Condensation Of Volatiles Research Articles

Syngenetic effects in co-activation of willow wood with homogenous biochar facilitate pore generation in activation

Mixing feedstocks of varied aromatic/aliphatic content is a simple method for tailoring pore structures of activated carbon (AC) in activation. Herein, willow wood and homogenous biochar produced at 300 or 500°C, which have distinct content of aliphatic component, were co-activated with K2C2O4, at 800°C for changing pore characteristics of resulting AC. The results indicated that co-activation of willow and biochar diminished production of AC and impacted evolution of organics and gases through intensive volatiles-char interactions. The AC from the co-activation of willow with either biochar-300 or biochar-500 exhibited higher specific surface area than that from direct activation of willow (1409.7 or 1297.0 m2 g−1 versus 1243.6 m2 g−1), which was also higher than calculated average of that from feedstock (ca. 1160 m2 g−1). This resulted from intensified gasification of the biochar with H2O/CO2 derived from willow, creating additional macropores and micropores of enlarged pore sizes. The enhanced gasification also reduced crystallinity of graphitic carbon, lowered O content via accelerated deoxygenation and diminished CO on nascent AC. Volatiles-char interactions also minimized pore filling from carbonaceous deposit generated from secondary condensation of primary volatiles. Additionally, direct activation of aliphatic-rich willow tended to form more micropores, while more mesopores were formed from aromatic-rich biochar.

Leaching char with acidic aqueous phase from biomass pyrolysis: Valorization of the leachate via catalytic hydrothermal gasification

Aqueous phase of bio-oil (APB) is a general stream of waste produced from biomass pyrolysis and fractional condensation of pyrolytic volatiles and has very limited applications. We have demonstrated a sequence of leaching of alkali and alkaline earth metallic species (AAEMs) from char and catalytic hydrothermal gasification (CHTG) for valorizing char and APB, respectively. The majority of AAEMs can be removed from the char by leaching with APB and the removal rates were almost equivalent to those leached with HCl (1.0 M). CHTG of an aqueous solution of the spent APB with a total organic carbon of 14,450 ppm was performed in a continuous flow reactor, employing an activated carbon-supported Ru catalyst (Ru loading, 4.6 wt%). The catalyst exhibited a stable activity for carbon conversion of 98.8 % at 350 °C for at least 360 min while gaseous product consisting of H2, CH4, and CO2 was produced with a cold gas efficiency of 101–103 %, on a higher heating value basis. The cold gas efficiency exceeding 100 % is mainly because of the generation of H2 from water through water-gas shift reaction. The CHTG performance of APB was enhanced by char leaching through the uptake of coke-forming precursors of APB onto char and the enrichment of AAEMs in the spent APB. These AAEMs played roles in suppressing coke formation and deposition onto the catalyst and maintaining Ru particle size by providing a less acidic hydrothermal environment.

Volatilisation Behaviour and Mechanism of Lead-Containing Slag during Physical Property Tests.

According to physical property tests of lead-containing slag, the volatilisation behaviour of lead slag will have adverse impacts on test accuracy and further affect the control of chemical reactions, solidification and removal of inclusions during smelting. To analyse the volatilisation characteristics of lead slag, in this paper, four kinds of lead slags from lead direct reduction smelting with different PbO and ZnO content are taken. thermogravimetry, ISP-TOF were used. Additionally, the changes in volatiles and slag composition and phases were analysed with XRD and ICPS, and the volatilisation reaction mechanism was discussed. The results indicated that the volatilisation of lead slag can lead to a big weight loss of about to the slag with higher PbO content. The weight loss increases with the PbO content in slag increases. The volatile corresponding to the weight loss above 900 °C is mainly PbO and less ZnO. The higher the temperature is, the stronger the volatilisation is. With the increase in temperature and keeping time, most of the PbO can be evaporated and leaves little PbO in the residual slag. This will has great effect to physico-chemical property measurement of the slag with higher PbO content, especially to the property measurement that be kept at high temperature for a long time. Because the volatiles is trend to condense with the temperature decrease, mass spectrometer is limited by the condensation of volatiles, i.e., PbO, ZnO and so on, in the connection pipeline. The device should be modified for this use.

Catalytic pyrolysis of poplar sawdust over biochar of varied origin: Impact of volatile-char interactions

Volatile-char interaction is almost unavoidable in pyrolysis, which is part of the process shaping composition of bio-oil/gases and properties of char. In this study, the influence of the char from sawdust/spinach/rice/spirulina/pig manure on pyrolysis of poplar sawdust was investigated at 500 °C, aiming to understand the impact of the char of same or varied origin on formation of volatiles/gases and change of the char catalysts themselves from the volatile-char interaction. The results suggested that the sawdust-, spinach- or rice-char catalyzed cracking of volatiles, reducing formation of heavy tar, decreasing production of bio-oil (28.6–35.5 % vs 49.4%) while enhancing gases generation (36.9–44.0 % vs 22.4%). The spirulina- and manure-char enhanced secondary condensation of volatiles, producing more heavy tar, more bio-oil, and additional oxygen-rich carbonaceous deposit with highly aliphatic nature. This reduced thermal stability, the C/O ratio of the char catalyst, and also led to coverage of char surface, especially for the manure-char catalyst. The in-situ IR techniques showed that manure-char catalyzed formation of abundant ketones and esters/lactones in intermediates, which further involved in polymerization. In comparison, the sawdust-char catalyst catalyzed cracking and aromatization of the volatiles of same origin, producing carbon- and hydrogen-rich carbonaceous solid, enhancing aromatic nature of the char catalyst, which was actually a real process for evolution of structure of biochar in pyrolysis of the sawdust.

Modeling Slope Microclimates in the Mars Planetary Climate Model

AbstractA large number of surface features (e.g., frost, gullies, slope streaks, recurring slope lineae) are observed on Martian slopes. Their activity is often associated with the specific microclimates on these slopes, which have been mostly studied with one‐dimensional radiative balance models to date. We develop here a parameterization to simulate these microclimates in 3D Global Climate Models. We first demonstrate that any Martian slope can be thermally represented by a poleward or equatorward slope, that is, the daily average, minimum, and maximum surface temperatures depend on the North‐South component of the slope. Based on this observation, we implement here a subgrid‐scale parameterization to represent slope microclimates (radiative fluxes, volatile condensation, ignoring slope winds for now) in the Mars Planetary Climate Model and validate it through comparisons with surface temperature measurements and frost detections on sloped terrains. With this new model, we show that slope microclimates do not have a significant impact on the seasonal CO2 and H2O cycles on a global scale. Furthermore, short‐scale slopes (i.e., less than ∼1 km in length) do not significantly impact the thermal state of the atmosphere. Ninety‐one percent of the active gullies are found where our model predicts CO2 frost, suggesting that their activity is related to processes involving CO2 ice. However, the low thicknesses (≤tens of cm) predicted at mid‐latitudes rule out mechanisms involving large amounts (∼meters) of ice. This model opens the way to new studies on surface‐atmosphere interactions in present and past climates.

Hydrothermal Alteration in the Nevados de Chillán Geothermal System, Southern Andes: Multidisciplinary Analysis of a Fractured Reservoir

The interplay between a heat source, primary plus secondary permeability, and hydrothermal fluids makes geothermal systems a highly dynamic environment where evolving physico-chemical conditions are recorded in alteration mineralogy. A comprehensive characterization of hydrothermal alteration is therefore essential to decipher the major processes associated with geothermal system development. In this study, we defined the hydrothermal mineralogical evolution of the Nevados de Chillán Geothermal System (NChGS), located in the Southern Volcanic Zone (SVZ) of the central Andes, where the regional framework of the system is formed by a direct association with a currently active volcanic complex, a favorable structural control, and vertically inhibited fluid circulation. To characterize the secondary mineralogy present in the NChGS, we integrated optical petrography, Scanning Electron Microscopy (SEM) observations, X-ray Diffraction (XRD) analysis, and microthermometric measurements along a drill core with a depth of 1000 m at the Nieblas-1 well. These mineralogical approaches were combined with a structural field analysis to highlight the relevance of multidisciplinary study in understanding active geothermal systems. The results indicated that the evolution of the system involved four paragenetic stages, with the main processes in each phase being the heating, boiling, and mixing of fluids and re-equilibration to new physico-chemical conditions. Additionally, three hydrothermal zones were recognized: an upper argillic section, an intermediate sub-propylitic zone, and a deep propylitic domain. Sampled thermal springs are characterized by pH values of 2.4–5.9 and high SO4= concentrations (>290 ppm). These acid-sulfate steam-heated waters suggest the contribution of primary magmatic volatiles to the hydrothermal system. Alunite recorded in the alteration halos of veinlets presents at depths of 170–230 m denote the circulation of acidic fluids at these levels which were favored by reverse faults. These findings indicate that, at this depth range, the condensation of magmatic volatiles into shallow aquifers controls the recharge area of the superficial thermal manifestations. Conversely, deep-seated hydrothermal fluids correspond to near-neutral chloride fluids, with salinities ranging from 0.1 to 6.9 wt.% NaCl eq. The distribution of illite/smectite and chlorite/smectite mixed-layered minerals outline the presence of a significant clay cap, which, in this system, separates the steam-heated domain from the deep hydrothermal realm and restricts fluid circulation to existing permeable channels. Our mineralogical and structural study provides critical data for the interpretation of heat–fluid–rock interaction processes in the NChGS. The interplay between hydrothermal fluids and active faults is also discussed in the context of the complex of geological processes in active geothermal systems along the Chilean Southern Volcanic Zone.

The effect of atmospheric media variation on liquid characteristics of torrefied coffee beans

Pollution and carbon footprints are still issues in the coffee roasting industry. Therefore, torrefaction of coffee beans with volatile condensation and atmospheric media variations can be an alternative to the roasting process. This study aims to determine the effect of the atmospheric media variations on the liquid characteristics resulting from coffee bean torrefaction using Gayo arabica green beans. The test was conducted with a fixed bed torrefier at 235 ± 8 °C for 60 min with a variety of oxidative air atmospheric media and non-oxidative inert gas (N2 &Ar) at a rate of 1 l/min. The torrefied coffee beans were cooled and removed at 50 °C. The volatile gas flowed to the condenser and flash tank, separating the liquid and uncondensed gas. The liquid yield was calculated based on mass data and its characteristics measured in pH, density and viscosity. Furthermore, FTIR and GC-MS methods were used to detect functional groups and the content of the compounds. The results showed that atmospheric media variations caused differences in yield for samples of liquid and air atmospheric of 11 % > N2: 10 % > Ar: 7 %. Insignificant differences were found in the value of pH, density and viscosity. These were also shown in functional groups and the content of liquid compounds. The difference was between samples using oxidative and non-oxidative gases and in between inert gases. Meanwhile, the variations in atmospheric media, impact differences in the number, type and amount of compound content.

Impact of biochar catalyst on pyrolysis of biomass of the same origin

In pyrolysis, the formed biochar is not an inert material as it could interact with of varied volatiles via distinct ways, modifying the composition of bio-oil and its own property. In this study, the pyrolysis of biomass with the biochar of the exactly same origin was conducted at 500 ºC with cellulose, lignin and poplar sawdust as the research objects, aiming to probe the potential involvement of biochar in pyrolysis. It has been demonstrated that, independent of feedstock, the presence of biochar decreased yields of newly formed biochar (41.0 % decrease for cellulose while 22.3 % for sawdust) via suppressing secondary condensation of volatiles. However, the biochar catalyst aided to form more bio-oil and gas via catalyzing the secondary cracking reactions such as decarboxylation and dehydrogenation reactions. In addition, during the volatile-char interaction, deposition of oxygen-containing species on surface of biochar was observed, which influenced the thermal stability, hydrophilicity, the crystallinity and regularity of the spatial arrangement of carbon crystals of the resulting biochar. The results from in-situ characterization showed that the biochar catalyst interfered with the dehydrogenation of the C-H, the dehydration of -OH and formation of the reaction intermediates with CO.

Study on Vacuum Roasting Pretreatment of Carbonaceous Gold Concentrates Based on Nonoxidation Technology

Carbonaceous gold ores are difficult to treat because of the “preg-robbing” by carbonaceous matters and locking by minerals. Roasting is the most commonly used method that is useful in dealing with carbonaceous gold ores. In this study, flotation gold concentrates containing sulfides and carbonaceous matters were investigated to ascertain the reaction process and the matters’ transformation characteristics in different temperatures by vacuum roasting pretreatment. Calcine and volatile condensates were characterized with several techniques. In the process of vacuum roasting, the main chemical reactions were decomposition reaction and carbothermic reduction reactions of sulfide ores, carbothermic reduction reactions of SiO2, and thermal decomposition reactions of organic carbon. The bad effects of “preg-robbing” by carbonaceous matters were greatly weakened by the thermal decomposition and carbothermal reduction. The gold locking minerals were mainly removed by reduction reactions. The sulfides were removed in ways that did not produce SO2. The removal of sulfur and carbonaceous matters during the vacuum roasting process was 95.83% and 65.38%, respectively. Direct cyanidation of the calcine extracted from 2.13% to 88.37% of the gold content with a vacuum degree of 10 Pa and roasting from 25°C to 1,200°C for 30 min.

Biochar catalyzing polymerization of the volatiles from pyrolysis of poplar wood

In this study, the pyrolysis of poplar wood chips with biochar catalyst produced from gasification of the same poplar wood chips was conducted, aiming to probe its influence on the evolution of the pyrolysis products. From the results, it was concluded that the biochar catalyst enhanced the polymerization of the volatiles produced from the pyrolysis, and thus reduced the yields of the gaseous compounds while increased the yield of char. The carbonaceous deposit on surface of the char was oxygen-rich and more aliphatic, which decreased the thermal stability and crystallinity of the char, while made the char prone to oxidation. The biochar catalyst also promoted the formation of methoxy phenols at the expense of alkyl phenols, and the formation of the phenolics with bigger π-conjugated structures. In addition, the volatile-biochar interaction removed the defective structures in the large aromatic structures in the biochar catalyst. Highlights Biochar catalyzed polymerization, but not cracking, of volatiles in pyrolysis. Biochar catalyst enhances char formation while reduces gas formation in pyrolysis. Char in catalytic pyrolysis is more O-rich and aliphatic and low thermal stability. Biochar catalyzed condensation of volatiles to form bigger fused ring structures. Biochar-volatiles interaction removes defective structure in fused ring of biochar.

Geology, Alteration, and Mineralization of the Kay Tanda Epithermal Gold Deposit, Lobo, Batangas, Philippines

AbstractThe Kay Tanda epithermal Au deposit in Lobo, Batangas is one of the Au deposits situated in the Batangas Mineral District in southern Luzon, Philippines. This study aims to document the geological, alteration, and mineralization characteristics and to determine the age of the mineralization, the mechanism of ore deposition, and the hydrothermal fluid characteristics of the Kay Tanda deposit. The geology of Kay Tanda consists of (i) the Talahib Volcanic Sequence, a Middle Miocene dacitic to andesitic volcaniclastic sequence that served as the host rock of the mineralization; (ii) the Balibago Diorite Complex, a cogenetic intrusive complex intruding the Talahib Volcanic Sequence; (iii) the Calatagan Formation, a Late Miocene to Early Pliocene volcanosedimentary formation unconformably overlying the Talahib Volcanic Sequence; (iv) the Dacite Porphyry Intrusives, which intruded the older lithological units; and (v) the Balibago Andesite, a Pliocene postmineralization volcaniclastic unit. K‐Ar dating on illite collected from the alteration haloes around quartz veins demonstrated that the age of mineralization is around 5.9 ± 0.2 to 5.5 ± 0.2 Ma (Late Miocene). Two main styles of mineralization are identified in Kay Tanda. The first style is an early‐stage extensive epithermal mineralization characterized by stratabound Au‐Ag‐bearing quartz stockworks hosted at the shallower levels of the Talahib Volcanic Sequence. The second style is a late‐stage base metal (Zn, Pb, and Cu) epithermal mineralization with local bonanza‐grade Au mineralization hosted in veins and hydrothermal breccias that are intersected at deeper levels of the Talahib Volcanic Sequence and at the shallower levels of the Balibago Intrusive Complex. Paragenetic studies on the mineralization in Kay Tanda defined six stages of mineralization; the first two belong to the first mineralization style, while the last four belong to the second mineralization style. Stage 1 is composed of quartz ± pyrophyllite ± dickite/kaolinite ± diaspore alteration, which is cut by quartz veins. Stage 2 is composed of Au‐Ag‐bearing quartz stockworks associated with pervasive illite ± quartz ± smectite ± kaolinite alteration. Stage 3 is composed of carbonate veins with minor base metal sulfides. Stage 4 is composed of quartz ± adularia ± calcite veins and hydrothermal breccias, hosting the main base metal and bonanza‐grade Au mineralization, and is associated with chlorite‐illite‐quartz alteration. Stage 5 is composed of epidote‐carbonate veins associated with epidote‐calcite‐chlorite alteration. Stage 6 is composed of anhydrite‐gypsum veins with minor base metal mineralization. The alteration assemblage of the deposit evolved from an acidic mineral assemblage caused by the condensation of magmatic volatiles from the Balibago Intrusive Complex into the groundwater to a slightly acidic mineral assemblage caused by the interaction of the host rocks and the circulating hydrothermal waters being heated up by the Dacite Porphyry Intrusives to a near‐neutral pH toward the later parts of the mineralization. Fluid inclusion microthermometry indicates that the temperature of the system started to increase during Stage 1 (T = 220–250°C) and remained at high temperatures (T = 250–290°C) toward Stage 6 due to the continuous intrusion of Dacite Porphyry Intrusives at depth. Salinity slightly decreased toward the later stages due to the contribution of more meteoric waters into the hydrothermal system. Boiling is considered the main mechanism of ore deposition based on the occurrence of rhombic adularia, the heterogeneous trapping of fluid inclusions of variable liquid–vapor ratios, the distribution of homogenization temperatures, and the gas ratios obtained from the quantitative fluid inclusion gas analysis of quartz. Ore mineral assemblage and sulfur fugacity determined from the FeS content of sphalerite at temperatures estimated by fluid inclusion microthermometry indicate that the base metal mineralization at Kay Tanda evolved from a high sulfidation to an intermediate sulfidation condition.

CfDNA in exhaled breath condensate (EBC) and contamination by ambient air: toward volatile biopsies

Exhaled breath is a source of volatile and nonvolatile biomarkers in the body that can be accessed non-invasively and used for monitoring. The collection of lung secretions by conventional methods such as bronchoalveolar lavage, induced sputum collection, and core biopsies is limited by the invasive nature of these methods. Non-invasive collection of exhaled breath condensate (EBC) provides fluid samples that are representative of airway lining fluids. Various volatile and nonvolatile biomarkers can be detected in volatile condensates, such as H2O2, nitric oxide, lipid mediators, cytokines, chemokines, DNA, and microRNAs. Studies have examined cell-free DNA (cfDNA) in plasma samples from non-small-cell lung cancer patients, offering to new insights and fostering development of the liquid biopsy. However, few studies have examined cfDNA in EBC samples. This study examined whether EBC is an appropriate source of cfDNA using housekeeping-gene-specific primer probes and quantitative real-time polymerase chain reaction in healthy subjects. Ambient (room) air is contaminated with DNA, so caution is needed. Preliminary studies indicated that volatile biopsies are becoming an important diagnostic tool in lung cancer.

Mechanistic study on direct synthesis of carbon nanotubes from cellulose by means of microwave pyrolysis

Abstract This paper investigates the impact of biomass components (i.e. cellulose and lignin) on direct production of carbon nanotubes (CNTs) from renewable biomass by means of microwave pyrolysis at low temperature. Palm Kernel Shell (PKS) was treated using two methods to isolate its bio-components, i.e. cellulose and lignin. The treated PKS samples were then pyrolyzed under microwave at 600 °C. Scanning electron microscopy (SEM) analysis revealed the formation of a large number of CNTs on the surface of cellulose bio-chars, while no CNTs were formed from lignin under the same pyrolysis conditions. It was inferred that cellulose was the component responsible for the formation of CNTs during microwave pyrolysis of biomass. High-resolution transmission electron microscope (HRTEM) analysis revealed that CNTs formed under such conditions had a multiwall structure. Raman spectroscopy analysis showed that the carbon order of CNTs increased when cellulose was used instead of the raw biomass for the synthesis of CNTs. Further analysis of the volatiles showed that unlike lignin, the volatile matter derived from cellulose were rich in monosaccharides such as D-Glucopyranose and glucopyranose which were postulated to have acted as an effective carbon source for the formation of CNTs. Self-extrusion of volatiles rich in monosaccharides and hydrocarbons during pyrolysis of cellulose, followed by the condensation and re-solidification of volatiles on the softened cellulose particles at elevated temperatures was proposed as the mechanism of formation of CNTs. The findings of this study may pave the way for the development of an effective, sustainable, and low-cost method for large scale production of CNTs from renewable biomass.

Properties of carbon black produced by the thermal decomposition of methane in the products of premixed flames

The thermal decomposition of methane is a technique used to manufacture hydrogen gas and carbon black. The physical properties of carbon black produced by the thermal decomposition of methane (TDM) in the O2-deficient gas products of two premixed flames (propane- or methane-air) were investigated under different flow rates of decomposing methane injection (0.5–5 SLPM). An inverted burner was designed to provide a fuel-rich, laminar premixed flame, to produce hot gas into which methane was injected to thermally decompose inside a reactor. Particles from TDM were extracted by a nitrogen dilution system at the immediate exit of the reaction chamber, where another branch of the exhaust was dried and directed to a gas chromatograph. The carbon black particles were characterized by size resolved number concentration, mass concentration, effective density, volatility, and internal mixing state using different arrangements of a differential mobility analyzer, catalytic denuder, centrifugal particle mass analyzer, and condensation particle counter, as well as by morphology and primary particle size using transmission electron microscopy. A bimodal number-size distribution was observed at all conditions with count median diameters (CMDs) less than 58 nm and 21 nm when using propane- or methane-air premixed flames as the heat source, respectively. Higher number concentrations and mass concentrations with larger CMDs were achieved under lower flow rates of decomposing methane injection. For a given flow rate of decomposition methane, mass concentration and CMD increased significantly when using propane as the fuel, compared to the methane fuel. The size segregated mass fraction of internally mixed volatile content in particles was similar for both heat sources, showing a roughly constant fraction of volatile material in particles produced by the decomposition of 0.5 and 5 SLPM of methane (10%–30%) but a measurably larger fraction (55%–30%) with a decreasing trend as a function of particle size from the decomposition of 1 SLPM of methane. The effective density of denuded particles was similar, but slightly higher, than the effective density of soot from a wide range of internal combustion engines. A higher denuded effective density was observed in the particles with higher volatile contents (particles from decomposition of 1 SLPM of methane), suggesting the restructuring of carbon black into more compact clusters due to excessive volatile condensation. TEM analysis revealed some similarity between the produced carbon black and engine soot in terms of morphology and primary particle diameter (both below 40 nm). Beside the carbon black properties, the efficiency of TDM in this configuration was also investigated by evaluation of methane destruction efficiency, as well as carbon black and hydrogen production efficiencies, based on the product gas composition and the particle mass concentration. It was found that longer residence times corresponding to lower flow rates resulted in higher conversion efficiencies in terms of methane destruction efficiency (maximum of ∼95%), hydrogen production efficiency (maximum of ∼80%), and carbon black production efficiency (maximum of ∼1%). It was concluded that the significantly low efficiency of carbon black production is due to the high amount of CO formation, likely through the gasification process.

Large scale preparation, stress analysis, and storage of headspace volatile condensates from Jasminum sambac flowers

In this study, a large-scale preparation of jasmine floral volatile condensate (FVC) was conducted using fresh flowers without any extraction solvent involvement. Condensate volatile profiles were compared to those of fresh flowers for their scent characteristics and ability to withstand manufacturing and storage. The FVC possessed a typical jasmine flower scent, a similar odor polygon shape and greatly enhanced odor intensity and character odorants linalool, indole, and methyl anthranilate. In late August and September in Fuzhou, China, the ratio of odor activity values for indole/linalool in FVCs was close to that of fresh flowers, indicating that these were suitable local harvest times for FVC preparation. Room temperature storage for 30 months dramatically reduced the abundance of potent odorants and FVC scent intensity, while cold temperature (4 °C) storage was able to maintain FVC clarity and scent intensity. Our findings should be helpful at improving FVC quantity, quality, and storage.

Estimating oil\u2013gas ratio for volatile oil and gas condensate reservoirs: artificial neural network, support vector machines and functional network approach

Laboratory experiment ideally, is the main method to obtain PVT properties of the oil and gas reservoir fluids. The alternative two methods widely used when laboratory experiments are not available are: equation of state (EOS) and empirical PVT correlations. The EOS requires lots of numerical computations based on identifying the full compositions of the reservoir fluids properties. The measurement and calculation of these properties are very expensive and time consuming. On the other hand, using of PVT correlations which are based on easily measured field data such as reservoir pressure and temperature, and gas and oil density is reliable and more economic. In this work, three artificial intelligence (AI) technique models were developed to predict the oil–gas ratio (Rv) for volatile oil and gas condensate reservoirs. Thirteen actual reservoir fluid samples (five volatile oils and eight gas condensates) covering a wide range of fluid behavior and characteristics were used. Whitson and Torp three parameters EOS were used to generate modified black oil (MBO) PVT properties that were used as a data set for model development. The MBO PVT data points were extracted for each sample using commercial PVT software at five different separator conditions. The nature of the input data was studied showing that data type is clustered. In addition, the correlations between the input parameters were checked. This preprocessed is helpful in selecting the best method to deal with the input parameters that will be fed to the developed models. According to this analysis and since the input parameters have different ranges, normalization of these parameters is vital to improve the accuracy of the models and to get the solution quickly and efficiently. Results showed that taking the log for the input parameters is the best among the other normalization techniques. The AI techniques that have been implemented in this research are; Artificial Neural Network (ANN) models, Functional Networks (FNs) and Support Vector Machines (SVMs). Models developed based on these techniques used 17,941 data points and a ratio of 70% for training, 15% for validation, and 15% for testing. To develop these models, three Matlab codes were written for each tool where the provided input data in excel format were read and prepressed before implementation. Results obtained using these techniques showed that the ANN model predicted Rv with an average square correlation coefficient of 0.9999 and an average relative error of 0.15% while FNs predicted Rv with an average correlation coefficient of 0.9635 and an average relative error of 27.6%. It was noted that SVMs gave the best results with an average correlation coefficient of 0.9990 and an average relative error of 0.12%. The results concluded that ANN and SVM accurately predicted such data since this type of data are clustered and these two models can handle this kind of data. The newly developed models depend only on easily obtainable parameters in the field and can have varied applications when typical lab PVT reports are not available.

Morphology and mobility diameter of carbonaceous aerosols during agglomeration and surface growth

Agglomeration and surface growth of fractal-like carbonaceous aerosols in the absence of oxidation and condensation of volatiles are investigated by Discrete Element Modeling (DEM) from the free molecular to transition regime, accounting for primary particle polydispersity and chemical bonding (aggregation). That way, carbon black or soot formation is elucidated in plasma reactors, quenched flames and combustion engines running at high exhaust gas recirculation where oxidation of carbon is limited or non-existent. During nascent soot formation polydisperse spheres and aggregates are formed, attaining an asymptotic geometric standard deviation of 1.2 ± 0.01, in agreement with experiments in premixed, diffusion flames and wood combustion. When surface growth stops, mature soot grows by agglomeration of these polydisperse spheres and aggregates before oxidation and condensation take over. The evolution from nascent to mature soot morphology quantified by its fractal dimension, Df, and mass-mobility exponent, Dfm, is in good agreement with measurements in premixed, diffusion flames and the Cast soot generator. The mobility diameter, dm, can be related to the average number of primary particles per agglomerate by nva = (dm/dva)0.45 and the relative effective density of soot by ρeff/ρs = (dm/dva)−0.78, where dva is the primary particle diameter and ρs the soot bulk density.

Hydrothermal treatment of grape marc for solid fuel applications

The treatment and disposal of grape marc, a residue from grape processing, represents a significant economic and environmental challenge for the winemaking industry. Hydrothermal treatment of grape marc could be an efficient way for producing solid fuels on-site at the wineries. In this work the effects of treatment temperature and liquid pH on grape marc char and liquid properties were determined based on laboratory experiments and the combustion characteristics of char were assessed through thermogravimetric analysis and fuel ash classification. The results showed that hydrothermal treatment increased the energy and carbon contents and decreased the ash content of grape marc. The effect of liquid pH was statistically significant (p<0.05) only for the determined carbon yield of liquid samples. The energy yield from grape marc was maximized at lower treatment temperatures, which also decreased the content of less thermally stable compounds in the attained char. Higher treatment temperatures decreased grape marc solid, carbon and energy yields and led to an increase in thermally labile compounds compared to lower temperatures likely due to the condensation of liquid compounds or volatiles trapped in the pores of char particles. The alkali metal contents of char ash were reduced coupled with an increase in respective phosphorus. Overall the results support the use of hydrothermally treated grape marc in solid fuel applications, if elevated levels of ash phosphorus can be tolerated.

Pluto: Pits and mantles on uplands north and east of Sputnik Planitia

The highlands region north and east of Sputnik Planitia can be subdivided into seven terrain types based on their physiographic expression. The northern rough uplands are characterized by jagged uplands and broad troughs, and it may contain a deeply-eroded ancient mantle. Dissected terrain has been interpreted to have been eroded by paleo-glaciation. The smooth uplands and pits terrain contains broad, rolling uplands surrounding complexes of pits, some of which contain smooth floors. The uplands are mantled by smooth-surfaced deposits possibly derived from adjacent pits through low-power explosive cryovolcanism or through slow vapor condensation. The eroded smooth uplands appear to have originally been smooth uplands and pits terrain modified by small-scale sublimation pitting. The bright pitted uplands features intricate texturing by reticulate ridges that may have originated by sublimation erosion, volatile condensation, or both. The bladed terrain is characterized by parallel ridges oriented north–south and is discussed in a separate paper. The dark uplands are mantled with reddish deposits that may be atmospherically deposited tholins. Their presence has affected long-term landform evolution. Widespread pit complexes occur on most of the terrain units. Most appear to be associated with tectonic lineations. Some pits are floored by broad expanses of ices, whereas most feature deep, conical depressions. A few pit complexes are enclosed by elevated rims of uncertain origin.

Examination of two assumptions commonly used to determine PM2.5 emission factors for wildland fires

There is a lack of in-depth examination of the two basic assumptions used in calculating particulate matter (PM2.5) emission factors (EFs): 1) that the ambient CO2 concentration is constant whether in a fire plume sample or in the ambient air (the constant ambient CO2 concentration assumption); and 2) there is no significant difference in diffusion rates between the fire-emitted CO2 and PM2.5 during a fire experiment (the equal diffusion assumption). We used carbon isotopic tracer and paired-sampling approaches to examine these assumptions. Our isotopic tracer results showed that the concentrations of ambient CO2 measured in fire plumes were generally greater than those measured in the ambient air, such that use of the constant ambient concentration assumption lead to a general overestimation of the fire-emitted CO2 by 10 ± 2.9% and a general underestimation of PM2.5 EF by 5.9 ± 1.8%. We also found evidence of significant differential diffusion between CO2 and PM2.5 in fire experiments, although increases in PM2.5 concentration through condensation of volatiles may contribute to the decoupling of relative concentrations of PM2.5 and CO2. Further research is warranted for identifying conditions under which the differential diffusion issues are reasonably resolved for accurate estimation of PM2.5 EF.