Ammonia Extraction Research Articles

Sustainable ammonia and amines from chitin

Efforts are underway to explore alternative methods to the Haber-Bosch process for sustainable ammonia production, while the potential for ammonia extraction from natural nitrogenous biomass is under-exploited. Here, a synergistic catalytic strategy involving acid and modified Ru-based catalysts is communicated for the direct production of amines and ammonia from chitin. Phosphoric acid promotes the cleavage of ether bonds in biomass polymers and also serves to protect amino groups from being removed. Selective hydrogenation, deoxygenation, and amination can be achieved by controllably adjusting the ratio of Ru0/Run+. The utilization of nitrogen atoms in chitin can reach up to 95 % (21 % amines, 74 % ammonium), and the catalytic process is applicable to waste shrimp shells. This study demonstrates the possibility of efficient production of nitrogen-containing compounds from abundant biopolymers.

Optimized Intermediates Adsorption Configuration on Co-Doped Fe2P@NiP2 Heterojunction Interface for Enhanced Electrocatalytic Nitrate-To-Ammonia Conversion.

The extraction of ammonia (NH3) through electrocatalytic nitrate reduction reaction (NO3 -RR) represents a sustainable avenue in NH3 generation and utilization. However, the catalytic efficiency of the NO3 -RR is hindered by the sluggish kinetics. This study first theoretically found that phosphide-based heterostructure can alter the adsorption structure of intermediates in the nitrate-to-ammonia process, thereby achieving precise regulation of the energy barrier in the rate-determining step. Based on theoretical design, a novel Co-doped Fe2P@NiP2 heterojunction catalyst is successfully synthesized, which deliver a notable NH3 yield rate of 0.395mmolh-1cm-2 at -0.7V versus RHE, as well as a remarkable ammonia Faraday efficiency of 97.2% at -0.6V versus RHE. Experimental and theoretical results further confirm that redistributing electrons and shifting the center of the d-band upwards through interfacial doping modulate intermediates adsorption strength and inhibition of hydrogen evolution, leading to excellent performance in NO3 --to-NH3. Further integrating the Co-Fe2P@NiP2 catalyst into a Zn-nitrate battery exhibits a substantial voltage output of 1.49V and a commendable power density of 13.2mWcm-2. The heteroatom-doped heterojunction strategy provides a versatile route for developing advanced catalysts, thereby broadening the horizons of electrocatalytic methodologies for nitrate reduction and ammonia synthesis.

Low-Temperature Vacuum Evaporation of Ammonia from Pig Slurry at Laboratory and Pilot-Plant Scale

Livestock manure has a high ammonium content that can limit its direct application on soil as a fertiliser in nitrate-vulnerable zones. Treatment technologies that are able to extract ammonium from livestock manure allow it to be concentrated in small volumes, making it cheaper and easier to transport and use as fertiliser in crop areas where there is a deficit of nitrogen. This study proposed using low-temperature vacuum evaporation to treat pig slurry in order to obtain marketable products that can be used as fertilisers and help close the nitrogen cycle. Two different configurations and scales were used. The first was a seven-litre laboratory-scale evaporator complemented with a condenser, a condensate trapper, an acid trap and a vacuum pump operated at −90 kPa vacuum pressure and at three different temperatures: 50.1 ± 0.2 °C, 46.0 ± 0.1 °C and 45.3 ± 1.3 °C. The second, Ammoneva, is an on-farm pilot-scale evaporator (6.4 m3), capable of working in four-hour batches of 1 t of liquid fraction of pig slurry with an operating temperature of 40–45 °C and −80 kPa vacuum pressure. The laboratory-scale evaporator, which features several novel improvements focused on increasing ammonia recovery, showed a higher nitrogen removal efficiency from the liquid fraction of pig slurry than the on-farm pilot plant, achieving 84% at 50.1 °C operation, and recovering most of it in ammonia solution (up to 77% of the initial nitrogen), with 7% of the ammonia not recovered. The Ammoneva pilot plant achieved a treated liquid fraction with 41% of initial nitrogen on average, recovering 15% in the ammonia solution in the acid trap; so, the NH3 gas absorption step needs to be further optimised. However, due to the simplicity of the Ammoneva pilot plant, which is easily placed inside a 20-foot container, and the complete automation of the process, it is suitable as an on-farm treatment for decentralised pig slurry management. The implementation of the novel design developed at laboratory-scale could help further increase recovery efficiencies at the pilot-plant scale.

Utilization of Rice Husk and Alum Sludge to Produce an Efficient Adsorbent Composite for Recovery of Nutrients from Wastewater

This study focused on developing an adsorbent composite from rice husk and alum sludge to recover nutrients from wastewater, which could be used in the future for slow-release fertilizer production. A biochar-sludge composite (80B/20S) was created by modifying rice husk biochar with MgCl2 and using acid- and heat-treated alum sludge to extract ammonium and phosphate contents from wastewater. The physical and chemical properties of the materials were analyzed using various techniques, such as X-ray diffraction and scanning electron microscopy. In the nutrient recovery test, the contact time, adsorbent dosage, and initial concentration were evaluated. The adsorption equilibrium contact time for both ammonium and phosphate were found to be 8 h, and the maximum adsorption capacity by Langmuir isotherm for the 80B/20S composite was 185.53 mgNH4 +/g and 63.78 mgPO4 3-/g. The composite material had a higher surface area of 141.32 m2/g, which promoted its adsorption capacity. Additionally, this material demonstrated a removal efficiency above 85% when applied to actual wastewater. Since the composite is composed mainly of natural components, it has the potential to be used as a sustainable slow-release fertilizer for agricultural growth.

Influence of free ammonia extraction in methane production from human urine

ABSTRACT Human urine has a high chemical oxygen demand (COD) content which makes anaerobic treatments potentially appropriate for the management of yellow waters, allowing for energy recovery. However, its high N content makes this treatment challenging. The present work studied the viability of performing an anaerobic digestion process for COD valorization on a real (not synthetic) urine stream at laboratory scale. To deal with nitrogen inhibition, two different ammonia extraction systems were proposed and tested. With them, a proper evolution of acidogenesis and methanogenesis was observed. Nitrogen was recovered in the form of ammonium sulphate, which could be used for agriculture, in two different ways: ammonia extraction from the urine stream before feeding the reactor and in situ extraction in the reactor. The first method, which proved to be a better strategy consisted in a desorption process (NaOH addition, air bubbling and acid (H2SO4) absorption column, HCl for final pH adjustment) whereas the in situ extraction in the reactor consisted of an acid (H2SO4) absorption column installed in the biogas recycling line of both reactors. Stable methane production over 220 mL/g COD was achieved and methane content in the biogas was stable around 71%.

Side-stream membrane-based NH3 extraction to improve the anaerobic digestion of poultry manure

The influence of membrane-based ammonia extraction on poultry manure (PM) wastewater treatment was assessed in a 3 L continuous stirred tank reactor (CSTR). The anaerobic digester operated for 91 days at a hydraulic retention time of 15 days and 37 °C. The flat sheet polytetrafluoroethylene (PTFE) membrane module was interconnected to the CSTR and operated at a recirculation flow rate of 0.25 L min−1. The membrane-based ammonia extraction mediated a decrease of total ammonia nitrogen of 64.5 % and of total nitrogen of 53.4 %, which induced an increase in the methane yields from 360 ± 70 up to 574 ± 5 N mL CH4 g VS fed−1. Similarly, chemical oxygen demand (COD) and volatile solids (VS) removal efficiencies increased from 59 % ± 2 % and 57 % ± 3 % up to 79.1 % ± 0.8 % and 65.8 % ± 0.2 %, respectively. This work targeted the enhancement of the performance of full-scale anaerobic digestion plants via reduction of NH3 concentration with a membrane-based extraction unit.

Chemical Constituents and Antimicrobial Activity of a Ganoderma lucidum (Curtis.) P. Karst. Aqueous Ammonia Extract.

Mushroom extracts have shown potential as a source of new antimicrobial agents. This study investigates the chemical profile of an aqueous ammonia extract obtained from the carpophores of Ganoderma lucidum, which grows on Quercus ilex trees, and explores its valorization as a biorational. The major chemical constituents of the extract, identified through gas chromatography-mass spectrometry, include acetamide, oleic acid, 1,2,3,4-butanetetrol, monomethyl azelate, undecane, and palmitic acid. The anti-oomycete and antifungal activity of G. lucidum extract was evaluated against Phytophthora cinnamomi, the primary threat to Quercus spp. in the dehesa biome, as well as three Botryosphaeriaceae fungi. In vitro tests revealed minimum inhibitory concentration (MIC) values of 187.5 μg·mL-1 against P. cinnamomi and 187.5-1000 μg·mL-1 against the fungi. Furthermore, conjugation of the G. lucidum extract with chitosan oligomers (COS) synergistically enhanced its antimicrobial activity, resulting in MIC values of 78.12 and 375-500 μg·mL-1 against P. cinnamomi and the fungi, respectively. These MIC values are among the highest reported to date for natural products against these phytopathogens. Subsequent ex situ testing of the COS-G. lucidum conjugate complex on artificially inoculated Q. ilex excised stems resulted in high protection against P. cinnamomi at a dose of 782 µg·mL-1. These findings support the potential utilization of this resource from the dehesa ecosystem to protect the holm oak, aligning with sustainable and circular economy approaches.

Highly Efficient Electrochemical Nitrate Reduction to Ammonia in Strong Acid Conditions with Fe2M‐Trinuclear‐Cluster Metal–Organic Frameworks

AbstractNitrate‐containing industrial wastewater poses a serious threat to the global food security and public health safety. As compared to the traditional microbial denitrification, electrocatalytic nitrate reduction shows better sustainability with ultrahigh energy efficiency and the production of high‐value ammonia (NH3). However, nitrate‐containing wastewater from most industrial processes, such as mining, metallurgy, and petrochemical engineering, is generally acidic, which contradicts the typical neutral/alkaline working conditions for both denitrifying bacteria and the state‐of‐the‐art inorganic electrocatalysts, leading to the demand for pre‐neutralization and the problematic hydrogen evaluation reaction (HER) competition and catalyst dissolution. Here, we report a series of Fe2M (M=Fe, Co, Ni, Zn) trinuclear cluster metal–organic frameworks (MOFs) that enable the highly efficient electrocatalytic nitrate reduction to ammonium under strong acidic conditions with excellent stability. In pH=1 electrolyte, the Fe2Co‐MOF demonstrates the NH3 yield rate of 20653.5 μg h−1 mg−1site with 90.55 % NH3‐Faradaic efficiency (FE), 98.5 % NH3‐selectivity and up to 75 hr of electrocatalytic stability. Additionally, successful nitrate reduction in high‐acidic conditions directly produce the ammonium sulfate as nitrogen fertilizer, avoiding the subsequent aqueous ammonia extraction and preventing the ammonia spillage loss. This series of cluster‐based MOF structures provide new insights into the design principles of high‐performance nitrate reduction catalysts under environmentally‐relevant wastewater conditions.

Highly Efficient Electrochemical Nitrate Reduction to Ammonia in Strong Acid Conditions with Fe2M-Trinuclear-Cluster Metal-Organic Frameworks.

Nitrate-containing industrial wastewater poses a serious threat to the global food security and public health safety. As compared to the traditional microbial denitrification, electrocatalytic nitrate reduction shows better sustainability with ultrahigh energy efficiency and the production of high-value ammonia (NH3). However, nitrate-containing wastewater from most industrial processes, such as mining, metallurgy, and petrochemical engineering, is generally acidic, which contradicts the typical neutral/alkaline working conditions for both denitrifying bacteria and the state-of-the-art inorganic electrocatalysts, leading to the demand for pre-neutralization and the problematic hydrogen evaluation reaction (HER) competition and catalyst dissolution. Here, we report a series of FeM2 (M = Fe, Co, Ni, Zn) trinuclear cluster metal-organic frameworks (MOFs) that enable the highly efficient electrocatalytic nitrate reduction to ammonium under strong acidic conditions with excellent stability. In pH=1 electrolyte, the Fe2Co-MOF demonstrates the NH3 yield rate of 20653.5 μg·h-1·mg-1site with 90.55% NH3-Faradaic efficiency (FE), 98.5% NH3-selectivity and up to 75 hr of electrocatalytic stability. Additionally, successful nitrate reduction in high-acidic conditions directly produce the ammonium sulfate as nitrogen fertilizer, avoiding the subsequent aqueous ammonia extraction and preventing the ammonia spillage loss. This cluster-based MOF structure provide new insights into the design principles of high-performance nitrate reduction catalysts under environmentally-relevant wastewater conditions.

Phytochemical Profile and Activity against Fusarium Species of Tamarix gallica Bark Aqueous Ammonia Extract

French tamarisk, Tamarix gallica L. (family Tamaricaceae) is a deciduous tree that, like other halophytes, grows in a wide variety of saline habitats thanks to its powerful phenolics-based antioxidant system. Given that antioxidant properties are usually linked to the presence of compounds with antifungal properties, in the work presented herein the antimicrobial activity of T. gallica bark extract was investigated against four phytopathogenic species of genus Fusarium. According to the results of gas chromatography–mass spectroscopy, the phytochemical profile of the aqueous ammonia extract included 1-(2,4,6-trihydroxyphenyl)-2-pentanone; 3,5-dimethoxy-4-hydroxycinnam aldehyde; trans-squalene; 4-hydroxy-3,5-dimethoxy-benzaldehyde; dihydro-3-methylene-2,5-furandione; 1-(4-hydroxy-3,5-dimethoxyphenyl)-ethanone; and 4-hydroxy-3,5-dimethoxy-benzoic acid as main constituents. Concerning in vitro antifungal activity, EC90 effective concentrations in the 335–928 μg·mL−1 range were obtained against F. acuminatum, F. culmorum, F. equiseti, and F. graminearum, remarkably lower than those of two conventional fungicides (viz. mancozeb and fosetyl-Al). The antifungal activity of the extract was tested further in wheat and maize grain protection bioassays, confirming that the treatment effectively controlled F. graminearum at a concentration of 375 µg·mL−1. Given this promising activity, T. gallica bark extracts may be susceptible to valorization as a natural and sustainable biorational for Fusarium spp. control.

Phytochemical Screening and Antibacterial Activity of Taxus baccata L. against Pectobacterium spp. and Dickeya chrysanthemi

The yew tree (Taxus baccata L.) is considered in folklore a symbol of immortality due to its qualities of longevity and regeneration. Despite its poisonous reputation, the yew tree has a long history of medicinal use, particularly in the form of extracts from its leaves and bark. In the work presented herein, gas chromatography–mass spectrometry (GC–MS) chemical profiling was applied to the aqueous ammonia/hydromethanolic extracts of several plant organs of T. baccata, leading to the identification of different bioactive compounds than those previously characterized by high-performance liquid chromatography with tandem mass spectrometry (HPLC–MS/MS) in other extraction media. The leaf aqueous ammonia extract was rich in 2-hexylthiophene and 3-O-methyl-d-fructose; 9-octadecenoic and hexadecanoic acid were the main constituents of the bark aqueous ammonia extract; and the fruit hydromethanolic extract contained methyl 2-O-methyl-α-d-xylofuranoside, 1,3-dioxolane derivatives, and erysimoside. The antimicrobial activity of the extracts was assayed against four bacterial pathogens responsible for the soft rot and blackleg diseases of potatoes, viz. Pectobacterium carotovorum subsp. carotovorum, Pectobacterium atrosepticum, Pectobacterium parmentieri, and Dickeya chrysanthemi, resulting in minimum inhibitory concentration (MIC) values as low as 187 μg·mL−1. Bioassays on potato slices confirmed the efficacy of the leaf extract at this dose when applied as a preventive treatment before artificial inoculation with P. carotovorum subsp. carotovorum. In view of this high activity, these extracts may find application in the integrated pest management of soft rot Pectobacteriaceae (SRP) diseases.

Phytochemical Profiling of Sambucus nigra L. Flower and Leaf Extracts and Their Antimicrobial Potential against Almond Tree Pathogens.

Despite extensive research on the chemical composition of elderberries and their numerous uses in pharmaceutical, beverage, and food production, there is still a lack of knowledge about Sambucus nigra leaves and flowers' antimicrobial activity against plant pathogens. In this study, the phytoconstituents of their aqueous ammonia extracts were first characterized by infrared spectroscopy and gas chromatography-mass spectrometry. The major phytocompounds identified in the flower extract were octyl 2-methylpropanoate; 3,5-dihydroxy-6-methyl-2,3-dihydropyran-4-one; propyl malonic acid; adenine; and 1-methyl-2-piperidinemethanol. Concerning the leaf extract, 1,6-anhydro-β-D-glucopyranose; oleic acid; 2,1,3-benzothiadiazole; 2,3-dihydro-benzofuran; and 4-((1E)-3-hydroxy-1-propenyl)-2-methoxyphenol and other phenol derivatives were the main constituents. The potential of the extracts to act as bioprotectants was then investigated against three almond tree pathogens: Diaporthe amygdali, Phytophthora megasperma, and Verticillium dahliae. In vitro tests showed higher activity of the flower extract, with EC90 values in the 241-984 μg·mL-1 range (depending on the pathogen) vs. 354-1322 μg·mL-1 for the leaf extract. In addition, the flower extract led to full protection against P. megasperma at a dose of 1875 μg·mL-1 in ex situ tests on artificially-infected excised almond stems. These inhibitory concentrations were lower than those of commercial fungicides. These findings suggest that S. nigra aerial organs may be susceptible to valorization as an alternative to synthetic fungicides for the protection of this important crop.

Valorization of Quercus suber L. Bark as a Source of Phytochemicals with Antimicrobial Activity against Apple Tree Diseases.

Cork, an anatomic adaptation of the bark of Quercus suber L. through its suberization process, finds its main application in the production of bottle stoppers. Its processing results in a large waste stream of cork fragments, granulates, and dust, which may be susceptible to valorization. The work presented here explored the use of its extracts to inhibit the growth of phytopathogenic microorganisms associated with apple tree diseases. The in vitro antimicrobial activity of cork aqueous ammonia extract was assayed against four fungi, viz. Monilinia fructigena and M. laxa (brown rot), Neofussicoccum parvum (dieback), and Phytophthora cactorum (collar and root rot), and two bacteria, viz. Erwinia amylovora and Pseudomonas syringae pv. syringae, either alone or in combination with chitosan oligomers (COS). Effective concentration values of EC90 in the 675-3450 μg·mL-1 range, depending on the fungal pathogen, were obtained in growth inhibition tests, which were substantially improved for the conjugate complexes (340-801 μg·mL-1) as a result of strong synergism with COS. Similar enhanced behavior was also observed in antibacterial activity assays, with MIC values of 375 and 750 μg·mL-1 for the conjugate complexes against P. syringae pv. syringae and E. amylovora, respectively. This in vitro inhibitory activity was substantially higher than those exhibited by azoxystrobin and fosetyl-Al, which were tested for comparison purposes, and stood out among those reported for other natural compounds in the literature. The observed antimicrobial activity may be mainly attributed to the presence of glycerin and vanillic acid, identified by gas chromatography-mass spectroscopy. In the first step towards in-field application, the COS-Q. suber bark extract conjugate complex was further tested ex situ against P. cactorum on artificially inoculated excised stems of the 'Garnem' almond rootstock, achieving high protection at a dose of 3750 μg·mL-1. These results suggest that cork industrial leftovers may, thus, be a promising source of bioactive compounds for integrated pest management.

Holm Oak (Quercus ilex subsp. ballota (Desf.) Samp.) Bark Aqueous Ammonia Extract for the Control of Invasive Forest Pathogens.

Holm oak (Quercus ilex subsp. ballota (Desf.) Samp.) bark is a commonly used remedy to treat gastrointestinal disorders, throat and skin infections, hemorrhages, and dysentery. It has also been previously reported that its methanol extracts possess antibacterial activity, which can be related to the richness of Quercus spp. extracts in phenolic compounds, such as flavonoids and tannins. However, there is no information on the antifungal (including oomycete) properties of the bark from Q. ilex or its subspecies (ilex and ballota). In this work, we report the characterization of the aqueous ammonia extract of its bark by FTIR and GC-MS and the results of in vitro and ex situ inhibition tests against three phytopathogens. The main phytochemical components identified were inositols (19.5%), trans-squalene (13%), 4-butoxy-1-butanol (11.4%), gulopyranose (9.6%), lyxose (6.5%), 2,4-dimethyl-benzo[H]quinoline (5.1%), catechol (4.5%), and methoxyphenols (4.2%). The efficacy of the extract in controlling forest phytopathogens was tested in vitro against Fusarium circinatum (responsible for pitch canker of Pinus spp.), Cryphonectria parasitica (which causes chestnut blight), and Phytophthora cinnamomi (which causes ‘root and crown rot’ in a variety of hosts, including Castanea, conifers, Eucalyptus, Fagus, Juglans, Quercus, etc.), obtaining EC90 values of 322, 295, and 75 μg·mL−1, respectively, much lower than those attained for a commercial strobilurin fungicide (azoxystrobin). The extract was further tested ex situ against P. cinnamomi on artificially inoculated, excised stems of ‘Garnem’ almond rootstock, attaining complete protection at a dose of 782 μg·mL−1. The results suggest that holm oak bark extract may be a promising source of bioactive compounds against invasive forest pathogens, including the oomycete that is causing its decline, the so-called ‘seca’ in Spain.

Determination of [N-13]-ammonia extraction fraction in patients with coronary artery disease by calibration to invasive coronary and fractional flow reserve

BackgroundThis study presents a new extraction fraction (EF) model based on physiological measures of invasive coronary flow reserve (CFR) and fractional flow reserve (FFR) in patients with suspected coronary artery disease (CAD) and normal index microcirculatory resistance (IMR). To ascertain the clinical relevance of the new EFs, flow measurements using the newly patient-determined EFs were compared to flow measurements using traditional animal-determined EFs. Methods39 patients were retrospectively selected that included a total of 91 vascular territories with invasive coronary angiography physiological measures. [N-13]-ammonia dynamic rest/adenosine-stress PET imaging was conducted in all patients and absolute myocardial flow was estimated using four published compartmental models. The extraction fraction during hyperemic flow was iteratively estimated by maximizing the agreement between invasive CFR and FFR with the non-invasive analogs myocardial flow reserve (MFR) and relative flow reserve (RFR) at similar physiological states, respectively. ResultsUsing the new patient-determined EFs, agreement between CFR vs MFR for Model 1 and 2 was moderate and poor for Model 3 and 4. All models showed moderate agreement for FFR vs RFR. When using published models of animal-determined EFs, agreement between CFR vs MFR remained moderate for Model 1 and 2, and poor for Model 3 and 4. Similarly, all models showed moderate agreement for FFR vs RFR using animal-determined EF values. None of the observed differences were statistically significant. ConclusionsFlow measurements using extraction fraction correction for [N-13]-ammonia based on calibration to invasive intracoronary angiography physiological measures in patients with CAD were not discordant from those reported in the literature. Either patient-determined or traditional animal-determined EF correction, when used with the appropriate flow model, yields moderate agreement with invasive measurements of coronary flow reserve and fractional flow reserve.

Bark Extract of Uncaria tomentosa L. for the Control of Strawberry Phytopathogens

Gray mold (Botrytis cinerea Pers.), crown and fruit rot (Phytophthora cactorum (Lebert and Cohn) J.Schröt), and verticillium wilt (Verticillium dahliae Kleb.) are among the main diseases that affect the strawberry crop. In the study presented herein, the bark extract of Uncaria tomentosa (Willd. ex Schult.) DC, popularly known as “cat’s claw”, has been evaluated for its capability to act as a sustainable control method. The bioactive compounds present in the aqueous ammonia extract were characterized by gas chromatography–mass spectroscopy, and the antimicrobial activity of the extract—alone and in combination with chitosan oligomers (COS)—was assessed in vitro and as a coating for postharvest treatment during storage. Octyl isobutyrate (30.7%), 19α methyl-2-oxoformosanan-16-carboxylate (9.3%), tetrahydro-2-methyl-thiophene (4.7%), and α-methyl manofuranoside (4.4%) were identified as the main phytoconstituents. The results of in vitro growth inhibition tests showed that, upon conjugation of the bark extract with COS, complete inhibition was reached at concentrations in the 39–93.75 μg∙mL−1 range, depending on the pathogen. Concerning the effect of the treatment as a coating to prolong the storage life and control decay during post-harvest storage, high protection was observed at a concentration of 1000 μg∙mL−1. Because of this effectiveness, higher than that attained with conventional synthetic fungicides, the bark extracts of cat’s claw may hold promise for strawberry crop protection.

Latest Trends on Ammonia Extraction

Purpose: This study was done to present a detailed review and analysis of the extraction of ammonia from a range of waste sources.
 Methodology: Ten excellent quality kinds of literature were selected for this study. In each literature, the authors have analysed, reviewed and described the adopted methodology, main findings and shortcomings of original research papers. 
 Main Findings: Extraction of ammonia is a challenge as well as an opportunity, due to its potential application in fertilizer and hydrogen production.
 Novelty: Unlike other reviews, it is detailed in nature. The authors have reviewed the methodology, important tables, and images from the original literature.

Isolation, chemical characterization and antioxidant activity of Prunus spinosa L. fruit phenolic polysaccharide-proteins

Wild blackthorn fruits are a slightly explored area and their use is negligible, although they show many therapeutic effects. Polysaccharide complexes were solubilized from ripe Prunus spinosa L. fruits by sequential extraction with water (cold and hot), oxalate, ammonia, and sodium hydroxide solutions. The extracted fractions were rich in carbohydrates, phenolics, and proteins, indicating the presence of complexes of these compounds. It was found that most of the material was released with 5% KOH and hot water. The aqueous fractions had a high molecular weight and also polydispersity index, while the other fractions had low molecular weight. Based on the monosaccharide composition, three groups of fractions were observed. The aqueous and oxalate fractions represent highly esterified pectin material, ammonia extraction provided a mixture of de-esterified pectin and hemicelluloses, and alkaline isolates were rich in arabinogalactan and hemicelluloses. Antioxidant activity tests revealed significant effects of blackthorn samples, alkali-extracted fractions at concentrations of 0.02 and 0.05 mg/mL achieved DPPH radical scavenging comparable to that of vitamin C. Most samples achieved maximum activity comparable to vitamin C at a concentration of 0.1 mg/mL. An analogous effect was also found by the FRAP test, all fractions had a significant reducing capacity at a concentration of 0.05 mg/mL, but only the alkaline fractions reached almost vitamin C level. Preliminary results may support interest in these “undiscovered” natural fruits as a rich source of natural antioxidants.

Development of an ammonia production method for carbon-free energy generation

Ammonia has great prospects in the context of the transition to carbon-free energy. It can be used as fuel in gas turbines, fuel cells, internal combustion engines, and burned together with coal. However, industrial production of ammonia is based on the Haber-Bosh process, which involves the use of natural gas and coal, which, in this case, does not make it really carbon-free. This study proposes a method to produce ammonia, which is environmentally friendly and does not require the use of fossil fuels. It is based on the approach to adjusting the concentration of ammonium nitrogen in a biogas reactor and implies the sorption of ammonia from the gas phase with a solution of monoammonium phosphate, obtaining diammonium phosphate, and subsequently heating it with the release of ammonia. The factors influencing the extraction of ammonia from waste have been considered, as well as the influence of temperature on the release of ammonia from the solution of diammonium phosphate; the energy efficiency of the method has been assessed. With increasing temperature, the degree of ammonia and the degree of sorbent regeneration increased. Under laboratory conditions, 111 J/g of ammonia energy was spent. The higher the concentration of (NH4)2HPO4 in the solution, the less energy is required to obtain a unit of ammonia mass. The total amount of ammonia released varies depending on the temperature. Sorbent regeneration can be carried out using thermal energy obtained at a cogeneration plant. The possibility of using this method to produce ammonia at an industrial scale has been estimated by analyzing the ways of ammonia utilization as a fuel. The potential for ammonia production in the main livestock industries in Europe and the United States is up to 11,482,651.15 and 11,582,169.5 tons per year, respectively. Applying this solution also makes it possible to improve the efficiency of biogas production from waste with high nitrogen content. The proposed method of ammonia production could potentially contribute to the development of carbon-free energy

Solvent extraction equilibrium modeling for the separation of ammonia, nickel(II), and copper(II) from the loaded LIX84-I

A novel solvent extraction equilibrium model has been developed to separate nickel and copper from the loaded LIX84-I (active component: 2-hydroxy-5-nonylacetophenone oxime dissolved in a nonpolar diluent, ShellSol D70) formed by the extraction from ammoniacal alkaline solutions. The targeted process consists of the scrubbing of ammonia and subsequent selective stripping of nickel(II) followed by stripping of copper(II), in which sulfuric acid is used in each step. The present model considers the equilibria of extraction of copper, nickel, and ammonia; distribution of metal-extractant complexes; and solution equilibria in aqueous and organic phases and was compared with the experimental results under varying sulfuric acid concentrations and phase ratios. As a result, this model was shown to accurately predict the equilibria after scrubbing and stripping from the initial operational conditions. This model is also applicable to the extraction of copper and nickel from an ammoniacal solution and thus facilitates the design, optimization, and control of the ammoniacal process for the separation of copper and nickel.