Showing papers on "Substitute natural gas published in 2013"
TL;DR: It is found that shale gas consumes more water over its life cycle than conventional natural gas consumes (9.3-9.6 L/GJ), but when used as a transportation fuel, shaleGas consumes significantly less water than other transportation fuels.
Abstract: Shale gas production represents a large potential source of natural gas for the nation. The scale and rapid growth in shale gas development underscore the need to better understand its environmental implications, including water consumption. This study estimates the water consumed over the life cycle of conventional and shale gas production, accounting for the different stages of production and for flowback water reuse (in the case of shale gas). This study finds that shale gas consumes more water over its life cycle (13–37 L/GJ) than conventional natural gas consumes (9.3–9.6 L/GJ). However, when used as a transportation fuel, shale gas consumes significantly less water than other transportation fuels. When used for electricity generation, the combustion of shale gas adds incrementally to the overall water consumption compared to conventional natural gas. The impact of fuel production, however, is small relative to that of power plant operations. The type of power plant where the natural gas is utilized ...
187 citations
TL;DR: In this paper, the bimetallic Ni-Fe catalysts used in CO total-methanation reaction were prepared by the impregnation method on γ-Al 2 O 3 support for the production of substitute natural gas (SNG).
112 citations
TL;DR: In this paper, a series of α-Al2O3-supported Ni catalysts with different Ni particle sizes (5-10, 10-20, and 20-35 nm) were prepared and applied in the CO methanation reaction for the production of synthetic natural gas (SNG).
111 citations
TL;DR: In this paper, the catalysts are tested for high temperature methanation, taking into account these challenges, in order to allow for more competitive and flexible plant design for substitute natural gas (SNG) production.
92 citations
01 Jan 2013
TL;DR: In this article, the authors discuss the global carbon cycle and the relationships among hydrocarbons, and the inorganic chemistry of coals, as well as the use of synthetic gas for coal pyrolysis.
Abstract: 1. Fuels and the global carbon cycle 2. Catalysis, enzymes and proteins 3. Photosynthesis and the formation of polysaccharides 4. Ethanol 5. Plant oils and biodiesel 6. Composition and reactions of wood 7. Reactive intermediates 8. Formation of fossil fuels 9. Structure-property relationships among hydrocarbons 10. Composition, properties and processing of natural gas 11. Composition, properties and classification of petroleum 12. Petroleum distillation 13. Heterogeneous catalysis 14. Catalytic routes to gasoline 15. Middle distillate fuels 16. Thermal processing in refining 17. Composition, properties and classification of coals 18. The inorganic chemistry of coals 19. Production of synthetic gas 20. Gas treatment and shifting 21. Uses of synthetic gas 22. Direct production of liquid fuels from coal pyrolysis 23. Carbonization and coking of coal 24. Carbon products from fossil and biofuels 25. Carbon dioxide.
88 citations
TL;DR: In this article, the fluidization behavior and CO methanation performance over a typical Ni/Al2O3 catalyst for synthetic natural gas production was systematically investigated in a fluidized bed reactor.
71 citations
TL;DR: Several nickel-incorporated SiO2 catalysts with MoO3 molar content in range of 0.5% to 5.0% were prepared by the hydrothermal synthesis method and investigated for synthetic natural gas (SNG) produ...
Abstract: Several nickel-incorporated SiO2 catalysts with MoO3 molar content in range of 0.5% to 5.0% were prepared by the hydrothermal synthesis method and investigated for synthetic natural gas (SNG) produ...
61 citations
TL;DR: In this article, the authors developed a process model for small-scale production of synthetic natural gas (SNG) based on an indirect gasifier with a thermal input of 500 kW.
Abstract: SUMMARY
The gasification of biomass can be coupled to a downstream methanation process that produces synthetic natural gas (SNG). This enables the distribution of bioenergy in the existing natural gas grid. A process model is developed for the small-scale production of SNG with the use of the software package Aspen Plus (Aspen Technology, Inc., Burlington, MA, USA). The gasification is based on an indirect gasifier with a thermal input of 500 kW. The gasification system consists of a fluidized bed reformer and a fluidized bed combustor that are interconnected via heat pipes. The subsequent methanation is modeled by a fluidized bed reactor. Different stages of process integration between the endothermic gasification and exothermic combustion and methanation are considered. With increasing process integration, the conversion efficiency from biomass to SNG increases. A conversion efficiency from biomass to SNG of 73.9% on a lower heating value basis is feasible with the best integrated system. The SNG produced in the simulation meets the quality requirements for injection into the natural gas grid. Copyright © 2012 John Wiley & Sons, Ltd.
52 citations
09 Sep 2013
52 citations
TL;DR: In this paper, the authors presented the thermodynamic analysis and the coupling and optimization between chemical synthesis and power generation in a poly-generation system and showed that the overall efficiency of the novel system can be as high as 59%-65% and compared to single production systems, the energy saving ratio ESR of the new system is over 11.0% and the energy consumption for SNG production can be decreased by around 12%.
48 citations
TL;DR: In this article, a magnetic fluidized bed (MFB) was used for synthetic natural gas production and the results indicated that the NiCo catalyst showed poor fluidization behavior, while the fluidization quality of the catalyst can be greatly improved by introducing an axial uniform magnetic field.
Abstract: CO methanation reaction over a nanosized NiCo aerogel catalyst (NiCo) for synthetic natural gas production was investigated in a magnetic fluidized bed (MFB) reactor. The results indicated that the NiCo catalyst showed poor fluidization behavior, while the fluidization quality of the catalyst can be greatly improved by introducing an axial uniform magnetic field. The catalyst in the MFB reactor afforded higher conversion of CO and higher selectivity and yield of CH4 than those in the conventional fluidized bed, which was attributed to the MFB reactor improved gas-solid contract efficiency and inhibited axial back-mixing of the product gas. The catalytic performance in the MFB reactor was quite stable during a 100 h reaction. Such good stability is attributed to the superior property of the catalyst and the improved gas-solid contact efficiency in the MFB reactor. Furthermore, the particle agglomeration was inhibited when the catalyst was explored to a magnetic assisted fluidized bed. The combination of magnetic nanosized catalyst and MFB intensification as a promising route was developed for synthetic natural gas production.
TL;DR: In this paper, a comparative study was conducted for laboratory syngas methanation over a self-made Ni-Mg/Al2O3 catalyst to demonstrate the technical advantages of fluidized bed over fixed bed reactor.
TL;DR: In this paper, the authors evaluate biomass and solid wastes co-gasification with coal for energy vectors poly-generation with carbon capture and evaluate fuel blending for optimizing gasification performance.
TL;DR: In this paper, the effect of S/AHM weight ratio and sulfidation atmosphere on catalyst methanation performance was studied and the optimum S/HM ratio was 3.
TL;DR: In this article, the thermodynamic efficiency of bio-fuels production is analyzed and compared using both the direct exergy analysis and the thermo-ecological cost, which leads to the detection of exergy losses in various elements which forms the starting point to the improvement of conversion efficiency.
TL;DR: In this paper, a superstructure optimization approach for the integration of the simultaneous production of liquid fuels and hydrogen from switchgrass and shale gas is presented, which is based on Fischer-Tropsch technology in which the shale gas was reformed with steam, while the switchgrass was gasified and reformed (with steam or partial oxidation).
TL;DR: In this article, the authors show that sulfur removal from the gas stream with integrated methane synthesis at high temperatures is possible over many cycles, using supported Ru catalysts, using a modulated excitation approach, showing that the catalyst is poisoned by sulfur, and it can be fully regenerated.
TL;DR: In this paper, the authors developed a phenomenological model for the bio-syngas to methane conversion process, which can be used in selection of operability window for commercialization of substitute natural gas synthesis (SNG) process.
TL;DR: In this article, the effects of gasifying medium i.e., oxygen or air, on the fluidized bed gasification system, the synthesis gas composition, and the downstream processes for the synthesized gas conversion to the synthetic natural gas (SNG) were evaluated.
TL;DR: In this paper, the authors investigated the use of metal-oxides in a simple fixed-bed adsorber to catalyze the methanation reaction of an allothermal bench-scale gasifier.
TL;DR: In this article, the authors derived kinetic parameters from experimental results in literature and compared them using the catalytic coal gasification model in Aspen Plus, and the experimental results based on the drying characteristics are reflected in this simulation process.
Dissertation•
01 Jan 2013
TL;DR: In this article, the authors present results from a comprehensive process integration study of different process alternatives for Bio-SNG production from gasified biomass, showing that drying of the biomass feedstock prior to gasification using excess process heat is an important aspect for improving the process energy efficiency.
Abstract: Biomethane or synthetic natural gas (Bio-SNG) produced from gasified renewable woody biomass is a promising option for replacing fossil natural gas. The complete interchangeability with natural gas in all its conventional applications such as in the power generation, transportation and chemical industry sector is of particular interest. This work presents results from a comprehensive process integration study of different process alternatives for Bio-SNG production from gasified biomass. The influence of the main conversion steps in the process chain – drying, gasification, gas cleaning, methanation, and gas upgrade – on the overall process performance is investigated. Process bottlenecks and both heat and material integration opportunities are highlighted. Using future energy market scenarios the energetic, economic, and carbon footprint performance of the investigated processes are evaluated from a system perspective clearly showing the sensitivity of the obtained results to underlying assumptions. It is shown that drying of the biomass feedstock prior to gasification using excess process heat – using steam drying or low-temperature air drying technology – is an important aspect for improving the process energy efficiency. The results also indicate that indirect and direct gasification technologies perform equally well within the overall Bio-SNG production process. Existing infrastructure in the form of biomass-fired combined heat and power plants based on fluidised bed combustion technology presents interesting opportunities for integrating indirect gasification for Bio-SNG production, with beneficial effects on the cogeneration of electricity from the Bio-SNG process excess heat. The choice of methanation technology between fixed and fluidised bed is not a critical one with respect to process integration, since both technologies allow for efficient heat recovery and consequent cogeneration. For gas upgrade, in particular removal of CO2 from the product gas, amine based separation is shown to achieve better energy efficiency and economic performance than membrane based or pressure swing adsorption processes. Preliminary estimations of Bio-SNG costs are significantly higher than current natural gas prices, thus dedicated and long term policy measures are necessary in order to stimulate Bio-SNG production. The process integration aspects presented in this thesis can contribute to reducing production costs by increasing energy efficiency and in consequence increasing economic robustness of Bio-SNG process concepts.
TL;DR: The main goal of gasification is the generation of synthesis gases for further catalytic synthesis into base chemicals or storable energy carriers such as liquid fuels (methanol, mixed alcohols, FischerTropsch liquids and dimethyl ether) or gaseous fuels such as substitute natural gas (SNG) or hydrogen.
Abstract: :
The gasification of biomass promises plentiful options for efficient feedstock utilization. Often, the main goal is the provision of energy in the form of heat or power (or cooling) by burning the combustible gases. Another goal of biomass gasification is the generation of synthesis gases for further catalytic synthesis into base chemicals or storable energy carriers such as liquid fuels (methanol, mixed alcohols, Fischer–Tropsch liquids and dimethyl ether) or gaseous fuels such as substitute natural gas (SNG) or hydrogen. This chapter describes the fundamentals of gasification, technological developments and future trends for different sizes of plants and gives an overview of the process chains incorporating biomass gasification.
TL;DR: In this article, the effect of operating parameters such as the reaction temperature, pressure, and feed compositions on the performance of the methanation reaction was investigated by equilibrium model calculations and dynamic numerical model simulations.
Abstract: Concerns about the depletion and increasing price of natural gas are generating interest in the technology of synthetic natural gas (SNG) production. SNG can be produced by the methanation reaction of synthesis gas obtained from coal gasification; this methanation reaction is the crucial procedure for economical production of SNG. We investigated the effect of operating parameters such as the reaction temperature, pressure, and feed compositions (H2/CO and CO2/CO ratios) on the performance of the methanation reaction by equilibrium model calculations and dynamic numerical model simulations. The performance of the methanation reaction was estimated from the CO conversion, CO to CH4 conversion, and CH4 mole fraction in the product gas. In general, a lower temperature and/or higher pressure are favorable for the enhancement of the methanation reaction performance. However, the performance becomes poor at low temperatures below 300 °C and high pressures above 15 atm because of limitations in the reaction kinetics. The smaller the amount of CO2 in the feed, the better the performance, and an additional H2 supply is essential to increase the methanation reaction performance fully.
TL;DR: In this paper, an exergy-based comparison of the two gasification technologies is performed using a simplified gasification reactor model, aiming at comparing the two technologies on a common basis without possible bias due to model regression on specific reactor data.
Abstract: Atmospheric indirect steam-blown and pressurised direct oxygen-blown gasification are the two major technologies discussed for large-scale production of synthetic natural gas from biomass (bio-SNG) by thermochemical conversion. Published system studies of bio-SNG production concepts draw different conclusions about which gasification technology performs best. In this paper, an exergy-based comparison of the two gasification technologies is performed using a simplified gasification reactor model. This approach aims at comparing the two technologies on a common basis without possible bias due to model regression on specific reactor data. The system boundaries include the gasification and gas cleaning step to generate a product gas ready for subsequent synthesis. The major parameter investigated is the delivery pressure of the product gas. Other model parameters include the air-to-fuel ratio for gasification as well as the H2/CO ratio in the product gas. In order to illustrate the thermodynamic limits and sources of efficiency loss, an ideal modelling approach is contrasted with a model accounting for losses in, e.g. the heat recovery and compression operations. The resulting cold-gas efficiencies of the processes are in the range of 0.66–0.84 on a lower heating value basis. Exergy efficiencies for the ideal systems are from 0.79 to 0.84 and in the range of 0.7 to 0.79 for the systems including losses. Pressurised direct gasification benefits from higher delivery pressure of the finished gas product and results in the highest exergy efficiency values. Regarding bio-SNG synthesis however, a higher energetic and exergetic penalty for CO2 removal results in direct gasification exergy efficiency values that are below values for indirect gasification. No significant difference in performance between the technologies can be observed based on the model results, but a challenge identified for process design is efficient heat recovery and cogeneration of electricity for both technologies. Furthermore, direct gasification performance is penalised by incomplete carbon conversion in contrast to performance of indirect gasification concepts.
TL;DR: The road transport sector today is almost exclusively dependent on fossil fuels as mentioned in this paper and it will need to face a radical change if it aims to switch from a fossil-based system to a renewable-b...
TL;DR: In this paper, several combustion tests using a diffusion type combustor were conducted to determine the effect of hydrogen content in SNG on gas turbine combustion, and three kinds of SNG with different H 2 content up to 3%vol were used for the combustion tests.
TL;DR: In this paper, the synthesis step in the production of synthetic natural gas from wood, i.e., the methanation, was investigated by systematic experiments with commercial nickel catalyst in a micro-fluidized bed reactor.
Abstract: The synthesis step in the production of synthetic natural gas from wood, i.e. the methanation, was investigated by systematic experiments with commercial nickel catalyst in a micro-fluidised bed reactor. Ethylene in the feed is always converted completely; dominantly serial reactions of ethylene to ethane and further to methane under isothermal fluidised bed methanation conditions could be shown. Lower temperatures favour the production of the intermediate ethane while high temperatures cause the formation of carbon depositions and carbon whiskers. Applying optimal operation conditions, the hydrogenation of the unsaturated olefin not only avoids the deposition of carbon or coke, but also leads to an increase of the higher heating value (HHV) of the produced (raw) SNG. © 2013 Elsevier B.V. All rights reserved.
TL;DR: In this article, a thermal decomposition of ammonium tetrathiomolybdate (ATM) or ammonium heptamolyb date (AHM) using sulfur powder as sulfiding agent at variable sulfidation temperature (400-550°C) was studied for the methanation reaction.
Abstract: Unsupported MoS2 catalysts were obtained by thermal decomposition of ammonium tetrathiomolybdate (ATM) or ammonium heptamolybdate (AHM) using sulfur powder as sulfiding agent at variable sulfidation temperature (400–550 °C). The CO conversion, selectivity and yield of CH4 on the catalysts were studied for the methanation reaction. It was found that CO conversion increased with temperature rise at first, reached maximum value at sulfidation temperature of 450 °C and then decreased sharply with further increase of temperature. The catalyst derived from ATM could get higher CO conversion than the catalyst from AHM because of the structural similarity between ATM and MoS2. XRD analysis demonstrated that amorphous MoS2 was favorable for the methanation reaction and a crystal transition of MoS2 nanoparticle happened during the methanation reaction. The higher the sulfidation temperature was, the more easily regular crystal structure of MoS2 formed. TEM characterization results showed that at the optimum sulfidation temperature of 450 °C, the length and stacking degree of MoS2 crystallite were the highest and so more active sites could reside on the edges of MoS2 slabs for CO methanation. The crystal growth of MoS2 particle and its structure change are probably the reasons for the deactivation of the MoS2 catalysts with the increase of sulfidation temperature. In addition, it is the loss of surface sulfur that caused deactivation of the catalyst with reaction time.
TL;DR: In this paper, the authors evaluated the biomass-to-synthetic natural gas (SNG) using calcium looping gasification with CaO sorbent (CLG-SNG), via thermochemical methods.
Abstract: This study evaluates the biomass-to-synthetic natural gas (SNG) using calcium looping gasification (CLG) with CaO sorbent (CLG-SNG) via thermochemical methods. The CLG-SNG process consists of three steps in sequence: steam gasification in situ CO2 capture using CaO sorbents, gas cleaning, and methanation. The concept of interconnected fluidized beds was adopted for repeated carbonation/calcination cycles of CaO sorbents in the gasification unit. A process simulation was conducted based on the chemical equilibrium method using Aspen Plus. Then, the effects of some key variables on the thermodynamic performances, such as the gas composition, yield of SNG (YSNG), cold gas efficiency (ηcold), the overall energy efficiency (η), exergy efficiency (ψ) of the process, and the unit power consumption (WSNG) were investigated. The variables include CaO-to-biomass ratio (Ca/B) in the range of 0.7–1, steam-to-biomass ratio (S/B) in the range of 0.1–1.5, and gasification temperature (tG) in the range of 600–700 °C. At ...