Substitute natural gas

About: Substitute natural gas is a research topic. Over the lifetime, 1216 publications have been published within this topic receiving 23604 citations. The topic is also known as: synthetic natural gas.

Development of a Hydrogasification Process for Co-Production of Substitute Natural Gas (SNG) and Electric Power from Western Coals

Abstract: This report presents the results of the research and development conducted on an Advanced Hydrogasification Process (AHP) conceived and developed by Arizona Public Service Company (APS) under U.S. Department of Energy (DOE) contract: DE-FC26-06NT42759 for Substitute Natural Gas (SNG) production from western coal. A double-wall (i.e., a hydrogasification contained within a pressure shell) down-flow hydrogasification reactor was designed, engineered, constructed, commissioned and operated by APS, Phoenix, AZ. The reactor is ASME-certified under Section VIII with a rating of 1150 pounds per square inch gage (psig) maximum allowable working pressure at 1950 degrees Fahrenheit ({degrees}F). The reaction zone had a 1.75 inch inner diameter and 13 feet length. The initial testing of a sub-bituminous coal demonstrated ~ 50% carbon conversion and ~10% methane yield in the product gas under 1625{degrees}F, 1000 psig pressure, with a 11 seconds (s) residence time, and 0.4 hydrogen-to-coal mass ratio. Liquid by-products mainly contained Benzene, Toluene, Xylene (BTX) and tar. Char collected from the bottom of the reactor had 9000-British thermal units per pound (Btu/lb) heating value. A three-dimensional (3D) computational fluid dynamic model simulation of the hydrodynamics around the reactor head was utilized to design the nozzles for injecting the hydrogen into the gasifier to optimize gas-solid mixing to achieve improved carbon conversion. The report also presents the evaluation of using algae for carbon dioxide (CO{sub 2}) management and biofuel production. Nannochloropsis, Selenastrum and Scenedesmus were determined to be the best algae strains for the project purpose and were studied in an outdoor system which included a 6-meter (6M) radius cultivator with a total surface area of 113 square meters (m{sup 2}) and a total culture volume between 10,000 to 15,000 liters (L); a CO{sub 2} on-demand feeding system; an on-line data collection system for temperature, pH, Photosynthetically Activate Radiation (PAR) and dissolved oxygen (DO); and a ~2 gallons per minute (gpm) algae culture dewatering system. Among the three algae strains, Scenedesmus showed the most tolerance to temperature and irradiance conditions in Phoenix and the best self-settling characteristics. Experimental findings and operational strategies determined through these tests guided the operation of the algae cultivation system for the scale-up study. Effect of power plant flue gas, especially heavy metals, on algae growth and biomass adsorption were evaluated as well.

Methanation catalyst used for preparing substitute natural gas from synthesis gas, and preparation method and application thereof

Abstract: The invention discloses a methanation catalyst The methanation catalyst comprises a 5-30wt% of nickel by metallic element, b 0-30wt% of magnesium and/or calcium by metallic element, c 0-50wt% of lanthanide series metals by metallic element, d 5-30wt% of magnesium aluminate spinel by magnesium element and e the balance of Al2O3 A preparation method of the catalyst comprises the following steps of: adhering a water-soluble salt containing magnesium to Al2O3 and roasting the components so that a magnesium aluminate spinel structure is generated on the surface of a catalyst support; dipping water-soluble salts of the components a, b and c on the support; and drying and roasting the support, thus obtaining the catalyst On the XRD (X-ray diffraction) spectrogram of the catalyst support, a group of obvious magnesium aluminate spinel characteristic diffraction peaks exist between 10 degrees and 80 degrees (angle 2theta) The catalyst has the characteristics of high low-temperature methanation activity, good heat stability, good anti-carbon deposition property and the like

Method for preparing liquefied natural gas (LNG) from tail gas produced by external-heat destructive distillation-type semicoke preparation

Abstract: The invention belongs to the technical field of chemical engineering and discloses a method for preparing liquefied natural gas (LNG) from tail gas produced by external-heat destructive distillation-type semicoke preparation. The method comprises the following steps of 1, pre-purification, 2, compression: compressing the pre-purified gas so that the gas pressure is in a range of 0.9-2.5MPa, 3, sulfur-tolerant shift, 4, deep purification, 5, methanation, 6, decarbonization: removing CO2 by a pressure swing adsorption humidification method to obtain high methane gas having methane content greater than 60%, and 7, separation liquidation: carrying out copious-cooling separation liquidation on the synthetic natural gas to obtain product gas having methane content greater than 99%. According to the composition and reaction characteristics of the tail gas produced by the external-heat destructive distillation-type semicoke preparation, the method adopts the specific processes and specific control parameters, realizes targeted treatment on the tail gas produced by the external-heat destructive distillation-type semicoke preparation, fills the blank of preparation of LNG from the semicoke tail gas, realizes chemical utilization of the tail gas produced by the external-heat destructive distillation-type semicoke preparation and creates a novel economic growth point for enterprises.

A Study of Catalytic Carbon Dioxide Methanation Leading to the Development of Dual Function Materials for Carbon Capture and Utilization

Abstract: A Study of Catalytic Carbon Dioxide Methanation Leading to the Development of Dual Function Materials for Carbon Capture and Utilization Melis S. Duyar The accumulation of CO2 emissions in the atmosphere due to industrialization is being held responsible for climate change with increasing certainty by the scientific community. In order to prevent its further accumulation, CO2 must be captured for storage or conversion to useful products. Current materials and processes for CO2 capture rely on the toxic and corrosive methylethanolamine (MEA) absorbents and are energy intensive due to the large amount of heat that needs to be supplied to release CO2 from these absorbents. CO2 storage technologies suffer from a lack of infrastructure for transporting CO2 from many point sources to the storage sites as well as the need to monitor CO2 against the risk of leakage in most cases. Conversion of CO2 to useful products can offer a way of recycling carbon within the industries that produce it, thus creating processes approaching carbon neutrality. This is particularly useful for mitigation of emissions if CO2 is converted to fuels, which are the major sources of emissions through combustion. This thesis aims to address the issues related to carbon capture and storage (CCS) by coupling a CO2 conversion process with a CO2 capture process to design a system that has a more favorable energy balance than existing technologies. This thesis presents a feasibility study of dual function materials (DFM), which capture CO2 from an emission source and at the same temperature (320C) in the same reactor convert it to synthetic natural gas (SNG), requiring no additional heat input. The conversion of CO2 to SNG is accomplished by supplying hydrogen, which in a real application will be supplied from excess renewable energy (solar and/or wind). The DFM consists of Ru as methanation catalyst and nano dispersed CaO as CO2 adsorbent, both supported on a porous γ-Al2O3 carrier. A spillover process drives CO2 from the sorbent to the Ru sites where methanation occurs using stored H2 from excess renewable power. This approach utilizes flue gas sensible heat and eliminates the current energy intensive and corrosive capture (amine solutions) and storage processes without having to transport captured CO2 or add external heat. The catalytic component (Ru/γ-Al2O3) has been investigated in terms of its suitability for a DFM process. Process conditions for methanation have been optimized. It has been observed that the equilibrium product distribution for CO2 methanation with a H2:CO2 ratio of 4:1 can be attained at a temperature of 280C with a space velocity of 4720 h. TGA-DSC has been employed to observe the sequential adsorption and reaction of CO2 and H2 over Ru/γ-Al2O3. It was shown that H2 only reacts with a CO2-saturated Ru/γ-Al2O3 surface but does not adsorb on the bare Ru surface at 260C, consistent with an Eley-Rideal type reaction. In this rate model CO2 adsorbs strongly on the catalyst surface and reacts with gas phase H2. Kinetic tests were employed to confirm this observation and demonstrated that the rate dependence on CO2 and H2 was also consistent with an Eley-Rideal mechanism. A rate expression according to the EleyRideal model at 230C was developed. Activation energy, pre-exponential factor and reaction orders with respect to CO2, H2, and products CH4, and H2O were determined in order to develop an empirical rate equation in a range of commercial significance. Methane was the only hydrocarbon product observed during CO2 hydrogenation. The activation energy was found to be 66.084 kJ/g-mole CH4. The empirical reaction order for H2 was 0.88 and for CO2 0.34. Product reaction orders were essentially zero.

Operating Characteristics of 1 $Nm^3/h$ Scale Synthetic Natural Gas(SNG) Synthetic Systems

Abstract: In this work, we proposed the three different reactor systems for evaluating of synthetic natural gas(SNG) processes using the synthesis gas consisting of CO and and reactor systems to be considered are series adiabatic reaction system, series adiabatic reaction system with the recirculation and cooling wall type reaction system. The maximum temperature of the first adiabatic reactor in series adiabatic reaction system raised to 800. From the these results, carbon dioxide in product gas as compared to other systems was increased more than that expected due to water gas shift reaction(WGSR) and the maximum concentration in SNG was 90.1%. In series adiabatic reaction system with the recirculation as a way to decrease the temperature in catalyst bed, the maximum concentration in SNG was 96.3%. In cooling wall type reaction system, the reaction heat is absorbed by boiling water in the shell and the reaction temperature is controlled by controlling the amount of flow rate and pressure of feed water. The maximum concentration in SNG for cooling wall type reaction system was 97.9%. The main advantage of the cooling wall type reaction system over adiabatic systems is that potentially it can be achieve almost complete methanation in one reactor.