Showing papers on "Substitute natural gas published in 2010"

The production of synthetic natural gas (SNG): A comparison of three wood gasification systems for energy balance and overall efficiency

Abstract: The production of Synthetic Natural Gas from biomass (Bio-SNG) by gasification and upgrading of the gas is an attractive option to reduce CO 2 emissions and replace declining fossil natural gas reserves. Production of energy from biomass is approximately CO 2 neutral. Production of Bio-SNG can even be CO 2 negative, since in the final upgrading step, part of the biomass carbon is removed as CO 2 , which can be stored. The use of biomass for CO 2 reduction will increase the biomass demand and therefore will increase the price of biomass. Consequently, a high overall efficiency is a prerequisite for any biomass conversion process. Various biomass gasification technologies are suitable to produce SNG. The present article contains an analysis of the Bio-SNG process efficiency that can be obtained using three different gasification technologies and associated gas cleaning and methanation equipment. These technologies are: 1) Entrained Flow, 2) Circulating Fluidized Bed and 3) Allothermal or Indirect gasification. The aim of this work is to identify the gasification route with the highest process efficiency from biomass to SNG and to quantify the differences in overall efficiency. Aspen Plus ® was used as modeling tool. The heat and mass balances are based on experimental data from literature and our own experience. Overall efficiency to SNG is highest for Allothermal gasification. The net overall efficiencies on LHV basis, including electricity consumption and pre-treatment but excluding transport of biomass are 54% for Entrained Flow, 58% for CFB and 67% for Allothermal gasification. Because of the significantly higher efficiency to SNG for the route via Allothermal gasification, ECN is working on the further development of Allothermal gasification. ECN has built and tested a 30 kW th lab scale gasifier connected to a gas cleaning test rig and methanation unit and presently is building a 0.8 MWth pilot plant, called Milena, which will be connected to the existing pilot scale gas cleaning.

Municipal Solid Waste to Energy Conversion Processes: Economic, Technical, and Renewable Comparisons

Abstract: Preface. Professional Biography. 1 Introduction to Gasification / Pyrolysis and Combustion Technology(s). Historical Background and Perspective. Introduction. What is Pyrolysis? What is Pyrolysis/Gasification? What is Conventional Gasification? What is Plasma Arc Gasification? What is Mass Burn (Incineration)? Which Thermal Process Technology is the Most Efficient and Economical? Performance/Thermal Efficiency of Technologies. What is the Economic Comparison Between the Thermal Processes? References. 2 How Can Plasma Arc Gasification Take Garbage to Electricity and a Case Study? Basis. Economic Cases. Logical Approach for Future Progress. References. 3 How Can Plasma Arc Gasification Take Garbage to Liquid Fuels and Case Studies? MSW To Syngas to Liquid Fuels Via Chemistry (Fischer Tropsch Synthesis) and a Case Study. Basis. Economic Case. Logical Approach for Future Progress. MSW to Syngas to Liquid Fuel via Biochemistry and a Case Study. Basis and Economics. References. 4 Plasma Economics: Garbage/Wastes to Electricity, Case Study with Economy of Scale. Conclusions and Recommendations (Opinions). References. 5 Plasma Economics: Garbage/Wastes to Power Ethanol Plants and a Case Study. Basis. Economic Cases. Logical Approach for Future Progress. References. 6 From Curbside to Landfill: Cash Flows as a Revenue Source for Waste Solids-to-Energy Management. References. 7 Plasma Economics: Garbage/Wastes to Power, Case Study with Economics of a 94 ton/day Facility. More Recent Events About the Project. References. 8 Plant Operations: Eco-Valley Plant in Utashinai, Japan: An Independent Case Study. References. 9 Municipal Solid Waste and Properties. What is Municipal Solid Waste (MSW) and How Much is Generated in the United States? MSW Properties. References. 10 MSW Processes to Energy with High-Value Products and Specialty By-Products. Production of Ammonia (NH3) from Syngas via Chemical Synthesis Route. Production of Gas to Liquids from Syngas via Chemical Synthesis Route. Production of Methanol (CH3OH) from Syngas via Chemical Synthesis Route. Production of Synthetic Natural Gas (SNG) from Syngas via Chemical Synthesis Route. Production of Hydrogen (H2) from Syngas via Chemical Synthesis Route(s). Gasifier. Air Separation Unit (ASU). Hot Gas Cleanup System. Sulfuric Acid Plant. CO2-Rich Separated Gas Stream/Conventional Turbine Expander. Production of Ethanol (CH3CH2OH) from Syngas via Chemical Synthesis Route. Production of Ethanol and Methanol from Syngas using Fischer Tropsch Synthesis Process. Production of Ethanol from Syngas via a Bio-Chemical Synthesis Route. Production of Ethanol via a Combination of Chemical and Bio-Chemical Synthesis Routes Using Biomass (Cellulosic Material). Oxosynthesis (Hydroformylation): Syngas and Olefinic Hydrocarbons and Chemical Synthesis. Slag or Vitrified Slag or Ash from Gasification Reactor and Specialty By-Product Options. Vitrified Slag, Slag, and Ashes: Research and Development (R&D), Marketing, and Sales. Process for Resolving Problems with Ashes. Production of Road Material from Slag and Vitrified Slag. Production and Uses of Rock Wool, Stone Wool, and Mineral Wool. Production of Aggregate. Production of Flame-Resistant Foam. Destruction of Asbestos Wastes via Vitrification. Discussion of Potential Markets for the Vitrified Slag. References. 11 MSW Gasifiers and Process Equipment. Conventional Gasifiers/Gasification Reactors. ChevronTexaco Entrained-Flow Gasifier. E-GasTM Entrained-Flow Gasifier. Shell Entrained-Flow Gasifier. Lurgi Dry-Ash Gasifier and British Gas/Lurgi Gasifier. Prenflo Entrained Bed Gasifier. Noell Entrained Flow Gasifier. High-Temperature Winkler Gasifier. KRW Fluidized Bed Gasifier. Plasma Arc Gasification Technology. Alter Nrg Plasma Gasifier (Westinghouse Plasma Corporation) System. EUROPLASMA, Plasma Arc System. Phoenix Solutions Plasma Arc Torches, Phoenix Solutions Company (PSC). PyroGenesis Plasma-Based Waste to Energy. Integrated Environmental Technologies, LLC (InEnTec). Other Gasification Technology. Thermoselect Process by Interstate Waste Technologies. Primenergy's Gasification System at Moderate Temperatures. Nexterra's Gasification System at Moderate Temperatures. Other Process Equipments. Candle Filter. Pressure Swing Adsorption (PSA) Units. Mercury Removal Systems. Main Sulfur Removal Technologies. Combustion Turbine for Syngas and Gas Engine for Syngas. Siemens-Westinghouse Syngas Combustion Turbine for Syngas. General Electric (GE) Combustion Turbine for Syngas. GE Gas Engine for Syngas. Noncontact Solids Flow Meter for Waste Solids (RayMas(R) Meter). References. 12 Other Renewable Energy Sources. Wind Energy: Introduction. Big Wind Systems to Energy. Economic Example and Cases. Discussion of Economics For the Large Wind Farm Cases. Economy of Scale Associated With Wind Farms. Small Wind Systems to Energy. Discussion of Economics for the Small Wind Farm Cases. Hydroelectric Energy: Introduction. Hydroelectric Mill Dam: Nashua, Iowa. Discussion of the Nashua Hydroelectric Economic Analyses. Hydroelectric Mill Dam: Delhi, Iowa. Discussion of the Delhi Hydroelectric Economic Analyses. Hydroelectric Mill Dam: Fort Dodge, Iowa. Discussion of the Fort Dodge Hydroelectric Economic Analyses. Daily Flow and Production Methodology, Fort Dodge Mill Dam Hydroelectric Facility. References. 13 Waste Energy to Recycled Energy. Introduction. References. Index.

Fluidized Bed Methanation of Wood-Derived Producer Gas for the Production of Synthetic Natural Gas

Abstract: For proving the concept of SNG production from wood gasification derived producer gas under real conditions, a mobile bench-scale fluidized bed reactor setup was fed with producer gas of the Fast Internally Circulating Bed (FICFB) wood gasifier in Gssing, Austria. In long-term experiments, it could be shown that the fluidized methanation catalyst allows for constantly high CO-conversion (about 98%) and CH4 concentration (about 40%) in the outlet. A similar experiment was conducted in a bench-scale reactor that allows for the measurement of axial gas phase concentration profiles by means of a movable sampling tube. It could be shown that under the chosen operation conditions, all three important reactions (methanation, water gas shift, and reforming of olefins) take place very rapidly in a region close to the reactor inlet. In the rest of the bed, the reaction of reactants transferred from the bubbles to the catalyst containing dense phase of the fluidized bed reactor is dominant.

Development of the MILENA gasification technology for the production of Bio-SNG

Abstract: The production of Substitute Natural Gas from biomass (Bio-SNG) is an attractive option to reduce CO2 emissions and replace declining fossil natural gas reserves. The Energy research Center of the Netherlands (ECN) is working on the development of the MILENA gasification technology that is ideally suited to convert a wide range of biomass fuels into a gas that can be upgraded into Bio-SNG. The MILENA gasification process is a new biomass gasification process designed to produce a medium calorific value gas (approximately 16 MJ nm-3 on dry basis) with a high content of hydrocarbons like methane and ethylene. A high hydrocarbon content is beneficial if the gas is going to be used in a prime mover or will be upgraded to Bio-SNG. The MILENA is best described as an Indirect or Allothermal fluidized bed gasifier. One of the major advantages of Indirect gasifiers is the near 100% conversion of the fuel into a combustible gas and sensible heat. The residual ash is virtually carbon free (<1 wt.% C), which means that the loss in heating value of the remains including the ash is close to zero.. The overall efficiency of the MILENA gasifier is relatively high, compared to the alternatives, because of the complete fuel conversion and the relatively low amount of steam required in the process. Chapter 4 presents an analysis of the obtainable Bio-SNG process efficiency using three different, more or less suitable, gasification technologies and associated gas cleaning and methanation equipment. These technologies are: 1) Entrained Flow, 2) Circulating Fluidized Bed and 3) Indirect gasification. Overall efficiency to SNG is highest for Indirect gasification. The net overall efficiencies on an LHV basis, including electricity consumption and pretreatment, but excluding transport of biomass, are 54% for Entrained Flow, 58% for CFB and 67% for Indirect gasification. Because of the significant differences in overall efficiencies to SNG for the different gasifiers, ECN has selected the Indirect gasification as the preferred technology for the production of SNG. A pseudo-equilibrium model is made to describe the MILENA gasification process. This MILENA model was used to design the lab-scale and pilot-scale installations. The model will be described in Chapter 5. The model is also usable for other fluidized bed biomass gasification processes operating at atmospheric pressure between 770 and 880°C. In 2004 the 30 kWth lab-scale MILENA gasifier was build. After successful operation of the MILENA lab-scale gasifier for some years it was, at the end of 2006, decided to start the realization of a pilot-scale gasifier. Construction started in 2007 and the 800 kWth pilot plant was taken into operation in 2008. First tests with the complete system (gasifier and gas cleaning) were done in 2009. The MILENA process and the lab-scale and pilot-scale installation are described in Chapter 6. An extensive test program was done in the lab-scale and pilot-scale MILENA installations. Different fuels, such as clean wood, demolition wood, sewage sludge and lignite were tested. Test results were used to verify the MILENA model. Only minor adjustments were made to the model. Tests with demolition wood were done to produce data for the engineering of a MILENA demonstration plant. Results of these tests are described in Chapter 7. A MILENA demonstration gasifier to be operated with demolition wood B (painted wood), in combination with OLGA gas cleaning, is planned for 2012. The cleaned gas will be used in a gas engine to produce heat and electricity. The MILENA demonstration is designed for a net electrical output of approximately 3 – 3.5 MWe. Residual heat will be used in the local heat grid. A 50 MWth Bio-SNG demonstration plant is scheduled to be started in 2015. Experimental work will focus on testing of the required catalysts as well as final gas conditioning steps that are required for upgrading the gas into Bio-SNG.

Production of Biofuels from Synthesis Gas Using Microbial Catalysts

Abstract: World energy consumption is expected to increase 44% in the next 20 years. Today, the main sources of energy are oil, coal, and natural gas, all fossil fuels. These fuels are unsustainable and contribute to environmental pollution. Biofuels are a promising source of sustainable energy. Feedstocks for biofuels used today such as grain starch are expensive and compete with food markets. Lignocellulosic biomass is abundant and readily available from a variety of sources, for example, energy crops and agricultural/industrial waste. Conversion of these materials to biofuels by microorganisms through direct hydrolysis and fermentation can be challenging. Alternatively, biomass can be converted to synthesis gas through gasification and transformed to fuels using chemical catalysts. Chemical conversion of synthesis gas components can be expensive and highly susceptible to catalyst poisoning, limiting biofuel yields. However, there are microorganisms that can convert the CO, H(2), and CO(2) in synthesis gas to fuels such as ethanol, butanol, and hydrogen. Biomass gasification-biosynthesis processing systems have shown promise as some companies have already been exploiting capable organisms for commercial purposes. The discovery of novel organisms capable of higher product yield, as well as metabolic engineering of existing microbial catalysts, makes this technology a viable option for reducing our dependency on fossil fuels.

Exceptional Durability of Solid Oxide Cells

Abstract: Extensive efforts to resolve the degradation normally associated with solid oxide electrolysis cells SOECs have been conducted during the past decade. To date, the degradation is assumed to be caused by adsorption of impurities in the cathode, although no firm evidence for this degradation mechanism has been presented. In this article, we demonstrate that the rapid degradation of these SOECs is indeed caused by impurities, and that operation without degradation is possible when removing these impurities from the inlet gases. Cleaning the inlet gases may be a solution for operating SOECs without long-term degradation. Production of synthetic hydrocarbon fuels from renewable energy is a solution to reduce oil consumption and carbon dioxide emissions without the need for modifications of existing infrastructure, e.g., in the production of methane synthetic natural gas or petrol/diesel, the infrastructure already exists in many countries. The raw material for synthetic hydrocarbon fuels is synthesis gas H2 +C O, which is traditionally produced via coal gasification or steam reforming of natural gas. Both processes consume fossil fuels and emit greenhouse gases. Coelectrolysis of H2O and CO2 H2O +C O2 → H2 cathode +C Ocathode +O 2 anode using renewable energy sources may be an alternative route for producing synthesis gas without consumption of fossil fuels and without emitting greenhouse gases. CO2 captured from air and/or recycling or reusing of CO2 from energy systems combined with coelectrolysis of H2O and CO2 seems to be an attractive method to provide CO2 neutral synthetic hydrocarbon fuels. Solid oxide electrolysis cells SOECs have the potential for cost-competitive production of hydrogen 1-4 and carbon monoxide, 1

Synthetic Natural Gas (SNG) from Coal and Biomass: a Survey of Existing Process Technologies, Open Issues and Perspectives

Abstract: Natural gas is a well known energy carrier. It is often used for producing heat and power, but can also be applied as a fuel in the transport sector. The production of synthetic natural gas (SNG) from coal or biomass is an interesting opportunity for both exploiting coal and biomass, and for replacing oil products for transportation and other uses. SNG has many important advantages with respect to other synfuels: it can be transported efficiently and cheaply using existing natural gas pipelines and distributing networks, it is an easily convertible feedstock, both in natural-gas combined-cycle power plants and in petrochemical facilities, it can count on a high social acceptance with respect to coal, and it can be stored underground, enabling efficient operation throughout the year independently of a fluctuating demand. Unfortunately, the commercial deployment of technologies for the production of SNG is currently constrained by technical barriers, so that more research is required before extensive applications on the industrial scale can be achieved. An important issue to be addressed is the strong exothermicity of the methane formation reactions, so that conventional fixed-bed catalytic reactors cannot be safely used (Sudiro et al., 2009). Following the 1970s energy crisis much work has been initiated in the US on coal-to-SNG: SNG process technologies and catalysts were developed and tested extensively. But most have been cancelled in the 1980 because of the changing energy picture. One industrial plant has actually been realized in North Dakota, which began operating in July 1984 and today produces more than 54 billion standard cubic feet of synthetic natural gas annually (1.53 billion Nm3/yr). Coal consumption is about 6 million tons each year. The heart of this plant is a building containing 14 gasifiers (www.dakotagas.com). Nowadays, the rise of natural gas prices have created a strong interest in producing SNG from the cheaper and much more abundant coal. A renewed interest in basing more energy consumption on coal and petcoke has resulted in a revival of several older technologies that have been enhanced to improve efficiency and to lower investment cost. Methanation is used as the final syngas purification step in the production of ammonia, but methanation for SNG production is more complex. The main industrial application of methanation has been the removal of CO from H2-rich feed gases in ammonia plants. With 5

Integration study for alternative methanation technologies for the production of synthetic natural gas from gasified biomass

Abstract: This paper analyzes the integration of two different methanation technologies – fixed bed adiabatic and fluidised bed isothermal - in a SNG production process and the consequences for the overall process energy conversion performance. The different operating conditions of the two methanation technologies lead to a change in temperature levels and quantities of recoverable heat, respectively, but also to differences in the overall processes’ power consumption. Using pinch methodology for optimal internal heat recovery in combination with flowsheeting software (ASPEN Plus), the two methanation alternatives are fitted into the SNG production process. The potential power production from recovered process heat is analysed based on the Carnot efficiency and compared to the overall power consumption within the SNG process. Both methanation alternatives perform equally within the given boundary conditions, resulting in an output of SNG of 63.3 MWLHV per 100 MWLHV dry fuel input and a ratio of about 1.22 between theoretical power production and overall power consumption.

Sorption enhanced methanation of biomass

Abstract: Disclosed embodiments provide a system and method for producing hydrocarbons from biomass. Certain embodiments of the method are particularly useful for producing substitute natural gas from forestry residues. Certain disclosed embodiments of the method convert a biomass feedstock into a product hydrocarbon by hydropyrolysis. Catalytic conversion of the resulting pyrolysis gas to the product hydrocarbon and carbon dioxide occurs in the presence of hydrogen and steam over a CO2 sorbent with simultaneous generation of the required hydrogen by reaction with steam. A gas separator purifies product methane, while forcing recycle of internally generated hydrogen to obtain high conversion of the biomass feedstock to the desired hydrocarbon product. While methane is a preferred hydrocarbon product, liquid hydrocarbon products also can be delivered.

Simulation of a structured catalytic reactor for exothermic methanation reactions producing synthetic natural gas

Abstract: Aim of this work is a theoretical investigation of the catalytic methanation reactions in externally cooled tubular reactors filled with novel monolithic catalysts with high thermal conductivity. Using the general purpose modelling tool gProms™ we have developed a steady-state, heterogeneous ID model, representing a single, externally cooled reactor tube loaded with cylindrical honeycomb catalysts with square channels, made of conductive material. The model equations include mass and energy balances for the gas and solid phases and the momentum balance for the gas phase. Two reactions are considered: carbon monoxide and carbon dioxide methanation, whose rate equations are taken from the literature. By reactor simulation it is shown that the problem of temperature control typical of fixed-bed methanation reactors can be overcome by the monolith reactor herein proposed. The effects of space velocity on conversion and temperature profiles are discussed, with a fixed geometrical configuration of the monolithic reactor.

Method and system for biomass hydrogasification

Abstract: The present invention provides a system and method for producing hydrocarbons from biomass. The method is particularly useful for producing substitute natural gas from forestry residues. Certain disclosed embodiments convert a biomass feedstock into a product hydrocarbon by fast pyrolysis, and conversion of the resulting pyrolysis gas to the product hydrocarbon and carbon dioxide in the presence of hydrogen and steam while simultaneously generating the required hydrogen by reaction with steam under prescribed conditions for self-sufficiency of hydrogen. Methane is a preferred hydrocarbon product. A system also is disclosed for cycling the catalyst between steam reforming, methanation and regeneration zones.

Production of bio-synthetic natural gas in Canada.

Abstract: Large-scale production of renewable synthetic natural gas from biomass (bioSNG) in Canada was assessed for its ability to mitigate energy security and climate change risks. The land area within 100 km of Canada’s network of natural gas pipelines was estimated to be capable of producing 67−210 Mt of dry lignocellulosic biomass per year with minimal adverse impacts on food and fiber production. Biomass gasification and subsequent methanation and upgrading were estimated to yield 16 000−61 000 Mm3 of pipeline-quality gas (equivalent to 16−63% of Canada’s current gas use). Life-cycle greenhouse gas emissions of bioSNG-based electricity were calculated to be only 8.2−10% of the emissions from coal-fired power. Although predicted production costs ($17−21 GJ−1) were much higher than current energy prices, a value for low-carbon energy would narrow the price differential. A bioSNG sector could infuse Canada’s rural economy with $41−130 billion of investments and create 410 000−1 300 000 jobs while developing a na...

Process for the production of substitute natural gas

Abstract: Process for the production of substitute natural gas (SNG) by the methanation of a synthesis gas derived from the gasification of a carbonaceous material together with water gas shift and carbon dioxide removal thereby producing a synthesis gas with a molar ratio (H 2 −CO 2 )/(CO+CO 2 ) greater than 3.00. At the same time, a gas with a molar ratio (H 2 −CO 2 )/(CO+CO 2 ) lower than 3.00 is added to the methanation section. The final product (SNG) is of constant high quality without excess of carbon dioxide and hydrogen.

Method and device for producing synthetic natural gas, and natural gas product thereof

Abstract: The invention provides a method for producing synthetic natural gas and a device thereof. The continuous technological process of the invention is realized in a way that gasified product gas is used as the raw material for producing high methane gas containing more than 94 mol% of methane. The method can well adjust the methanation reaction temperature and avoid the problems of catalyst temperature-runaway sintering and the like due to improper material composition, excessive fluctuation or unexpected accident, thereby reducing the recycle gas amount and enhancing the energy comprehensive utilization efficiency.

Catalytic Conversion of High‐Moisture Biomass to Synthetic Natural Gas in Supercritical Water

Abstract: Methane produced from waste biomass is a renewable and clean biofuel that can be distributed using the existing natural gas infrastructure. It can be used for heat and power generation and as a transportation fuel. High-moisture biomass is a relatively untapped resource with a significant energetic potential and attractive costs. However, new technologies are needed for converting high-moisture biomass efficiently into methane and recovering the nutrients for use as a fertilizer. Gasification of the biomass in a hydrothermal environment is an emerging technology that offers many advantages over gas-phase conversion processes or anaerobic digestion. Heterogeneous catalysis is the key to a successful hydrothermal gasification process for the synthesis of methane. Only a few metals, including Ru, Ni, Rh and Pt, are useful under these conditions. Pd and Co catalysts might also be suitable but conclusive data are lacking. Alloying is another approach that holds promise to yield active and stable catalysts. The choice of hydrothermally stable supports is limited to some insoluble oxides and carbon. Some of these oxides have not yet been tested as catalyst supports (e.g. Nb2O5, Ta2O5 and UO2) and might prove useful. The mechanism for the gasification of the organic compounds to CO and H2 is likely to follow a Mars–van-Krevelen redox cycle with two oxides of the catalytic metal involved. The strongest evidence for such a mechanism was found for RuO2, but specific in situ studies are needed for corroborating this hypothesis and determining the actual oxidation states involved in the mechanism. Deactivation in hydrothermal gasification follows the same modes as in gas-phase and liquid-phase catalysis. Coke deposition is not a primary cause of deactivation due to the high partial pressure of water and the high solubility of coke precursors in near- and supercritical water. Salts play a crucial role in catalyst deactivation. Sulfate was found to be a strong poison for Ru catalysts, but the actual poison might be sulfide, formed by reduction of the sulfate with hydrogen or organic compounds. Based on this knowledge, a continuous catalytic hydrothermal gasification process is under development at PSI featuring continuous on-line salt precipitation and removal before the catalytic reactor. Keywords: biomass; natural gas; methane; catalytic hydrothermal gasification; supercritical water; heterogeneous catalysis

Method for realizing methanation of coke oven gas through carbon-replenishing hydrogen-returning process for synthetic natural gas

Abstract: The invention relates to the field of coal coking production, in particular to a method for realizing methanation of coke oven gas through carbon-replenishing hydrogen-returning process for synthetic natural gas. The method comprises: pressurizing purified coke oven gas to 1 MPa; raising temperature to 250 DEG C for heat exchange; under the action of catalysts, performing three-stage methanation reaction of CO2 recycled by a low-partial-pressure system added with flue gas and H2 obtained through the separation of a membrane separation device after methanation to obtain synthetic gas of which the concentration of methane is over 94 percent. The method adopts a low-pressure non-cyclic methanation process, and the reaction temperature of the method is as follows: a primary stage is at 600 DEG C; a carbon-replenishing hydrogen-returning stage is at about 500 DEG C; a final stage is at 360 DEG C; and the temperature before every stage of methanation reaction is controlled at 250 DEG C through balancing control. Through a heat-insulating reactor and a waste-heat boiler heat exchange system, the method not only controls reaction temperature, but also produces steam serving as a byproduct at 3.8 MPa and 450 DEG C. Compared with other synthesis methods, waste heat energy produced during the methanation reaction is utilized more fully, so that the aims of saving energy, reducing emission and causing no environmental pollution are achieved while capacity is expanded.

Process Integration Opportunities for Synthetic Natural Gas (SNG) Production by Thermal Gasification of Biomass

Abstract: Synthetic natural gas (SNG) from gasified biomass is one promising option to produce renewable transport fuels. This thesis presents a process integration study investigating thermal gasification of biomass for the production of SNG and identifies critical conversion steps for the overall process performance. A base case process consisting of an indirect gasification unit followed by tar reforming, aminebased CO2 separation, isothermal methanation and, finally, compression, H2-purification by membrane separation and gas drying is presented. Based on the lower heating value (LHV) of the wet fuel feedstock, the estimated conversion efficiency from biomass to SNG is 69.4 %. The process mass and energy balances are obtained by using flow-sheeting software and are analysed by using pinch methodology. The integration studies performed highlight the significant potential for improvement of the overall process performance offered by integrated feedstock drying. In particular, steam drying and low-temperature air drying – using available process excess heat – are shown to influence the process performance favourably. The integration of SNG production with existing combined heat and power (CHP) steam power plants is proven to be a promising option to efficiently convert excess heat of the SNG process to electricity. The process integration study performed shows that an increased level of thermal integration leads to an increase in electricity production attributed to the SNG process (100 MWLHV dry fuel input) from 2 to 4.9 MW when using steam drying for feedstock drying, and from 0.5 to 5.6 MW for air drying, without any negative effects on SNG yield. Alternative integration opportunities for biomass gasification not aiming at SNG production specifically, but at replacing fossil fuels for power production, are also highlighted. Biomass gasification integrated to a fossil natural gas combined cycle plant results in high biomass-specific electrical efficiencies of up to 49.6 %.

Synthetic natural gas (SNG) production at pulp mills from a circulating fluidized bed black liquor gasification process with direct causticization

Abstract: Synthetic natural gas (SNG) production from black liquor gasification (BLG) replacing conventional recovery cycle at chemical pulp mills is an attractive option to reduce CO2 emissions and replace

Method for producing synthetic natural gas SNG from coal and processing installation thereof

Abstract: The invention relates to a method for producing synthetic natural gas SNG from coal and a processing installation thereof. The method includes the following steps that: coal is gasified and goes through sulfur-tolerant shift, the proportion between CO, CO2 and H2 in the gas is regulated, organic sulfur is converted into inorganic sulfur, the gas is then purified to remove the sulfur and part of the CO2 in the gas, and after the components of the gas meet the following formula: the ratio of(H2-3CO)to CO2 is about 4, the gas is sent into a methanation reactor, so that the H2, the CO and the CO2are methanated to synthesize the SNG (synthetic natural gas). The installation consists of a coal gasification process, a sulfur-tolerant shift process, a purification process and a methanation process, in particular, the methanation reactor in the methanation process adopts a water-cooled tube array structure, which can quickly take away reaction heat, so that the overheat of catalyst can be prevented, the high-pressure steam in the removed heat by-product serves as power for equipment such as a compressor and a pump, consequently, the reaction heat is rationally utilized, and the produced synthetic natural gas can be directly used as fuel for urban residents or further processed into SNG and LNG. Compared with the prior reactor methanation process, the method has the advantages of shortprocess, investment saving and high heat energy utilization rate.

Process for preparing synthetic natural gas from coke oven gas

Abstract: The invention provides a process for preparing synthetic natural gas from coke oven gas, which is characterized in that: the coke oven gas is subjected to precleaning, sulfur tolerant methanation, advanced purification, methane synthetic reaction, natural gas separation and the like so as to prepare CH4-rich natural gas and hydrogen-rich gas, wherein methane synthetic reaction, organic sulfur conversion reaction, olefin hydrogenation saturation, deoxidization and the like are performed simultaneously in a sulfur tolerant methanation reactor between a precleaning section and an advanced purification section, so that the purification process can be saved and heat loss due to repeated temperature rise and reduction in the purification process is avoided; meanwhile, quantity of gas treated by an acidic gas purification system after the sulfur tolerant methanation is reduced, energy consumption and investment are reduced; and parts of CO and CO2 in the coke oven gas are converted in the sulfur tolerant methanation reaction, so that the load of a methane synthesis reactor can be reduced and the rest CO and CO2 in the coke oven gas can be completely reacted after a period of methane synthetic reaction.

Coal and Biomass Conversion to Multiple Cleaner Energy Solutions System producing Hydrogen, Synthetic Fuels, Oils and Lubricants, Substitute Natural Gas and Clean Electricity

Abstract: The system contained within this application for patent protection provides the ability to produce clean syngas, natural gas, synthetic fuels, electricity, hydrogen fuels, and oil substitutes using a variety of materials. These materials include, but are not limited to: coal, biomass (including but not limited to municipal solid wastes), and agricultural byproducts. The fuels and electricity generated by this system can immediately be utilized by existing power and transportation grids, and as such, allow for rapid integration into the nation's energy needs. The system also removes and sequesters carbon dioxide, creating a clean, environmentally responsible supply of multiple types of power. The overall process provides an alternative to current oil and power solutions, allowing for domestic production of various energy requirements, creating the possibility for the reduced dependence on foreign imports for energy needs.

Method and device for preparing synthetic natural gas

Abstract: The invention provides a method for preparing a synthetic natural gas. The method comprises the step of performing a methanation reaction on a raw material gas which contains CO, CO2 and H2 in the presence of liquid saturated water. The invention also provides a device for implementing the method. The device comprises a methanator which is provided with a raw material gas inlet, a product outlet,and a nickel-based catalysts and liquid water inlet. The method of the invention is convenient and easy, and is suitable for various raw material gases; the ratio of H2 to CO in the raw material gas is improved by a water gas shift reaction; and a great amount of heat released by the methanation reaction is removed fast by vaporizing the liquid saturated water, so that a reaction temperature is controlled effectively, high-temperature carbon deposit of a catalyst is slowed down and the service life of the catalyst is prolonged. The device of the invention has the characteristics of simple structure and convenient operation.

Formation of Synthesis Gas Using Solar Concentrator Photovoltaics (SCPV) and High Temperature Co-electrolysis (HTCE) of CO2 and H2O

Abstract: Carbon dioxide is considered a greenhouse gas (GHG) that reflects solar radiation and consequently increases the temperature of the earth. Many countries are now considering putting a tax on CO2 emissions that will increase the cost of products that are associated with those emissions. The most common method currently considered for dealing with CO2 emissions is the capture of the gas, pressurization, and then sequestration in either rock formations or saline aquifers. This is relatively costly in both capital investment and operation of the equipment. Also, there is the possibility that this CO2 will escape at some point in the future subjecting the company in question to an uncertain risk. Ceramatec has been investigating an alternative approach that converts the CO2 into a useful product that can then be sold. Using solid oxide fuel cell materials in conjunction with a non-carbon source of energy it is possible to generate synthesis gas (CO and H2) and oxygen from CO2 and H2O. SCPV (Solar Concentrator Photovoltaic) systems are the most efficient generators of solar electricity and generate high quality heat at the same time. HTCE (High Temperature Co-electrolysis) uses both the solar electricity and the heat to electrolyze the CO2 and H2O at double the total cycle efficiency of traditional electrolysis. The synthesis gas that is produced can be used to produce synthetic fuels such as synthetic natural gas or Fischer Tropsch liquid fuels, or chemicals. This paper will discuss this alternative approach to the disposal of CO2. This approach has the following advantages: permanent disposal, usable product, storage of solar energy in fuel, reduction of GHG, reduction in solar radiation, and no additional GHG.

Process and device for integrally producing substitute natural gas by coal gasification and methanation

Abstract: The invention relates to a process and a device for integrally producing substitute natural gas by coal gasification and methanation, which comprises the following steps: manufacturing the raw material coal into pulverized coal or coal water slurry; feeding the raw materials into a gasification furnace for partial oxidation reaction to generate a gas mixture; and enabling the gas mixture to enter a subsequent device for processing to obtain the substitute natural gas, wherein the gasification furnace and/or the subsequent device are subject to methanation catalysis and strengthen process, and the gas mixture generates a methanation reaction in the gasification furnace and/or the subsequent device. The devices comprise the following equipments: the gasification furnace, a dust filter, a gas chiller and/or a coal gas heat exchanger, wherein one or more of the devices are subject to the methanation catalysis and the strengthen process. The process and the device for integrally producing the substitute natural gas through the coal gasification and methanation provided by the invention has high cost efficiency and competitiveness.