Showing papers on "Substitute natural gas published in 2009"

Thermo-economic process model for thermochemical production of Synthetic Natural Gas (SNG) from lignocellulosic biomass

Abstract: A detailed thermo-economic model considering different technological alternatives for thermochemical production of Synthetic Natural Gas (SNG) from lignocellulosic biomass is presented. First, candidate technology for processes based on biomass gasification and subsequent methanation is discussed and assembled in a general superstructure. Both energetic and economic models for biomass drying with air or steam, thermal pretreatment by torrefaction or pyrolysis, indirectly and directly heated gasification, methane synthesis and carbon dioxide removal by physical absorption, pressure swing adsorption and polymeric membranes are then developed. Performance computations for the different process steps and some exemplary technology scenarios of integrated plants are carried out, and overall energy and exergy efficiencies in the range of 69-76% and 63-69%, respectively, are assessed. For these scenarios, the production cost of SNG including the investment depreciation is estimated to 76-107 EUR/MWh SNG for a plant capacity of 20 MWth biomass, whereas 59-97 EUR/MWh SNG might be reached at scales of 150 MWth biomass and above. Based on this work, a future thermo-economic optimisation will allow for determining the most promising options for the polygeneration of fuel, power and heat.

Catalytic gasification of algae in supercritical water for biofuel production and carbon capture

Abstract: There has been growing concern about the way cultivating biomass for the production of agro-biofuels competes with food production. To avoid this competition biomass production for biofuels will, in the long term, have to be completely decoupled from food production. This is where microalgae have enormous potential. Here we propose a novel process based on microalgae cultivation using dilute fossil CO2 emissions and the conversion of the algal biomass through a catalytic hydrothermal process. The resulting products are methane as a clean fuel and concentrated CO2 for sequestration. The proposed gasification process mineralizes nutrient-bearing organics completely. Here we show that complete gasification of microalgae (Spirulina platensis) to a methane-rich gas is now possible in supercritical water using ruthenium catalysts. 60–70% of the heating value contained in the algal biomass would be recovered as methane. Such an efficient algae-to-methane process opens up an elegant way to tackle both climate change and dependence on fossil natural gas without competing with food production.

Oil‐based gas washing—Flexible tar removal for high‐efficient production of clean heat and power as well as sustainable fuels and chemicals

Abstract: The Energy research Centre of the Netherlands (ECN) and Dahlman Industrial Group have developed a flexible tar removal process. This oil-based gas washing process, OLGA, besides tars, also removes dust as well as contaminants like thiophenes and dioxins from the product gas of a (biomass) gasifier. At ECN, the OLGA technology is currently applied within the Substitute Natural Gas (SNG) production process based on indirect gasification. As OLGA removes tars, but not the valuable lighter hydrocarbons like methane (CH 4 ), acetylene (C 2 H 2 ), and ethylene (C 2 H 4 ), it plays a crucial role in high-efficient SNG production processes. The OLGA in the past has been demonstrated successfully upstream Fischer-Tropsch diesel (FT) synthesis and in Combined Heat and Power (CHP) line ups as well though, where in the latter case besides the crucial tar removal it showed also to remove dioxins present in the product gas. As such, OLGA plays a crucial role in the production of clean heat and power.

Employing Catalyst Fluidization to Enable Carbon Management in the Synthetic Natural Gas Production from Biomass

Abstract: By measurements of axial gas phase concentration profiles in a fluidized-bed methanation reactor for the production of synthetic natural gas, regeneration of the catalyst inside the fluidized-bed reaction system could be proven. Moreover, by varying space velocity, bed height, catalyst mass, flow rates, and dilution rates, it could be shown that both hydrodynamic as well as chemical boundary conditions can influence the surface coverage and therefore selectivity and deactivation processes.

Exergetic evaluation and improvement of biomass-to-synthetic natural gas conversion

Abstract: Synthetic natural gas (SNG) is suggested as an important future energy carrier. The conventional route for SNG production is based on gasification of biomass to synthetic gas and the subsequent methanation of synthetic gas to SNG. This study is aimed to analyze the process units using the concept of exergy. Exergy analysis is a promising method, based on the 2nd law of thermodynamics, to analyze and improve chemical processes. In this work a detailed exergy analysis is performed for the SNG process based on woody biomass gasification. The main elements of the system are gasifier, gas cleaning, synthetic gas compression, methanation and final SNG condition. The above-mentioned process was simulated with a computer model using the flow-sheeting program Aspen Plus. Optimal values of the process conditions, particularly for the methanation reactors, are found. The internal exergy losses of different system units are evaluated. The largest internal exergy losses take place in the gasifier, methanation section and CO2 capture unit. The highest overall exergetic efficiency of 72.6% was found applying the following operating conditions: gasifier 700 °C and 1 bar; 1st methanation reactor 580 °C and 2nd methanation reactor 405 °C.

Method for making synthetic natural gas by utilizing coke oven gas

Abstract: A method for making synthetic natural gas by utilizing coke oven gas includes that a carbon source is supplied to the coke oven gas after rough desulfuration so as to lead the volume percentage of the coke oven gas to meet stoichiometric ratio that (H2-3CO)/CO2 is approach to 4, the coke oven gas is compressed to increase the pressure to be 05-54MPa, refined desulfuration is carried out and then the coke oven gas is led into a methanator, methanation reaction is carried out under the action of Ni series catalyst, thus obtaining artificial natural gas and further obtaining liquid natural gasby preparation The invention, by supplying carbon into the coke oven gas, optimizes stoichiometric ratio of H2, CO and CO2 in the coke oven gas and improves the yield of synthetic natural gas The synthetic natural gas making technology of the invention is suitable for a coke-oven plant with yield of dozens to hundreds tons, thus making the best of H2, CO and CO2 in the coke oven gas and the supplied CO2 and having realistic significance on improving resource utilization and strengthening environmental protection

Method and apparatus for substitute natural gas generation

Abstract: A system comprising a multi-stage reactor. The multi-stage reactor may include a water gas shift (WGS) reactor and a sour methanation reactor configured to generate methane without prior removal of acid gas. Furthermore, the multistage reactor may be a single unit having both the WGS reactor and the methanation reactor.

Bioenergy II: Scale-up of the Milena biomass gasification process

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 a technology to convert a wide range of biomass into Bio-SNG. The ECN Bio-SNG technology is based on indirect gasification of biomass. The MILENA indirect gasifier is developed to produce a gas, which can be upgraded into SNG with a high efficiency. Because of the indirect heating of the gasification process, no air separation is required. Char and tar are removed from the producer gas and are used as fuel to produce the required heat for the gasification process. The OLGA tar removal technology is used to remove tar and dust from the gas. After gas cleaning, the gas is catalytically converted into a mixture of CH4, CO2 and H2O. After compression and removal of CO2 and H2O, the remaining methane can be used as Bio-SNG. ECN produced the first Bio-SNG in 2004, using a conventional fluidized bed gasifier. The lab-scale MILENA gasifier was built in 2004. The installation is capable of producing approximately 8 Nm3/h methane-rich medium calorific gas with high efficiency. The lab-scale installation has been in operation for more than 1000 hours now and is working fine. Several biomass fuels were tested. Woody biomass appears to be the most suited fuel. The lab-scale gasifier is coupled to lab-scale gas cleaning installations (including OLGA) and a methanation unit. The integrated system was tested during several duration tests. The 30 kWth lab-scale gasifier was scaled up to 800 kWth biomass input. ECN has recently finished the construction of this pilot-scale gasifier, which has been taken into operation in the summer of 2008. First results, using wood as a fuel, show that the gas composition is similar to gas from the lab-scale installation. The pilot scale gasifier will be coupled to the existing pilot scale OLGA gas cleaning unit in 2009. Tests with the pilot-scale MILENA and OLGA will form the basis of a 10 MW MILENA – OLGA – gas engine demonstration plant. This demonstration will be taken into operation in 2012 and will be followed by a large SNG demonstration. 10 MW biomass input is seen as an attractive commercial scale for combined heat and power production from biomass. The scale foreseen for a commercial single-train Bio-SNG production facility is between 50 and 500 MWth. The expected net overall efficiency from wood to Bio-SNG is 70%.

Fuels for the future

Abstract: There are unconventional fuels that may serve as near term major replacements for conventional mineral oil and natural gas. These include fuels from oil shale and bitumen, liquid fuels from coal, methane from methane hydrates, biofuels and the secondary fuel hydrogen. Here, these fuels will be reviewed as to their presumable stocks and life cycle wastes, emissions and inputs of natural resources. The unconventional fuels are usually characterized by a relatively poor source-to-burner energy efficiency when compared with current conventional mineral oil and gas. Apart from some varieties of hydrogen and biofuel, their life cycles are characterized by relatively large water inputs, emissions, and wastes. The unconventional fuels shale oil, bituminous oil, coal liquids, and methane from methane hydrates are based on natural resources which are practically finite. This does not hold for biofuels, but the sustainable supply thereof is severely limited when large numbers of people also have to be fed. In view o...

Production of synthetic natural gas from biomass - Process integrated drying

Abstract: Opportunities for process integrated feedstock drying in connection with the production of synthetic natural gas (SNG) from wet biomass via indirect gasification are investigated in this study. Drying is a very energy-intensive process step – corresponding to about 10% of the dry fuel lower heating value for woody biomass. Process integrated drying offers opportunities for reducing the external energy supply necessary for drying, thereby improving the overall process efficiency. Simulation models for three drying technology options – air, steam and flue gas drying – have been developed using the flowsheeting software tool ASPEN Plus. The influence of basic operation parameters on the performance of the different drying configurations is investigated using sensitivity analysis. Based on a proposed SNG production process that is built as an extension of a fluidized bed boiler for a combined heat and power plant, the potential for heat integrated drying is assessed using pinch analysis in combination with the developed drying models. The biomass – 100 MWth input for both combustion and gasification, respectively - needs to be dried from 50 to 10 weight-% moisture content prior to combustion/gasification. It is shown that it is not possible to cover all feedstock drying needs for the process by internal heat recovery. Steam drying offers the highest potential for heat integration with the proposed SNG process, making it possible to cover 47.7 % of the necessary total dry fuel supply to both combustion and gasification. However, not all process heat used in the steam dryer can be recovered, increasing the external heat need to the SNG process at a lower temperature level. Nevertheless, substantial savings are possible making use of integrated drying within the SNG production process compared to stand-alone drying.

Synthetic natural gas (sng) from petcoke: model development and simulation

Abstract: In this work the issue of producing SNG from petcoke was addressed by developing a complete process. First, a model for coal gasification, taking into account kinetics and mass transfer was developed; the simulation model was applied to a conceptual dual bed gasification (Sudiro et al., 2008). Then, a process to produce synthetic natural gas (SNG) from syngas was developed, facing the main issue of this process: the temperature control of the methanator. Performances of the global process simulated with Aspen PlusTM have been evaluated, with respect to product yield, CO2 emissions and overall energy efficiency.

Methanation reaction process using oven gas to prepare substitute natural gas

Abstract: The invention discloses a methanation reaction technique using oven gas for preparing synthetic natural gas. A multilevel methanation reactor is adopted to control the temperature of gas at the inlet of every level of methanation reactor and the total content of CO+CO2 in the gas at the inlet to be less than or equal to 3.5%, so as to ensure the temperature of gas at the outlet of every level of methanation reactor to be less than or equal to 450 DEG C after methanation. By adopting the technique, the quantity of the gas used for diluting CO+CO2 in the oven gas of the raw materials can be greatly reduced, and the energy consumption is remarkably lowered; meanwhile, the gas temperature at the outlet of the methanation reactor can be effectively controlled, thus being beneficial to methanation reaction and the selection of the materials of the reactor.

Measurement of the Hydrocarbon Dew Point of Real and Synthetic Natural Gas Mixtures by Direct and Indirect Methods

Abstract: A detailed comparison of the performance of direct and indirect methods for measuring the hydrocarbon dew point (i.e., the temperature at which the condensation of hydrocarbons in a gas mixture fir...

The new Chalmers research-gasifier

Abstract: A cost-effective production of second generation biofuels require highly efficient gasification processes. For Substitute Natural Gas (SNG) to compete with natural gas, a cold gas efficiency of over 80 % related to the biomass dedicated for the gas production is required. Furthermore, as much “instant” methane as possible should be produced already during gasification. To optimize the gasification process towards a distinct product is a challenging task. The Chalmers gasifier provides unique possibilities to investigate the important parameters for this optimization by in-situ measurements in an industrial sized installation. It also demonstrates an innovative possibility to retrofit existing heat or heat and power plants for gas production. The gasifier is designated to research and, therefore, equipped with a multitude of sampling ports spread out over the front of the reactor. By means of different probes, sampling of gas and bed material is possible to acquire information of the progress of the fuel-conversion. A first set of measurement data from sampling of gas and bed material was successfully achieved during the firing season 08/09 and results from these measurements are presented in this paper.

Method for synthesizing methane by using coke-oven gas

Abstract: The invention discloses a method for synthesizing methane by utilizing oven gas. Product gas with methane concentration of more than 90 percent is obtained through the main steps of purifying to remove impurities, compressing to exchange heat, adding water vapor, first stage of methanation reaction, second stage of methanation reaction, third stage of methanation reaction, PSA methane separation and the like. By adopting the method and utilizing the oven gas as raw materials, synthetic natural gas with high content of methane, low content of impurities and high heating value can be obtained, which is favorable to protecting the environment, saving energy and developing new energy; in addition, in the method, the addition of appropriate water vapor in the raw materials of oven gas before the fist sage of reaction properly inhibits the depth of the methanation reaction, reduces the heat amount released in the whole reaction process, conduces the cooling of the gas after the reaction and prevents the occurrence of carbon deposition reaction to devitalize the activity of a catalyst, thus being beneficial to the continuous normal operation of the whole synthesizing process.

Present Coal Potential of Turkey and Coal Usage in Electricity Generation

Abstract: Total coal reserve (hard coal + lignite) in the world is 984 billion tons. While hard coal constitutes 52% of the total reserve, lignite constitutes 48% of it. Turkey has only 0.1% of world hard coal reserve and 1.5% of world lignite reserves. Turkey has 9th order in lignite reserve, 8th order in lignite production, and 12th order in total coal (hard coal and lignite) consumption. While hard coal production meets only 13% of its consumption, lignite production meets lignite consumption in Turkey. Sixty-five percent of produced hard coal and 78% of produced lignite are used for electricity generation. Lignites are generally used for electricity generation due to their low quality. As of 2003, total installed capacity of Turkey was 35,587 MW, 19% (6,774 MW) of which is produced from coal-based thermal power plants. Recently, use of natural gas in electricity generation has increased. While the share of coal in electricity generation was about 50% for 1986, it is replaced by natural gas today.

FUELS – HYDROGEN PRODUCTION | Absorption Enhanced Reforming

Abstract: The article addresses the production of renewable fuels for fuel cells (FCs), in particular hydrogen-rich synthesis gas, hydrogen, and substitute natural gas (SNG). These gaseous fuels can be generated via gasification of solid biomass, which is a thermochemical conversion process. Attention is placed on the absorption-enhanced reforming (AER) process as a means to improve the gas quality. By separating carbon dioxide inside the AER gasifier, the product gas composition can be adjusted for subsequent applications, especially for hydrogen or SNG production and for direct combined heat and power (CHP) generation, e.g., in gas engines, solid oxide fuel cells (SOFCs), or molten carbonate fuel cells (MCFCs). Whereas hydrogen can be used in low-temperature FCs (e.g., proton-exchange membrane fuel cells (PEMFCs), in the transportation sector), SNG is distributed via the gas grid. Therefore, SNG can be supplied to CHP plants operating with high-temperature FCs, or converted into hydrogen for PEMFCs to generate electricity at remote sites. The state-of-the-art of AER gasification and SNG generation from biomass is reviewed.

Cobalt-based catalyst for the oil-wax co-production of synthetic natural gas, preparation method and application thereof

Abstract: A cobalt-based catalyst for the oil-wax co-production of synthetic natural gas comprises the following components by the weight percentage: 5% to 30% of metal cobalt, 5% to 20% of metal nickel, 0% to 2.0% of metal promoter and 48% to 90% of carrier. The invention has the advantages of simple preparation technique and concentrated product (mainly oil gas); and the synthetic natural gas can be directly reclaimed and offered for sale as products without adding methane conversion devices, thereby reducing the equipment cost and improving the process economical efficiency.

Process efficiency of small scale SNG production from biomass

Abstract: Biomass can be converted to synthetic natural gas (SNG) by thermochemical gasification and a subsequent methanation. For a multi megawatt process the conversion efficiency of biomass to SNG is up to 74

Production of alternative motor fuels based on natural gas

Abstract: Basic trends in the refining of natural gas into alternative fuels are discussed.

Comparison between liquefied natural gas,pipe natural gas and substitute natural gas

Abstract: Coal based substitute natural gas industry is advocated to develop on a large scale with the aim of reducing gas supply gap in China.Compared with natural gas coming from other approaches,will coal based substitute natural gas show environmental and economic advantages? Therefore life cycle assessment is adopted here.Coal based substitute natural gas is compared with pipe natural gas imported from Russia and liquefied natural gas imported from Australia in term of energy consumption,environment emission and economic benefit.In the calculation,the related items in gas consumption link are omitted.Included industry links are construction link,mining link,production link and transportation link.Environment emission from production link of substitute natural gas project is serious.Although CO2 produced from coal transform process can be compressed and used in oil field to increase oil yield,substitute natural gas project still shows the highest CO2and SO2 emission.As admitted,coal mining regions have already involved severe ecology destroy.It is no doubt that coal based substitute natural gas industry which always develops in coal mining regions will sharpen environment deterioration there.Construction link of pipe natural gas project involves the largest amount of emission in the whole industry chain.So does the liquefied natural gas project.But Russia and Australia possess excellent environment capacity.The same amount of emission will produce less damage in Russia and Australia than in China.Therefore pipe natural gas project and liquefied natural gas project show advantages in term of environment emission.Energy efficiency of coal based substitute natural gas industry is about 35%.If the final gas burning efficiency is computed too,then it can be concluded that the efficiency of the whole industry chain will lower than that of coal power industry,which is the general coal consumption routine in China.The price of wood coal,the raw material of substitute natural gas industry,grows fast nowadays.The economic benefit of coal based substitute natural gas industry is sensitive to the price of wood coal.As a result,economic prospect of coal based substitute natural gas industry is suffering challenge in term of economic benefit.