Progress in Petrochemical Science
EISSN : 2637-8035
Current Publisher: Crimson Publishers (10.31031)
Total articles ≅ 58
Latest articles in this journal
Progress in Petrochemical Science; doi:10.31031/pps
Progress in Petrochemical Science, Volume 3, pp 1-3; doi:10.31031/pps.2020.03.000567
Makarand R Gogate* Independent Consultant for Ch.E Education and Research, India *Corresponding author: Makarand R Gogate, Independent Consultant for Ch.E Education and Research, India Submission: June 05, 2020;Published: August 20, 2020 DOI: 10.31031/PPS.2020.03.000567 ISSN 2637-8035Volume3 Issue4 Methane is the principal constituent of natural gas and constitutes over 90% (v/v) by volume, regardless of the source. Coal, oil, and natural gas have traditionally been the 3 fossil fuels of choice for further conversion and upgrading to fuels and fuel additives, chemicals, and petrochemicals, and for generation of electric power. The advent of “Fracking”, a technology first commercialized in the United States around 2008, made it possible to harvest and recover huge quantities of shale gas and associated gas liquids, trapped within tight pore spaces of shale rock deposits or coal bed methane, considered to be 2 unconventional sources of methane [1-3], other than gas hydrates. The production of domestic natural gas saw a hugh spike in about 2008 (about 1Tnm3) and is expected to grow by up to 44% by 2035. The U.S. is now the world’s largest producer of natural gas, and the cost of natural gas is at about the lowest it has been in over 2 decades, at $1.85/MM BTU. The historical trends in the production and price of domestic natural gas, 1900 onwards to 2020, is shown in Figure 1. Instructively, the hugh spike in the production capacity of natural gas is clearly seen around 2005-2010, which coincides with the advent of new “Fracking” capacity in the United States . Figure 1: Historical trends in price of domestic natural gas, 1900 onwards to 2020 . Not surprisingly, natural gas surpassed coal (in 2007) for the largest installed electricity generation capacity in the United States. In addition, the E.I.A. estimates that the unconventional resource base (primarily shale and coal bed methane) of natural gas is around 65Tnm3, out of which about 5Tnm3 are considered to be “proven” reserves, i.e., recoverable under the current economic and environmental conditions . Natural gas, a versatile fuel feedstock, with a high calorific value - one with the lowest C footprint on account of its highest H:C ratio – is primarily used for electricity generation, and for home heating/cooking applications. More than 90% of U.S. domestic production is burned to create energy, for heating, cooking, and transportation purposes, or for generation of electric power (for residential and commercial use). The use of natural gas as a chemical feedstock for further conversion into fuels/fuel additives, chemicals, and petrochemicals, is still very limited. The reason for this is primarily economic in nature. Most natural gas wellhead locations/deposits are found in remote, inaccessible locations. Natural gas, a vapor under ambient conditions, has a very low mass and volumetric energy density, and is difficult and uneconomical to transport over long distances, using gas pipelines, or even LNG tanker trailers. Unfortunately, thus, apart from conversion to synthesis gas, hydrogen cyanide, acetylene, and chlorinated hydrocarbons, methane conversion pathways are not yet cost-competitive to oil-based fuels and chemicals/petrochemicals. However, natural-gas based indirect liquefaction technologies, based on syngas, offer a critical potential avenue (to reduce our dependence on oil and to reduce the C footprint), for further high-volume growth and market share in syngas-based bulk chemicals. The top 3 chemical products, based on natural gas-based syngas, are, ammonia (worldwide capacity 175MMtpa, 11MMtpa U.S.), methanol (110MMtpa, 4.5MMtpa U.S.), and F.-T.-based synfuels products (over 220,000bpd). While the U.S. capacity of the top-3 chemicals above is still a very small fraction of the worldwide capacity, more than a dozen methanol mega projects are currently in various stages of planning, design, and construction, all along the U.S. gulf coast. Natural-gas based syngas is an ideal feedstock for production of above 3 chemicals, as it affords a stoichiometric inlet H2:CO ratio of 2-2.5, directly possible with both conventional steam reforming and autothermal reforming (ATR), without need for any additional shift conversion [5-8]. In this article, we offer an insightful analysis of the current status of syngas production technologies and assess future projections and forecast for the industry. Steam reforming of natural gas is a conventional and now mature technology, for synthesis of “syngas”, a mixture of CO, CO2, and H2 [9-12]. In steam reforming, CH4 reacts with steam to reform CH4 into a mixture of CO, CO2, and H2, as given below: The synthesis reactions are highly endothermic and thus limited by chemical equilibrium; heat is supplied to the reformer tubes (in a vertical, parallel arrangement), by combustion of natural gas inside a firebox. The product gases leave the reformer unit at 855 oC and 2MPa. In industrial practice, heat is recovered from this gas stream by a series of heat exchange operations. As noted above, only 2 of the 3 reactions above are independent; the H2:CO ratio for the overall product gas is between 2-2.5. The kinetic studies on a commercial Ni/γ-Al2O3 or a ceramic support indicate that it is the reforming of CH4 to CO and the water gas shift reaction that take place under industrial conditions. The dry reforming reaction can also be postulated to occur in the overall series of reactions, as follows : As discussed above, steam reforming of natural gas is a mature process technology, and discussed extensively in several recent reviews [6,7,9-12]. Steam reforming is catalyzed by Group VIII transition metals, including Ru, Rh, Ir, and Ni. While extensive experimental and theoretical studies (DFT calculations, scaling relationships, and microkinetic models) show that Ru and Rh are the most active transition group metals for...
Progress in Petrochemical Science, Volume 3, pp 1-6; doi:10.31031/pps.2020.03.000566
Yi’en Zhou1 and Liang Hong2* 1,2Department of Chemical and Biomolecular Engineering, Singapore *Corresponding author: Liang Hong, Department of Chemical and Biomolecular Engineering, Singapore Submission: July 14, 2020;Published: August 13, 2020 DOI: 10.31031/PPS.2020.03.000566 ISSN 2637-8035Volume3 Issue4 When a cool N2-CO2 co-gas stream flows over superheated activated carbon (AC) flakes, a vortex field near the interface is induced as a consequence of the confrontation of the cool co-gas stream and the hot vaporized carbon stream, where the pre-deposited Pt atom clusters on AC catalyze gasification of AC by CO2 to produce CO, and the CO undergoes immediate disproportionation to release carbon atoms in vapor form. The vortex field functions as a dynamic template for deposition of carbon vapor, leading to the proliferation of nano-sized carbon needles with characteristic spikes (ca. 1µm) and short in length through an anisotropic assembling of carbon atoms. A trace amount of Pt pre-coated on the AC flakes is sufficient to catalyze gasifying AC by CO2. This phenomenon is the first observation over the surface of amorphous carbon via catalytic pyrolysis without electric potential assistance. Keywords: Nano carbon spines; Polypyrrole; HEC polymer; Raman spectra; Dendritic nano carbons; AC catalyze gasification; catalytic pyrolysis; Pt atom; CO gas treatment; Reverse boudouard reaction; AC flakes Dendritic growth is characterized by the presence of side branches that evolve under two different ways when the latent heat of fusion is removed from the interface . Growth resulting from an undercooled melt (usually in alloys) results in equiaxed dendritic crystal formations when latent heat is dissipated through the cooler fluid at the interface whilst directional solidification or constrained growth results when the latent heat is dissipated swiftly. This study unveils that the Pt atom clusters assist the generation of carbon atoms forming a vapor stream via a two-step reaction mechanism, which is responsible for the growth of dendritic dense carbon nanofibers from a porous carbon flakes. Such dendritic growth has been observed previously in cells [2-5], crystals [6,7] and metal alloys [8-13] with a characteristic tree-like structure, which is considered as the result of mass transfer under meta-stable thermodynamic state. Namely, the growth happens through a series of thermodynamic instabilities when the growth rate is limited by the rate of diffusion of solute atoms to the interface and the material is supercooled at the same time . Dendrites have shapes that are most suitable for heat and mass transfers at small scales and hence, are highly attractive for applications seeking these properties. Numerous studies undertaken over the years offered the insights in dendritic growth of crystals , as well as mathematical models and simulations [6, 12-13,15-18] about the growth. These growths are a result of faster material packing along energetically favorable crystallographic directions and may be due to anisotropy in the surface energy. In trying to minimize the area of these surfaces with the highest surface energy, the dendrite would exhibit a sharper and sharper tip as it grows . When the crystallization front becomes morphologically unstable, small perturbations at the interface will lead to the formation of various polycrystalline structures, especially so for dendritic growth. The dendritic growth theory using Ivantsov transport theory relating to the dendrite tip radius and velocity of growth to the tip has been found to predict the growth rates and limitation of the existence of dendrites in 2D fairly accurately [1,14]. To the best of our knowledge, no reports or discussions on the dendritic carbon spinal growth in N2-CO2 co-gas atmosphere have been published nor observed before. Contrary to the growth of porous carbon fibers described explicitly in our previous work  caused by the random stacking of polyaromatic hydrocarbons (PAH) in the axial direction leading to the formation of fibers, this work proposes a different gowth path catalyzed by platinum atom clusters that assist with generation of CO via the reverse Boudouard reaction , which subsequently releases carbon atoms in vapor form that condense to form dense dendritic structures in the vortex field as illustrated in Figure 1. Although the incubation environment of this study is similar to that reported in , the resulting growth looks drastically different due to mediation by Pt atom clusters or colloids spread on the surface of the sample prior to the co-gas treatment. This paper aims to report and explain the growth mechanism we observed in detail. Figure 1: Preparation of AC Flakes An initial sample of 2-Hydroxyethyel cellulose (HEC) is carbonized by the method discussed elsewhere . The resulting carbonaceous material from HEC was then activated at 700 oC under CO2 for 1 hour and cooled in an Ar purging stream. The carbon powder obtained was washed in water until the filtrate became colorless. This protocol resulted in an AC powder consisting of dense carbon flakes, which was used as the starting material for the preparation of the carbon needles. Carbon Spinal Growth and Characterizations Two separate, independent methods were employed to incorporate platinum onto the samples. The final carbon samples obtained from both Pt-deposition methods were characterized by electron microscopy (JSM-6700F Field Emission Scanning Electron Microscope (FESEM), JEOL), Raman spectroscopy (Renishaw in Via Raman Microscope), and X-ray Diffraction (XRD, Bruker D8 Advance, Cu Ka radiation, l=1.54Å) using Cu target Ka-ray (40kV and 30mA) as X-ray source, respectively. Formation of Dendritic Structures Over the Surface of AC Under Purge of CO-Gas Under close examination using the transmission electron microscope (TEM), tree-like dendritic structures are observed to have formed from the sputtering...
Progress in Petrochemical Science, Volume 3, pp 1-6; doi:10.31031/pps.2020.03.000565
Krzysztof Biernat1* and Monika Ziółkowska2 1Department for Fuels and Bioeconomy, Poland 2Department of Petroleum Engineering, Poland *Corresponding author: Krzysztof Biernat, Department for Fuels and Bioeconomy, Poland Submission: July 02, 2020;Published: July 29, 2020 DOI: 10.31031/PPS.2020.03.000565 ISSN 2637-8035Volume3 Issue3 The article discusses the process of gelation of engine oils and its influence on exploitative properties. The results of research on the propensity of engine oils for gelation at low and high temperatures are presented. The influence of various factors such as: base oil, vegetable oil, FAME and soot on the gelling process was determined. It was found that the cause of gelation of oils, depending on the operating conditions, oil components, may be several factors independent of each other. These factors are discussed in the article. Keywords: Gel; Gelling process; Engine oil; Oil components; Vegetable oil; Fame; Soot In the 1990s, the problem of forming a gelatinous (gel) oil structure in the operation of vehicles powered by diesel oil appeared in Poland. However, the problem of gelation of motor oils was already noticed in Europe in the 1980s. At that time, it was assumed that this could be related to the introduction of a new category of engine oils, including the CD class according to API. The quality class CD introduced then a new generation of additives improving detergents and dispersants. In addition, the process of limiting sulfur content in diesel oil started, which was initially thought to have adversely affected the performance of engine oil. In Poland, the phenomenon of gelation was observed mainly in the late autumn and early spring periods, i.e. during periods in which large temperature fluctuations could occur. In winter or summer, when the temperature jumps were not large, this problem did not occur. In addition, the problem of gelation included engine oils of various quality and viscosity grades of known domestic and foreign producers. A characteristic feature of gelation is the rapid increase in kinematic viscosity at both 40°C and 100°C, the other parameters do not change much in relation to fresh oil. The problem of gelation is a very unfavorable phenomenon for the engine. Gelled oil completely loses its operational functions, i.e. it does not provide lubrication, does not dissipate heat, does not neutralize acidic products originating, among others from incomplete burning of fuel, etc. which leads to engine seizure. Based on the collected literature on the operational problems of motor oils, including the phenomenon of gelation, several factors can be distinguished that can cause the formation of a gelatinous oil structure. The most important of them are: But in addition to the factor that triggers the gelling process, temperature also plays a key role. Under the same atmospheric conditions, during the operation of vehicles, some oils show a greater tendency to form a gel while others are less and undoubtedly related to the temperature, not only of the engine itself, but also of the ambient temperature. A gel is a colloidal system that consists of at least two components. Each of the components forms a separate continuous phase extending over the entire volume of the mixture. The gelling agent forms a rigid, branched, porous network spreading in the liquid constituting the second component of the gel, causing it to immobilize . The gel structure consists of network nodes, loops, and free ends of chains. The diagram of the gel structure is shown in Figure 1 [2,3]. The division of gels is related to the type of interactions responsible for creating a rigid network, and thus with the type of gelling agent. There are chemical gels in which in the process of gel formation gelling agent molecules create covalent bonds between them, and physical gels in which the molecules of the gelling agent are bound by much weaker intermolecular interactions, mainly hydrogen bonds and electrostatic, dipoledipole interactions, van der Waals, as well as hydrophobic. The physical gels are thermally reversible, because the change of external parameters such as temperature and pressure lead to the disintegration of the gel network. In contrast, chemical gels are formed in the polycondensation, polymerization and copolymerization of multifunctional monomers or because of introducing a cross-linking agent into the polymer. The chemical (covalent) bonds formed in this way create nodes of the network . The best-known methods for obtaining gels are shown in Figure 2 [4,5]. Figure 1: Gel structure scheme. Figure 2: Chemical and physical methods of obtaining gels. Multigrade engine oils have been introduced to reduce the viscosity of the oil at low temperatures to facilitate engine starting. With the easier start-up of the engine at low temperatures, there was a problem with the oil pumpability. This problem turned out to be much more serious because the lack of pumpability of the oil could lead to engine damage. In bench tests, it was found that at low temperatures we have two types of problems related to pumpability: Research on oil-air binding led to the development of a method for testing the tendency of oil to gel using a Brookfield scanning viscometer. The STB method as an international standard ASTM D 5133 allowed the study of the tendency of oil to form a gel. The method consists in heating the tested sample to 90 °C, and then slowly cooling it, while continuously measuring the viscosity . Based on this method, you can designate: The literature data show that the highest gelation and consequent air retention were found at temperatures much higher than those associated with limited flow, for the same class of SAE motor oils. Modern multi-grade motor oils require a maximum gelation index value of 12. This is the value at which the resulting gels in the engine oil do not endanger the engine's operation. The value of the gelation...
Progress in Petrochemical Science, Volume 3, pp 1-7; doi:10.31031/pps.2020.03.000564
Ji Xin Mao1, Quan Xi Zheng1*, Xin Xu1,2, Li Guo1, Yong Liang Xin1, Shi Zhao Yang1, Jian Jian Zhang1, Bing Hao Chen1 and Jian Qiang Hu1* 1Department of Aviation Oil, China 2State Key Laboratory of Tribology, China *Corresponding author: Quan Xi Zheng, Department of Aviation Oil, China Jian Qiang Hu, Department of Aviation Oil, China Submission: April 07, 2020;Published: July 20, 2020 DOI: 10.31031/PPS.2020.03.000564 ISSN 2637-8035Volume3 Issue3 The effect of concentrations of titrant, delivery rates, stirring rates, and oil mass on catalytic thermometric titration for the determination of the lower acidity of jet fuel were investigated, using KOH in isopropanol and paraformaldehyde as titrant and a catalytic thermometric indicator respectively. The results show that paraformaldehyde used as a catalytic indicator exhibits strongly endothermic effects to reflect end point significantly. When the oil mass is from 10g to 30g, the titration concentration is 0.01mol/L and the delivery rate is 1.0mL/min with moderate stirring, the tested acid numbers have good reproducibility and accuracy. The linear coefficient R2 of the fitting curve is 0.995. Using benzoic acid as a standard acid with concentration of 0.0105mg KOH/g to verify the accuracy of catalytic thermometric titration, the verified acid number is 0.0115mg KOH/g and basically consistent with the actual acid number, indicating that catalytic thermometric titration has good agreement with standard potentiometric titration methods and can be used for determination of acid number of jet fuels. It can accurately determine the acid number of jet fuel as low as 0.015mg KOH/g or even lower at optimized test conditions. The procedure is fast, easy to use, accurate, and highly reproducible to measure lower acidity in jet fuel. It is very suitable for the routine process and quality control of many types of oils. Keywords: Acidity; Jet fuel; Catalytic thermometric titration; Paraformaldehyde As an important quality control index to evaluate corrosion, especially for fuel oil, aviation oil, and hydraulic oil, the acidity of oils is applied to estimate the properties and deterioration of oils during usage and storage [1-3], which is determined with the standard methods based either on visual indicators titration or potentiometric titration [4-7]. However, accuracy of visual titration is strongly influenced by the skills and color perception of the analyst, and especially differential color perception of analysts is considerable for coloured oils. Potentiometric titration, especially for oils containing trace weak polyacids, is subject to the noxious influence of the sample solutions and is always unreliable because of the weak change of potential during acid-base neutralization titration, which results in difficult detection of end-point and repeatability. In order to achieve more fast and efficient determination of the end-point in titrations, there is increasing attention for a simple, fast, accurate, and precise automatic titrimetric operation that is substantially independent of analysts’ skills and suitable for routine process and quality control. As a new method, catalytic thermometric titration has several attractive features:  the apparatus is simple, and all that required is a temperature measuring probe such as a thermometer or a thermistor as the sensing element;  the thermometric probes are inert to most solutions, and temperature changes in highly colored can be detected easily;  the range of indication reaction is unlimited because all of reactions are accompanied with temperature changes, the magnitude of which can be adjusted by changing reagents’ concentrations [8-11]. The basic principle of this method is catalytic initiation of an exothermic or endothermic reaction with an excess of titrant, as a consequence, the end-point can be indicated by obvious temperature changes of the solution [8-15]. It has been successfully applied for determining acidic substances in aluminum ion concentration of waste water and vegetable oils [16-19]. However, as so far, there are few reports on application of catalytic thermometric titration on lower acidity of jet fuels. When small amounts of weak acidic species are titrated in nonaqueous solution with a titrant of strong alkali, the heat produced from the neutralization reactions may be quite small and easy to be confused by solvent evaporation and the mixing heat of the titrant with sample solution [4-7]. If the special thermometric indicator is added to sample solution, excess hydroxide ions would react quickly with them in endothermic or exothermic reactions, the end-point can be easily determined by temperature increase or decrease of the solution [20,21]. However, practical experience has demonstrated that the endpoint in thermometric titration showed excessive rounding, with consequent loss of precision and accuracy for some oils with lower acidity, such as aviation oil, hydraulic oil and fuel oils. Many studies have shown that titration error or the sharpness of the endpoint can be related to the concentration and delivery rate of titrant, volumes, and types of thermometric indicator [22-27]. In our previous studies [9,10], the trace water in jet fuels, as well as the acidity of several coloured oils, could be accurately and rapidly determined by catalytic thermometric titration using the mixture of acetone and chloroform as the end-point indicator. In this paper, we report herein our results on the determination of the lower acidity of jet fuels with catalytic thermometric titration employing paraformaldehyde as the end-point indicator, which exhibits strongly endothermic effects to reflect end point significantly and can determinate much more lower acidity than ASTM thermometric titration, and compared with potentiometric titration, the accuracy and repeatability of the thermometric titration is further investigated. Materials Paraformaldehyde, potassium hydroxide...
Progress in Petrochemical Science, Volume 3, pp 1-2; doi:10.31031/pps.2020.03.000563
Bereslavsky EN** Department of Physics and Mathematics, Russia *Corresponding author: Bereslavsky EN, Department of Physics and Mathematics, Russia Submission: May 25, 2020;Published: July 01, 2020 DOI: 10.31031/PPS.2020.03.000563 ISSN 2637-8035Volume3 Issue3 Summary In the hydrodynamic formulation, the problem of liquid filtration from a channel filled with water through a soil layer with an underlying pressure horizon of relatively high permeability in the presence of evaporation from the free surface of groundwater is solved. When considering flows from channels, it is usually assumed [1-5]. that filtration occurs only through their bottom, which is usually taken as a horizontal segment. Taking into account the influence of the depth of water in the channels, that is, the study of movement not only through the bottom, but also through the slopes of the channels makes an additional angular special point in the physical area, which significantly complicates the solution of the problem. In this paper, the method developed earlier  is used to study the regime of ground water when filtering from such channels filled with water, in the presence of evaporation from a free surface. In the framework of the theory of plane steady filtration of an incompressible fluid according to Darcy's law deals with the flow of rectangular channel of width 2l with water depth H in the soil capacity T, underlain by the well permeable pressurized horizon is relatively high permeability, the pressure of which is equal to H0 (0
Progress in Petrochemical Science, Volume 3, pp 1-3; doi:10.31031/pps.2020.03.000562
Makarand R Gogate* Independent Consultant for Ch.E Education and Research, India *Corresponding author: Makarand R Gogate, Independent Consultant for Ch.E Education and Research, India Submission: June 05, 2020;Published: June 22, 2020 DOI: 10.31031/PPS.2020.03.000562 ISSN 2637-8035Volume3 Issue3 The use of hydraulic fracturing the extract oil and gas from the earth, dates back to 1940s, but only in the last decade or so, has the word “Fracking” become a buzzword. Fracking alludes primarily to the shale gas boom in the United States, since about 2008, and also refers to the process - the high pressure injection of water, chemicals, and sand into the shale rock deposits – to release gas and oil trapped within shale rock by fracturing it, to harvest stores of gas and oil, previously unfeasible to access or recover. As stated above, Fracking became commercial in the United States in 2008, first at the Bakken Shale deposits in North Dakota, and later at Barnett Shale Basin in Texas. The production of domestic natural gas thus saw a high spike in about 2008, and is expected to grow by up to 44% by 2035. For example, the domestic production was at 17Tn cu ft/year in 2008, and now stands at 27Tn cu ft/year (2017), an increase of 59%. As a result, the price of domestic natural gas (Henry Hub Index) was $15.46/MM BTU (2008 basis), and has steadily declined to the current $1.85/MM BTU (2020). The historical trends in the natural gas prices are illustrated in Figure 1; . Not surprisingly, the oil prices, seen historically to trend directly with price of natural gas, have also steadily declined: Oil prices peaked to over $110/bbl (2008) - when the cost of gasoline was over $4/gal -- and have also steadily declined to $30/bbl, as of today. Fracking is a uniquely and hugely successful American story, that, by safely unlocking America’s abundant natural resources, has created millions of jobs, reduced energy prices (oil and natural gas), and also brought cleaner air by significantly reducing greenhouse gas emissions (to lowest levels in 25 years), and transformed the United States back into a global superpower . The global chemical industry is heavily dependent on stable and inexpensive sources of fossil fuel feedstock, such as crude oil and natural gas. However, increasing utilization and exploitation of crude oil in the 1980s and 1990s, fueled by cheap prices and plentiful supply, led to eventual price instability, and supply chain issues. Consequently, the United States chemical industry was in decline in the late 1990s and early 2000s. Many chemical producers were thus faced with either using syngas as a chemical feedstock - a mixture of CO, CO2, and H2, from domestic coal, biomass, and natural gas, or disassemble existing chemical plants and facilities altogether and relocate them outside of the United States. As discussed above, a major technological breakthrough, called as “Hydraulic Fracturing”, or, “Fracking”, for short, occurred in about 2008, which made possible the very economical recovery of natural gas and gas liquids associated with high amounts of shale oil deposits in the United States. The shale gas boom, as it is commonly called now, led to gigantic increases in the production/recovery of both natural gas and gas liquids in the United States. This has clearly led to a “rebirth” of the U.S. chemical industry, and the business of industrial chemistry is growing, with a very rosy outlook to the future. It is a very opportune time now for the U.S chemical industry, and clearly behooves on us to develop cost-effective process alternatives, due to the strong interest and economic incentives of shale gas. Currently, the catalytic upgrading of methane to value-added chemicals proceeds via the indirect liquefaction route. The resulting syngas is then converted into a host of chemicals and chemical feedstocks, including methanol, ethanol, higher alcohols, light olefins, acrylonitrile, ethylene oxide, propylene oxide, 1,3 butadiene, etc. However, the steam reforming of natural gas is a strongly endothermic and an energy-intensive process, and requires a large energy input. The traditional thrust has therefore been to find process alternatives to steam reforming, or to use syngas from coal gasification as an alternative. Two approaches for the indirect conversion of methane into liquid hydrocarbons are now practiced on an industrial scale: methanol-to-gasoline (MTG) process and Fischer-Tropsch (FT) synthesis [3-8]. It is imperative at this time to enable transformational thinking and pursue transformational discoveries in methane functionalization, towards direct conversion of methane to value-added chemicals. Figure 2 shows the various approaches and pathways for the direct conversion of methane and ethane to value-added chemicals. As stated above, the plentiful availability of the low-cost natural gas feedstock allows a transformational opportunity to lower the C footprint of the chemical industry. Methane (CH4) has the highest H:C ratio of any fuel, and the highest calorific value, but from a chemical standpoint, the linear single C-H bonds in a perfectly tetrahedral symmetry in methane have a very high bond strength (over 440kJ/mol) and are very difficult to break. Because it a saturated linear hydrocarbon, it is very difficult to activate the C-H bonds, except in very harsh environments, such as very high temperatures (>1100 K), highly oxidative conditions, or highly acidic/alkaline ones. For these reasons, the direct and selective conversion of methane to higher-value chemicals is often considered to be the “Holy Grail” of experimental/theoretical research in heterogeneous catalysis and catalytic chemistry. Despite these difficulties and the chemical recalcitrance of methane, several pioneering technologies for direct catalytic upgrading of methane have been developed. This bodes very well for the United...
Progress in Petrochemical Science, Volume 3, pp 1-6; doi:10.31031/pps.2020.03.000561
Aroloye O Numbere* Department of Animal and Environmental Biology, Nigeria *Corresponding author: Aroloye O Numbere, Department of Animal and Environmental Biology, Nigeria Submission: April 09, 2020;Published: May 06, 2020 DOI: 10.31031/PPS.2020.03.000561 ISSN 2637-8035Volume3 Issue3 The tropics are generally evergreen and have large tree populations that make up the bulk of plant biomass. The Niger Delta is rich in biodiversity and has the largest mangrove system in Africa and the Atlantic. Above ground biomass (ABG) is a good indicator of stand productivity in mangroves, and can be calculated with allometric method using tree structural characteristics of dbh and tree height. Red mangroves are the most dominant species, and the species mostly used for making firewood and charcoal. The carbon stock estimates was higher in locations with more red mangrove trees (66.1 ± 15.1 Mgha-1) than locations with fewer red mangrove trees (36.0 ± 12.8 Mgha-1), which indicates that they are excellent carbon sequesters. Mangrove forest therefore supplies low cost renewable energy and also reduces global warming through carbon sequestration. Already, utilization of firewood and charcoal for cooking is a booming business in many communities in the Niger Delta. But the issue is that deriving sustainable energy from mangrove forest requires modern technology. Energy production from mangrove raw material will reduce the burden of energy generation from petroleum. This will thus, save the environment from pollution from oil and gas exploration which has led to ozone layer depletion. Nonetheless, mangrove-derived biomass energy will thus save the environment from sulphur and radioactive contamination. Keywords: Goniopsis pelii; Rhizophora; Heavy metals; Bioaccumulation; Niger Delta; Hydrocarbons; Biomass; Calories; Carbon; Charcoal; Energy; Firewood; Mangrove; Rhizophora; Energy; Pollution Mangrove forest are found in the interface between the land and the sea where most negative impact of nature and humans are being felt the most because of the actions of hurricanes, and tsunamis , and crude oil spillages . Mangroves are at the frontlines of the battle to recapture the environment from the jaws of anthropogenic devastation. They are naturally found in laborious terrain where they face onslaught from high velocity hurricanes, which break their branches and fall their stems. They are also battered by tidal surge from cyclone which sweeps through the entire forests and levels the trees . Despite this natural attack by hazardous environmental phenomenon they still stand their ground defiantly and remain resilient . This resilience can be attributed to their tough and flexible stems, which makes them elastic to pressures. Their stems have high recoiling ability to tidal pressure and keep them standing after hurricanes and tsunami had come and gone . Mangroves forest therefore, absorbs and disorganizes high velocity winds and tidal surge, which is capable of wiping out a whole generation of plant community. Although, bad for the trees, this action protects human community from utter destruction. The stems don’t only serve as wind and water breaks but also serve as biomass energy for producing renewable energy through firewood and charcoal manufacture for cooking in rural communities. Wood from trees and other plant material make up the traditional sources of biomass energy in rural areas . Biomass is solar energy stored in organic matter via photosynthetic process where energy from the sun reacts with carbon dioxide to form food material. Biomass can produce solid fuel, liquid fuel, gas and electricity , but out of these forms of energy the solid fuel (i.e. fire wood and charcoal) are the most utilized in Africa and other third world countries. This is because these countries most often lack the needed technology to convert biomass to liquid, gaseous or electrical energy. Globally, biomass is the fourth source of energy, but in Nigeria it is the second source of energy after petroleum [8,9]. Nigeria is the highest producer of crude oil and has the largest mangrove vegetation in Africa . Therefore, the energy potentials of biomass in Africa and other developing countries of the world are great if it can be efficiently utilized. For instance, 96% of rural dwellers in Tanzania  and 90% of rural dwellers in Nigeria utilize firewood and charcoal for cooking and heating. Solid biomass fuel typically includes: Figure 1: Ecosystem services of mangroves forest. Timber and fuel are produced from mangrove stem and branches. (Source: . There are over 150 species of mangroves globally, but the most dominant species in most parts of the world are the red mangroves (Rhizophora spp). In the Niger Delta there are three major species: the red (Rhyzophora racemosa), white (Avicennia germinans) and black (Laguncularia racemosa) mangroves and their percentage occurrence are 62.5%, 25% and 12.5% respectively [14,15]. All these three species are used to produce fire wood, but the most commonly used is the red mangrove because it has the highest potential (Table 1). This is followed by Sonneratia species. Rhizophora species is the best source of biomass energy because the stems are resilient and can catch fire and burn faster than stems of other species. They are thus used in producing firewood and charcoal, which are used for cooking, barbecue, heating of homes, drying of fish, baking, brick making, earthen pot making, casting of metal and ceramics. Red mangroves are used to produce firewood and charcoal. Similarly, Bruguiera, Ceriops, Conocarpus, Heritiera and Laguncularia can also be used to produce firewood and charcoal. Table 1: Potential of using different mangrove species to produce firewood and charcoal. Source: . Figure 2: Conversion of red mangrove stem (Rhizophora spp) to charcoal log, which is further broken into smaller pieces for local cooking and roasting ....
Progress in Petrochemical Science, Volume 3, pp 1-11; doi:10.31031/pps.2020.03.000560
E Santacesaria1*, M Cozzolino2, R Tesser3 and M Di Serio3 Faculty of Chemistry and Chemical Engineering, Slovenia *Corresponding author: E Santacesaria, Eurochem Engineering srl, Via Codogno 5 (IT-20139) Milano, Italy Submission: April 16, 2020;Published: March 16, 2020 DOI: 10.31031/PPS.2020.03.000560 ISSN 2637-8035Volume3 Issue2 Metal alkoxide grafting technique can be used for changing the acid-base and/or the redox properties of the surface of an oxide rich in hydroxyls. The preparation of catalysts by grafting different commercial available alkoxides, such as: Si, Ti, Zr, and V on the surface of oxides, such as: SiO2, Al2O3 and TiO2, is reviewed. The performances of the acid catalysts were evaluated by adequate test reactions such as: methanol dehydration, skeletal isomerization of 1-butene and alkane isomerization and cracking. The redox properties of vanadium based catalysts, obtained by grafting vanadyl alkoxide on SiO2 and TiO2/SiO2 supports, have been tested in reactions, such as: the SCR of NO with NH3, the Oxidative Dehydrogenation (ODH) of ethanol and methanol to formaldehyde and acetaldehyde, the ODH of propane, isobutane and n-butane. Keywords: Grafting; Metal alkoxides; Silica; Alumina; Titania; Vanadia Metal alkoxides are nowadays largely employed for preparing ceramic materials, for thin coating films and for supports and catalysts preparation using in the different cases the sol-gel technique or the chemical vapour deposition . Although very promising, less popular is the employment of metal alkoxides for preparing supports and catalysts by using the grafting technique. This technique can usefully be used for deeply changing the acid-base and/or the redox properties of the surface of an oxide rich of hydroxyls. As the catalytic properties depends almost exclusively on the surface properties of the solid used as catalyst, modifying opportunely the surface by contacting it with reactive substances like the metal alkoxides can give surprising results in terms of activity and selectivity in different reactions. In particular, the properties of the new surfaces obtained by reacting the superficial hydroxyls with a metal alkoxide, after a stabilizing treatment of hydrolysis and calcinations, are quite different from the original surface. A systematic work has been made on the subject by our research group in the past and a review of the most significant obtained results is reported in this paper. Summary of the properties of some alkoxides affecting the grafting procedure Metal alkoxides are characterised by the presence of M-O-C bonds. Due to the strongly electronegative character of oxygen (3.5 in the Linus Pauling electronegativity scale) the ionic character of the metal-oxygen bond would be preminent. Metal alkoxides exhibit both Lewis and base properties. It could be expected 80% of ionic character for the more electropositive metals (electronegativity in the range 0.9-1.2, that is, alkaly metals, alkaline earths and lanthanons, while, it could be expected 65% of ionic character for metals having electronegativity values in the range 1.3-1.5 such as in the case of aluminium, titanium and zirconium . However, some of the mentioned alkoxides show a fair degree of volatility and solubility in common organic solvents, that is, have properties which can be considered characteristics of covalent compounds. The attenuation of the polarity of the metal-oxygen bond can be attributed to two main factors: The oligomerization of alkoxide complexes [M(OR)n]x depends on a number of factors such as: Bradley  suggested the following rules: Examples of aluminium alkoxides association are reported below: Silicon and Germanium alkoxides are all monomeric (see Mehrotra et al. ). Summary of the properties of some oxide surface that can be used as support for grafting Alumina is an amphoteric oxide with a moderate basic character having a ZPC (Zero Point Charge) = 8-9. According to Peri , on the alumina surface there are 5 different type of hydroxyls A, B, C, D and E, as it can be seen in Figure 1. The difference is given by the number of groups O2- surrounding the hydroxyls and clearly these hydroxyls have different acid-base characters. Figure 1: Different types of hydroxyls on the surface of alumina . Moreover, Tanabe  has demonstrated that on alumina there are both acid sites of Bronsted & Lewis character in an approximately equal amount. However, considering an amphoteric oxide in acid environment the hydroxyls of the support will react as it follows S- OH + H+ A- ↔ S- OH2+ A- (3) On the contrary, in a basic environment the reaction will be: S- OH + B+ OH- ↔ SO- B+ + H2O (4) The hydroxyls on the silica surface are more uniform and have a moderately acid character being the ZPC=1-2. No Lewis acid sites are present. Description of the grafting technique The grafting technique [6-8] consists in putting in contact a metal alkoxide pure or dissolved in a opportune solvent with the surface of an oxide rich of hydroxyls. By grafting a metal alkoxide on a support it is possible: The grafting operation occurs through three different steps that are: A. Grafting: Reaction between the metal alkoxide and the superficial hydroxyls. This reaction can occur with different a stochiometry according to the type of alkoxide employed and the surface density of the hydroxyls: B. Steaming or burning: Have the scope of stabilizing the obtained surface eliminating the organic groups bonded to the grafted metal. C. Calcination: A dehydration occurs and the original oxide surface is more or less coated with another different oxide. Metal alkoxides eventually can also be modified before grafting for a better control of the properties of the heterogenized catalytic site: By changing the alkoxide groups through equilibrium exchange reactions of the type: Me(OR)n + nR’OH ⇄ Me (OR’) + n ROH (6) By introducing other elements changing the electron density on the...
Progress in Petrochemical Science, Volume 3, pp 1-2; doi:10.31031/pps.2020.03.000559
Anita Kovac Kralj* Faculty of Chemistry and Chemical Engineering, Slovenia *Corresponding author: Anita Kovac Kralj, Faculty of Chemistry and Chemical Engineering, Slovenia Submission: March 10, 2020;Published: March 16, 2020 DOI: 10.31031/PPS.2020.03.000559 ISSN 2637-8035Volume3 Issue2 Over recent years, engineers and scientists have directed their attentions to the waste heat flow rate and mass recoveries for cheaper energy and mass generation. Mass and energy re-usage techniques can be useful for increasing the efficiencies of conventional energy and mass systems. The re-usage of waste heat would have positive effects on the amount of resources and waste and pollutants generated within industries. Waste-heat recovery techniques that are environmentally friendly and have technical and economic advantages should be assessed for possible contributions to the energy economy and the national economy. The mass and energy re-usage technique, as a simple method by using air heat flow rate from the dryer, is based on more efficient steam generation targets, using pinch analysis and/or MINLP. The benefit of this technique allows the maximal recovery of heat and mass. This technique is a simple method for estimating of the maximal the maximal recovery of heat and mass. The aim of the presented research is an investigation of heat flow rate and condensate recovery improvement opportunities within food plants. The mass and energy re-usage of air outlet after drying indicates major potential for improvement within the following drying systems: Modified existing sugar process allows additional profit of 756,000EUR/a by using the replacing of low-pressure steam with air heat flow rate from dryer. The mass and energy re-usage technique is a very simple method that was tested during existing sugar production. The existing evaporators used low-pressure steam for heating, which could be replaced by heat flow rate from the dryer. The usable air heat flow rate (Qair) was 14.100kW, which shared with the vapour (Qvap=1,100kW) and condensing (Qcond=13,000kW) parts and located above the GCC of cold streams of evaporators (Figure 1). The condensing heat flow rate (Qcond,i) is split into smaller parts regarding the number of individual evaporators (Nev). The vapour heat flow rate was too small for splitting. The inlet and outlet temperatures of the vapour air streams (Tvap,in, Tvap,out) were 125 °C and 90 °C. The started condensing temperature (Tcond) was 90 °C. The output temperature (Tcond,out), fraction of condensing (fcond) and condensing heat flow rate (in kW) would be calculated by using a linear function. Figure 1: The diagram of energy re-usage techniques for the existing evaporators. © 2020 Ruizhong Jiang. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and build upon your work non-commercially.