130 results about "Substitute natural gas" patented technology

A process purifies raw biogas created from a renewable source into pipeline grade natural gas and/or D.O.T. specification, or other predetermined specification, gas. The automated scrubbing processed employed and the particular attributes of the system allow the system to function under extreme weather conditions by employing specific tools to control the temperature of the scrubbing water to allow for efficient and effective removal of the carbon dioxide gas. The system also employs specific measures to use recycled scrubbing water, thus eliminating the need for excessive water generally needed to economically employ this type of scrubbing process. The recycled water is continuously de-carbonated to allow the recycled water stream to effectively scrub the raw biogas. Treated gas from the process is then dried, and compressed for introduction into storage tanks or a natural gas pipeline delivery system.

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.

A combined cycle system based on coal gasification and methanation gas-steam and a technique thereof, wherein, the method comprises the following steps: oxygen produced by an air separation unit and coal powder or water-coal-slurry are sent into coal gasification equipment, the produced crude gasification gas is sent to a carbon monoxide sulfur-tolerant shift reactor to adjust the ratio of hydrogen and carbon after the sensible heat recollecting, and is then sent into sulfur-tolerant methanation reactor to produce methane and carbon dioxide, then the reaction product is sent into desulfurization and decarbonization equipment so that element sulfur can be recovered and carbon dioxide can be separated so as to obtain substitute natural gas with high content of methane, part of which is sent to the gas-steam combined cycle equipment while the other part is sent to a urban gas system. The enriched CO2 density of the system can reach 50 to 60 percent, technical probability is provided for reasonably realizing low-energy-consumption reduced exhaust of CO2, no change needs to be done with gas turbines, each chemical unit operates according to established rated condition and needs not to change load owing to power conditioning so as to improve the economy of the operation of power plants; compared with the prior art, the energy utilization efficiency of the whole system is improved so as to realize the efficient clean utilization of coal.

The invention relates to a synthesis gas methanation catalyst, which uses nickel oxide as active ingredients, uses cerium oxide modified medium-pore gamma-aluminum oxide as carriers and use oxide of transition metals of iridium, lanthanum, copper and ferrum or alkaline-earth metals of magnesium and calcium as auxiliary agents, wherein a preparation method of the medium-pore gamma-aluminum oxide adopts a hydrothermal synthesis method, and a nickel base catalyst is prepared by a soaking process, wherein the medium-pore gamma-aluminum oxide has the specific surface area being 200 to 400m<2>/g, the pore volume being 0.2 to 0.9cm<3>/g and the pore diameter being 2 to 15nm, the content of the active ingredients of the nickel oxide is 10 to 30 percent of the total weight of the catalyst, the content of the cerium oxide is 1 to 20 percent of the weight of the aluminum oxide, and the content of the auxiliary agents is 0.1 to 15 percent of the total weight of the catalysts. The synthesis gas methanation catalyst has the advantages that the preparation process is simple, the cerium oxide modified medium-pore gamma-aluminum oxide is used as the catalyst carriers, the obtained nickel base catalyst has good high-temperature resistance and anti-sintering resistance performance and has the advantages of high activity at low temperature, stability at high temperature and high methane selectivity, and the synthesis gas methanation catalyst has an important application value for synthesizing the substitute natural gas and solving the problem of natural gas shortage in the prior art.

A process and apparatus for converting a coal into a substitute natural gas generates raw gas in a conventional coal gasification unit and passes at least a portion of the raw gas into a partial oxidation unit to convert the at least portion of the raw gas into a secondary raw synthesis gas substantially devoid of higher hydrocarbons. Optionally, the raw gas is quenched and only the resulting condensate is passed to the partial oxidation unit for conversion to the secondary raw synthesis gas.

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 (H₂—CO₂)/(CO+CO₂) greater than 3.00. At the same time, a gas with a molar ratio (H₂—CO₂)/(CO+CO₂) 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.

A method for converting a raw gas into a methane-rich and/or hydrogen-rich gas includes the following steps: a) providing the raw gas stemming from a coal and/or biomass gasification process, thereby the raw gas comprising beside a methane and hydrogen content carbon monoxide, carbon dioxide, alkanes, alkenes, alkynes, tar, especially benzole and naphthalene, COS, hydrogen sulfide and organic sulfur compounds, especially thiophenes; thereby the ratio of hydrogen to carbon monoxide ranges from 0.3 to 4; b) bringing this raw gas into contact with a catalyst in a fluidized bed reactor at temperatures above 200° C. and at pressures equal or greater than 1 bar in order to convert the raw gas into a first product gas, thereby simultaneously converting organic sulfur components into hydrogen sulfide, reform tars, generate water/gas shift reaction and generate methane from the hydrogen/carbon monoxide content; c) bringing the first product gas into a sulfur absorption process to generate a second product gas, thereby reducing the content of hydrogen sulfur and COS from 100 to 1000 ppm down to 1000 ppb or less; d) optionally bringing the second product gas into a carbon dioxide removal process to generate a third product gas at least almost free of carbon dioxide; e) bringing the third product gas into a second methanation process to generate a fourth product gas having a methane content above 5 vol %; f) optionally bringing the fourth product gas into a carbon dioxide removal process to generate a fifth product gas at least almost free of carbon dioxide g) bringing the fifth product gas into an hydrogen separation process in order to separate a hydrogen rich gas from a remaining methane-rich gas, called substitute natural gas.

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.

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.

The present invention provides a system and method for producing substitute natural gas and electricity, while mitigating production of any greenhouse gasses. The system includes a hydrogasification reactor, to form a gas stream including natural gas and a char stream, and an oxygen burner to combust the char material to form carbon oxides. The system also includes an algae farm to convert the carbon oxides to hydrocarbon material and oxygen.

A method of producing substitute natural gas (SNG) includes providing a syngas stream that includes at least some carbon dioxide (CO₂) and hydrogen sulfide (H₂S). The method also includes separating at least a portion of the CO₂ and at least a portion of the H₂S from at least a portion of the syngas stream provided. The method further includes channeling at least a portion of the CO₂ and at least a portion of the H₂S separated from at least a portion of the syngas stream to at least one of a sequestration system and a gasification reactor.

The invention discloses a methanation technology for preparing substitute natural gas by using coal based syngas, and belongs to the technical field of new energy utilization. The coal based synthetic gas undergoes fine desulfurization, the obtained fresh gas is divided into two parts comprising a fresh gas A and a fresh gas B, the fresh gas A is mixed with recycle gas, the obtained gas mixture enters a first methanation reactor, the total concentration of CO and CO2 is not greater than 11%, the obtained first reaction product gas is mixed with the fresh gas B, the obtained mixed gas enters a second methanation reactor, the total concentration of CO and CO2 is not greater than 12%, parts of the above obtained second reaction product gas is recycled by a recycle compressor and returns to the inlet of the first methanation reactor, the rest of the second reaction product gas sequentially enters a third methanation reactor and a fourth methanation reactor for a methanation reaction, and the obtained fourth reaction product gas is condensed and separated to obtain the substitute natural gas with the methane content of 95% or less.

The invention provides a process for preparing substitute natural gas through sulphur-tolerant methanation of coal synthesis gas. The process is characterized in that the synthesis gas enters sulphur-tolerant methanation reactors I and II in sequence, and the mixed gas of the synthesis gas and water vapor enters a rectisol system so as to remove the impurities such as CO2, H2S and the like in the gas after undergoing sulphur-tolerant shift and sulphur-tolerant methanation reaction on a molybdenum-based bifunctional catalyst and then undergoes methanation reaction in methanation reactors I and II in sequence under the action of Ni-based methanation catalysts, thus obtaining the natural gas product. The process has the advantages of simple process flow, small equipment investment, low comprehensive energy consumption and excellent natural gas products.

A technology for producing methane through low-rank coal is that the low-rank coal is pyrolyzed so as to obtain pyro-char and pyrolysis gas which contains tar. The pyrolysis gas which contains the tar is cooled and separated so as to obtain the tar, water and the pyrolysis gas; the pyro-char is fed into a methanator, the easily reactive pyro-char is reacted with circulated hydrogen at a high temperature and a high pressure so as to obtain methanation gas, and the difficult reactive pyro-char is fed into a gasification reactor to be reacted with water vapor and oxygen, so that gasification gas is produced. The methanation gas and the gasification gas are used as heat sources to directly supply heat for the pyrolytic reaction of feed coal in a pyrolysis reactor. The pyrolysis gas and the gasification gas are separated or mixed to be converted, decarbonized and separated, so that hydrogen-rich gas is obtained, and the pyrolysis gas and the methanation gas are subjected to heat exchange, purified and separated to obtain the hydrogen-rich gas, so that hydrogen sources are provided for a methanation unit. The substitute natural gas which is produced by the technology has the advantages of high thermal efficiency, low hydrogen consumption, quick methanation reaction speed and the like.

Systems and methods for producing synthetic gas are provided. The method can include gasifying a carbonaceous feedstock in the presence of an oxidant within a gasifier to provide a raw syngas. The raw syngas can be cooled within a cooler to provide a cooled syngas. The cooled syngas can be processed within a purification system to provide a treated syngas. The purification system can include a saturator adapted to increase a moisture content of the cooled syngas. The treated syngas and a first heat transfer medium can be introduced to a methanator to provide a synthetic gas, a second heat transfer medium, and a methanation condensate. At least a portion of the methanation condensate can be recycled from the methanator to the saturator.

Systems and methods for producing synthetic natural gas are provided. The method can include gasifying a carbonaceous feedstock within a gasifier to provide a raw syngas. The raw syngas can be cooled to provide a cooled raw syngas. The cooled raw syngas can be processed in a purification system to provide treated syngas. The purification system can include a flash gas separator in fluid communication with the gasifier and a saturator. The treated syngas can be converted to synthetic natural gas to provide steam, a methanation condensate, and a synthetic natural gas. The methanation condensate can be introduced to the flash gas separator.

The invention relates to a process for preparing substitute natural gas from synthesis gas, which comprises the following steps that: after being subjected to detoxification and desulfuration, the raw materials are subjected to heat exchange and are mixed with recycle gas from a third methanator and the obtained mixture is divided into two strands, wherein the first strand enters a first methanator to be subjected to the methanation reaction; all high-temperature first synthesis gas obtained after the first strand of raw material gas reacts in the first methanator is sequentially fed into a steam superheater and a first waste heat boiler to be subjected to heat exchange and then is fed into a second methanator to be subjected to the further methanation reaction to obtain second synthesis gas; after being subjected to heat exchange, the second synthesis gas is mixed with the second strand of raw material gas, and then the mixture is fed into the third methanator; and third synthesis gas discharged out of the third methanator is divided into two strands after being subjected to heat exchange compression, one strand of the third synthesis gas serving as the recycle gas is mixed with the raw material gas, the rest of the third synthesis gas enters a fourth methanator to enable the unreacted raw material gas to be synthesized into methane so as to obtain the synthesis gas capable of replacing the natural gas. The process has the characteristics that the reaction temperature rise is easy to control; the utilization of system energy is optimized; and the like.

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. 0-5.0wt% 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.

The invention discloses a preparation method of a synthetic gas methanation catalyst. The preparation method is characterized in that a polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer, one or more aluminum sources, nickel nitrate and one or more auxiliaries as raw materials undergo a one-step synthesis reaction according to a certain ratio by a solvothermal method to produce a desired product. The preparation method has simple processes. The synthetic gas methanation catalyst obtained by the preparation method has a mesoporous structure and controllable aperture sizes and catalyst particle dispersity, can show good sintering resistance, high activity at a low temperature, stability at a high temperature and high methane selectivity in methanation, and has important application values in synthesis of substitute natural gas and solution of the existing natural gas shortage problem.

The invention relates to a methanation method for synthesizing substitute natural gas by using industrial hydrocarbon exhaust gas. The methanation method comprises the following steps of: carrying out third-order or fourth-order methanation reaction on the feed gas of the industrial hydrocarbon exhaust gas; thermally recycling; and cooling and separating to produce a qualified synthetic natural gas product. CO and CO2 in the industrial hydrocarbon exhaust gas are completely converted into methane to achieve the purpose of zero emission of CO2. According to the methanation method, the gas passes through a multistage methane reactor once, CO conversion and CO2 separation are not needed, meanwhile, a segmented cycle and a compressor are not needed for the process gas, thus the investment cost and the operation cost can be greatly reduced; the process flow is simple, reliable and efficient; the operation is convenient and stable, the temperature is easy to control; the energy consumption is low; and the economic benefit is obvious. The synthetic natural gas produced by using the industrial hydrocarbon exhaust gas meets the international standards, and can be directly used for producing compressed natural gas and liquefied natural gas.

The invention specifically relates to a core-shell cerium oxide-coated nickel catalyst for methanation, and a preparation method and application thereof, belonging to the field of preparation and application of methanation catalysts used for synthesis of substituted natural gas. The preparation method comprises the following steps: (1) preparation of core-shell nickel oleate-coated HPS sphere; (2) preparation of a precursor solution capable of forming a cerium oxide shell layer; and (3) preparation of a Ni-coated HPs-coated CeO2 precursor. The preparation method for the core-shell cerium oxide-coated nickel catalyst used for methanation is advanced, has accurate and detailed data and produces the catalyst with high quality and high purity, as high as 98%; the produced catalyst can effectively inhibit migration, agglomeration and sintering of the active component Ni at high temperature through confinement effect of the shell layer, prevents growth of Ni crystal grains to inhibit carbon deposit and has high catalytic activity, high methane selectivity and good stability; and the preparation method is an ideal method for preparation of the anti-sintering and anti-carbon deposit methanation catalyst.