Mixture Of HC Research Articles

DEVELOPMENT OF AN ALGORITHM FOR CALCULATING COMPONENT COMPOSITION TO IMPROVE THE DEVELOPMENT OF OFFSHORE OIL FIELDS IN THE NORTH CASPIAN BASIN

The paper presents an algorithm to reconstruct the component composition of the mixture based on the results of production modeling in the black oil format and a fixed set of tables with the results of phase equilibrium calculations in a given pressure range. The approach is based on analyzing the ratio of flow rates for each phase and the ratio between average reservoir pressure and saturation pressure. The algorithm takes into account the possibility of oil degassing when saturation pressure decreases, as well as gas breakthrough of gas caps to the bottoms of producing wells.Implementation of the method is based on a unified thermodynamic model of multilayer reservoir, built on the principles of a single set of HC mixture components and uniform parameters of the equation of state on a set of fluid samples for all modeling stages: reservoir model, model of the gathering system and site facilities. In addition to steady-state flow calculations performed together with reservoir modeling, the unified model is planned to be used for dynamic flow calculations in the corresponding simulator (well start/stop), which will allow solving production problems in the process of operation of wells with complex completions.The conversion algorithm is automated using modern high-level tools: Python and data automation components from MS Excel, which eliminates the need for manual data input at all stages and makes it possible to obtain the estimated component composition of produced fluid for any set of wells and for any time step within the forecasting horizon.The obtained compositions are used to verify the reproduction of the main controlled parameters (oil density and gas oil ratio) and can be used for subsequent calculations of fluid transportation and treatment systems.The implemented algorithm has been tested for stability at different ratios of gas and oil flow rates by wells and meets the practical requirements of engineering calculations — the error of oil density is not higher than 2 % and gas factor is not higher than 10 %.

Study of refrigeration system with minichannel condenser using R1234ze, R134a, R152a, R600a, R290 and mixture of R290/R600a (50/50)

A versatile vapor compression refrigeration (VCR) system is designed, developed and manufactured for testing different alternative refrigerants to R134a. The refrigerants such as R1234ze, R152a, R600a, R290 and mixture of R290/R600a (50/50) refrigerants are tested with an aluminum minichannel condenser which is designed for R134a. All the refrigerants are experimented for condensation temperature varying from 40 to 55°C while evaporation temperature varying from −10 to +15°C for every condensing temperature. The performance parameters like volumetric refrigerating capacity, actual work consumption of compressor, coefficient of performance (COP) and condenser capacity are compared for different alternative refrigerants. Aluminum minichannel condenser has reduced condensing temperature by 2–3°C with an increase in COP by 10%. The ratio of volumetric refrigerant capacities for R152a, R1234ze, R600a, R290 and HC mixture of R290/R600a (50/50) with respect to R134a are found to be 1.296, 1.143, 0.736, 1.749 and 1.067, respectively which is useful to select specific compressor. The ratio of compressor work for R600a, R290, HC mixture of R290/R600a, R152a and R1234ze with respect to R134a are found to be 1.81, 1.812, 1.867, 1.6 and 1.1, respectively. The ratios of condenser capacity of R600a, R290, HC mixture of R290/R600a, R152a and R1234ze with respect to R134a are found to be 1.914, 2.061, 1.939, 1.65 and 1.064, respectively. It is found that COP of R152a, R600a and R1234ze are larger by 11.53, 5.38 and 27% over R134a whereas COP of R290/R600a (50/50) and R290 are decreased by 0.75% and 14.23% over R134a, respectively. The exergy loss analysis for VCR system components is carried out at condensing temperature of 44°C while evaporating temperature ranging from −10 to +15°C for all the refrigerants and found that total exergy loss is more for R600a among all refrigerants.

Exploring Eco-Friendly Alternatives: Experimental Study of a Refrigerator with R600a and HC Mixture Refrigerants

Exploring Eco-Friendly Alternatives: Experimental Study of a Refrigerator with R600a and HC Mixture Refrigerants

Experimental investigation on split type window Air conditioner using HFC and HC mixture as ecofriendly refrigerant alternate to HCFC-22

This paper reports on an experimental study evaluating a window air conditioner's performance when R152a/R290/R600/R600a refrigerant mixture (by various mass percentages) is used as a possible alternative to R-22. Alternative refrigerants are local, cheap, and environmentally friendly. Unmodified R-22 window AC was charged with R152a/R290/R600/R600a. During the experiment, parameters such as coefficient of performance, refrigeration effect, pressure ratio, compressor discharge temperature, refrigerant mass flow rate, and compressor power are analyzed. The present work shows that R152a-15%/R290-15%/R600-35%/R600a-35% is the best-performing alternative refrigerant. Proposed blends and R22's performance were compared.

Drop-in and retrofit refrigerants as replacement possibilities of R134a in domestic/commercial refrigeration and automobile air conditioner applications

According to the EU F-gas Regulation, the phase-out of the high global warming potential (GWP) refrigerants (with higher than 150 GWP value) had been established. The most currently existing household and commercial refrigerators and automobile air conditioners applications based on single-stage vapour compression systems operate with R134a as working fluid. The present paper aims, to review and evaluate the performance of a set of eco-friendly alternatives refrigerants to replace R134a, without change or with minor modifications in refrigeration equipment. The theoretical and experimental studies performed in this field of research were reviewed for this objective. These alternative refrigerants are some of HFCs, HFOs and HCs and their mixtures, which are expected to be an excellent candidates in many refrigeration applications. There are Many replacement possibilities had been proposed viz. drop-in replacement, retrofit refrigerant, and new systems. The results exhibited that the most suitable refrigerants as R134a drop-in substitutes are R1234yf, R152a, R450A, and R513A. The pure R1234ze and its mixtures are not suitable drop-in replacements of R134a but can be a good alternative to R134a only in new refrigeration systems. In terms of hydrocarbon refrigerants R290, R600, and R600a could replace R134a with some modifications to existing refrigeration systems to overcome the flammability issue. We should be using certain HFC and HC mixtures with the lowest TEWI index.

Novel neutralizing human monoclonal antibodies against tetanus neurotoxin

Tetanus is a fatal disease caused by tetanus neurotoxin (TeNT). TeNT is composed of a light chain (Lc) and a heavy chain, the latter of which is classified into two domains, N-terminus Hn and C-terminus Hc. Several TeNT-neutralizing antibodies have been reported, but it remains unclear which TeNT domains are involved in neutralization. To further understand the mechanism of these antibodies, we isolated TeNT-reactive human antibody clones from peripheral blood mononuclear cells. We then analyzed the reactivity of the isolated antibody clones to each protein domain and their inhibition of Hc-ganglioside GT1b binding, which is critical for TeNT toxicity. We also investigated the TeNT-neutralizing ability of isolated antibody clones and showed that an Hn-reactive clone protected strongly against TeNT toxicity in mice. Furthermore, combination treatment of Hn-reactive antibody clones with both Hc-reactive and TeNT mix (the mixture of Hc, Hn, and Lc proteins)–reactive antibody clones enhanced the neutralizing effect. These results indicated that antibody clones targeting Hn effectively neutralized TeNT. In addition, the use of a cocktail composed of Hc-, Hn-, and TeNT mix–reactive antibodies provided enhanced protection compared to the use of each antibody alone.

Performance Evaluation of VCR System using Hydrocarbon Mixture as a Working Medium with Diffuser and Nozzle

In today's world, refrigeration systems have shown significant applications in both industrial and domestic sectors. The majority of the domestic sector refrigerators work on vapour compression system. The leakages of widely used hydro fluorocarbon refrigerants from refrigerator show a severe impact on the environment like global warming, ozone depletion, etc. In order to overcome these problems, eco-friendly refrigerants like hydrocarbons, their Mixtures, etc. are to be used in place of HFCs. in this experiment, the HC Mixture of both R600a and R290 is used. HC refrigerant has negligible GWP (0-3) and zero ODP. In the domestic refrigerator, the power requirement to compressor increases with an increase in compression load. The Diffuser reduces the mechanical work required for the compressor by providing extra work to the refrigerant and nozzle enhances the Refrigeration effect by providing an increase in velocity to the refrigerant. Experiments are conducted to analyse the performance.

Thermal Decompositions of the Lignin Model Compounds: Salicylaldehyde and Catechol.

The nascent steps in the pyrolysis of the lignin components salicylaldehyde ( o-HOC6H4CHO) and catechol ( o-HOC6H4OH) were studied in a set of heated microreactors. The microreactors are small (roughly 1 mm ID × 3 cm long); transit times through the reactors are about 100 μs. Temperatures in the microreactors can be as high as 1600 K, and pressures are typically a few hundred torr. The products of pyrolysis are identified by a combination of photoionization mass spectrometry, photoelectron photoion concidence mass spectroscopy, and matrix isolation infrared spectroscopy. The main pathway by which salicylaldehyde decomposes is a concerted fragmentation: o-HOC6H4CHO (+ M) → H2 + CO + C5H4═C═O (fulveneketene). At temperatures above 1300 K, fulveneketene loses CO to yield a mixture of HC≡C-C≡C-CH3, HC≡C-CH2-C≡CH, and HC≡C-CH═C═CH2. These alkynes decompose to a mixture of radicals (HC≡C-C≡C-CH2 and HC≡C-CH-C≡CH) and H atoms. H-atom chain reactions convert salicylaldehyde to phenol: o-HOC6H4CHO + H → C6H5OH + CO + H. Catechol has similar chemistry to salicylaldehyde. Electrocyclic fragmentation produces water and fulveneketene: o-HOC6H4OH (+ M) → H2O + C5H4═C═O. These findings have implications for the pyrolysis of lignin itself.

A short-cut analytical model of hydrocarbon pool fire of different geometries, with enhanced view factor evaluation

Abstract In analyzing pool fires and the potential for domino effects, the most important aspects to be addressed on the basis of a proper consequence analysis are the evaluation of thermal radiation, the issues of interplant spacing, the employees’ safety zones and fire wall specifications. Even if scientific literature on pool-fire is sparse and modeling is well developed, the usual approach considers circular geometry, pseudo steady-state conditions, uniform flame temperature, cylindrical/conical flame shape with height depending on pool diameter. The specific analysis of rather complicated situations (partial confinement, irregular shapes, complex kinetics, heavy hydrocarbon fire, unsteady-state) usually requires the use of sophisticated integral models and/or time consuming CFD calculations, but when conservative results are enough, analytical models can be more useful especially in hazard assessment. We propose a modelling of a pool fire of a multi-component hydrocarbon mixture, under semi-confined geometry. The physical model of the pool is solved to provide a description of a variable heat emitting flame area, as a function of the vertical flame axis, thus representing a peculiar novelty of the approach. Starting from a real accident in a downstream oil industry involving pool fire of a heavy liquid HC mixture and domino effect, the application to an industrial case study is presented, in order to evidence the effective potentialities of the method.

Optimization Process of a Visi-Cooler Using Ternary Mixtures of R134a and Hydrocarbons

Ozone depletion and global warming phenomenon necessitates the replacement of widely used refrigerants which consist of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) in refrigeration and air-conditioning systems. In this paper, experimental analysis on the performance of hydrofluorocarbon/hydrocarbon (HFC/HC) mixture as a possible drop-in replacement for R134a refrigerant is presented. The influence of capillary length, composition of the mixture and refrigerant charge at various evaporator temperatures on coefficient of performance (COP) are investigated. The optimum operating conditions are obtained by applying Taguchi technique for the acquired experimental results. The results of analysis of variance indicated that for a given evaporator temperature, HFC/HC mixture charge amount is the most influencing parameter. At the optimum condition, the simulation showed that the amount of charge required for HFC/HC mixture in visi-cooler is 120[Formula: see text]g which is 50% lower than required quantity of R134a for the same system. The HC mixture quantity amounted to 90[Formula: see text]g in the HFC/HC mixture which is lower than the safe limit of 150[Formula: see text]g. This eliminates the risk of flammability of HC in the proposed mixture while reducing the quantity of R134a by 87.5%.

Exergy analysis of a domestic refrigerator with brazed plate heat exchanger as condenser

Domestic refrigeration system is one of the major energy-consuming devices. Improving its energy and exergy efficiencies plays a vital role in the energy conservation strategies on domestic energy sector. One of the methods to improve the performance is the replacement of existing components and operation of the system in low condensing pressure. Therefore, in this work, the conventional air-cooled condenser has been replaced with water-cooled brazed plate heat exchanger. Besides the COP, exergy efficiency and irreversibility in all the basic components of a 190-L domestic refrigerator have been studied. The experimental results show that the COP and exergy efficiency of the proposed system are 52–68 and 46–55 %, respectively. This is higher than that of the conventional system. Moreover, the irreversibility of the proposed system is 34 % less than that of the conventional system, and the exergy efficiency of HC mixture is 4–7 % higher than R134a under similar operating conditions.

Investigation of the effect of different refrigerants on performances of binary geothermal power plants

The paper tries to review the argument of the use of working fluids for binary cycle power plants and has been dedicated to this specific argument with a more general perspective. Binary cycle that allows the production of electricity from geothermal energy sources is one of these systems. In this cycle, thermal energy obtained from geothermal sources is transferred to second working fluid. Therefore, selection of second working fluid plays a key role on the cycle performance. In this study, a sample geothermal binary power cycle was modeled and 12 refrigerants that are HFC, HC, and zoetrope refrigerant mixtures were selected as working fluid. Energy and exergy efficiencies of binary cycle were calculated for 12 refrigerants. Dry type fluids of investigated refrigerants R 236ea, R 600, R 600a, and R 227ea showed higher energy and exergy efficiencies, respectively. On the other hand, R 143a, R 415A, R 290, and R 413A that are wet fluids indicated lower energy and exergy efficiencies, respectively.

Fractionation of multi-component hydrocarbon droplets in water at supercritical or near-critical conditions

The mixing of a hydrocarbon droplet, containing a mixture of toluene and either n-decane or tetralin, in a reservoir of supercritical or near-critical water is modeled. This study is an extension of our previous work on the mixing of a single-component hydrocarbon droplet in SCW. The current study provides microscale information, such as multi-component partitioning, and insight into large scale mixing in applications that include supercritical water oxidation, supercritical water desulfurization, etc. Transport, thermodynamics, and phase equilibrium sub-models are used to estimate the relevant physical properties. Results show that fractionation, i.e., the preferred dissolution of a specific hydrocarbon component into the water-rich phase, characterizes the transport and mixing process at various water temperatures. We find that the upper critical solution temperature (UCST) for binary water–HC mixtures control the mixing or fractionation of ternary water–HC–HC mixtures. Fractionation is: modest at water temperatures less than the water–toluene binary UCST (which is the lower UCST); substantial at water temperatures greater than the water–toluene binary UCST but less than the water–decane binary UCST (which is the higher UCST); and negligible at water temperatures greater than the ternary UCST. At water temperatures when fractionation is noticeable, the less water-soluble hydrocarbon (e.g., decane) composition in the droplet may increase over time and the water fraction in the droplet may go through a maximum, as more of the more water-soluble hydrocarbon (e.g., toluene) diffuses into the water-rich phase than the less water-soluble hydrocarbon. Varying the initial toluene concentration can either increase or decrease the droplet radius depending on the water temperature relative to the UCSTs.

Vertical distribution of hydrocarbons in the low troposphere below and above the mixing height: Tethered balloon measurements in Milan, Italy

A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92–97%, while HCs showed a more pronounced decrease (74–95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 ± 20 min.

The reactive oxidant potential of different types of aged atmospheric particles: An outdoor chamber study

The reactive oxygen species (ROS) potential of aged diesel exhaust particulate matter (PM) and other aged aerosol systems in the presence and absence of an urban hydrocarbon environment was assessed. Experiments were performed in a 274 m 3 dual outdoor Teflon film chamber. Filter samples were taken to assess the oxidant generation associated with PM by an optimized dithiothreitol (DTT) method. Diesel exhaust PM had a higher ROS response when it was in the presence of an urban hydrocarbon mixture and was associated with significant O 3 production. For all the aged dilute diesel systems, ROS expression increased by a factor of 2–4 over fresh diesel particles. Other particle systems were also investigated. A low ROS was observed in most of the nighttime experiments, including the nighttime aerosols from SO 2 with O 3 and SO 2 aged by itself. However, when all the systems were compared, aged diesel exhaust tended to express very high ROS potentials, with secondary organic aerosols from an α-pinene + toluene + an urban HC mixture giving the highest ROS response. ► ROS from diesel particles increased by a factor of 2–4 as they aged in sunlight. ► Increases in Diesel ROS were associated with PAH decay and increases in SOA. ► ROS from toluene and α-pinene SOA formation were among the highest observed.

Optimisation of visi cooler with the low global warming potential refrigerant mixture as an alternative to R134a and HC blend

In this study, the performance of a visi cooler has been evaluated by using the ternary mixture of R134a/R290/R600a with five different mass fractions as an alternative to R134a and HC mixture. Baseline tests have been carried out with R134a and HC mixture and the performance parameters were compared with the five selected alternative refrigerant mixtures. The performance is optimised by varying the refrigerant charge and capillary tube length under experimental conditions for both the pull-down test and the energy consumption test. The optimised refrigerant charge of the ternary mixture is approximately 50% of that of the optimised R134a system and the global warming effects will be decreased by two-thirds. The cooling speed is increased by 25% and COP is increased by 9.9%. The length of the capillary is increased by 63.63% to obtain the best performance. The agreement between the predicted values and experimental values is found to be satisfactory.

J. Cosmet. Sci., 59, 105–115 (March/April 2008) Influence of cellulose polymers on the semipermanent dyestuff process for yak hair: An analytical investigation

SynopsisThe aim of this study was to investigate the effect of some cellulose polymers mixed in a semipermanent dyestuff on the dye uptake of yak hair fiber and color fading after repeated washing cycles. Two different classes of commercial polymers were tested: non‐ionic and cationic. Formulations based on a mixture of HC and basic dyes, with different molecular sizes, were employed as representative dyestuffs. UV‐Vis spectroscopy and colorimetric measurements were used to analyze the extracted dyes from the yak hair cuticle and cortex. The results obtained indicate that the presence of cationic polymers in the dye bath improves both the quality of the dyeing process and the anti‐fading effect during the first washing cycles.

Infrared band intensities of cyanobutadiyne (HC 5N) between 400 and 4000 cm −1

We report the first infrared spectra of pure gaseous cyanobutadiyne between 400 and 4000 cm −1. A great care has been taken to obtain a pure sample so that, for the first time, intensities could be determined for all the main bands in the studied domain. The results are compared with available theoretical works. A sample containing a mixture of HC 5N and DC 5N was also studied in the same wavenumber range. The data obtained in this study should be very useful to identify those compounds by IR spectroscopy and will allow the quantification of cyanobutadyine in various environments.

C Terminal Half Fragment (50 kDa) of Heavy Chain Components of Clostridium botulinum Type C and D Neurotoxins Can Be Used as an Effective Vaccine

Recombinant whole heavy chains (H, 100 kDa) and their N-terminal (Hn, 50 kDa) and C-terminal (Hc, 50 kDa) half fragments of Clostridium botulinum type C and D neurotoxins were expressed as glutathione S-transferase (GST) fusion proteins in Escherichia coli. GST eliminated-preparations of H (10 microg), Hn (5 microg), Hc (5 microg), or a mixture of Hn (5 microg) and Hc (5 microg) of types C and D were mixed with an equal volume of adjuvant, and then were twice injected into mice subcutaneously. After immunization, the mice were challenged with up to 10(6) the minimum lethal doses (MLD)/0.5 ml of C or D toxin, the type of which was same as that of the immunogens. All of the mice immunized with antigens except for Hn survived against 10(5) to 10(6) MLD/0.5 ml of the toxins, but the mice immunized with Hn were killed by 100 MLD/0.5 ml. The mice immunized with a mixture of C-Hc and D-Hc, each 5 microg, also showed a high level of resistance against both C and D toxins. Antibody levels immunized with GST fused-or GST eliminatedpreparation were quite similar. These results indicate that recombinant GST-fused Hc can be used as a safe and effective vaccine for type C and D botulism in animals. It also became clear that one time inoculation with a large amount of C-Hc or D-Hc, 100 microg, is useful for vaccine trials in mice.

Tripodal Amido Boron and Aluminum Complexes

The synthesis and structural elucidations of novel boron and aluminum complexes incorporating the tripodal triamido [N3]3- ligand framework that is hypothesized to promote the preorganized pyramidal geometry for high Lewis acidity are reported. Salt metathesis between the in situ-generated trianionic lithium complexes of the tripodal amido ligands with BCl3 leads to boranes HC[SiMe2N(4-MeC6H4)]3B (1) and MeSi[SiMe2N(4-MeC6H4)]3B (2); however, substitution of the N-Ar group with the bulky tBu affords the unexpected non-boron-containing LiCl adduct {[HC(SiMe2NtBu)2(SiMeNtBu)]Li3(Et2O)Cl}2 (3) via apparent elimination of MeBCl2. The products derived from the salt metathesis reaction with AlCl3 are determined by the reaction medium: while the reaction in a hexanes-ether mixture or toluene affords solvated salt adduct HC[SiMe2N(4-MeC6H4)]3Al.ClLi(Et2O)2 (4) or salt adduct HC[SiMe2N(4-MeC6H4)]3Al.ClLi (5), respectively; the addition of a small amount of THF produces a mixture of complexes HC[SiMe2N(4-MeC6H4)]3Al.(THF) (6, major) and HC[SiMe2N(4-MeC6H4)]3Al(OCH=CH2).Li(THF)2 (7, minor). The desired complex 6 can be exclusively formed using HC[SiMe2N(4-MeC6H4)]3Li3.(THF)3 and the hexanes-ether mixture solvent. The molecular structures of complexes 1, 3, 5, 6, and 7 have been elucidated by X-ray diffraction studies. The structure of 1 shows an approximately trigonal pyramidal geometry at B with no significant N-B p-p pi-interactions. The strong salt adduct and solvate formation of the tripodal amido Al complex, as well as its similarity to the strong Lewis acid Al(C6F5)3 in the THF adduct and enolaluminate formation and structure, indicate the desired core structure [N3]Al is indeed highly Lewis acidic.