Production Of Liquid Hydrocarbons Research Articles

Pyrolytic Decarboxylation and Cracking of Stearic Acid

The primary objective of this work was to study the pyrolytic conversion of fatty acids to produce deoxygenated, liquid hydrocarbon products for use as renewable chemicals or fuels. Stearic acid (n-octadecanoic acid) was chosen as a model compound for the free fatty acids liberated through the hydrolysis of beef tallow. Batch pyrolysis of stearic acid was conducted over a range of temperatures and times, and the reaction products were extracted and identified through gas chromatography and mass spectrometry. Under mild conditions, n-heptadecane was the main product, with concurrent production of CO2, showing that decarboxylation was likely the first reaction to occur. Distinct series of n-alkanes and 1-alkenes developed and shifted to lower carbon numbers with increased temperature and time, consistent with hydrocarbon cracking reactions. Eventually, the series decomposed to aromatics, insoluble solids, and unidentified low-molecular-weight species. Semiquantitative analysis of the chromatographic data co...

Effect of operating conditions and potassium content on Fischer-Tropsch liquid products produced by potassium-promoted iron catalysts

The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium molar content. The study followed an experimental planning and the results were analyzed based on surface response methodology. The effects of different operating conditions and potassium contents on the liquid product distribution were compared based on number average carbon number and dispersion. Results showed that high pressures (25 to 30 atm) favored the production of waxes that could be converted into liquid fuels through hydrocracking, while greater direct selectivity towards diesel was favored by low pressure (20 atm) using catalysts with low potassium to iron molar ratios. The liquid product distribution produced using an iron catalyst with high potassium content presented higher number-average number of carbons when compared to the distribution obtained using an iron catalyst with low potassium content.

Thermocatalytic Conversion of Landfill Gas and Biogas to Alternative Transportation Fuels

Landfill gas (LFG) and biogas are important renewable resources for production of alternative transportation fuels. The resources of LFG and biogas are vast and widely available but remain mostly unused. In this paper, the authors assess the technical feasibility of direct catalytic reforming (i.e., without preliminary methane recovery from these gases) of LFG and biogas to synthesis gas that could further be processed to synthetic liquid hydrocarbon fuels via Fischer–Tropsch (FT) synthesis. The catalytic activity and selectivity of a number of noble metal (Ru, Ir, Pt, Rh, Pd) and Ni-based catalysts for reforming of a model CH4−CO2 mixture mimicking a typical LFG into a synthesis gas were evaluated. The issues related to the catalysts stability and process sustainability under the conditions that are favorable for carbon deposition were explored. The experimental data are in a good agreement with AspenPlus simulation results. It was shown that the syngas produced by Ni-catalyzed steam-assisted reforming of a model LFG is suitable for production of liquid hydrocarbons via FT synthesis.

Imperial oil: the anatomy of a Nigerian oil insurgency

Alternative non-Persian Gulf sources of oil-supply are central to American geostrategic interests in the period since 2001. Vice President Cheney’s National Energy Strategy Report in 2001 bemoaned a dependency on foreign powers that “do not have America’s interests at heart”. Africa has emerged as one of the major new sources of US oil and gas supply. If Africa is not as well endowed in hydrocarbons (both oil and gas) as the Persian Gulf states, the West African Gulf of Guinea has nonetheless become the subject of fierce competition by energy companies over the continent’s copious reserves of natural gas and its sweet light oil. IHS Energy – one of the oil industry’s major consulting companies – expects African oil production, especially along the Atlantic littoral, to attract huge exploration investment contributing over 30% of world liquid hydrocarbon production by 2010. Over the last five years when new oil-field discoveries were a scarce commodity, Africa contributed one in every four barrels of new petroleum discovered outside of Northern America. This article addresses the new scramble for Africa in the context of a new conjuncture of global forces: military neoliberalism and the Global War on Terror (GWOT). I lay out the broad landscape of oil production on the continent and the extent to which, in the wake of a catastrophic two decades of neoliberal structural adjustment, investment in oil and gas dominates direct foreign investment in Africa. I then turn to the specific case of Nigeria – the most important producer of oil and gas on the continent and the petro-state of most geostrategic concern to the US – and use it as an exemplar of the failure of oil-based development. Central to this analysis is the emergence of new forms of armed insurgency in the oil producing Niger Delta that has rendered the entire area virtually ungovernable, increasingly so since the emergence in late 2005 of a new armed group MEND (the Movement for the Emancipation of the Nigeria Delta). I conclude with an account of the dynamics of this ungovernability – a pattern replicated throughout the Gulf of Guinea – and how this instability feeds into an American imperial vision to militarize the region.

Pyrolysis of High-density Polyethylene for the Production of Fuel-like Liquid Hydrocarbon

Pyrolysis of high density polyethylene (HDPE) was carried out in a 750 cm3 stainless steel autoclave reactor, with temperature ranging from 470 to 495° C and reaction times up to 90 minute. The influence of the operating conditions on the component yields was studied. It was found that the optimum cracking condition for HDPE that maximized the oil yield to 70 wt. % was 480°C and 20 minutes. The results show that for higher cracking temperature, and longer reaction times there was higher production of gas and coke. Furthermore, higher temperature increases the aromatics and produce lighter oil with lower viscosity.

Effect of interaction between potassium and structural promoters on Fischer–Tropsch performance in iron-based catalysts

The Fischer–Tropsch synthesis (FTS) performances of iron-based catalysts promoted with/without potassium compounds containing different acidic structural promoters (Al 2O 3, SiO 2, and ZSM-5) were studied in this research. Characterization technologies of temperature-programmed reduction with CO (CO-TPR), powder X-ray diffraction (XRD) and Mössbauer effect spectroscopy (MES) were used to study the effect of K–structural promoter interactions on the carburization behaviors of catalysts. It showed that the addition states of potassium (K–Al 2O 3, K–SiO 2, K–ZSM-5 and K-free) have a significant influence on the formation of iron carbides, which shows a following sequence in promotion of carburization: K–Al 2O 3 > K–SiO 2 > K–ZSM-5 > K-free. The FTS reaction test was performed in a fixed bed reactor. It is found that Fe/K–Al 2O 3 catalyst leads to the highest CO conversion, Fe/K–ZSM-5 catalyst shows the highest H 2 conversion, and Fe/K-free catalyst shows the lowest CO and H 2 conversion. As for the hydrocarbon selectivity, Fe/K–SiO 2 catalyst yields the lowest methane and the highest C 5 + products, Fe/K–ZSM-5 catalyst yields higher methane and the highest liquid hydrocarbon product, whereas Fe/K-free catalyst yields the highest methane and the lowest C 5 + products. These results can be explained from the interaction between potassium and structure promoters, and the spillover of reactants or intermediates from Fe sites to the surfaces of structural promoters.

Fischer-Tropsch synthesis using bio-syngas and CO 2

While Fischer-Tropsch synthesis (FTS) using coal and natural gas in conventional reactors is an almost well-established technology, the production of liquid hydrocarbons from syngas obtained from biomass is in its preliminary stages of commercialization in countries like Germany. With concerns about global warming and ways of disposing of CO 2 being searched for, CO 2 hydrogenation using FTS to liquid hydrocarbons can act as a CO 2 sink. A brief review of FTS using CO 2 -rich syngas is given in this paper, looking at FTS as a technology that can help reduce global warming and as a process integration alternative. The reverse water gas shift (r-WGS) reaction is vital for CO 2 hydrogenation. We have studied the effect of this using an FT kinetic model and have proposed a new flow sheet alternative for FTS using CO 2 -rich syngas. Simulations suggested that this new process gives better conversion of CO 2 . The product selectivity and yields from an FT plant are vital to make the process viable economically.

Transformation of ethanol into hydrocarbons on ZSM-5 zeolites modified with iron in different ways

ZSM-5 zeolites modified by iron incorporation through post-synthesis ion exchange and those synthesized with iron addition to the synthesis medium were compared in the reaction of liquid hydrocarbons production from ethanol. AA, TPR, FTIR, XRD, SEM, nitrogen adsorption and photoacoustic spectroscopy were used for the samples characterization. Acid leaching and ammonium exchange were tested for obtaining the acid form of the zeolite, with similar results, the major difference being a faster deactivation in the latter case. The best yield of liquid hydrocarbons was obtained with the samples with low iron content. The product distribution in both gaseous and liquid phases was independent of the way the zeolite was obtained or the iron was introduced, with major variations only with time (due to deactivation).

Chemical catalysed recycling of waste polymers: Catalytic conversion of polypropylene into fuels and chemicals over spent FCC catalyst in a fluidised-bed reactor

Polypropylene (PP) was pyrolysed over spent FCC commercial catalyst (FCC-s1) using a laboratory fluidised-bed reactor operating isothermally at ambient pressure. The influence of reaction conditions including catalyst, temperature, and ratio of polymer to catalyst feed and flow rates of fluidising gas was examined. The yield of gaseous and liquid hydrocarbon products at 390 °C for spent FCC commercial catalyst (87.8 wt%) gave much higher yield than silicate (only 17.1 wt%). Greater product selectivity was observed with FCC-s1 as a post-use catalyst with about 61 wt% olefins products in the C 3–C 7 range. The selectivity could be further influenced by changes in reaction conditions. Valuable hydrocarbons of olefins and iso-olefins were produced by low temperatures and short contact times used in this study. It is also demonstrated that a post-use catalyst system under appropriate conditions the resource potential of polymer waste can be economically recovered and also can address the recycling desire to see an alternative to solve a major environment problem.

Green chemistry perspectives of methane conversion via oxidative methylation of aromatics over zeolite catalysts

Methane gas is known to be the most destructive greenhouse gas. The current world reserves of natural gas, which contains mainly methane, are also still underutilized due to high transportation costs. Thus, considerable interest is presently shown in conversion of methane to transportable liquid fuels and chemicals of importance to the petrochemical industry. The catalytic methylation of aromatics is one possible new route for converting methane to more valuable higher hydrocarbons. This paper provides a general overview of the recent work that we and other researchers have done on the utilisation of methane for catalytic methylation of aromatic compounds and for direct coal liquefaction for the production of liquid hydrocarbons. In particular, the paper presents a detailed description of more recent substantial experimental evidence that we have provided for the requirement of oxygen as a stoichiometry reactant for benzene methylation with methane over moderately acidic zeolite catalysts. The reaction, which has been termed “oxidative methylation”, was thus postulated to involve a two-step mechanism involving intermediate methanol formation by methane partial oxidation, followed by benzene methylation with methanol in the second step. However, strongly acidic zeolites can cause cracking of benzene to yield methylated products in the absence of oxygen. The participation of methane and oxygen, and the effective use of zeolite catalysts in this methylation reaction definitely have some positive green chemistry implications. Thus, the results of these previous studies are also discussed in this review in light of the principles and tools of green chemistry. Various metrics were used to evaluate the greenness, cost-effectiveness, and material and energy efficiency of the oxidative methylation reaction.

Hydrocarbons from ethanol using [Fe,Al]ZSM-5 zeolites obtained by direct synthesis

The search for new energy sources has impulsed hydrocarbon production from methanol and ethanol over ZSM-5 zeolites. Iron incorporation by different methods has led to a variety of chemical applications. Thus, hydrocarbon production from ethanol was evaluated using a [Fe,Al]ZSM-5 zeolite which was synthesized without nitrogenated templates, using ethanol and crystallization seeds and partially substituting iron for aluminium in the reaction mixture. Characterization was done by X-ray diffraction (XRD), Fourier-transform infra-red spectroscopy (FTIR), temperature programmed reduction (TPR), temperature programmed desorption of ammonia (TPD), nitrogen adsorption, electron paramagnetic resonance (EPR) and photoacoustic spectroscopies. Iron content in the synthesized samples varied from 0.02 to 1.82%. The obtained samples were used for the ethanol transformation, producing hydrocarbons from ethene to aromatics. Maximum production of liquid hydrocarbons was achieved with the zeolite with 0.5% iron. The procedure for obtaining the acid form of the zeolites, involving ammonium exchange and calcinations, has changed the iron species, probably with extraction from the structure, migration and agglomeration.

Fischer‐Tropsch synthesis product grade optimization in a fluidized bed reactor

AbstractFischer‐Tropsch synthesis is an important chemical process for the production of liquid fuels and olefins. In recent years, the abundant availability of natural gas and the increasing demand of olefins, gasoline, diesel and waxes have led to a high interest in further developing this process. A mathematical model of a fluidized‐bed reactor used for syngas polymerization was developed and the carbon monoxide polymerization was studied from a modeling point of view. Simulation results show that several parameters affect syngas conversion and carbon product distribution, such as operating pressure, superficial gas velocity, bed porosity, and syngas composition. Optimization of liquid hydrocarbon products was done and the best operating conditions for their production were found for an iron catalyst that produces hydrocarbon chains according to a dual mechanism theory. © 2006 American Institute of Chemical Engineers AIChE J, 2006

Pyrolysis study of a PVDC and HIPS-Br containing mixed waste plastic stream: Effect of the poly(ethylene terephthalate)

Pyrolysis of poly(vinylidene chloride) (PVDC), brominated flame retardant containing high impact polystyrene (HIPS-Br), poly(ethylene) (PE), poly(propylene) (PP), poly(styrene) (PS) mixed were performed in the presence and absence of poly(ethylene terephthalate) (PET) under atmospheric pressure at 430 °C using a semi-batch operation. We attempted the dehalogenation (Cl, Br) of chlorinated and brominated liquid hydrocarbons using iron oxide and calcium hydroxide based carbon composites for the production of halogen free liquid hydrocarbons. The presence of PET in the plastics mixture of PP/PE/PS/PVDC/HIPS-Br affected significantly the formation of pyrolysis products and the pyrolysis behavior of plastic mixture. We observed the following effects of PET on the pyrolysis of PP/PE/PS/PVCD/HIPS-Br mixed plastic pyrolysis: (i) The yield of liquid product was decreased and the formation of gaseous products increased during the thermal decomposition, (ii) the waxy residue was observed in addition to the solid carbon residue and (iii) use of calcium hydroxide carbon composite (CaH–C) removed the major portion of chlorine and bromine content from the liquid products from PP/PE/PS/PVDC/HIPS-Br pyrolysis, however in the presence of PET, the combination of calcium hydroxide carbon composite (CaH–C) and iron oxide carbon composites could not dehalogenate the liquid products effectively. X-ray diffraction analysis reveals the presence of antimony compounds in carbon and wax residues.

Production of Liquid Hydrocarbons from Biomass

Research is being conducted worldwide to develop new technologies for the generation of liquid fuels from renewable resources. In this context, it was stated recently that “biomass is the only practical source of renewable liquid fuel”. This is of utmost importance for sustainable development. Currently, biodiesel is produced by transesterification of vegetable oils and ethanol by fermentation of glucose. Processes for the efficient gasification of biomass to produce CO and H2 (synthesis gas) are being developed. The synthesis gas can be further processed to produce methanol or liquid alkanes by Fischer– Tropsch synthesis using well-established industrial processes. In Agenda 21, Chapter 4.20, the United Nations call for “criteria and methodologies for the assessment of environmental impacts and resource requirements throughout the full lifecycle of products and processes”. A simple metric for biofuel production is the overall energy efficiency, that is, the heating value of the biofuel divided by the energy required to produce the biofuel from the respective biomass. Biodiesel production from rapeseed oil in Germany has an overall energy efficiency (not taking into account potential glycerol use) of about 1.9 and from soybean oil in the USA of about 3. The overall energy efficiency for the production of ethanol from corn in the USA equals about 1.1 without energy credits for coproducts. However, Pimentel pointed out quite recently: “In the U.S. ethanol system, considerably more energy, including high-grade fossil fuel, is required to produce ethanol than is available in the energy ethanol output. Specifically about 29% more energy is used to produce a gallon of ethanol than the energy in a gallon of ethanol.” Approximately 67% of the energy required for ethanol production is consumed in the fermentation/distillation process, of which over half is used to distill ethanol from water. A process without the energy-consuming distillation step would be most important. Huber et al. have recently demonstrated that it is possible to produce light alkanes by aqueous-phase reforming (APR) of biomass-derived oxygenates such as sorbitol, which can be obtained from glucose by hydrogenation. 11] The production of alkanes from aqueous carbohydrate solutions would be advantageous because of the easy separation of the alkanes from water. Accordingly, it was estimated that the overall energy efficiency for alkane production from corn would be increased to approximately 2.2, assuming that this process eliminates the energy-intensive distillation step but still requires all of the remaining energy input needed for the production of ethanol from corn. Much hydrogen is needed to reduce biomass-derived oxygenates to alkanes as shown in Equation (1). The main

Geochemical evaluation of the hydrocarbon prospects of sedimentary basins in Northern Nigeria

Sedimentary basins of Northern Nigeria comprise the Middle and Upper Benue Trough, the southeastern sector of the Chad Basin, the Mid-Niger (Bida) Basin, and the Sokoto Basin. Organic geochemical and organic petrologic studies indicate the existence of potential source rocks in the Benue Trough and the Chad Basin, with coal beds constituting major potential source rocks in the whole of the Benue Trough. The generation and production of liquid and gaseous hydrocarbons from coal beds presently is world-wide indisputable. Although TOC values and liptinite contents are relatively high in the Mid-Niger (Bida) Basin, Tmax values and biomarker data show that hydrocarbons are probably just being generated in the basin and may not yet have been expelled nor migrated in large quantities.

Catalytic Activity of Copper Oxide Impregnated HZSM‐5 in Methanol Conversion to Liquid Hydrocarbons

AbstractA number of CuO/HZSM‐5 catalysts have been studied in a small scale fixed bed reactor for the conversion of methanol to gasoline range hydrocarbons at 673 K and at one atmospheric pressure. All the catalysts were prepared by wet impregnation technique. The copper oxide loading over HZSM‐5 (Si/Al=45) catalyst was studied in the range of 0 to 9 wt%. XRD, surface area analyzer, metal trace analyzer, SEM techniques and TGA were used to characterize the catalysts. Incorporation of CuO onto HZSM‐5 zeolite significantly increased conversion and liquid hydrocarbon product yields. The major liquid products of the reactions were ethyl benzene, toluene, xylene, isopropyl benzene, ethyl toluene, trimethyl benzene and tetramethyl benzene. The maximum methanol conversion and hydrocarbon product yield was obtained at a copper oxide loading of 7 wt%. Effect of run time on conversion and product distribution was also investigated to compare the performance of these catalysts and coke on the catalyst was determined. Effect of space‐time and temperature on methanol conversion and products yield with 7 wt% CuO/HZSM‐5 has also been investigated and analyzed qualitatively.

Production of gasoline range hydrocarbons from catalytic reaction of methane in the presence of ethylene over W/HZSM-5

The catalytic conversion of a methane and ethylene mixture to gasoline range hydrocarbons has been studied over W/HZSM-5 catalyst. The effect of process variables, such as temperature, percentage of volume of ethylene in the methane stream and catalyst loading on the distribution of hydrocarbons was studied. The reaction was conducted in a fixed-bed quartz-micro reactor in the temperature range of 300–500 °C using percentage of volume of ethylene in methane stream between 25 and 75% and catalyst loading of 0.2–0.4 g. The catalyst showed good catalytic performance yielding hydrocarbons consisting of gaseous products along with gasoline range liquid products. The mixed feed stream can be converted to higher hydrocarbons containing a high-liquid gasoline product selectivity (>42%). Non-aromatics C 5–C 10 hydrocarbons selectivity in the range of 12–53% was observed at the operating conditions studied. Design of experiment was employed to determine the optimum conditions for maximum liquid hydrocarbon products. The distribution of the gasoline range hydrocarbons (C 5–C 10 non-aromatics and aromatics hydrocarbons) was also determined for the optimum conditions.

04/01789 Selective removal of oxygen from syngas in production of liquid hydrocarbons: Wang, D. et al. U.S. Pat. Appl. Publ. US 2003 153,632 (Cl. 518–703; C07C27/06), 14 Aug 2003, US Appl. PV353,774

04/01789 Selective removal of oxygen from syngas in production of liquid hydrocarbons: Wang, D. et al. U.S. Pat. Appl. Publ. US 2003 153,632 (Cl. 518–703; C07C27/06), 14 Aug 2003, US Appl. PV353,774

Synthesis of composite material MCM-41/Beta and its catalytic performance in waste used palm oil cracking

Composite materials composed of MCM-41/Beta were synthesized using two methods: (1) seeding method, and (2) two-step crystallization process. Powder XRD showed the existence of well-structured microphase zeolite Beta and mesophase MCM-41 in the composite materials. The performance of the composite material as a catalyst was investigated in the cracking of waste used palm oil for the production of liquid hydrocarbons and its activity was compared with the catalytic activity of a physical mixture of zeolite Beta and MCM-41. The composite material synthesized via seeding method gave a better performance in terms of conversion and yield of liquid fuel gasoline fraction compared to composite material obtained from two-step crystallization process and physical mixing. The composite material was found to be more selective for liquid fuel gasoline fraction enriched with more olefins compared to zeolite Beta or MCM-41 catalyst alone.

Hydrocarbon prospectivity of Nigeria's inland basins: From the viewpoint of organic geochemistry and organic petrology

Hydrocarbon prospectivity of Nigeria's inland basins: From the viewpoint of organic geochemistry and organic petrology