urea electrosynthesis under mild conditions starting from the adsorption of inert N2 molecules has brought out a promising alternative experimentally to conquer its huge energy consumption in industrial Haber‐Bosch process. The most crucial and inevitable reaction is the formation of urea precursor *NCON from *N2 and CO based on the pre‐selected reaction pathway, together with the following protonated processes. It is significant to comprehend their intrinsic intercorrelation and explore the principal descriptor from massive reaction data. Hereby, the authors study the dispersed dual‐metals (homonuclear MN3–MN3 moiety and heteronuclear MN3–M'N3 moiety) anchored on N‐doped graphene as electrocatalysts to synthesize urea. Based on the screened out 72 stable systems by ab initio molecular dynamics (AIMD) simulations as the database, six significant linear correlations between the computed Gibbs free energy and other important factors are achieved. Most encouragingly, the principal descriptor (ΔE(*NCONH)) is established because 72% low‐performance systems can be filtered out and its effective range (−1.0 eV < ΔEE(*NCONH) < 0.5 eV) is identified by eight optimal systems. This study not only suggests that dispersed dual‐metals via MN3 moiety can serve as promising active sites for urea production, but also identifies the principal descriptor and its effective range in high‐throughput methods.

Solvay invests in DMC Biotechnologies to advance bio-based innovation

One of the main goals of the green chemistry is to develop sustainable and less hazardous chemical processes and products. Dimethyl carbonate (DMC) is attracting attention due to the wide variety of applications and the possibility of producing it from carbon dioxide. In this work, the DMC production process via urea has been optimized. Two main sections can be distinguished: the synthesis of urea and the production of DMC. An equation based approach is used to model the system. The DMC production from renewable ammonia/methanol/CO2 presents a promising production cost, around 520 €/t. The production of urea alone has also been evaluated in this work. A sensitivity analysis is carried out showing the influence of the methanol price in the DMC cost and the ammonia price in the urea cost. A simplified sustainability index is used to evaluate the environmental performance of urea/DMC production.

Design and analysis of a new solar hydrogen plant for power, methane, ammonia and urea generation

In this paper, a solar power-based combined plant for power, hydrogen, methane, ammonia and urea production is proposed. A parabolic trough collector is utilized for the system prime mover. Moreover, steam Rankine cycle, organic Rankine cycle, hydrogen production and compression subsystem, ammonia, methane and urea production units, single-effect absorption cooling unit, and freshwater production plant are integrated together to develop the present system for better system performance and cost-effectiveness and reduced environmental impact. In order to analyze and evaluate the proposed multigeneration plant, thermodynamic, parametric and economic studies are performed. According to the assessment results, it is found that energetic and exergetic efficiencies of the present multigeneration plant are 66.12% and 61.56%, respectively. The comparisons of the subsystem and overall plant efficiencies show that the highest energetic and energetic efficiencies belong to freshwater production plant by 79.24% and 75.62%, respectively. In addition, the present parametric analysis indicates that an increase in the reference temperature, solar radiation intensity and working pressure of the solar process has a positive effect on the plant's performance. The cost analysis reveals that as the solar radiation intensity and the working pressure of the solar process increase, the hydrogen generation cost decreases. Furthermore, the hydrogen generation cost is achieved to be 1.94 $/kgH2 at 650 W/m2 of the solar radiation intensity, with other parameters remaining constant.

Exploiting maleimide-functionalized hyaluronan hydrogels to test cellular responses to physical and biochemical stimuli

Current in vitro three-dimensional (3D) models of liver tissue have been limited by the inability to study the effects of specific extracellular matrix (ECM) components on cell phenotypes. This is in part due to limitations in the availability of chemical modifications appropriate for this purpose. For example, hyaluronic acid (HA), which is a natural ECM component within the liver, lacks key ECM motifs (e.g. arginine–glycine–aspartic acid (RGD) peptides) that support cell adhesion. However, the addition of maleimide (Mal) groups to HA could facilitate the conjugation of ECM biomimetic peptides with thiol-containing end groups. In this study, we characterized a new crosslinkable hydrogel (i.e. HA-Mal) that yielded a simplified ECM-mimicking microenvironment supportive of 3D liver cell culture. We then performed a series of experiments to assess the impact of physical and biochemical signaling in the form of RGD peptide incorporation and transforming growth factor ß (TGF-ß) supplementation, respectively, on hepatic functionality. Hepatic stellate cells (i.e. LX-2) exhibited increased cell–matrix interactions in the form of cell spreading and elongation within HA-Mal matrices containing RGD peptides, enabling physical adhesions, whereas hepatocyte-like cells (HepG2) had reduced albumin and urea production. We further exposed the encapsulated cells to soluble TGF-ß to elicit a fibrosis-like state. In the presence of TGF-ß biochemical signals, LX-2 cells became activated and HepG2 functionality significantly decreased in both RGD-containing and RGD-free hydrogels. Altogether, in this study we have developed a hydrogel biomaterial platform that allows for discrete manipulation of specific ECM motifs within the hydrogel to better understand the roles of cell–matrix interactions on cell phenotype and overall liver functionality.

Environmental Performance in the Production and Use of Recovered Fertilizers from Organic Wastes Treated by Anaerobic Digestion vs Synthetic Mineral Fertilizers.

Recovered fertilizers (RFs), in the form of digestate and digestate-derived ammonium sulfate, were produced from organic wastes by thermophilic anaerobic digestion (AD) at full scale. RFs were then used for crop production (maize), substituting synthetic mineral fertilizers (SFs). Environmental impacts due to both RF and SF production and use were studied by a life cycle assessment (LCA) approach using, as much as possible, data directly measured at full scale. The functional unit chosen was referred to as the fertilization of 1 ha of maize, as this paper intends to investigate the impacts of the use of RF (Scenario RF) for crop fertilization compared to that of SF (Scenario SF). Scenario RF showed better environmental performances than the system encompassing the production and use of urea and synthetic fertilizers (Scenario SF). In particular, for the Scenario RF, 11 of the 18 categories showed a lower impact than the Scenario SF, and 3 of the categories (ionizing radiation, fossil resource scarcity, and water consumption) showed net negative impacts in Scenario RF, getting the benefits from the credit for renewable energy production by AD. The LCA approach also allowed proposing precautions able to reduce further fertilizer impacts, resulting in total negative impacts in using RF for crop production. Anaerobic digestion represents the key to propose a sustainable approach in producing renewable fertilizers, thanks to both energy production and the modification that occurs to waste during a biological process, leaving a substrate (digestate) with high amending and fertilizing properties.