Secondary Products Research Articles

Overall quality changes and deterioration mechanism of fragrant rapeseed oils during 6-Month storage

The strong-fragrant rapeseed oil (SFRO) is a popular rapeseed oil in China with a low refining degree only degumming with hot water, which remarkably affects its storage stability. The present study compared the overall changes of physical/chemical/nutrient quality of FROs at various temperatures, light wavelengths and headspace volumes. Results showed that red light (680 nm) had a most significant adverse effect on the overall quality of SFRO with the higher correlation coefficients to PV and TOTOX of 0.71 and 0.70, and lower correlation coefficients to chlorophyll and tocopherol of −0.95 and −0.53, respectively. Further studies revealed that red light accelerated the oxidation of fragrant rapeseed oils by degrading chlorophyll to initiate the photo-oxidation process and synthesize high amount of secondary oxidation products including aliphatic and aromatic oxidized compounds from linolenic acid. These findings provided a reference to control the deterioration of FROs by preventing the transmittance of red light.

PHYSICO-MATHEMATICAL MODEL OF THE PROCESS OF PRESSING FUEL BRIQUETTES FROM PLANT MATERIALS

In the process of forming a briquette, compression is characterized by a change in density, i.e., the process of translating a solid medium that has the properties of a bulk material and has a complex three-phase system consisting of natural polymers, sorbed moisture, air and particles of different shapes and sizes into a continuous solid medium with the properties of a monolith given shape and size. In it, the connection between particles is characterized by Van der Waals and Laplace forces. Different researchers describe this process with different empirical formulas, which are based on taking into account the relevant physico-mechanical and technological properties of pressed materials and their individual components. The plant materials considered in the article, which are secondary products of the agro-industrial complex, have specific physical and mechanical properties. As a result, the development of a physico-mathematical model of the process of pressing fuel briquettes from vegetable materials of small-seeded and cereal crops is proposed for the purpose of research. As a result of the analysis of literary sources, it was found that the physical and mechanical properties of pressed materials are determined by the fractional composition, humidity, pressing temperature, type and content of the binder. These indicators affect both the energy indicators of the process and the quality indicators of the briquettes. The multi-component nature, origin and structure of materials of different nature entails the expansion of the variety of physical and mechanical properties that must be taken into account. The influence of elastic, viscous and frictional properties of the materials selected for pressing is considered and taken into account. A physico-mathematical model of the process of pressing fuel briquettes from plant materials was developed, which allows determining the final density of the material, taking into account the peculiarities of briquetting using a stamp press with a crank mechanism. It was established that the parameters and modes of operation of the stamp press briquetting machine with a crank-and-rod mechanism are interconnected with each other and the physical, mechanical and technological properties of the pressed material

Formation of free acetaldehydes derived from lipid peroxidation in U937 monocyte-like cells

Acetaldehyde can be found in human cells as a byproduct of various metabolic pathways, including oxidative processes such as lipid peroxidation. This secondary product of lipid peroxidation plays a role in various pathological processes, leading to various types of civilization diseases. In this study, the formation of free acetaldehyde induced by oxygen-centred radicals was studied in monocyte-like cell line U937. Exposure of U937 cells to peroxyl/alkoxyl radicals induced by azocompound resulted in the formation of free acetaldehyde. Acetaldehyde is formed by the cleavage of fatty acids, which represents the breakdown of fatty acids into smaller fragments initiated by the cyclization of lipid peroxyl radical and β-scission of lipid alkoxyl radical. The cleavage of fatty acids alters the integrity of the plasma and nuclear membrane, leading to the loss of cell viability. Understanding the pathological processes of acetaldehyde formation is an active area of research with potential implications for preventing and treating various diseases associated with oxidative stress.

Acetaminophen-traces bioremediation with novel phenotypically and genotypically characterized 2 Streptomyces strains using chemo-informatics, in vivo, and in vitro experiments for cytotoxicity and biological activity

We isolated two novel bacterial strains, active against the environmental pollutant acetaminophen/Paracetamol®. Streptomyces chrestomyceticus (symbol RS2) and Flavofuscus (symbol M33) collected from El-Natrun Valley, Egypt—water, sediment, and sand samples, taxonomically characterized using a transmission electron microscope (TEM). Genotypic identification, based on 16S rRNA gene sequence analysis followed by BLAST alignment, were deposited on the NCBI as 2 novel strains https://www.ncbi.nlm.nih.gov/nuccore/OM665324 and https://www.ncbi.nlm.nih.gov/nuccore/OM665325. The phylogenetic tree was constructed. Acetaminophen secondary or intermediate product’s chemical structure was identified by GC/LC MS. Some selected acetaminophen secondary-product extracts and derived compounds were examined against a panel of test micro-organisms and fortunately showed a good anti-microbial effect. In silico chemo-informatics Swiss ADMET evaluation was used in the selected bio-degradation extracts for absorption (gastric), distribution (to CNS), metabolism (hepatic), excretion (renal), and finally not toxic, being non-mutagenic/teratogenic or genotoxic, virtually. Moreover, in vitro cytotoxic activity of these selected bio-degradation secondary products was examined against HepG2 and MCF7 cancer cell lines, where M33 and RS2 extract effects on acetaminophen/paracetamol bio-degradation products were safe, with higher IC50 on HepG2 and MCF7 than the acetaminophen/paracetamol IC50 of 108.5 μg/ml. Moreover, an in vivo oral acute single-dose toxicity experiment was conducted, to confirm these in vitro and in silico lower toxicity (better safety) than acetaminophen/paracetamol.

Seed treatment with clothianidin induces changes in plant metabolism and alters pollinator foraging preferences

Neonicotinoids, systemic insecticides that are distributed into all plant tissues and protect against pests, have become a common part of crop production, but can unintentionally also affect non-target organisms, including pollinators. Such effects can be direct effects from insecticide exposure, but neonicotinoids can affect plant physiology, and effects could therefore also be indirectly mediated by changes in plant phenology, attractiveness and nutritional value. Under controlled greenhouse conditions, we tested if seed treatment with the neonicotinoid clothianidin affected oilseed rape’s production of flower resources for bees and the content of the secondary plant products glucosinolates that provide defense against herbivores. Additionally, we tested if seed treatment affected the attractiveness of oilseed rape to flower visiting bumblebees, using outdoor mesocosms. Flowers and leaves of clothianidin-treated plants had different profiles of glucosinolates compared with untreated plants. Bumblebees in mesocosms foraged slightly more on untreated plants. Neither flower timing, flower size nor the production of pollen and nectar differed between treatments, and therefore cannot explain any preference for untreated oilseed rape. We instead propose that this small but significant preference for untreated plants was related to the altered glucosinolate profile caused by clothianidin. Thereby, this study contributes to the understanding of the complex relationships between neonicotinoid-treated crops and pollinator foraging choices, by suggesting a potential mechanistic link by which insecticide treatment can affect insect behavior.

Secondary Products Obtained from Saponite-Bearing Process Water: Theoretical and Experimental Justification

Secondary Products Obtained from Saponite-Bearing Process Water: Theoretical and Experimental Justification

Introduction and Training on Cosmetics with Natural Ingredients as an Effort to Enhance the Creativity of Al Azhar Students

As a form of improving the quality of Indonesian education and also graduating Islamic-based high school students, Al Azhar High School has a mission, namely one of them is for Al Azhar High School students to become religious beings and also have abilities and skills that can be applied directly to society. Steps that can be taken are to provide skills to be able to make innovative products made from natural ingredients, one of which is a body scrub made from coffee grounds typical of Lampung Province. Cosmetic product innovation was chosen because today both at the national and world level the development of the use of cosmetics is increasing, of course this is a great opportunity to start entrepreneurship. In addition, the use of coffee grounds also supports the main results of Lampung plantations which have an area of coffee plantations of around 156,458 ha in 2020, in order to produce secondary products that have higher economic value. The purpose of community service is to provide introduction, education, and train Al Azhar Bandarlampung High School students to make coffee-based cosmetic products, namely Becoffee Body Scrub. The specific target is to make students become pioneers in increasing MSMEs in the field of cosmetics specifically in exploiting the Natural Potential of Sumatra, especially in Lampung province, into cosmetic products.

From Oxidized Fatty Acids to Dimeric Species: In Vivo Relevance, Generation and Methods of Analysis

The occurrence of free fatty acids (FFAs) and the generation of reactive oxygen species (ROS) such as hydroxyl radicals (HO●) or hypochlorous acid (HOCl) is characteristic of inflammatory diseases, for instance, rheumatoid arthritis. Unsaturated fatty acids react with ROS yielding a variety of important products such as peroxides and chlorohydrins as primary and chain-shortened compounds (e.g., aldehydes and carboxylic acids) as secondary products. These modified fatty acids are either released from phospholipids by phospholipases or oxidatively modified subsequent to their release. There is increasing evidence that oligomeric products are also generated upon these processes. Fatty acid esters of hydroxy fatty acids (FAHFAs) are considered as very important products, but chlorinated compounds may be converted into dimeric and (with smaller yields) oligomeric products, as well. Our review is structured as follows: first, the different types of FFA oligomers known so far and the mechanisms of their putative generation are explained. Industrially relevant products as well as compounds generated from the frying of vegetable oils are also discussed. Second, the different opinions on whether dimeric fatty acids are considered as “friends” or “foes” are discussed.

Development, intercomparison, and evaluation of an improved mechanism for the oxidation of dimethyl sulfide in the UKCA model

Abstract. Dimethyl sulfide (DMS) is an important trace gas emitted from the ocean. The oxidation of DMS has long been recognised as being important for global climate through the role DMS plays in setting the sulfate aerosol background in the troposphere. However, the mechanisms in which DMS is oxidised are very complex and have proved elusive to accurately determine in spite of decades of research. As a result the representation of DMS oxidation in global chemistry–climate models is often greatly simplified. Recent field observations and laboratory and ab initio studies have prompted renewed efforts in understanding the DMS oxidation mechanism, with implications for constraining the uncertainty in the oxidation mechanism of DMS as incorporated in global chemistry–climate models. Here we build on recent evidence and develop a new DMS mechanism for inclusion in the UK Chemistry Aerosol (UKCA) chemistry–climate model. We compare our new mechanism (CS2-HPMTF) to a number of existing mechanisms used in UKCA (including the highly simplified three-reactions–two-species mechanism used in CMIP6 studies with the model) and to a range of recently developed mechanisms reported in the literature through a series of global and box model experiments. Global model runs with the new mechanism enable us to simulate the global distribution of hydroperoxylmethyl thioformate (HPMTF), which we calculate to have a burden of 2.6–26 Gg S (in good agreement with the literature range of 0.7–18 Gg S). We show that the sinks of HPMTF dominate uncertainty in the budget, not the rate of the isomerisation reaction forming it and that, based on the observed DMS / HPMTF ratio from the global surveys during the NASA Atmospheric Tomography mission (ATom), rapid cloud uptake of HPMTF worsens the model–observation comparison. Our box model experiments highlight that there is significant variance in simulated secondary oxidation products from DMS across mechanisms used in the literature, with significant divergence in the sensitivity of the rates of formation of these products to temperature exhibited; especially for methane sulfonic acid (MSA). Our global model studies show that our updated DMS scheme performs better than the current scheme used in UKCA when compared against a suite of surface and aircraft observations. However, sensitivity studies underscore the need for further laboratory and observational constraints. In particular our results suggest that as a priority long-term DMS observations be made to better constrain the highly uncertain inputs into the system and that laboratory studies be performed that address (1) the uptake of HPMTF onto aerosol surfaces and the products of this reaction and (2) the kinetics and products of the following reactions: CH3SO3 decomposition, CH3S + O2, CH3SOO decomposition, and CH3SO + O3.

Molecular Characterization and Zoonotic Significance of Cryptosporidium spp. and Giardia duodenalis in Asymptomatic Adult Stray Cats and Dogs in Turkey

Background: Cryptosporidium species and Giardia duodenalis are important protozoan parasites due to their wide host range and potential as zoonotic diseases. These parasites, responsible for Cryptosporidiosis and Giardiasis, are significant health concerns and have garnered attention from both the public and veterinary fields. Pets, such as dogs and cats, are susceptible to these infections and play a crucial role in transmitting these protozoans to humans. This study was conducted to determine the prevalence, species, genotypes and zoonotic significance of Cryptosporidium and Giardia in asymptomatic adult stray cats and dogs. Methods: Fecal samples from 75 adult stray animal, 42 dogs and 33 cats, were collected in Diyarbakýr city, southeastern Anatolia, Turkey. Direct immunofluorescence test was used to confirm the presence of G. duoenalis cysts and cryptosporidium spp. oocysts in collected fecal samples. Microscopic analysis was used to count the number of cysts/oocysts per gram as specified by the manufacturer. Molecular confirmation was done with Polymerase chain reaction (PCR) using Giardia SSU-rDNA and Cryptosporidium spp. SSU rRNA gene. The secondary PCR products of all positive samples were sequenced in one directions on an automated sequencer. Nucleotide sequence analysis was performed by BLAST alignment using the National Center for Biotechnology Information database. Result: The prevalence of Cryptosporidium was 7.14% in 42 cats and 9.09% in 33 dogs. The prevalence of G. duodenalis was 23.80% in cats and 54.54% in dogs. The average number of Cryptosporidium spp. oocysts per gram of cat and dog feces was 1866.3 and 1813.3, respectively. The average number of G. duodenalis cysts per gram of cat and dog feces was 1011.6 and 4786, respectively. All Cryptosporidium isolates were determined as C. canis in dogs and C. felis in cats. C. canis and C. felis isolates identified in the study, MT329018.1 and MN696800.1, AF159113.1 and KM977642.1 showed similarity with Genbank number, respectively. Assemblages A, E, C, D were found in dogs and assemblages A and E in cats in the result of the sequence of 130 bp gene fragments obtained from G. duodenalis isolates. This study sequence analysis of G. duodenalis cat isolates identified assemblages A (50%/10) and E (50%/10). In this study, assemblage E was the most common genotype isolated in dogs (38.8%), followed by Assemblage C (27.7%), Assemblage D (16.6%) and Assemblage A (15.5%). Assemblage A, which has zoonotic importance, was detected in cats and dogs, while assemblage E in cats and dogs was reported for the first time in Turkey.

Genome-Wide Analysis of Family-1 UDP-Glycosyltransferases in Potato (Solanum tuberosum L.): Identification, Phylogenetic Analysis and Determination of Response to Osmotic Stress.

Family-1 UDP-glycosyltransferases (UGTs) are the most common and functional glycosyltransferases in the plant world. UGT is closely related to plant growth and the response to abiotic stress. However, despite systematic research, our understanding of potato UGT genes is still unclear. In this study, we identified 174 potato UGT proteins based on their conserved plant secondary product glycosyltransferase (PSPG) motifs. Phylogenetic analyses were used to compare these proteins with Arabidopsis UGTs and other plant UGTs, and it was found that they could be clustered into 18 distinct groups. Patterns of intron gain/loss and intron phases within potato UGTs revealed highly conserved intron insertion events. The promoter cis-elements of these 174 UGT genes were systematically investigated. The promoter regions of these UGT genes are known to contain various classes of cis-acting compounds. These include elements that are light-responsive, phytohormone-responsive, and stress-responsive. Transcriptome data analysis established that 25, 10, 6, and 4 of these 174 UGT genes were specifically expressed in leaves, roots, stolons, and young tubers, respectively. The mannitol-treated transcriptomic data showed thirty-eight UGT genes were significantly upregulated. The quantitative real-time PCR results showed that the four genes were all responsive to osmotic stress under a 10% PEG6000 treatment. The results of our study provide a basis for clarifying the molecular mechanism of potato osmotic stress resistance and better understanding its function in the future.

Evaluation of primary and secondary oxidation products in fish oil-in-water emulsions: Effect of metal-complexing peptides and protein hydrolysates

A novel approach consisting of preselection of peptides using bioinformatics tool followed by final selection using Surface Plasmon Resonance (SPR) - an efficient technique to investigate metal complexing properties of peptides/hydrolysates - was developed. Selected pea hydrolysates and synthetic metal chelating peptides potentially present in pea hydrolysates were investigated for their ability to inhibit the lipid oxidation in emulsions composed of 5 % w/w fish oil and stabilized with Tween® 20. Results indicated that addition of peptides/hydrolysates did not impact the physical stability of emulsions and led to lower level of lipid hydroperoxides. Moreover, peptide KGKSR inhibited the generation of 1-penten-3-ol and hexanal to the same level as ethylenediaminetetraacetic acid (EDTA) did and the formation of 2 ethyl-furan was lower than when EDTA was added. Peptide GRHRQKHS showed same concentration of hexanal as EDTA thus confirming efficacy of using SPR for selecting peptides/hydrolysates to use as antioxidants in emulsions.

Exploring Deposition Observations of Oxidized Sulfur and Nitrogen as a Constraint on Emissions in the United States

AbstractEmissions of anthropogenic sulfur and nitrogen oxides form secondary pollutants that impact human health, ecosystems, and climate. Accurate estimates of emissions trends are needed to verify the effectiveness of the regulation of these species. We explore the utility of deposition measurements of SOx (=SO2 + SO42−) and TNO3 (=HNO3 + NO3−) as constraints on emissions trends of SOx and NOx in the conterminous United States (CONUS) from 1990 to 2021. The GEOS‐Chem model captures observed annual SOx and TNO3 wet deposition at NADP‐NTN sites in 2011 with a −15% and +15% normalized mean bias (NMB), respectively. The model overestimates the dry deposition of SOx and TNO3 estimated at CASTNET sites in 2011 (NMB >100%), however, this bias is substantially reduced when using an alternate derived dry deposition data set at the same sites, highlighting the uncertainty in dry deposition velocities. Despite this, we find that the model (driven by scaled NEI emissions) captures the relative trend in dry deposition of SOx (−93% observed and −94% simulated) and TNO3 (−66% observed and −68% simulated) from 1990 to 2021 and that these decreases closely reflect the trends in anthropogenic SO2 emissions (−93%) and anthropogenic NOx emissions (−71%), respectively. SOx and TNO3 wet deposition observations are dominated by soluble secondary products and are more influenced by natural and transboundary sources, and therefore have decreased more modestly over the same period (−78% and −52%). Natural sources of NOx are relatively constant during this time and therefore moderate the reduction in total NOx emissions (−55%).

A novel “Snowflake”--rGO-CuO for ultrasonic degradation of rhodamine and methyl orange

Graphene-doped CuO (rGO-CuO) nanocomposites with flower shapes were prepared by an improved solvothermal method. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and UV–visible spectroscopy. The active species in the degradation reaction of rGO-CuO composites under ultrasonic irradiation were detected by electron paramagnetic resonance. On the basis of comparative experiments, the photodegradation mechanisms of two typical dyes, Rhodamine B (Rh B) and methyl orange (MO), were proposed. The results demonstrated that the doped CuO could improve the degradation efficiency. The catalytic degradation efficiency of rGO-CuO (2:1) to rhodamine B (RhB) and methyl orange (MO) reached 90 ​% and 87 ​% respectively, which were 2.1 times and 4.4 times of the reduced graphene oxide. Through the first-principles and other theories, we give the reasons for the enhanced catalytic performance of rGO-CuO: combined with internal and external factors, rGO-CuO under ultrasound could produce more hole and active sites that could interact with the OH· in pollutant molecules to achieve degradation. The rGO-CuO nanocomposite has a simple preparation process and low price, and has a high efficiency of degrading water pollution products and no secondary pollution products. It has a low-cost and high-efficiency application prospect in water pollution industrial production and life.

Direct Access to Quinone-Fused 5-Substituted-1,4-Benzodiazepine Scaffolds from Azidoquinones with/without [1,2]-Azide-Nitrogen Migration: Mechanistic Insights.

Seven-membered nitrogen heterocycles have a strong influence in drug discovery due to their inherent 3D character, which allows the ability to explore a vast conformational space with a biological target. Notably, the privileged 1,4-benzodiazepine scaffold is dominant in treating the central nervous system due to its binding affinity with the GABAA receptor. Herein, we report a protocol for the transformation of azidoquinones to p-quinone fused 5-substituted-1,4-benzodiazepines (p-QBZDs) from InCl3-catalyzed intermolecular tandem cycloannulation of azidoquinones with amines and aldehydes. Detailed mechanistic studies reveal that the EDA complex between azidoquinones and InCl3 is crucial in determining the reaction pathway. In the absence of EDA complex formation, the reaction proceeds via the intermediacy of 2,3-bridged-2H-azirine followed by regiospecific addition of an amine to C═N/ring opening/cyclization to deliver p-QBZD with 1,2-azide-nitrogen migration. In the case of EDA complex formation, the reaction proceeds through regioselective aza-Michael addition/nitrene insertion with aldehyde and subsequent cyclization to deliver p-QBZD and p-quinone fused imidazole as a secondary product without 1,2-azide-nitrogen migration. This protocol provides straightforward access to redox-active quinone embedded 5-substituted-1,4-benzodiazepines from azidoquinones with diverse substrate scopes that would find potential applications in medicinal chemistry and drug discovery.

Reactivity of MSWI-fly ash in Mg-K-phosphate cement

In this study, the behaviour and reactivity of Municipal Solid Waste Incineration Fly Ash (MSWI-FA), introduced in the formulation of magnesium potassium phosphate cement (MKPC), was investigated by considering the waste either as fully inert or reactive. MSWI-FA induced structural and compositional modifications in MKPC as a consequence of dissolution/precipitation processes which involved many MSWI-FA elements (e.g., Ca, Mg, Al, Si, Zn) and led to the formation of mostly amorphous phosphate secondary products. The reaction path has been described in terms of the early fast dissolution of MSWI-FA, with precipitation of very low solubility phases, and subsequent late precipitation due to pH changes and water subtraction during MKPC gelification. The increase in amorphous content peaked to 50 wt.% and it has been related to the improved behaviour with respect to the leaching of heavy metals (reduced by 70-99%), pointing to this cement as an excellent matrix for their chemical stabilization. The obtained MKPC microstructure exhibited better mechanical performance, with an improvement of up to 60% in compressive strength. All in all, the results indicated that the incorporation in MKPC is a viable recycling opportunity for MSWI-FA, although, for an effective cement formulation, its reactivity must be taken into account.

Streptomyces rare codon UUA: from features associated with 2 adpA related locations to candidate phage regulatory translational bypassing

ABSTRACT In Streptomyces species, the cell cycle involves a switch from an early and vegetative state to a later phase where secondary products including antibiotics are synthesized, aerial hyphae form and sporulation occurs. AdpA, which has two domains, activates the expression of numerous genes involved in the switch from the vegetative growth phase. The adpA mRNA of many Streptomyces species has a UUA codon in a linker region between 5’ sequence encoding one domain and 3’ sequence encoding its other and C-terminal domain. UUA codons are exceptionally rare in Streptomyces, and its functional cognate tRNA is not present in a fully modified and acylated form, in the early and vegetative phase of the cell cycle though it is aminoacylated later. Here, we report candidate recoding signals that may influence decoding of the linker region UUA. Additionally, a short ORF 5’ of the main ORF has been identified with a GUG at, or near, its 5’ end and an in-frame UUA near its 3’ end. The latter is commonly 5 nucleotides 5’ of the main ORF start. Ribosome profiling data show translation of that 5’ region. Ten years ago, UUA-mediated translational bypassing was proposed as a sensor by a Streptomyces phage of its host’s cell cycle stage and an effector of its lytic/lysogeny switch. We provide the first experimental evidence supportive of this proposal.

The dark side of orange: Multiorganismic continuum dynamics within a lichen of the Atacama Desert

ABSTRACT Over the decades our understanding of lichens has shifted to the fact that they are multiorganismic, symbiotic microecosystems, with their complex interactions coming to the fore due to recent advances in microbiomics. Here, we present a mutualistic-parasitic continuum dynamics scenario between an orange lichen and a lichenicolous fungus from the Atacama Desert leading to the decay of the lichen’s photobiont and leaving behind a black lichen thallus. Based on isolation, sequencing, and ecophysiological approaches including metabolic screenings of the symbionts, we depict consequences upon infection with the lichenicolous fungus. This spans from a loss of the lichen’s photosynthetic activity and an increased roughness of its surface to an inhibition of the parietin synthesis as a shared pathway between the photobiont and the mycobiont, including a shift of secondary metabolism products. This degree of relations has rarely been documented before, although lichenicolous fungi have been studied for over 200 years, adding an additional level to the view of interactions within lichens.

Experimental Study on Effects of CO2 Curing Conditions on Mechanical Properties of Cement Paste Containing CO2 Reactive Hardening Calcium Silicate Cement.

Human survival is threatened by the rapid climate change due to global warming caused by the increase in CO2 emissions since the Second Industrial Revolution. This study developed a secondary cement product production technology by replacing cement, a conventional binder, with calcium silicate cement (CSC), i.e., CO2 reactive hardening cement, to reduce CO2 emissions and utilize CO2 from the cement industry, which emits CO2 in large quantities. Results showed that the carbonation depth, compressive strength increase rate, and CO2 sequestration rate increased as the CSC content increased, suggesting that CSC can be applied as a secondary cement product.

Secondary reactions of propylene on Ga/γ-Al2O3 propane dehydrogenation catalysts

Supported Ga catalysts have been widely studied for propane dehydrogenation (PDH). In this study, Ga/γ-Al2O3 catalysts were evaluated for PDH. The propylene selectivity decreased with increasing propane conversion. It is generally thought that propylene and light gas by-products occur from chemisorbed propane and are, therefore, primary products. By extrapolating the product selectivities to zero per cent propane conversion, the initial propylene selectivity was near 100% and is a primary product. The light gas selectivities, however, are near 0% indicating that these are secondary products. The direct reaction of propylene produced the same light gas products, e.g., methane, ethylene, propane, butenes and pentenes, observed for PDH and confirmed that these occur by an independent reaction of propylene. Thus, while the intrinsic PDH propylene selectivity is high, these secondary propylene reactions lower the selectivity, especially, at higher conversions and higher partial pressures.