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Fuel production via catalytic cracking of pre-hydrotreated heavy-fuel oil generated by marine-transport operations
Abstract
We examine the conversion of heavy-fuel oil waste generated by marine-transport operations into drop-in transportation fuels. The proposed conversion process comprises two steps: (i) hydrotreatment and (ii) fluid catalytic cracking (FCC) under industrially relevant conditions. CoMo/Al2O3 is employed as the catalyst for hydrotreating, primarily aimed at sulfur reduction. In the second stage, a highly intensive study of the FCC over an equilibrated steamed zeolite catalyst is performed. We provide a complete analytical overview of all the products and byproducts of these two reactions, including the coke deposited over the FCC catalysts using various characterization techniques, including high-resolution mass spectrometry. The hydrotreatment eliminates 67% of sulfur present in the original ship oil, while the cracking yields up to 47 wt% high-quality gasoline, containing 37 wt% aromatics, and 23 wt% i-paraffins. Based on the molecular-level characterization of the formed coke species and the performed parametric study, this work provides insights into the optimum operational conditions for minimizing coke deposition and improving the gasoline yield and quality.
... Nowadays there is huge interest in resources for alternative and renewable energy such as biomass since the current environmental concerns regarding the greenhouse effect and climate change, the increasing demand for energy associated with the dwindling of fossil reserves, and the restrictive emissions on the environment. [1][2][3] Fuels derived from biomass have some advantages compared to traditional fuels, such as decreased emissions of greenhouse gases, regional production, and advantageous cost-effective use. [4] In particular, the use of vegetable oils and fats (waste residues) represents a promising alternative to producing jet fuels, and platform chemicals from renewable resources. ...
Transition metal phosphide nanoparticles supported on silica were used as catalysts to investigate the hydrodeoxygenation of methyl laurate (used as a model compound for vegetable oils). Ni2P, Ni1Mo1P, and Ni1.6Mo0.4P were synthesized using a molecular precursor route. The nanoparticles were added to the silica support without any changes in their structure or particle size. As a reference and for comparison, MoP/SiO2 was also prepared by the phosphite method. The prepared catalysts were characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, transmission electron microscopy, and chemical analysis. A higher conversion is reached with the MoP/SiO2 monometallic catalyst, close to that with Ni1Mo1P/SiO2. However, this observation is misleading because the differences in dispersion obscure the result that the intrinsic activity (turnover frequency) of the bimetallic catalyst, prepared by a molecular precursor route, is significantly higher than that of the monometallic catalyst, prepared by the phosphite route, revealing a synergistic effect on the catalytic activity due to the formation of the bimetallic phosphide.
... In most crude oil refineries, the PVB to send the visbreaker unit to reduce the viscosity and pour point to produce fuel oils [26,27]. Due to the high percentage of asphaltene compounds in PVB, the use of PVB in visbreaker units is usually associated with coking and sedimentation in reactor furnace pipes and increases process costs [28]. Increasing operating temperature and residence time may be to increase the tendency to create coke in the thermal reactor [29][30][31][32][33]. Reducing and controlling each of the above factors reduces coke and thus longer performance operational units. ...
In this present work, a zeolitic imidazolate framework, ZIF-8, an oil-soluble long chain Ionic Liquids, [OMIM][NTf2], was separately synthesized and characterized. Ex-situ preparation of [OMIM][NTf2]-ZIF8 (IL@ZIF8) nanostructures were performed solvothermal, and the products were specified by the several techniques including XRD, FESEM, H-NMR, FTIR, TGA and N2 adsorption-desorption. The products were evaluated as a highly effective material in visbreaking process of petroleum vacuum bottoms (PVBs). To best our knowledge, no was reported in survey on the literature for MOFs as conversion enhancer and viscosity modifier in a visbreaking process especially for atmospheric pressure and elevated temperatures of 375 -400 °C during maximum 120 min. Injection of a little amount of the synthesized products to PVBs caused to produce gaseous compounds, naphtha, middle distillates, lubricating oil and tar. However, viscosity measurement results revealed that IL@ZIF8 was ideally suited for viscosity reduction of PVBs up to 321% after cracking and conversion of PVBs to its distillates up to 1400%. Catalytic upgrading with IL@ZIF-8 also yielded a liquid with 50% light hydrocarbon without any further coke formation.
... As shown in Table 4 and fouling of heat exchanger surfaces [92]. The hydrotreatment step prior to catalytic cracking and steam cracking can efficiently decrease the concentration of unsaturated hydrocarbons and remove heteroatoms and metals [93]. Our previous work (Table 4) also proved this conclusion. ...
The unsuitable disposal of plastic wastes has caused serious environmental pollution, and finding a green manner to address this problem has aroused wide concern. Plastic wastes, especially polyolefin wastes, are rich in carbon and hydrogen, and chemical recycling shows high advantages in their conversion into olefins and realizes a closed-loop cycling of plastic wastes. Plastic wastes should be labeled before disposal. The necessity and methods of pretreatment are introduced in this paper. Meanwhile, the whole recycling process of polyolefin wastes is also summarized. As the core technology, pyrolysis including thermal, catalytic and solvolysis processes, is introduced in detail due to its enormous development potential in the future. We also briefly describe the feasible strategies of pyrolytic-oil refining and life cycle assessment of the chemical recycling process. In addition, suggestions and perspectives concerning the industrial improvement of polyolefin chemical recycling are proposed.
The valorization of polymeric wastes, such as biomass, tires, and plastics,viathermal depolymerization (i.e., pyrolysis or liquefaction) and simultaneous or subsequent catalytic treatment has gained enormous momentum. The inherent hurdles when using complex polymeric wastes or their products as feedstock have led researchers to conclude that obtaining a fundamental kinetic understanding of the catalytic stage is unfeasible. To overcome the issues related to feedstock complexity, the majority of researchers have decided to use representative model compounds or probe molecules (i.e., surrogates). Two separate mainstreams have emerged in this field: one focusing on the fundamental kinetic understanding of model molecules and the other focused on studying real feedstock. We aimed to merge these approaches to utilize and acknowledge their potential and drawbacks. Therefore, herein, we provide ten recommendations for exploiting the existing synergies between the two approaches. This manuscript first contextualizes our proposed recommendations with a short overview on the thermocatalytic valorization field for polymeric waste, the complex compositions of reactants and products, the progress made in the individual fields of model and real feedstock, comparisons of both feedstock types, and some previous history on hydrocarbon conversion. Subsequently, we present guidelines for a truly cooperative and synergetic research effort.
The dynamics of retained and deactivating species in a SAPO‐18 catalyst during the methanol‐to‐olefins reaction have been followed using a combination of ex‐situ and in‐situ techniques in differential and integral reactors.The retained species were analyzed using extraction, in‐situ FTIR and in‐situ UV‐vis spectroscopies combined with online product analysis (gas chromatography and mass spectrometry). The composition of the extracted soluble species was determined using gas chromatography‐mass spectrometry and that of the insoluble species using high‐resolution mass spectrometry. We observe a decrease in the formation and degradation rates of retained species when co‐feeding water, whereas the extent of the decreases is the same across the entire spectrum of retained molecules. This indicates that co‐feeding water unselectively quenches the formation of active and deactivating species. At the same time, the catalyst has an extended lifetime when co‐feeding water due to the diffusion of species (particularly olefins) out of the SAPO‐18 crystals, and subsequent growth of heavy polycyclic aromatic structures that imply less deactivation. These conclusions can be extrapolated to other MTO catalysts with relatively similar pore topology such as SAPO‐34 or SSZ‐13 structures.
Catalytic conversion of useless chlorinated heavy wax (chlorine, 0.14 wt%) obtained from pyrolysis of refuse plastic fuel was studied using iron oxide impregnated HY zeolite to produce a useful liquid product. It was found that the largest liquid fraction (gasoline and kerosene/ diesel, 66.9 wt.%) with very low chlorine content was achieved when using Fe[3]/HY among impregnated HY catalysts. This demonstrated that the Fe impregnated HY catalyst had a dual function of catalytic cracking of HY zeolite and dechlorination of iron oxide. Excessive impregnation of Fe, i.e., Fe[20]/HY, showed the least cracking activity of heavy wax owing to the catalyst having lowest total acid sites, but yielded liquid product with the lowest chlorine content (60 ppm) among the tested catalysts. The spent catalysts were deposited by a significant amount of soft coke and chlorine, and they were totally restored by thermal treatment in air (700 ℃).
The complexity of crude oil samples has hindered its detailed analysis and understanding. Although modern analytical methods such as ultrahigh-resolution mass spectrometry have opened the understanding of the molecular composition, discrimination due to the complexity is sabotaging a better understanding. Therefore, the SARA fractionation has been used to reduce complexity by adding a fractionation step prior to analysis. However, our studies indicate that the conventional combinations of solvents used for SARA fractionation are inefficient for the elution of heavier fractions of crude oil from the alumina stationary phase. Adding an additional step to the conventional SARA scheme provides a second resin fraction using ethyl acetate as an additional mobile phase and provides a new material that has not yet been reported. For a better understanding of the differences between both resin fractions, detailed studies have been carried out utilizing ultrahigh-resolution mass spectrometry with different types of ionization methods, one of the best scenarios to reduce discrimination and suppression effects.
About 80% of the total pollution from ships is caused by operational oil discharges into the sea, often made deliberately and in violation of international rules; the main reasons can be due to cost savings or lack of adequate facilities in ports to receive waste oils. Therefore, reducing waste oil discharges is crucial for a proper protection of the marine environment. In this regard, the paper presents the preliminary feasibility of a particular waste recycling technology, aimed at obtaining marine fuel oil from sludge, through a pyrolysis process to be carried out in a small reactor onboard. The originality of the research consists in the adaptation of pyrolysis to oily waste produced by ships, since this technology is traditionally applied to solid waste and biomass. Furthermore, the plant has to be designed for operation on board the ship, therefore under very different constraints compared to traditional land plants. Although the preliminary lab tests and simulation results in the chemical process are promising enough, there are still some technical criticalities due to the energy optimization of the reactor for an efficient use onboard of the whole system. In addition, the possibility of recycling waste, directly onboard ships, is not yet covered by mandatory regulations, which is why shipowners generally still feel unmotivated to invest in such technologies.
The performance of a commercial FCC catalyst (designated as CY) and a physically mixed hybrid catalyst (80 wt.% CY and 20 wt.% HZSM-5-based catalyst, designated as CH) have been compared in the catalytic cracking of a vacuum gasoil (VGO)/bio-oil blend (80/20 wt.%) in a simulated riser reactor (C/O, 6gcatgfeed−1; t, 6 s). The effect of cracking temperature has been studied on product distribution (carbon products, water, and coke) and product lumps: CO+CO2, dry gas, liquified petroleum gases (LPG), gasoline, light cycle oil (LCO), heavy cycle oil (HCO), and coke. Using the CH catalyst, the conversion of the bio-oil oxygenates is ca. 3 wt.% higher, while the conversion of the hydrocarbons in the mixture is lower, yielding more carbon products (83.2–84.7 wt.% on a wet basis) and less coke (3.7–4.8 wt.% on a wet basis) than the CY catalyst. The CH catalyst provides lower gasoline yields (30.7–32.0 wt.% on a dry basis) of a less aromatic and more olefinic nature. Due to gasoline overcracking, enhanced LPG yields were also obtained. The results are explained by the high activity of the HZSM-5 zeolite for the cracking of bio-oil oxygenates, the diffusional limitations within its pore structure of bulkier VGO compounds, and its lower activity towards hydrogen transfer reactions.
Asphaltenes are a complex mixture of molecular structures with a variety of functionalities, which in turn impacts their physical properties. Discriminating between asphaltenes that are strongly and weakly interfacially active is providing a new direction to mitigate asphaltene-related problems. Whole asphaltenes (WA) were extracted from a South American heavy crude oil, further fractionated into interfacially active asphaltenes (IAA) and remaining asphaltenes (RA), and molecularly characterized by positive-ion (+) atmospheric pressure photoionization (APPI) using a 9.4 T Fourier transform ion cyclotron mass spectrometer (FT-ICR MS). The IAA fraction was found to contain a greater abundance of heteroatoms with >50% of IAA containing two or more heteroatoms as compared to ∼30% for RA. The IAA fraction was enriched in oxygen-containing species, more specifically higher-order Ox and OxSy groups that were predominantly of low DBE. Gas-phase fragmentation of RA and IAA precursor ions (m/z 650) by infrared multiphoton dissociation (IRMPD) revealed an abundance of multi-core motifs in IAA, while RA was found to be a mixture of single-core and multi-core structures. Analysis of the fragmented ions showed a prevalence of nitrogen-containing species of high DBE (aromatic molecular structures), while oxygen-containing species were most likely associated with aliphatic side chains. Extrography fractionation of RA and IAA verified the abundance of multi-core motifs in IAA, which were highly polar and of low DBE and carbon number. These “atypical” structures of IAA are classified as asphaltenes as a result of their functionality and polarity rather than high aromaticity.
Direct visualization of spatiotemporal evolution of molecules and active sites during chemical transformation in individual catalyst crystal will accelerate the intuitive understanding of heterogeneous catalysis. So far, widespread imaging techniques can only provide limited information either with large probe molecules or in model catalyst of large size, which are beyond the interests of industrial catalysis. Herein, we demonstrate a feasible deep data approach via synergy of multiscale reaction-diffusion simulation and super-resolution structured illumination microscopy to illustrate the dynamical evolution of spatiotemporal distributions of gas molecules, carbonaceous species and acid sites in SAPO-34 zeolite crystals of several micrometers that are typically used in industrial methanol-to-olefins process. The profound insights into the inadequate utilization of activated acid sites and rapid deactivation are unveiled. The notable elucidation of molecular reaction-diffusion process at the scale of single catalyst crystal via this approach opens an interesting method for mechanism study in materials synthesis and catalysis. Imaging zeolites in catalysis relies on the use of probe molecules or model catalysts. Here the authors show the synergy of a multiscale reaction-diffusion model and structured illumination microscopy to illustrate spatiotemporal evolution of molecules and acid sites in SAPO-34 zeolites in methanol-to-olefins reaction.
Abstract
Ship wastes are incidentally regulated within the regime of marine pollution and the prevention of ship-source pollution is heavily reliant on the provision of adequate port reception facilities on land. However, the coordination between these facilities and further downstream management operations is still an unresolved issue. This paper examines from a legal perspective the challenges and opportunities related to the management of wastes generated on-board vessels after they are discharged to port reception facilities. Ship wastes are studied from a European Union (EU) law
perspective and the author evaluates the integration of ship waste management within wider EU waste legislation and national waste management plans.
Keywords: Ship wastes, Port reception facilities, Sea/land interface, Waste
management, Directive (EU) 2019/883
Extension and clustering of polycyclic aromatic hydrocarbons (PAHs) are key mechanistic steps for coking and deactivation in catalysis reactions. However, no unambiguous mechanistic picture exists on molecule-resolved PAHs speciation and evolution, due to the immense experimental challenges in deciphering the complex PAHs structures. Herein, we report an effective strategy through integrating a high resolution MALDI FT-ICR mass spectrometry with isotope labeling technique. With this strategy, a complete route for aromatic hydrocarbon evolution is unveiled for SAPO-34-catalyzed, industrially relevant methanol-to-olefins (MTO) as a model reaction. Notable is the elucidation of an unusual, previously unrecognized mechanistic step: cage-passing growth forming cross-linked multi-core PAHs with graphene-like structure. This mechanistic concept proves general on other cage-based molecule sieves. This preliminary work would provide a versatile means to decipher the key mechanistic step of molecular mass growth for PAHs involved in catalysis and combustion chemistry. Coke-induced catalyst deactivation draws increasing concerns in industrially catalytic processes. Here the authors provide a strategy integrating advanced mass spectroscopy and isotope labeling to uncover a cage-passing molecular route of coking species in molecular sieve catalysts.
Oily wastewater from shipping waste and marine accidents have seriously polluted the marine environment and brought great harm to human production and health. With the increasing awareness of environmental protection, the treatment of marine oily wastewater has attracted extensive attention from the international community. Marine oily wastewater has various forms and complex components, so its treatment technology faces great challenges. Sources, types, supervision, and treatment of marine oily wastewater are introduced in this paper. The research progress of marine and ship’s oily wastewater treatment technologies in recent years are reviewed from the perspectives of physical treatment, chemical treatment, biological treatment, and combined treatment, respectively. Principles and characteristics of all kinds of technologies were analyzed. In addition, this paper shows that multiple processing technologies used in combination for the purpose of high efficiency, environmental protection, economy, and energy conservation are the future development trend.
Design of experiments (DOE) applied to mass spectrometry (MS), mainly focusing on the optimization of ionization techniques, has been applied to optimize experiments in order to provide the highest amount of information with the lowest number of experiments. However, DOE has not been used in petroleomics. For the first time, we applied DOE to optimize the main parameters associated with the crude oil analysis in a petroleomics approach. For the ionization technique, atmospheric pressure photoionization (APPI) has been selected and data were acquired in a high resolution (400,000 at m/z 400) and high mass accuracy (< 1 ppm) Fourier transform ion cyclotron resonance (FT-ICR) MS. Full and fractional two-level factorial designs were applied for the APPI(±) FT-ICR MS data set from two different crude oil samples with distinct physical and chemical characteristics. The standard ionization parameters that affect the MS responses of the crude oil analysis were optimized for both APPI(+)-MS and APPI(–)-MS. Such ionization parameters were then successfully applied to a crude oil and its saturated, aromatics, resin and asphaltene fractions, all with superior features of merit. Thus, the optimized APPI(±)-MS parameters should serve as reference and can be used as a guide for new studies in petroleomics.
Marine transportation drives global trade, moving over 10 billion tonnes of containers, solid and liquid bulk cargo across the world's seas annually. Historically, shipping companies and ports operated with limited environmental oversight, but accidental oil spills in the 1960s, caused widespread coastal pollution and seabird mortality, triggering the International Convention for the Prevention of Pollution from Ships (MARPOL). MARPOL is the main international convention to prevent marine pollution by ships from operational or accidental causes. Additionally, the International Maritime Organization (IMO) uses various instruments to protect the marine environment from shipping activities. Nevertheless, marine transportation still generates negative impacts on the marine environment, including air pollution; greenhouse gas emissions; releases of ballast water containing aquatic invasive species; historical use of antifoulants; oil and chemical spills; dry bulk cargo releases; garbage; underwater noise pollution; ship-strikes on marine megafauna; risk of ship grounding or sinkings; and widespread sediment contamination of ports during trans-shipment or ship breaking activities. This chapter summarizes environmental effects of marine transportation and describes mitigative, legislative and environmental performance measures currently available to improve management of these global issues.
Oxidative desulfurization of model oil and heavy fuel oil (HFO) was investigated under mild conditions using H2O2 as an oxidant and acetonitrile as an extractant. The influence factors in the oxidation and extraction processes were evaluated and optimized. The molecular characteristics of the raw feedstock and the desulfurized oils, and the corresponding extraction phases were systematically analyzed by APPI FT-ICR MS, ¹H NMR, etc. The results showed that the desulfurization rate of dibenzothiophene reached 97.7% after 10 min reaction, while the sulfur removal efficiency of HFO was 30.7% under optimized conditions. The structures of sulfur compounds were described in heteroatom type, carbon number distribution vs unsaturation degree. The detected main sulfur-containing compounds are S1, S2, S3, NS, OS, O2S, O2S2, and O4S2. Based on the APPI FT-ICR MS results, it can be found that almost all the S1 species have been transformed into sulfone after the oxidation process. Furthermore, the sulfone of O2S1 and O4S2 species in extraction phases were in double bond equivalent (DBE) range from 9 to 25 and carbon number with ≤40. ¹H NMR results showed that the α to aromatic CH3 combined naphthenic CH-CH2 group accounted for 73.2% in the extraction phase.
The distribution of various types of sulfur in Buton oil sand bitumen (OSB) were investigated at the level of group-fractions corresponding to saturates, aromatics, resins and asphaltens (SARA). The separation of different types of sulfur-containing compounds (SCCs) in saturates and aromatics with weak polarity was performed using selective oxidization coupled with alumina column chromatography. However, various types of SCCs were isolated from resins via selective oxidization combined with solvent fractional extraction. It was found that sulfide sulfur, thiophenic sulfur and sulfoxide/sulfone sulfur accounted for 39.31%, 53.93% and 6.74% in total sulfur of OSB, respectively. Sulfidic sulfur and thiophenic sulfur in OSB had the highest enrichment in aromatics, followed by that in asphaltenes and resins. In order to further link the theoretical study with the actual process of thermal cracking process, the fast thermal cracking of OSB to produce oil sand oil under different temperature and over silica sand, calcium aluminate and FCC catalyst was conducted by a laboratory-scale fluidized bed reactor. The composition and classes of SCCs existed in oil sand oil were evaluated via GC–MS, which were indispensable to gain an in-depth insight into thermal cracking behavior of SCCs in OSB. Results indicated that SCCs in oil sand oil obtained under different temperature and over different heat carriers had the distinct composition, and yet were all classified into up to 11 classes. The detected SCCs in oil sand oil obtained over silica sand at different temperatures all contained AT&AM, thiophenes, BTs, HydroDBTs, DBTs, HydroNTs, and NTs. The composition and classes of SCCs in oil sand oil, nonetheless, were inclined to be enriched as the temperature enhanced. Furthermore, the detected SCCs in oil sand oil obtained over calcium aluminate featured the most abundant class distribution, followed by that over silica sand and FCC catalyst. The relative content of AT&AM, thiophenes and BTs, the relative content of NTs and four species of Hydrothiophenes, and the relative content of DBTs, PTs and BNTs accounting for SCCs in oil sand oil was largest when the heat carriers were silica sand, calcium aluminate and FCC catalyst, respectively.
Tar is one of the biggest obstacles for commercial application of biomass gasification. Microwave catalytic cracking shows potential for not only removal but also conversion of tar. However, the coke formation under microwave has not been investigated. In the present work, a microwave applicable catalyst, [email protected], was prepared. The effects of temperature and inlet tar concentration on toluene and phenol conversions were investigated under both microwave and conventional heating conditions, and the influences on coking rate were also focused. Results showed that increasing temperature and reducing inlet tar concentration improved tar conversion. Inlet tar concentration and cracking of phenol typically caused more coke deposition. Based on the characterizations of the spent catalysts, the microwave could eliminate the coke deposition and alter the coke types. The mechanism of microwave on the coke suppression was revealed. This study provids an in-depth understanding of the coke formation during the microwave process, and also builds foundation for the design and operation of catalytic process.
Petroleum waste occurring during operation of marine power systems in compliance with Marpol convention [1] needs to be collected on the ship, and the crew is obliged to run the record of their amount in so called oil record book. Collected waste is transported to the land or can be used as a fuel on the ships. Physico-chemical properties of petroleum waste containing different types of petroleum waste mixed in different proportions are difficult to define what makes it more difficult to choose a correct heating temperature in order to obtain required viscosity that would enable correct spraying and obtaining good combustion quality. Moreover, petroleum waste usually contains high amount of water, solid emissions and coagulants originating as a result of reactions between different types of petroleum products that are part of petroleum waste. Petroleum waste before and after homogenization have undergone laboratory tests by processing microscopic images of their samples with the use of specialized computer programme and spectral analysis in order to specify the morphology of the waste. The physico-chemical properties of the waste have also been determined. The results of the studies carried out showed a significant variety of physicochemical properties and composition of petroleum waste taken from the ships. Density in 15 °C changed in the range of 924.9–986.1 kg/m³, kinematic viscosity in 50 °C in the range 12.25–28.74 mm²/s, water content from 9.80 to 28.74 % mass, caloric value from 21.5 to 33.2 MJ/kg, resins in the range 12.1 – 38.2 % mass, and asphaltenes insoluble in n-hexane from 3.2 to 28.3 % mass. The size of asphaltene-resin particles and a number of water droplets of minimal and maximal measured diameter affecting the quality of spraying process and fuel combustion changed in the following range:
Asphaltene-resin particles Water droplets.
Particle size: Diameter and number: 0.5 µm: 0.0 – 0.8 % volume 5–15 µm: (1.0 – 11) 103.
100 µm: 0.0 – 6.8 % volume 50–100 µm: (0.6 – 0.8) 103.
This requires proper preparation process of waste before combustion. Taking into consid- eration the fact that the combustion quality control is facilitated, petroleum waste can be used as a fuel in the boilers. The article presents studies’ results of morphology of petroleum waste that undergoes cleaning process and process of preparation for combustion with different methods, their physicochemical properties as well as exhaust emissions in the marine boiler For this reason we designed and made the modernization of fuel system for the ship boiler on the specialized ship for collection and combustion of petroleum waste with use of static and dynamic homogenizer. We have carried out homogenization with use of each of homogenizers at their serial operation. After homogenization petroleum waste samples were subjected to laboratory studies with use of microscope pictures processed with use of computer programme and spectral analysis in order to determine their morphology. Physico-chemical properties of studied petroleum waste have been determined. It has been proventhat the best effects have been achieved when both static and dynamic homogenizer were working in series. The sizes of asphaltene-resin particles and number of water droplets of minimal and maximal measured diameter changed in the following range:
Asphaltene-resin particles Water droplets.
Particle size: Diameter and number: 0.5 µm: 0.2 – 3.2 % volume 5–15 µm: (24 – 45) 103.
100 µm: 0.0 – 0.1 % volume 50–100 µm: (0.0 – 0.0) 103.
In order to obtain the correct spraying quality of petroleum waste and their combustion it is required that asphaltane-resin particles are of size in the range from 5 µm to 30 µm and water roplets of diameter up to 20 µm. The developed technology of preparing for petroleum waste combustion ensures achieving the required diameters. It needs to be highlighted that all particles of size between 50 and 100 µm underwent fragmentation and the number of particles fragmented to the diameter of 0.5 µm and size of 5–15 µm increased.The authors believe that the obtained research results are valuable and worth making available through publication for a wide audience. The research was carried out with the use of 6 types of specific marine petroleum waste collected from ships, which differ significantly in composition, water content and properties. The designed and constructed fuel installation enables to obtain the morphology of waste enabling good quality of its atomization and combustion in the boiler furnace chamber. The technology developed in this way and the wide scope of research carried out with the use of marine petroleum waste are not found in the literature.
Bioenergy generated from vegetable oils is an interesting alternative energy source to fossil fuel in terms of reducing carbon footprint and realizing circular economy. Among many routes in transforming vegetable oils into biofuels, the catalytic cracking route is a promising method due to its capability to process a wide variety of feedstocks and its ability to produce a wide range of fuels. This paper aims to give a comprehensive overview of the state-of-the-art catalytic cracking technology in vegetable oils upgrading and provide a solid foundation to design a high-quality biofuel production system. This review covers the physical and chemical properties of various types of vegetable oils, the recent development of catalytic cracking mechanism of vegetable oils, especially the reaction pathways of the primary fatty acid constituents in most of the vegetable oils, the associated catalyst characteristics and the properties of the final products. Lastly, catalytic cracking of vegetable oils using the conventional fluidized catalytic cracking unit has also included.
The pyrolysis of scrap tires is a very attractive strategy to valorize chemically these end-of-life wastes. The products of this step and any additional one, such as hydrotreating, are relatively complex in nature entangling the understanding and limiting the viability. In this work, we have investigated in detail the composition of a tire pyrolysis oil blended with light cycle oil (from a refinery) and its hydrotreated products using a bifunctional NiW/HY catalyst at 320–400 °C. We have applied a set of analytical techniques to assess the composition, namely simulated distillation, ICP, GC/FID-PFPD, GC × GC/MS, and APPI FT-ICR/MS. Our results show the strength of our analytical workflow to highlight the compositional similarities of this pyrolysis oil with the standard refinery streams. The main differences arise from the higher boiling point species (originated during the pyrolysis of tires) and relatively high concentration of oxygenates. These effects can be minimized by hydrotreating the feed which effectively removes heteroatomic compounds from the feed while boosting the quantity and quality of gasoline and diesel fractions.
The present work studies the influence of nitrogen compounds in hydrotreated fluid catalytic cracking (FCC) feedstock on the material balance of FCC process focused on petrochemistry. Vacuum gas oil was hydrotreated at the temperatures of 340 to 370 °C in typical FCC pretreatment conditions. The obtained hydrotreated products contained 370-750 ppm of nitrogen and 150-820 ppm of sulfur. Hydrotreated feedstock was exposed to the FCC process over a zeolite catalyst at the laboratory unit with a fixed bed catalyst at 527 °C and catalyst/oil ratio - 2-6. The FCC feedstock before and after hydrotreatment and FCC products were characterized by different methods to study the effect of nitrogen compounds on the FCC process.
Microwave-assisted catalytic pyrolysis of ship oil sludge is a promising method of recovering oil and gas for further energy replenishment on board. In this study, experiments on catalytic pyrolysis of ship oil sludge with the presence of 10 inexpensive metal additives under microwave irradiation were carried out. The introduction of all metal catalysts enhanced the temperature rising rate of oil sludge. The catalysts promoted the cracking of organic components following the orders of Fe2(SO4)3 > CaO ≈ CaCO3 > NiO > CaSO4 ≈ γ-Al2O3 > CaCl2 ≈ TiO2 > CuSO4 ≈ NiCl2 in terms of total yield of pyrolysis oil and gas. Ca-based catalysts exhibited a better performance on accelerating the formation of alkanes and consequently elevated the heating values of pyrolysis oil. The addition of Fe2(SO4)3, γ-Al2O3 and NiO only gave rise to a mild improvement of oil quality. CaO addition remarkably increased the proportion of H2 and the molar ratio of H2/CO in syngas. In general, CaO was the most beneficial for conversion of ship oil sludge into fuel oil and gas with the characteristic of high heating values. The obtained results provide the references for development of microwave-assisted catalytic pyrolysis of ship oil sludge while sailing.
Biomass pyrolysis liquids (bio-oils) unavoidably require catalytic hydrodeoxygenation (HDO) for their upgrading and stabilization for commercial usage. The complex composition of bio-oil constrains the fundamental kinetic understanding of HDO. Here, we propose a multitechnique methodology to compositionally assess the complete spectrum of the HDO reactants and products and then use it to pre-evaluate different catalysts in the HDO of a raw bio-oil obtained from black poplar. The used techniques are: Micro (gas) chromatography (GC), GC with mass spectrometry (GC/MS), bidimensional GC × GC/MS, elemental analysis (EA), gel permeation chromatography (GPC), Karl Fischer, thermogravimetric analysis (TGA), as well as Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS) using different ionization sources (electrospray ionization (ESI) and atmospheric pressure photoionization (APPI)). FT-ICR/MS allows for the assessment of the heaviest and most refractory oxygenates in bio-oil, which have a pivotal role in HDO catalyst performance. Three activated carbon-supported catalysts based on PtPd, NiW, and CoMo mixed with a commercial HZSM-5 zeolite were used. We have been able to evaluate the multiple facets of catalyst performance: Production of gases, catalytic coke, thermal lignin, and, most importantly, the aqueous and organic product fractions (hydrodeoxygenation of heavy species and production of light aromatics). The results of the detailed analytical methodology highlight their potential for understanding the HDO mechanism and for a detailed catalyst screening.
The hydrodesulfurization (HDS) of dibenzothiophene (DBT) over a NiMo/Al-SBA-15 catalyst was performed in different solvent systems and the results showed that the solvent selection had a great impact on the TOF values and the reaction networks. The phase equilibrium experiments, and the PRO/II stimulation ascribed the solvent effects as the partial evaporation of DBT and the large diffusion resistance in the gas-liquid-solid reaction. The density functional theory (DFT) simulation and the GC–MS results attributed the solvent effects to the competitive adsorption of H2, DBT, and the solvent molecules on the active sites. Hydrogen donations of decalin and tetralin were found to have negligible contributions to the HDS processes, while the corresponding dehydrogenation process of decalin and tetralin would produce naphthalene and the other polycyclic aromatic compounds, consequently leading to the lower HDS efficiencies. Furthermore, the internal diffusion effectiveness factors (η) were calculated, and the results demonstrated that the HDS of DBT in the p-xylene and tetralin solvent systems were limited by the surface-reactions, while that in the DBT-cyclohexane system was limited by the intraparticle diffusion.
The molecular structure of sulfur compounds in residual oils and their desulfurization reactivity during residue hydroprocessing (RHT) process were investigated by virtue of the self-established semiquantitative APPI FT-ICT MS combined with the kinetic analysis of the hydrodesulfurization of individual sulfur compounds. In order to increase the characterization accuracy and gain more structure details on the sulfur compounds, a prior SARA separation scheme of residual oils into clearly-defined fractions was performed. Results show that S1, S2, S3, and N1S1 class were the dominated species in the residual oil feedstock. During RHT process, the S1 class species were identified as the key refractory sulfur compounds, while S2 and S3 class species were identified as the easily-removed sulfur compounds. The molecular structure change of S1 class species during RHT process was marked by a drastic increase in the aromaticity and polycondensation, indicating that S1 class species with less-aromatic cores exhibited higher reactivity. Moreover, a novel DBE-based lumping kinetics approach containing 6 sulfur groups of S1 class compounds was developed to investigate the desulfurization reactivity of individual sulfur compounds. The results revealed that the reactivity of sulfur compounds depends on their structure, and different molecular structure brings distinctly different reactivity. The reactivity difference between the individual sulfur compounds in residual oils is considerably smaller than that in other petroleum fractions with lower boiling points, such as VGO, diesel. This research provides a deep insight into complex desulfurization chemistry during RHT process.
Characterization of heteroatom compounds in crude oils is very important in petroleum production and processing. The ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is a powerful MS technique for it but with expensive costs. It is necessary to develop a generally accepted alternative analytical approach to replace FT-ICR MS. In this study, a reversed-phase liquid chromatography (RPLC)-high-resolution (HR) MS method was proposed on an Orbitrap MS with electrospray ionization (ESI). The optimal chromatographic and MS parameters and internal mass calibration method were suggested. The sample complexity was greatly reduced by RPLC separation. Mass resolution (240 K at m/z 200) of Orbitrap MS was enough to obtain an accurate elemental assignment in complex petroleum fractions. False-positive element composition assignment could be easily excluded by the RPLC retention behavior of isomers. The performance of RPLC-Orbitrap MS was evaluated in comparison with direct injection (DI)-FT-ICR MS and DI-Orbitrap MS in positive ion mode for heavy oil analysis. The results showed that heteroatom class species, DBE vs carbon number distributions were very similar between RPLC-Orbitrap MS and DI-FT-ICR MS. The developed methods were further used to analyze petroleum oil fractions with boiling ranges at 180–350 °C, 350–530 °C and >530 °C. Detailed heteroatom class species and corresponding DBE vs carbon number distributions were obtained. This study demonstrated that the RPLC-Orbitrap MS technique could successfully be applied for heteroatom compound characterization in petroleum fractions.
We have studied the effect of adding scrap tire pyrolysis oil (STPO) as feed or co-feed in the cracking of vacuum gasoil (VGO) using a commercial equilibrated catalyst. The cracking experiments were performed in a laboratory scale fluid catalytic cracking (FCC) simulator using VGO, STPO, or a blend of the two (20 wt% of STPO), contact time = 6 s, catalyst/feed ratio = 5, and 530 °C. The composition of the different feeds has been correlated with the yield of products and the amount-location-nature of the deactivating species (coke). Our results indicate that adding STPO increases proportionally the gasoline yield, synergistically increase the yield of light cycle oil while uncooperatively decrease the yields of heavy cycle oil and coke. We further investigated the effect on coke formation, characterizing deeply the coked catalyst and coke. In fact, the coke deposited under the cracking of STPO is more aliphatic, lighter, and located in the micropores of the catalyst. The complete analysis of the coke fractions (soluble and insoluble) have lighted the peculiar chemistry of these species as a function of the type of feed used. The results point to a viable and economically attractive valorization route for discarded tires.
Some aromatic sulfur compounds contained in vacuum gas oils are known to be very refractory to hydrotreatment. Thus, a better knowledge of these molecules would help to improve hydrodesulfurization efficiency by designing targeted catalysts or choosing adequate operating conditions for hydrotreatment process. The characterization of such compounds using advanced analytical techniques such as Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) can give more information about the aromaticity and the number of carbon atoms of these refractory molecules. One vacuum gas oil feed and six hydrotreated samples obtained from pilot plant tests at several temperatures or using different catalysts have been analyzed using APPI(+)-FT-ICR MS. The differences of the aromaticity and number of carbon atoms among the several hydrotreated samples have been investigated to identify the effects of catalysts and temperatures over hydrotreatment process. Principal Component Analysis was used to explore the obtained data and put forward the variables explaining most of the variance between the hydrotreated samples.
Catalytic cracking is a conversion process that can be applied to a variety of feedstocks ranging from gas oil to heavy crude oil and residuum. The concept of catalytic cracking is basically the same as thermal cracking, but it differs by the use of a catalyst that is not (in theory) consumed in the process, and it is one of several practical applications used in a refinery that employ a catalyst to improve process efficiency and product slate.
Catalytic cracking in the usual commercial process involves contacting a feedstock (usually a gas oil fraction) with a catalyst under suitable conditions of temperature, pressure, and residence time. By this means, a substantial part (>50%) of the feedstock is converted into gasoline and lower boiling products, usually in a single-pass operation. However, during the cracking reaction, carbonaceous material is deposited on the catalyst, which markedly reduces its activity, and removal of the deposit is very necessary. The carbonaceous deposit arises from the thermal decomposition of high-molecular-weight polar species (asphaltene constituents and resin constituents) in the feedstock. The removal of the deposit from the catalyst is usually accomplished by burning in the presence of air until catalyst activity is reestablished.
The purpose this chapter is to present catalytic cracking processes in the light of their use and development in modern refineries as well as potential innovations that will be used in the refineries of the future.
Ship wastes are incidentally regulated within the regime of marine pollution and the prevention of ship-source pollution is heavily reliant on the provision of adequate port reception facilities on land. However, the coordination between these facilities and further downstream management operations is still an unresolved issue. This paper examines from a legal perspective the challenges and opportunities related to the management of wastes generated on-board vessels after they are discharged to port reception facilities. Ship wastes are studied from a European Union (EU) law
perspective and the author evaluates the integration of ship waste management within wider EU waste legislation and national waste management plans.
Keywords: Ship wastes, Port reception facilities, Sea/land interface, Waste
management, Directive (EU) 2019/883
Reducing emissions from internal combustion engines is becoming one of the most important tasks for engine manufactures and transport regulatory organizations. In particular, the marine transportation sector is one of the most polluting, due to the intense maritime activity and the use of low-quality fuels, burned in Heavy Duty Diesel Engines, for ship propulsion and auxiliary power generation. In order to reduce the global shipping environmental impact, the IMO (International Maritime Organization) is restricting NO x and SO x ships' emissions through the introduction of the IMO Tier III legislation, which requires to consider a wide spectrum of emissions reduction technologies and strategies, which are going to have an impact on the engine performance and fuel consumption. In this work, the main solutions being currently developed or adopted for low and medium speed Diesel engines have been reviewed from a qualitative, and sometimes quantitative, point of view, but, in comparison to previous literature, focusing more on their potential with respect to possible waste heat recovery systems utilization , such as, in particular, steam Rankine cycles and Organic Rankine Cycles (ORC). Indeed, even though many of the considered emissions mitigation technologies lead to a certain amount of penalty in fuel economy, the use of waste heat recovery systems to recover wasted engines energy could become interesting in order to develop more efficient but, at the same time, cleaner engines.
The co-feeding of scrap tires pyrolysis oil (STPO) on the catalytic cracking of vacuum gasoil (VGO) has been investigated with the aim of exploring the capacity of the refinery fluid catalytic cracking (FCC) unit to upgrade discarded tires at large-scale. The runs have been carried out in a CREC (Chemical Reactor Engineering Centre) riser simulator reactor that mimics the behavior of the industrial unit at the following conditions: 500-560 °C; catalyst/oil ratio, 3-7 gcat goil-1; contact time, 6 s. Obtained results with the blend of 20 wt% STPO in VGO have been compared with those obtained in the cracking of the pure streams, i.e., STPO and VGO, to get a proper idea of the synergetic effects that could be involved in the co-feeding. This way, when the STPO is co-fed with the VGO the production of naphtha (C5-C12) and light cycle oil (C13-C20) lumps are maximized, as the over-cracking reactions that convert them into gaseous products (C1-C4) are mitigated. Consequently, the co-feeding promotes the production of high-interest hydrocarbons for refineries. Additionally, the naphtha obtained in the cracking of the blend shows a lower content of paraffins and naphthenes than that obtained with the VGO, and higher of olefins and aromatics.
In this work, a detailed analysis of a bio-oil obtained by pyrolysis of softwoods and its esterified product is described. Information of the type of chemical function groups were obtained by 13C and 1H nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR) and compositional analysis was obtained by Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). The results obtained indicate that aliphatic hydrogen and carbon atoms are found in higher abundance, compared with aromatic hydrogen-carbon frameworks. Furthermore, a decrease in oxygen functional groups was observed after esterification. According to the FTICR MS results, the samples contain highly oxygenated species corresponding to compound classes Ox, NOx and BOx, with a high predominance of Ox species. After esterification, the compositions shifted towards lower oxygen-content, lower number of rings and double bonds, and longer alkyl chains as a consequence of the water removal via the condensation reaction.
The catalytic and thermal cracking of three types of whole crude oils, having API gravity at 34° (AL), 39° (AXL) and 51° (ASL), were investigated via a fixed-bed micro-activity test (MAT) unit at high temperature between 600 and 650 °C. Equilibrium FCC catalyst (E-Cat)/ZSM-5 additive was used for catalytic cracking tests at 30 s and catalyst/oil (C/O) ratio of 2.0–6.0. For both thermal and catalytic cracking of all crude oils, the increase in reaction temperature resulted in higher conversion and enhanced yields of C2-C4 light olefins, LPG, coke, and dry gas at the expense of naphtha, heavy cycle oil (HCO), and light cycle oil (LCO). In thermal cracking, the yields of C2-C4 olefins at 650 °C were as follows: AL (22.8 wt.%) > AXL (19.0 wt.%) > ASL (18.8 wt.%) associated with naphtha yields of 34.4, 38.1 and 48.0 wt.%, respectively. Compared with thermal, catalytic cracking over E-Cat/ZSM-5 enhanced conversion, doubled the yields of light olefins and showed an increase in aromatics content of naphtha fraction. Contrary to thermal cracking, the yields of C2-C4 olefins in catalytic cracking were as follows: ASL (42.9 wt.%) > AXL (41 wt.%) > AL (39.1 wt.%) associated with naphtha yields of 31.7, 27.5, and 23.0 wt.%, respectively.
Hierarchical micro-mesoporous ZSM-5 zeolites synthesized via an embedded nanocarbon cluster approach were studied for isomerization of n-butene, catalytic cracking of n-hexane, catalytic cracking and hydrocracking of n-hexadecane. The introduction of mesoporosity into ZSM-5 zeolite framework was achieved by using carbon/SiO2 composite obtained from a carbonaceous gas deposition on silica gel as a mesoporogen. The synthesized hierarchical ZSM-5 zeolites with different Si/Al ratios were characterized by means of XRD, ICP-OES, N2 adsorption-desorption isotherm measurement, TEM, ²⁷Al MAS NMR, NH3-TPD, FTIR of pyridine adsorption and constraint index (CI) test. Compared with the conventional H-ZSM-5, the hierarchical H-ZSM-5 exhibits an enhancement in the catalytic activity in terms of higher reactant conversion and product yield for isomerization of n-butene and catalytic cracking of n-hexadecane, as the mesopores provide larger pores as well as improved accessible active sites. Moreover, Pt loaded on hierarchical H-ZSM-5 exhibit a remarkably enhanced catalytic activity in hydrocracking of n-hexadecane compared to Pt loaded on conventional H-ZSM-5 due to a smaller and higher dispersion of Pt nanoparticles. For n-hexane cracking, the presence of mesopores does not improve n-hexane conversion on the fresh catalyst because this reaction proceeds via monomolecular pathway and the corresponding reaction species are smaller than 10-ring pore windows of ZSM-5 zeolite. However, the hierarchical structure improves the catalytic stability in n-hexane cracking due to the presence of mesopores, which can shorten the diffusion path length, suppressing the consecutive reactions and, thus reducing the coke formation.
23 gas oil samples from different origins were analyzed in positive and negative ion modes by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI(+/-)-FT-ICR MS). Sample ionization and ion transfer conditions were first optimized using Design of Experiment approach. Advanced characterization of basic and neutral nitrogen compounds in these samples was then performed through ESI(+/-)-FT-ICR MS analysis. A good repeatability was observed from the analysis of six replicates for each gas oil sample. Significant differences in molecular composition were spotted between the gas oils, either considering identified heteroatomic classes or within nitrogen families and were later correlated to samples macroscopic properties. The evolution of nitrogen relative intensities for one feed and two corresponding effluents has also been studied to monitor hydrotreatment reaction pathways towards aromaticity and alkylation levels evolutions.
This study delves into the performance of a Pt-Pd and a Ni-W catalyst supported on a phosphorus-containing activated carbon (ACP) in the hydrodeoxygenation (HDO) of raw bio-oil, as well as the enhancement of phenolic and aromatic product yields produced by incorporating physically mixed HZSM-5 zeolites (20 wt%) of different Si/Al ratio (15 and 140 in zeolites Z15 and Z140, respectively) in the catalytic bed. The HDO runs have been conducted in a fixed bed reactor at: 450 °C; 65 bar; space time, 0.15 gcat h g⁻¹bio-oil; 90 ml min⁻¹ H2; and time on stream up to 6 h. After a fast initial deactivation due to coke deposition the catalysts reached a pseudosteady state at which the carbon product yields are higher than in fresh catalyst conditions. The NiW catalyst provided yields of 42.3 wt% liquid carbon products (in a dry bio-oil basis), yielding 5.3 wt% phenolic and 12.3 wt% aromatic product yields. The NiW + Z140 combination was the most efficient catalyst (with a 47.3 wt% carbon production, including 6.8 wt% phenolics and 15.5 wt% aromatics) as a consequence of this low-acidity zeolite promoting the synergy with the dehydrogenation activity of metallic sites by favoring the acid-catalyzed cracking reactions of the bio-oil oxygenates, while simultaneously limiting gas product and coke formation. Two types of coke were detected, of thermal origin and catalytic coke, with the formation of the latter being dependent on the acidity of the zeolite.
Predicting the hydrotreating performance of industrial catalysts used for upgrading heavy oils is hampered by the unknown chemistry behind it. In this work, we have used a set of chromatographic and mass spectrometric techniques (APPI/ESI FT-ICR MS, FID-MS GC × GC and PFPD GC) for acquiring a more precise composition of the feed and products of the hydrotreatment of a blend of light cycle oil and scrap tire oil (20 vol%) using three benchmark catalysts: CoMo/Al2O3, NiMo/SiO2-Al2O3 and NiW/USY zeolite. Despite the different nature of the catalysts, the composition of the products was relatively similar, indicating the slower and controlled transformation of the heaviest molecules of the feed, particularly in tire oil. A faithful analysis of these molecules by combining the results of the analysis clarifies the multiple mechanisms affecting hydrotreating simultaneously: hydrodearomatization, hydrocracking, hydrodesulfurization, hydrodeoxygenation and hydrodenitrification. An effort has been made to use these results in a quantitative manner for catalyst screening.
The performance of different zeolite-based catalysts (HY, HZSM-5 and HBeta) on the catalytic cracking of bio-oil has been explored, using a simulated riser reactor and resembling industrial FCC conditions. The effect of the C/O (catalyst/bio-oil) ratio and the zeolite types have been assessed. The level of deoxygenation is >61% (increasing with C/O ratio). Total hydrocarbon yield was higher for the HBeta catalyst (56 wt%), while the liquid hydrocarbons yields were relatively similar for all catalysts, obtaining higher gasoline yields with the HY catalyst (46–55 wt%), and higher LPG yields with the HZSM-5 catalyst (12–14 wt%) due to its higher acidity. The HY zeolite produced more coke (4–7 wt%) given its capacity for retaining coke precursors within its micropores.
Different commercial equilibrium FCC (Fluidized Catalytic Cracking) catalysts have been tested in the upgrading of scrap tires pyrolysis oil (STPO) with the aim of obtaining automotive like fuels. The runs have been performed in a CREC riser simulator reactor under FCC conditions: 470–560 °C; catalyst to oil mass ratio (C/O), 5 gcat gSTPO 1; contact time, 6 s. The performance of the different catalysts, i.e., the extent of cracking reactions and product distribution, has been quantified by means of chromatographic techniques. Quantified product fractions have been the following: dry gas (C1–C2), liquefied petroleum gas (LPG, C3–C4), naphtha (C5–C12), light cycle oil (LCO, C13–C20), and heavy cycle oil (HCO, C20+). Obtained results expose the capacity of the FCC unit for the valorization of STPO, remarking the relevance of the properties of the catalyst, i.e., porous structure and acidity, in reached conversion and product yields.
Effective remediation of bilge water, a shipboard oily liquid waste, is important for both commercial and military vessels due to the domestic and international regulations. In this study, bilge water was used as a substrate for exoelectrogenic bacteria and biodegradation of bilge water and concurrent electricity generation were investigated using Pseudomonas putida ATCC 49128 in single chamber microbial fuel cells (MFCs). To enhance bioavailability of the bilge water, two types of surfactants were added (100 ppm) into the oily wastewater containing 0.1% standard bilge mix (SBM) and their impacts on electricity production were evaluated under various conditions. Anionic surfactant (sodium dodecyl sulfate, SDS) addition increased soluble chemical oxygen demand (SCOD) by forming micelle, producing maximum power density of 225.3 ± 3.2 mW m⁻². However, the MFC with nonionic surfactant (Triton X-100) produced only 2.3 ± 0.1 mW m⁻² due to no enhancement on biodegradable SCOD. A high NaCl concentration (100–500 mM) adversely affected power production due to decrease in available SCOD caused by emulsion coalescence. This is a first study to use surfactants to enhance bioavailability of non-biodegradable oily wastewater in a single chamber MFC.
The porosity and acidity of three commercial FAU Y zeolites (including the original HY-2.6 and dealuminated HY-15/-30 zeolites) were studied comprehensively using nitrogen (N2) physisorption, and mercury (Hg) porosimetry, ammonia temperature-programmed desorption (NH3-TPD) and pyridine Fourier transform infrared (pyridine-IR) analyses. The combined N2 physisorption and Hg porosimetry is a useful tool to evaluate the hierarchical mesoporosity in the dealuminated samples, revealing that HY-15 and HY-30 possess >50% open mesoporosity in the mesopores range of 5–10 nm. The acidity of the dealuminated Y zeolites has been reduced significantly in comparison to that of the original HY-2.6, e.g. Brønsted acidity decreased by ca. 69 folds by dealuminating HY-2.6 to HY-30. Catalytic results of Fischer esterification of methanol with carboxylic acids and aldol condensation of benzaldehyde with 1-heptanal have evidenced that the critical role of mesoporosity of the dealuminated Y zeolites in liquid-phase reactions. For example, in the esterification of lauric acid with methanol, HY-15 and HY-30 with hierarchical mesopores showed better catalytic activity (i.e. conversion of lauric acid: 7.9% and 24.5%, respectively) than HY-2.6 (4.0%). The analysis of the catalytic results along with the acidic property suggests that the acidity is less influential than the porosity of zeolite catalysts. Results from this study allow us to explain the origin of the high activity of zeolites with mesoporosity in the liquid-phase catalysis.
A bacterial strain capable of producing polyhydroxybutyrate (PHB) utilizing hydrocarbon wastes was isolated from oily bilge waste contaminated sea water. The isolate was identified as Ochrobactrum intermedium based on biochemical, 16S rRNA partial gene sequencing. Tolerance and growth of the isolate with different hydrocarbons were analysed. Hydrocarbon degrading ability of O.intermedium was determined by emulsification index and cell surface hydrophobicity analysis. The isolate utilized aliphatic hydrocarbons efficiently than aromatic hydrocarbons. PHB accumulation by the isolate was confirmed by Sudan black and Nile red staining. FTIR, ¹H and ¹³C NMR scans confirm the polymer to be of poly3-hydroxybutyrate. Optimization of Bushnell Hass (BH) medium constituents was carried out by 2 level factorial design and response surface methodology (RSM). Interactive influence of variables having high t-values was analysed by 23 central composite design for the enhancement of PHB production. Optimization of BH medium composition resulted in 37.00% increase in PHB accumulation.
The analyses of thermochemically-derived bio-oil properties and composition are challenging due to the diversity of compounds present and the reactivity of the oils. There are currently a variety of techniques used and no standard method established for the analysis of the molecular weight distribution, weight average molecular weight (Mw) and other molecular weight metrics of bio-oils. This review focuses on the challenges and variation in methodologies employed for the analysis of bio-oils on the basis of molecular weight, particularly by gel permeation chromatography (GPC). GPC is the most practical means for determination of molecular weight metrics of bio-oils but needs to be refined using appropriate standards and/or detectors to ensure consistency and accurate quantification of molecular weight metrics. Future method development for a robust technique with accurate and comparable molecular weight data should focus on GPC with multiple detection methodology on whole bio-oils, verified relative to another technique such as mass spectrometry (MS). MS techniques, such as Fourier transform-ion cyclotron resonance (FT-ICR MS), have also been utilized for the determination of molecular weight distribution of bio-oils and are briefly addressed in this review. Many MS methods can provide extensive characterization and structural speciation of components in bio-oils, and while accurate molecular weight metrics can be obtained with the appropriate use of ionization techniques and optimized parameters to ensure appropriate range of m/z and signals representative of abundance, MS is not a robust or an economically practical method for routine molecular weight analyses. Physical separation techniques such as preparative scale GPC, distillation, and liquid-liquid extraction methods are also briefly addressed in this review in the context of molecular weight analyses.
A new nine-lumped kinetic model is proposed to describe the VGO catalytic cracking
using equilibrium fluid catalytic cracking catalyst (E-CAT) modified with ZSM-5 and
MCM-41 additives. The kinetic model contained 18 kinetic parameters and 2
parameters for the catalyst deactivation. The catalyst deactivation model was
described by an exponential function of time on stream and temperature. Kinetic
parameters were estimated based on experimental data at 500, 530, 550, 580, 600, and
620°C by fourth order Runge–Kutta algorithm and genetic algorithm method.
Frequency factors and apparent activation energies were calculated according to
Arrhenius equation. The apparent activation energies were mainly in the range of 20–
*Manuscript
Click here to download Manuscript: final manuscript1.docx Click here to view linked References
75 kJ mol-1. The apparent activation energies for VGO to LCO +slurry oil, gasoline
and alkanes were much lower than the other cracking paths. The optimum operation
temperature which led to the maximum gasoline yield and maximum propylene yield
were 550oC and 600oC respectively. The deactivation constant which was described
by Arrhenius model, resulted in frequency factor of 23695 and activation energy of
65.198 kJ/mol.
Modeling fluid catalytic cracking (FCC) riser reactors is of significant importance in FCC unit control, optimization and failure detection, as well as development and design of new riser reactors. In this study, kinetic behavior of vacuum gas oil (VGO) catalytic cracking is studied by developing an 8-lump kinetic model to describe the product distribution. The feedstock and products are divided into eight lumps by reasonably simplifying reaction network, including VGO feed, diesel oil and gasoline, LPG, butylenes, propylene, ethylene, light gases, and coke. A time-on-stream non-selective catalytic activity equation is also assumed to model deactivation mechanism. Twenty-seven pairs of model kinetic parameters are estimated using two different optimization methods, namely: non-dominated sorting genetic algorithm II (NSGA-II), and chaotic particle swarm optimization (C-PSO) algorithm. Performances of both optimization methods are compared and C-PSO algorithm is selected as the superior method in terms of computation time and finding the global optimum. In the current research, based on validated estimated parameters of the preferred C-PSO method, the effects of some operating parameters on product yields distribution are investigated and discussed. This model can be used to predict the riser key products and their compositions with high degree of accuracy which may be especially useful for the conventional FCC processes with olefins production streams.
The impact of the composition of the various hydrocarbon fractions in a conventional VGO (saturated SF, aromatic AF and resin RF) and the whole VGO on the coke formed in their catalytic cracking was evaluated over two Y zeolites with different degree of mesoporosity. The parent zeolite was in its protonic form, Si/Al relationship of 30 and the modified sample was desilicated by alkaline treatment. The fractions were separated from the VGO by means of ASTM D2007-11 method. The catalytic conversion experiments were performed in a batch, fluidized bed laboratory Riser Simulator reactor at 500 °C in the 0.7–3.0 s reaction time range, with a zeolite mass of 0.2 g and a zeolite/reactant mass of 1. Independent of zeolite, fraction SF was the easiest to crack. In the case of the AF fraction, the modified zeolite, with the highest intracrystalline mesoporosity, was more active than the parent zeolite. Gasoline was always the main product, with selectivities from 60 to 70%. All the feedstocks produced more coke on the modified zeolite; however, in spite of the higher coke yields, this zeolite suffered a lower loss of total acidity. As expected, a negative change in both acidity and textural properties (specific surface area and pore volume) were observed as a consequence of the formation of coke. The reactivity of VGO over both zeolites differed from that of fraction SF, even though it was the major fraction (68%). This behavior could be the consequence of interactions between the various fractions composing VGO.
We describe complex organic mixture analysis by 21 tesla (T) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ultrahigh mass-resolving power (m/Δm50% > 2 700 000 at m/z 400) and mass accuracy (80 ppb rms) enable resolution and confident identification of tens of thousands of unique elemental compositions. We demonstrate 2.2-fold higher mass-resolving power, 2.6-fold better mass measurement accuracy, and 1.3-fold more assigned molecular formulas compared to our custom-built, state-of-the-art 9.4 T FT-ICR mass spectrometer for petroleum and dissolved organic matter (DOM) analyses. Analysis of a heavy petroleum distillate exemplifies the need for ultrahigh-performance mass spectrometry (49 040 assigned molecular formulas for 21 T versus 29 012 for 9.4 T) and extends the identification of previously unresolved Oo, SsOo, and NOo classes. Mass selective ion accumulation (20 Thompson isolation) of an asphalt volcano sample yields 462 resolved mass spectral peaks at m/z 677 and reveals previously unresolved CcHhNnOoSs mass differences at high mass (m/z > 600). Similar performance gains are realized in the analysis of dissolved organic matter, where doubly charged Oo species are resolved from singly charged SOo species, which requires a mass-resolving power greater than 1 400 000 (at m/z 600). This direct comparison reveals the continued need for higher mass-resolving power and better mass accuracy for comprehensive molecular characterization of the most complex organic mixtures.