Potential For Production Of Fuels Research Articles

The Role of Zeolite (Microporous Crystalline Aluminosilicates) In Catalytic Pyrolysis of Waste High- and Low-Density Polyethylene Bags for Production of Fuel and Chemicals: A Review

This review provides a state-of-the-art summary of the role which zeolite plays as a catalyst via pyrolysis as a way of recovering fuels and chemicals from waste high and or low density polyethylene bags. It also highlighted the two types of zeolite (natural or synthetic) which are used as a two-stage pyrolysis−catalysis in giving a free waxing product to pure fuel and chemicals which can be subjected to further analyzing and or upgrading. As yield of oil/wax decreased with the addition of a zeolite as catalyst from 44 and 51 wt.%, (depending on the waste high density polyethylene “HDPE” or low density polyethylene bags “LDPE” and other factors). However, the composition of the pyrolysis−catalysis oils significantly increased in aromatic hydrocarbon content accordingly. In addition, the composition of the oils shifted from high molecular weight hydrocarbons (C16+) to fuel range hydrocarbons (C5−C15), with a high content of single-ring aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylenes, and styrene. This process shows great potential for production of fuels or chemicals, and also addresses the urgent issue of waste HDPE and or LDPE disposal.

Life‐cycle analysis of sustainable aviation fuel production through catalytic hydrothermolysis

AbstractCatalytic hydrothermolysis (CH) is a sustainable aviation fuel (SAF) pathway that has been recently approved for use in aircraft fuel production. In alignment with broader sustainable aviation goals, SAF production through CH requires a quantitative assessment of carbon intensity (CI) impacts. In this study, a current‐day life‐cycle analysis (LCA) was performed on SAF produced via CH to determine the CI. Various oily feedstocks were considered, including vegetable oils (soybean, carinata, camelina and canola) and low‐burden oils and greases (corn oil, yellow grease and brown grease). Life‐cycle inventory data were collected on all processes within the CH LCA boundary: feedstock cultivation and/or collection, preprocessing, hydrothermal cleanup and CH, biocrude refining, fuel transportation and end use through combustion. Baseline results show that the CH‐produced SAF can be generated with CI reductions ranging from 48 to 82% compared with conventional jet fuel. Modest improvements to CI can be achieved through incremental changes to the brown grease CH process, such as relaxing the dewatering specification and implementing renewable natural gas and electricity, which could decrease the CI from 22.9 to 7.9 g CO2e/MJ. Total CH fuel production potential was also assessed on the basis of current or near‐future feedstock availability and CI. The total biofuel production potential of CH (SAF and renewable fuel co‐products) in the US sums to approximately 3487 million gallons per year, with 97% of these volumes having a CI below 50% of that for petroleum jet fuel. The study shows that from an LCA perspective, CH offers a viable SAF pathway that is comparable with existing SAF pathways like hydroprocessed esters and fatty acids.

Titania-Supported Ni2 P/Ni Catalysts for Selective Solar-Driven CO Hydrogenation.

Solar-driven Fischer-Tropsch synthesis (FTS) holds great potential for the sustainable production of fuels from syngas and solar energy. However, the selectivity toward multi-carbon products (C2+ ) is often hampered by the difficulty in the regulation of transition metals acting as both light absorption units and active sites. Herein, a partial phosphidation strategy to prepare titania supported Ni2 P/Ni catalysts for photothermal FTS is demonstrated. Under Xenon lamp or concentrated sunlight irradiation, the optimized catalyst shows a C2+ selectivity of 70% at a CO conversion of >20%.Conversely, nickel metal in the absence of Ni2 P delivers negligible C2+ products (≈1%) with methane being the major product (>90%). Structural characterization and density functional theory calculation reveal that the partial phosphidation allows exposed metallic Ni to be active for CO adsorption and activation, while the existence of Ni2 P/Ni interface is responsible to inhibit CO methanation and promote C-C coupling of adsorbed *CH intermediates. This work introduces a novel phosphidation strategy for nickel-based photothermal catalysts in efficiently harnessing solar energy, and regulating the reaction pathways for CO hydrogenation to deliver high value products.

Catalytic conversion of C1 molecules under mild conditions

C1 catalysis based on the transformation of methane, carbon monoxide, methanol and carbon dioxide offers great potential for the sustainable production of fuels and chemicals in response to the decrease of the energy consumption and plant maintenance. While the relatively inert nature of CH and CO bond (e.g., methane and carbon dioxide) and uncontrollable coupling of CC bond render the selective activation and controllable transformation of C1 molecules to high-value-added products challenging in C1 chemistry. Catalytic conversion of C1 energy molecules under mild conditions enables a better control of the selectivity of the desired products, however, which requires highly active catalysts to lower the reaction energy barriers. Besides designing efficient catalysts to promote C1 molecules conversion, employing electro-catalysis and photo-catalysis to circumvent the thermodynamic limitations is regarded as promising ways for C1 catalysis at low temperatures. Benefiting from the advanced technology for catalyst synthesis, reactor design, mechanism understanding, catalytic conversion of C1 molecules under mild conditions has made significant progress from 2010 to 2020. In this review, we summarized the typical catalytic processes and representative catalysts for transforming methane, carbon monoxide, methanol and carbon dioxide into high value-added chemicals with a reaction temperatures below 200 °C driven by thermo-catalysis, electro-catalysis, and photo-catalysis. Besides, a short perspective is offered to highlight possible future research directions towards C1 molecules conversion under mild conditions. It is expected to provide a useful reference for the readers to design better catalysts and reaction process for mild conversion of C1 molecules efficiently in future.

Feedstock-Dependent Phosphate Recovery in a Pilot-Scale Hydrothermal Liquefaction Bio-Crude Production

Microalgae (Spirulina) and primary sewage sludge are considerable feedstocks for future fuel-producing biorefinery. These feedstocks have either a high fuel production potential (algae) or a particularly high appearance as waste (sludge). Both feedstocks bring high loads of nutrients (P, N) that must be addressed in sound biorefinery concepts that primarily target specific hydrocarbons, such as liquid fuels. Hydrothermal liquefaction (HTL), which produces bio-crude oil that is ready for catalytic upgrading (e.g., for jet fuel), is a useful starting point for such an approach. As technology advances from small-scale batches to pilot-scale continuous operations, the aspect of nutrient recovery must be reconsidered. This research presents a full analysis of relevant nutrient flows between the product phases of HTL for the two aforementioned feedstocks on the basis of pilot-scale data. From a partial experimentally derived mass balance, initial strategies for recovering the most relevant nutrients (P, N) were developed and proofed in laboratory-scale. The experimental and theoretical data from the pilot and laboratory scales are combined to present the proof of concept and provide the first mass balances of an HTL-based biorefinery modular operation for producing fertilizer (struvite) as a value-added product.

Thermodynamic analysis of novel vanadium redox materials for solar thermochemical ammonia synthesis from N2 and CH4

Owing to the wide applications of ammonia in hydrogen field and high energy consumption of the Haber-Bosch process, developing economic and environmentally benign ammonia synthesis process has attracted great interests. This work focuses on the moderately high two-step solar water-splitting of VN to produce ammonia, thus avoiding the reliance of fossil-fuel based heating source and pure hydrogen. Based on the equilibrium composition analysis, we find that V2O3, CH4 and N2 with mole ratio of 1:3:1.5 at TH = 1050 °C is enough for complete methane reforming and sufficient nitrogen fixation of V2O3. As for the water-splitting of VN, the production of NH3 is only possible at TL ≤ 400 °C, and inputting excessive water vapors is found to exert little effect on ammonia production at H2O:AlN>3:2. At the temperature range of full conversion between V2O3 and VN, the cycle efficiency, ηcycle, and solar-to-fuel efficiency, ηsolar-to-fuel, under different operating temperatures are compared, in which the highest ηcycle and ηsolar-to-fuel are 31.9% and 35.3% respectively. Moreover, efficiencies could be increased up to more than 37% with consideration of heat recuperation, demonstrating the great solar energy storage and fuel production potential of the proposed system.

Potential for biojet production from different biomass feedstocks and consolidated technological routes: a georeferencing and spatial analysis in Brazil

AbstractThis paper assesses the biojet fuel production potential in Brazil. It evaluates feedstock availability by applying a georeferencing analysis, and determines the cost‐effectiveness and greenhouse gas (GHG) emissions of selected production routes throughout their entire life cycle. This study identifies and locates Brazilian hotspots in terms of bioenergy availability and proximity to the main sites of fuel consumption and handling in the country. Findings show that the biomass availability for each crop in the hotspots would be sufficient to feed the biojet conversion plants proposed in this study. The biojet production potential in the hotspots would represent 48% of the country's jet fuel consumption in 2014, allowing the current certificated 50% blend with conventional fuel. The major biomass hotspots are close to airport and fuel logistic basis. However, even with a US$ 200.tCO–1 2 tax, hydroprocessed esters and fatty acids (HEFA) biojet is far from being competitive with petroleum‐based jet fuel, whereas the Fischer–Tropsch synthetic paraffinic kerosene (FT‐SPK) route may produce a competitive biojet. One possible pathway to incentivize biojet fuel production in Brazil would be, first, to implement carbon taxes that would allow the development of smaller plants. Then, with technological learning and larger production scales, it would be possible to reduce or even eliminate the carbon taxes. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Opportunities for phycoremediation approach in tannery effluent: A treatment perspective

Consumer demand for the leather products intensifies every year, especially in the fashion sector. With increasing pressure regarding chemicals, water usage, and landfill issues, the leather industries require ongoing research at production as well as effluent treatment level to ensure the stability of the industry. Industrialization made the outbreak of economic growth and energy demand with least consideration of environmental issues, especially in developing countries. Currently, microalgae have shown a significant promise in industrial effluent treatment. Further, the microalgal lipid accumulation potential has a substantial share in meeting the energy demand as renewable energy resource (e.g., Biofuel). Hence, microalgae assimilation of atmospheric CO2 and pollutants from the aqueous environment has overwhelming interest among researchers for combined treatment of industrial effluents and greenhouse gas mitigation from industrial emissions. This review focuses on identifying the potentials of integrating CO2 sequestration in tannery effluent treatment by microalgae. In addition, it summarizes the ability of microalgae for nutrient removal under flue gas environment and fuel production potential under stress condition. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13078, 2019

Investigation of long term reactive stability of ceria for use in solar thermochemical cycles

The use of an intermediate reactive material composed of cerium (IV) oxide (ceria) is explored for solar fuel production through a CO2-splitting thermochemical redox cycle. To this end, powder and porous ceria samples are tested with TGA (thermogravimetric analysis) to ascertain their maximum fuel production potential from the CeO2 → CeO2−δ cycle. A maximum value of the non-stoichiometric reduction factor δ of ceria powder was 0.0383 at 1450 °C. The reactive stability of a synthesized porous ceria sample is then observed with carbon dioxide splitting at 1100 °C and thermal reduction at 1450 °C. Approximately 86.4% of initial fuel production is retained after 2000 cycles, and the mean value of δ is found to be 0.0197. SEM (scanning electron microscopy) imaging suggests that the porous ceria structure is retained over 2000 cycles despite apparent loss of some surface area. EDS (energy dispersive x-ray spectroscopy) line scans show that oxidation of porous ceria becomes increasingly homogenous throughout the bulk material over an increasing number of cycles. Significant retention of reactivity and porous structure demonstrates the potential of porous ceria for use in a commercial thermochemical reactor.

Recent Advances in Hydrotreating of Pyrolysis Bio-Oil and Its Oxygen-Containing Model Compounds

Considerable worldwide interest exists in discovering renewable energy sources that can substitute for fossil fuels. Lignocellulosic biomass, the most abundant and inexpensive renewable feedstock on the planet, has a great potential for sustainable production of fuels, chemicals, and carbon-based materials. Fast pyrolysis integrated with hydrotreating, one of the simplest, most cost-effective, and most efficient processes to convert lignocellulosic biomass to liquid hydrocarbon fuels for transportation, has attracted significant attention in recent decades. However, effective hydrotreating of pyrolysis bio-oil presents a daunting challenge to the commercialization of biomass conversion via pyrolysis-hydrotreating. Specifically, the development of active, selective, and stable hydrotreating catalysts is problematic due to the poor quality of current pyrolysis bio-oil feedstock (i.e., high oxygen content, molecular complexity, coking propensity, and corrosiveness). Significant research has been conducted to address the practical issues and provide fundamental understanding of hydrotreating and hydrodeoxygenation (HDO) of bio-oils and their oxygen-containing model compounds, including phenolics, furans, and carboxylic acids. A wide range of catalysts have been studied, including conventional Mo-based sulfide catalysts and noble metal catalysts. Noble metal catalysts have been the primary focus of recent research because of their excellent catalytic performances and because they do not require the use of environmentally unfriendly sulfur. Recently, the reaction mechanisms of the HDO of model compounds on noble metal catalysts and their efficacy for hydrotreating or stabilization of bio-oil have been reported. This review provides a survey of relevant literature, published over the past decade, reporting advances in the understanding of the HDO chemistry of bio-oils and their model compounds, mainly on noble metal catalysts.

A Genetic System for Clostridium ljungdahlii: a Chassis for Autotrophic Production of Biocommodities and a Model Homoacetogen

Methods for genetic manipulation of Clostridium ljungdahlii are of interest because of the potential for production of fuels and other biocommodities from carbon dioxide via microbial electrosynthesis or more traditional modes of autotrophy with hydrogen or carbon monoxide as the electron donor. Furthermore, acetogenesis plays an important role in the global carbon cycle. Gene deletion strategies required for physiological studies of C. ljungdahlii have not previously been demonstrated. An electroporation procedure for introducing plasmids was optimized, and four different replicative origins for plasmid propagation in C. ljungdahlii were identified. Chromosomal gene deletion via double-crossover homologous recombination with a suicide vector was demonstrated initially with deletion of the gene for FliA, a putative sigma factor involved in flagellar biogenesis and motility in C. ljungdahlii. Deletion of fliA yielded a strain that lacked flagella and was not motile. To evaluate the potential utility of gene deletions for functional genomic studies and to redirect carbon and electron flow, the genes for the putative bifunctional aldehyde/alcohol dehydrogenases, adhE1 and adhE2, were deleted individually or together. Deletion of adhE1, but not adhE2, diminished ethanol production with a corresponding carbon recovery in acetate. The double deletion mutant had a phenotype similar to that of the adhE1-deficient strain. Expression of adhE1 in trans partially restored the capacity for ethanol production. These results demonstrate the feasibility of genetic investigations of acetogen physiology and the potential for genetic manipulation of C. ljungdahlii to optimize autotrophic biocommodity production.

Impact of water provision on herbaceous vegetation in Kruger National Park, South Africa

Herbaceous vegetation was sampled in transects starting at drinking troughs in four land systems in the Kruger National Park, South Africa. The step point method was used to measure the botanical composition and basal cover, and a disc pasture meter was used to measure standing crop. Botanical composition was converted to herbaceous forage and fine fuel production potential. All of these parameters were then used to test for and describe the impact of large herbivores on the herbaceous vegetation near drinking troughs. It was found that provision of water for large herbivores in troughs has a negative impact on herbaceous forage and fine fuel production potential, basal cover and standing crop. The logistic equation adequately describes this impact and the radii of impact extend to between 25 and 250m from water. Habitat and herbivore species diversity are likely to be adversely affected by the lack of areas farther than 10km from permanent water. Accelerated soil loss may occur within the sacrifice areas of watering points because of the lack of a protective herbaceous sward.

The case for the fusion hybrid

The use of nuclear fusion to produce fuel for nuclear fission power stations is discussed in the context of a crucial need for future energy options. The fusion hybrid is first considered as an element in the future of nuclear fission power to provide long term assurance of adequate fuel supplies for both breeder and convertor reactors. Generic differences in neutronic characteristics lead to a fuel production potential of fusion-fission hybrid systems which is significantly greater than that obtainable with fission systems alone. Furthermore, cost benefit studies show a variety of scenarios in which the hybrid offers sufficient potential to justify development costs ranging in the tens of billions of dollars. The hybrid is then considered as an element in the ultimate development of fusion electric power. The hybrid offers a near term application of fusion where experience with the requisite technologies can be derived as a vital step in mapping a credible route to eventual commercial feasibility of “pure” fusion systems. Finally, the criteria for assessment of future energy options are discussed with prime emphasis on the need for rational comparison of alternatives. This approach is contrasted with the dual standard too often used in judging the risks and benefits of nuclear power where, for example, rather minor radiological effects are highlighted while much larger exposures to radiation from medical x-rays, airplane travel, color television sets, etc., are ignored. It is concluded that the fusion hybrid deserves a prominent place among new energy resources but that early attention to insure an adequately informed public is a vital ingredient in assuring reasonable prospects of success.

The case for the fusion hybrid

The use of nuclear fusion to produce fuel for nuclear fission power stations is discussed in the context of a crucial need for future energy options. The fusion hybrid is first considered as an element in the future of nuclear fission power to provide long term assurance of adequate fuel supplies for both breeder and convertor reactors. Generic differences in neutronic characteristics lead to a fuel production potential of fusion-fission hybrid systems which is significantly greater than that obtainable with fission systems alone. Furthermore, cost benefit studies show a variety of scenarios in which the hybrid offers sufficient potential to justify development costs ranging in the tens of billions of dollars. The hybrid is then considered as an element in the ultimate development of fusion electric power. The hybrid offers a near term application of fusion where experience with the requisite technologies can be derived as a vital step in mapping a credible route to eventual commercial feasibility of pure fusion systems. Finally, the criteria for assessment of future energy options are discussed with prime emphasis on the need for rational comparision of alternatives.