Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified...Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified cellulosic material gained from spent coffee grounds as a tertiary adsorption treatment. The earth-alkaline metal ions and heavy metals were separated from the de-oiled produced water by addition of either sodium or potassium hydroxide in the presence of carbon dioxide or by direct addition of solid sodium carbonate. The resulting filtrate gave salt of industrial purity upon selective crystallization on evaporation.展开更多
Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline ...Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline metal ions, specifically calcium ions, of the de-oiled PW were removed by precipitation with sodium carbonate to give access to pure sodium chloride as industrial salt from the remaining PW. While the purity of the precipitated calcium carbonate (CaCO3) depends on the precipitation conditions, CaCO3 of up to 95.48% purity can be obtained, which makes it a salable product. The precipitation of CaCO3 decreases the amount of calcium ions in PW from 11,300 ppm to 84 ppm.展开更多
Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produc...Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produced water is either reinjected or disposed of after treatment, treated produced water is increasingly seen as an interesting resource, especially in water-scarce regions. This review looks at different PW treatment methods available, with an emphasis on the management of PW in oil- and gas production on the Arabian Peninsula.展开更多
Nowadays, we are in great lack of the technology theory for the storage and transportation of gas hydrate. Under this condition, after checking out related theory of these, we established the technology roadmap of the...Nowadays, we are in great lack of the technology theory for the storage and transportation of gas hydrate. Under this condition, after checking out related theory of these, we established the technology roadmap of the storage and transportation of gas hydrate by LNG technology. Study has shown that the technology of LNG is more saving than that of pipeline. Then we came out with the new idea of storage and transportation of hydrate by LNG technology.展开更多
The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydrauhc tractunng stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion o...The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydrauhc tractunng stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion of gas leaves the valuable condensate behind. In this paper, three enhanced gas recovery （EGR） methods including produced gas injection, CO2 injection and water injection are investigated to increase the well productivity for a tight gas condensate reservoir in the Montney Formation, Canada. The production performance of the three EGR methods is compared and their economic feasibility is evaluated. Sensitivity analysis of the key factors such as primary production duration, bottom-hole pressures, and fracture conductivity is conducted and their effects on the well production performance are analyzed. Results show that, compared with the simple depletion method, both the cumulative gas and condensate production increase with fluids injected. Produced gas injection leads to both a higher gas and condensate production compared with those of the CO2 injection, while waterflooding suffers from injection difficulty and the corresponding low sweep efficiency. Meanwhile, the injection cost is lower for the produced gas injection due to the on-site available gas source and minimal transport costs, gaining more economic benefits than the other EGR methods.展开更多
In this study,NiO/SBA-15 was prepared by both direct and post synthesis methods.TEM images revealed that NiO particles aggregated in NiO/SBA-15 obtained with post synthesis method,regardless of NiO loading.However,NiO...In this study,NiO/SBA-15 was prepared by both direct and post synthesis methods.TEM images revealed that NiO particles aggregated in NiO/SBA-15 obtained with post synthesis method,regardless of NiO loading.However,NiO particles were monodispersed in NiO/SBA-15 with a NiO loading of less than 15 wt%by using the direct synthesis method.In this case,NiO particles aggregated when NiO loading was over 20 wt%.TPR analysis verified that with direct synthesis method the location boundary of NiO particles on outer and pore surface could be observed clearly,whereas that could not observed in the case of post synthesis method.This indicates that the type of synthesis method displays significant effect on the location of NiO particles dispersed into the SBA-15.Producer gas conversion was carried out using NiO/SBA-15 as catalysts,which were synthesized with different synthesis methods.The gas conversion including methanation occurred at low temperature(i.e.,300-400℃)and the reverse water gas shift(RWGS)reaction at hightemperature(i.e.,400-900℃).High temperatures facilitated CO conversion to CO with CO selectivity close to 100%,regardless of the synthesis method of the used catalyst.At low temperatures the dispersion type of NiO particles affectedthe CO,conversion reaction,i.e.,monodispersed Ni0 particles gave a CO selectivity of close to 100%,similar to thatobtained at high temperature.The aggregated NiO particles resuled in a CO selectivity of less than 100%owing to CH,formation,regardless of synthesis method of catalyst.Therefore,NiO/SBA-15 obtained with direct synthesis methodfavored RWGS reaction because of high CO selectivity.NiOSBA-15 obtained with post synthesis method is suited formethanation because of high CH selectivity,and the conversion of CO,to CHa through methanation increased withincreasing NiO loading.展开更多
The electromotive force （e.m.f.） of solid oxide fuel cells using biomass produced gas （BPG） as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis...The electromotive force （e.m.f.） of solid oxide fuel cells using biomass produced gas （BPG） as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2, CO, CO2 and CH4. Compared with using hydrogen as a fuel, the e.m.f. for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition, the optimum amount of H2O to add is determined at various operating temperatures. Further the e.m.f, for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared. The study reveals that when using BPG as fuel, the depression of e.m.f, for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.展开更多
Producer gas through gasification of biomass can be used as an alternate fuel in rural areas due to high potential of biomass resources in India.Experiments were conducted to study the performance of a diesel engine(f...Producer gas through gasification of biomass can be used as an alternate fuel in rural areas due to high potential of biomass resources in India.Experiments were conducted to study the performance of a diesel engine(four stroke,single cylinder,5.25 kW) with respect to its thermal efficiency,specific fuel consumption and diesel substitution by use of diesel alone and producer gas-cum-diesel(dual fuel mode).Three types of biomass,i.e.wood chips,pigeon pea stalks and corn cobs were used for generation of producer gas.A producer gas system consisting of a downdraft gasifier,a cooling cum cleaning unit,a filtering unit and a gas air mixing device was designed,fabricated and used to power a 5.25 kW diesel engine on dual fuel mode.Performance of the engine was reported by keeping biomass moisture contents as 8%,12%,16%,and 21%,engine speed as 1 600 r/min and with variable engine loads.The average value of thermal efficiency on dual fuel mode was found slightly lower than that of diesel mode.The specific diesel consumption was found to be 60%-64% less in dual fuel mode than that in diesel mode for the same amount of energy output.The average diesel substitution of 74% was observed with wood chips followed by corn cobs(78%) and pigeon pea stalks(82%).Based on the performance studied,the producer gas may be used as a substitute or as supplementary fuel for diesel conservation,particularly for stationary engines in agricultural operations in the farm.展开更多
A high-density gas jet supersonic nozzle is reported in this paper. The jitter and actuation time of the nozzle is determined by the pin discharge and laser spark radiation respectively. The jitter time of the nozzle ...A high-density gas jet supersonic nozzle is reported in this paper. The jitter and actuation time of the nozzle is determined by the pin discharge and laser spark radiation respectively. The jitter time of the nozzle is within 10μs with the backing pressure as high as 25 bar. With a nanosecond laser pulse focused on the gas jet about 1 mm below the nozzle, the actuation time is calculated to be about 15 ms by detecting the laser produced spark radiation, which reveals the existence of the gas jet and the relative gas density evolving with time. Consequently the gas density is estimated to be well above 10^19 cm^-3, compared with theoretical simulations from the nozzle parameters.展开更多
To seek effective ways of lowering development cost and tapping inter-well remaining reserves, sidetracking horizontal wells from old wells in Su10 and Su53 Block were conducted. The engineering and geological problem...To seek effective ways of lowering development cost and tapping inter-well remaining reserves, sidetracking horizontal wells from old wells in Su10 and Su53 Block were conducted. The engineering and geological problems such as leakage, collapse and sticking in slim-hole sidetracking, and difficult evaluation of remaining gas were gradually overcome, and a set of drilling and completion technology, well deployment optimization technology and geo-steering technology suitable for sidetracking horizontal wells in tight sandstone gas reservoirs have been worked out. By making full use of the old well, sidetracking horizontal wells can greatly reduce development costs, enhance the producing degree of inter-well remaining reserves, and get production 3-5 times of that of adjacent vertical wells.Its production effect is influenced by encountered sandstone length, the position of the horizontal segment in the reservoir, produced effective reservoir thickness, gas saturation, controlled reserves and fracturing effect, etc. Up to now, in Block Su10 and Su53, 12 sidetracking horizontal wells have been drilled, which have an average drilling cycle of 49 days, average horizontal section length of 689 m,average effective drilling ratio of 61.5%, average well-head pressure of 16.2 MPa, and daily output of 4.7×10~4 m^3 at the initial stage after production. By the end of 2017, the average yield increment was more than 1 000×10~4 m^3 with good effect. With the increase of low yield old wells, wells in the enrichment regions tend to be saturated and the rest gas-bearing areas are lower in grade, therefore, sidetracking horizontal well can be used for optimization of well pattern, well deployment mode and exploitation of remaining oil areas.展开更多
The mulberry paper handmade dryer uses downdraft gasifier, which is a continuous hot air dryer. The downdraft gasifier uses charcoal or wood chip as fuel to produce the producer gas for a dryer heat source. Two steps ...The mulberry paper handmade dryer uses downdraft gasifier, which is a continuous hot air dryer. The downdraft gasifier uses charcoal or wood chip as fuel to produce the producer gas for a dryer heat source. Two steps operation of a dryer as follows： The frst was to reduce mulberry paper pulp moisture by an air vacuum pump; the second was a continuous hot air drying process. The optimum condition drying, the capacity of dryer, the fuel consumption, the drying constant （k） and economics analysis were investigated. It was found that the first step could be to reduce mulberry paper pulp moisture content about 25% and the suitable condition drying was 80 ~C drying temperature, 0.04 kg/s air mass flow rate and 0.29 m/min chain conveyor speed, respectively. The capacity of this dryer was 20 sheets per hour. The quality of mulberry paper product was very good （based on the standard of mulberry paper community 41/2546） and the fuel consumption rate was 5 kg/h （charcoal）. The drying constant was about 0.532933-0.541367 min~ and the drying constant was a function of drying temperature （T）, air mass flow rate （F） and conveyor speed （10 as equation of k（T, F, V） = 0.567494 ＋ 0.000422T- 1.40588F- 0.000205 V （R2 = 0.9254） and the breakeven point of dryer was 0.79 years.展开更多
With the opening of the Kela No. 2 gas field in the Tarim basin in China’s northwest Xinjiang Uygur Autonomous Region on Dec. 1, Xinjiang will produce 10 billion cubic meters of natural gas next year, becoming the co...With the opening of the Kela No. 2 gas field in the Tarim basin in China’s northwest Xinjiang Uygur Autonomous Region on Dec. 1, Xinjiang will produce 10 billion cubic meters of natural gas next year, becoming the country’s largest gas producer, according to an official with the China National Petroleum Corporation.展开更多
The Daning-Jixian block,the eastern edge of the Ordos Basin,is one of the most potential areas for CO_(2)geological storage,enhanced coalbed methane recovery(ECBM)exploration and production in China in recent decades....The Daning-Jixian block,the eastern edge of the Ordos Basin,is one of the most potential areas for CO_(2)geological storage,enhanced coalbed methane recovery(ECBM)exploration and production in China in recent decades.The ionic composition and total dissolved solids(TDS)of the produced water,coal organic matter maturity,molecular composition and carbon isotope characteristics of the produced gas were utilized to analyze the hydrogeological condition,CBM generation and migration characteristics in this area.The CBM enrichment patterns and the geological impacts on gas well production characteristics were revealed.The optimal area for CBM development and CO_(2)geological storage in the study area were also proposed.Dominated by the Xueguan reverse fault zone,the hydraulic unit in this area can be divided into two parts(i.e.,the recharge-runoff zone in the east and the weak runoff-stagnation zone in the west).The thermogenic gas is dominating CBM genesis in this area.Secondary biogenic gas replenishment is only distributed in the eastern margin area,where theδ13C1 value is less than the thermal simulation results as an influence of hydrodynamic fractionation.Finally,two models of CBM formation and accumulation were proposed,1)thermogenic CBM migrated by hydrodynamic and resorbed for preservation at impermeable fault boundaries;2)thermogenic CBM trapped by fault and accumulated by hydrodynamic in slope zone.The gas production performance,generally increased from east to west,is mainly dominated by hydrogeological conditions.Generally,the west side of the fault zone is the enrichment and high-yield area for ECBM development and CO_(2)geological storage in the study area.展开更多
The core of coal-derived gas theory is that coal measure is the gas source, and the hydrocarbon generation of coal measure is dominated by gas and supplemented by oil, so discoveries in related basins are dominated by...The core of coal-derived gas theory is that coal measure is the gas source, and the hydrocarbon generation of coal measure is dominated by gas and supplemented by oil, so discoveries in related basins are dominated by gas fields. Discovering and developing giant gas fields, especially those super giant gas fields with recoverable reserves more than 1×10^12 m^3, plays a key role in determining whether a country can be a major gas producing country with annual output over 500×10^8 m^3. The coal resource and coal-derived gas reserves are abundant and widespread in the world, and coal-derived gas makes a major contribution to the gas reserves and gas production in the world. By the end of 2017, 13 super giant coal-derived gas fields have been discovered in the world. The total initial recoverable reserves were 49.995 28×10^12 m^3, accounting for 25.8% of the total remaining recoverable reserves (193.5×10^12 m^3) in that year in the world. In 2017, there were 15 giant gas producing countries in the world, with a total gas yield of 28 567×10^8 m^3. Among them, six major coal-derived gas producing countries had a total gas yield of 11 369×10^8 m^3, accounting for 39.8% of total gas yield of major gas producing countries. The Urengoi gas field is a super giant coal-derived gas field with the most cumulative gas production in the world. By the end of 2015, the Urengoi gas field had cumulative gas production of 63 043.96×10^8 m^3, with the highest annual gas yield in the world. Its gas output was 3 300×10^8 m^3 in 1989, accounting for 41.4% and 15.7% of the gas output of Russia and the world, respectively. This study introduces the gas source rocks of the basins with super giant coal-derived gas fields in Russia, Turkmenistan, Netherlands, Mozambique and China, and their significances for these countries becoming giant gas producing countries in the world.展开更多
Biomass gasification is a well-developed technology with the potential to convert agricultural residues to value-added products. The availability of on-farm gasifiers that can handle low-density agricultural wastes su...Biomass gasification is a well-developed technology with the potential to convert agricultural residues to value-added products. The availability of on-farm gasifiers that can handle low-density agricultural wastes such as soybean residue, an underutilized feedstock, is limited. Therefore, the goal of this research was to install and assess an allothermal, externally heated, auger gasifier capable of converting agricultural wastes to combustible gas for on-farm grain drying. The system was used to convert soybean residues under different reactor temperature, i.e., 700°C, 750°C, 800°C, and 850°C. The results showed that increasing the reactor temperature from 700°C to 850°C increased the producer gas molar fractions of H2, CO, and CH4, from 1.1% to 1.5%, from 15.0% to 23.8%, and from 5.1% to 7.7%, respectively. The higher heating value of the producer gas reached 6.3 MJ/m3 at reactor temperature of 850°C. Specific gas yield increased from 0.32 to 0.58 m3/kgbiomass while char and particulate yield decreased from 41.7% to 33.6% by increasing the reactor temperature from 700°C to 850°C. Maximum carbon sequestration achieved, in the form of biochar-carbon, was 32% of the raw feedstock carbon. Gasification of collectable soybean residues from 1 acre would be sufficient to dry 1132 kg of soybean seeds (the average yield from one acre)展开更多
Sawdust which is basically considered as?a timber-industrial waste?that pollutes the environment can become a valuable commodity which is considered in three ways: Manufacturing, Energy and Agricultural utilization. T...Sawdust which is basically considered as?a timber-industrial waste?that pollutes the environment can become a valuable commodity which is considered in three ways: Manufacturing, Energy and Agricultural utilization. The sawdust is burnt in an updraft gasifier under a limited supply of air to obtain?producer gas which is carbon II oxide and hydrogen as main components. The sawdust and other biomass materials are mixed in certain proportions, then bound together and palletized to a small blocks called briquettes. The material?was also considered to be composted by mixing it with animal digestion or?wood ashes and calcium carbonate to form fertilizers. The sawdust and wood shavings can be used for particle board as well as oil production.展开更多
During the last years many authors have char-acterized the produced formation waters (PFWs) with respect to chemical compounds and toxic-ity. Most of data are related to PFWs collected on offshore platform after treat...During the last years many authors have char-acterized the produced formation waters (PFWs) with respect to chemical compounds and toxic-ity. Most of data are related to PFWs collected on offshore platform after treatment process. The available results showed that the particulate phase had an influence on PFW toxicity. As-suming the toxicity of PFWs treated on platform, the aim of this paper is to study the toxicity of these PFWs after a further filtration treatment carried out in laboratory. For this purpose PFWs were sampled from three natural gas platforms located in the Adriatic Sea (Italy) below treat-ment system. The eco-toxicological bioassays have been conducted on test-organisms be-longing to different trophic levels such as bac-teria, algae, crustaceans and fishes. The PFWs resulted toxic according to an overall assess-ment obtained through the bioassays. Further-more, it has been possible to identify the spe-cies that were more sensitive to the tested PFWs, namely Tigriopus fulvus, Dicentrarchus labrax and Vibrio fischeri. Besides, a chemical char-acterization was reported related to the con-taminants present in the PFWs to go with eco-toxicological assessment. Barium, zinc and manganese showed the most concentrations among the metals and the lower molecular weight components were common among the organic compounds. Some differences among PFWs were observed both for toxicity and chemical composition. The highest toxicity was recorded in PFWs (PFW1 and PFW2) containing the highest concentrations of some metals (Ba, Mn and Zn) and/or BTEX.展开更多
The most important waste stream created during oil and gas production is oilfield-produced water.When discharged without treatment,it poses a significant risk of pollution of marine ecosystems.While adequate treatment...The most important waste stream created during oil and gas production is oilfield-produced water.When discharged without treatment,it poses a significant risk of pollution of marine ecosystems.While adequate treatment before disposal is acceptable,achieving authorized discharge criteria continues to be a problem for the petroleum sector.This research examined the physicochemical characteristics of produced water at various month intervals before and after treatment.Heavy metal and organic component concentrations in water samples were determined using atomic absorption spectroscopy and gas chromatography.The results indicate that produced water from a certain Niger Delta oilfield contains significant amounts of heavy metals and some organic compounds after treatment.The present laws,as well as the measurement of dispersed oil and grease content,have been in place for a long period of time without considerable change,even though most dangerous components in produced water are dissolved.It is recommendable for the prospective field developers/operators to consider the dissolved components of produced water and consider the economic consequences of adopting tertiary produced water polishing technologies.展开更多
文摘Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified cellulosic material gained from spent coffee grounds as a tertiary adsorption treatment. The earth-alkaline metal ions and heavy metals were separated from the de-oiled produced water by addition of either sodium or potassium hydroxide in the presence of carbon dioxide or by direct addition of solid sodium carbonate. The resulting filtrate gave salt of industrial purity upon selective crystallization on evaporation.
文摘Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline metal ions, specifically calcium ions, of the de-oiled PW were removed by precipitation with sodium carbonate to give access to pure sodium chloride as industrial salt from the remaining PW. While the purity of the precipitated calcium carbonate (CaCO3) depends on the precipitation conditions, CaCO3 of up to 95.48% purity can be obtained, which makes it a salable product. The precipitation of CaCO3 decreases the amount of calcium ions in PW from 11,300 ppm to 84 ppm.
文摘Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produced water is either reinjected or disposed of after treatment, treated produced water is increasingly seen as an interesting resource, especially in water-scarce regions. This review looks at different PW treatment methods available, with an emphasis on the management of PW in oil- and gas production on the Arabian Peninsula.
文摘Nowadays, we are in great lack of the technology theory for the storage and transportation of gas hydrate. Under this condition, after checking out related theory of these, we established the technology roadmap of the storage and transportation of gas hydrate by LNG technology. Study has shown that the technology of LNG is more saving than that of pipeline. Then we came out with the new idea of storage and transportation of hydrate by LNG technology.
基金funding from Natural Sciences and Engineering Research Council of Canada (NSERC) for this researchsupport from the University of Calgary Beijing Research Site, a research initiative associated with the University of Calgary Global Research Initiative in Sustainable Low Carbon Unconventional Resources, the Kerui Group, and the Mitacs Accelerate program
文摘The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydrauhc tractunng stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion of gas leaves the valuable condensate behind. In this paper, three enhanced gas recovery （EGR） methods including produced gas injection, CO2 injection and water injection are investigated to increase the well productivity for a tight gas condensate reservoir in the Montney Formation, Canada. The production performance of the three EGR methods is compared and their economic feasibility is evaluated. Sensitivity analysis of the key factors such as primary production duration, bottom-hole pressures, and fracture conductivity is conducted and their effects on the well production performance are analyzed. Results show that, compared with the simple depletion method, both the cumulative gas and condensate production increase with fluids injected. Produced gas injection leads to both a higher gas and condensate production compared with those of the CO2 injection, while waterflooding suffers from injection difficulty and the corresponding low sweep efficiency. Meanwhile, the injection cost is lower for the produced gas injection due to the on-site available gas source and minimal transport costs, gaining more economic benefits than the other EGR methods.
文摘In this study,NiO/SBA-15 was prepared by both direct and post synthesis methods.TEM images revealed that NiO particles aggregated in NiO/SBA-15 obtained with post synthesis method,regardless of NiO loading.However,NiO particles were monodispersed in NiO/SBA-15 with a NiO loading of less than 15 wt%by using the direct synthesis method.In this case,NiO particles aggregated when NiO loading was over 20 wt%.TPR analysis verified that with direct synthesis method the location boundary of NiO particles on outer and pore surface could be observed clearly,whereas that could not observed in the case of post synthesis method.This indicates that the type of synthesis method displays significant effect on the location of NiO particles dispersed into the SBA-15.Producer gas conversion was carried out using NiO/SBA-15 as catalysts,which were synthesized with different synthesis methods.The gas conversion including methanation occurred at low temperature(i.e.,300-400℃)and the reverse water gas shift(RWGS)reaction at hightemperature(i.e.,400-900℃).High temperatures facilitated CO conversion to CO with CO selectivity close to 100%,regardless of the synthesis method of the used catalyst.At low temperatures the dispersion type of NiO particles affectedthe CO,conversion reaction,i.e.,monodispersed Ni0 particles gave a CO selectivity of close to 100%,similar to thatobtained at high temperature.The aggregated NiO particles resuled in a CO selectivity of less than 100%owing to CH,formation,regardless of synthesis method of catalyst.Therefore,NiO/SBA-15 obtained with direct synthesis methodfavored RWGS reaction because of high CO selectivity.NiOSBA-15 obtained with post synthesis method is suited formethanation because of high CH selectivity,and the conversion of CO,to CHa through methanation increased withincreasing NiO loading.
基金V. ACKN0WLEDGMENT This work was supported by the National Natural Science Foundation of China （No.50372066 and No.50332040）.
文摘The electromotive force （e.m.f.） of solid oxide fuel cells using biomass produced gas （BPG） as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2, CO, CO2 and CH4. Compared with using hydrogen as a fuel, the e.m.f. for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition, the optimum amount of H2O to add is determined at various operating temperatures. Further the e.m.f, for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared. The study reveals that when using BPG as fuel, the depression of e.m.f, for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.
文摘Producer gas through gasification of biomass can be used as an alternate fuel in rural areas due to high potential of biomass resources in India.Experiments were conducted to study the performance of a diesel engine(four stroke,single cylinder,5.25 kW) with respect to its thermal efficiency,specific fuel consumption and diesel substitution by use of diesel alone and producer gas-cum-diesel(dual fuel mode).Three types of biomass,i.e.wood chips,pigeon pea stalks and corn cobs were used for generation of producer gas.A producer gas system consisting of a downdraft gasifier,a cooling cum cleaning unit,a filtering unit and a gas air mixing device was designed,fabricated and used to power a 5.25 kW diesel engine on dual fuel mode.Performance of the engine was reported by keeping biomass moisture contents as 8%,12%,16%,and 21%,engine speed as 1 600 r/min and with variable engine loads.The average value of thermal efficiency on dual fuel mode was found slightly lower than that of diesel mode.The specific diesel consumption was found to be 60%-64% less in dual fuel mode than that in diesel mode for the same amount of energy output.The average diesel substitution of 74% was observed with wood chips followed by corn cobs(78%) and pigeon pea stalks(82%).Based on the performance studied,the producer gas may be used as a substitute or as supplementary fuel for diesel conservation,particularly for stationary engines in agricultural operations in the farm.
基金supported by the National Natural Science Foundation of China (No.10474081)
文摘A high-density gas jet supersonic nozzle is reported in this paper. The jitter and actuation time of the nozzle is determined by the pin discharge and laser spark radiation respectively. The jitter time of the nozzle is within 10μs with the backing pressure as high as 25 bar. With a nanosecond laser pulse focused on the gas jet about 1 mm below the nozzle, the actuation time is calculated to be about 15 ms by detecting the laser produced spark radiation, which reveals the existence of the gas jet and the relative gas density evolving with time. Consequently the gas density is estimated to be well above 10^19 cm^-3, compared with theoretical simulations from the nozzle parameters.
基金Supported by the Project of Great Wall Drilling Company in CNPC(2015A25-2(2012))
文摘To seek effective ways of lowering development cost and tapping inter-well remaining reserves, sidetracking horizontal wells from old wells in Su10 and Su53 Block were conducted. The engineering and geological problems such as leakage, collapse and sticking in slim-hole sidetracking, and difficult evaluation of remaining gas were gradually overcome, and a set of drilling and completion technology, well deployment optimization technology and geo-steering technology suitable for sidetracking horizontal wells in tight sandstone gas reservoirs have been worked out. By making full use of the old well, sidetracking horizontal wells can greatly reduce development costs, enhance the producing degree of inter-well remaining reserves, and get production 3-5 times of that of adjacent vertical wells.Its production effect is influenced by encountered sandstone length, the position of the horizontal segment in the reservoir, produced effective reservoir thickness, gas saturation, controlled reserves and fracturing effect, etc. Up to now, in Block Su10 and Su53, 12 sidetracking horizontal wells have been drilled, which have an average drilling cycle of 49 days, average horizontal section length of 689 m,average effective drilling ratio of 61.5%, average well-head pressure of 16.2 MPa, and daily output of 4.7×10~4 m^3 at the initial stage after production. By the end of 2017, the average yield increment was more than 1 000×10~4 m^3 with good effect. With the increase of low yield old wells, wells in the enrichment regions tend to be saturated and the rest gas-bearing areas are lower in grade, therefore, sidetracking horizontal well can be used for optimization of well pattern, well deployment mode and exploitation of remaining oil areas.
文摘The mulberry paper handmade dryer uses downdraft gasifier, which is a continuous hot air dryer. The downdraft gasifier uses charcoal or wood chip as fuel to produce the producer gas for a dryer heat source. Two steps operation of a dryer as follows： The frst was to reduce mulberry paper pulp moisture by an air vacuum pump; the second was a continuous hot air drying process. The optimum condition drying, the capacity of dryer, the fuel consumption, the drying constant （k） and economics analysis were investigated. It was found that the first step could be to reduce mulberry paper pulp moisture content about 25% and the suitable condition drying was 80 ~C drying temperature, 0.04 kg/s air mass flow rate and 0.29 m/min chain conveyor speed, respectively. The capacity of this dryer was 20 sheets per hour. The quality of mulberry paper product was very good （based on the standard of mulberry paper community 41/2546） and the fuel consumption rate was 5 kg/h （charcoal）. The drying constant was about 0.532933-0.541367 min~ and the drying constant was a function of drying temperature （T）, air mass flow rate （F） and conveyor speed （10 as equation of k（T, F, V） = 0.567494 ＋ 0.000422T- 1.40588F- 0.000205 V （R2 = 0.9254） and the breakeven point of dryer was 0.79 years.
文摘With the opening of the Kela No. 2 gas field in the Tarim basin in China’s northwest Xinjiang Uygur Autonomous Region on Dec. 1, Xinjiang will produce 10 billion cubic meters of natural gas next year, becoming the country’s largest gas producer, according to an official with the China National Petroleum Corporation.
基金the National Natural Science Foundation of China(Grant No.41902178)the National Science and Technology Major Project(Oil&Gas)(No.2016ZX05065)+1 种基金the Natural Science Foundation of Shanxi Province,China(No.20210302123165)the Open Fund of Beijing Key Laboratory of Unconventional Natural Gas Geological Evaluation and Development Engineering,China University of Geosciences(Beijing)(No.2019BJ02001).
文摘The Daning-Jixian block,the eastern edge of the Ordos Basin,is one of the most potential areas for CO_(2)geological storage,enhanced coalbed methane recovery(ECBM)exploration and production in China in recent decades.The ionic composition and total dissolved solids(TDS)of the produced water,coal organic matter maturity,molecular composition and carbon isotope characteristics of the produced gas were utilized to analyze the hydrogeological condition,CBM generation and migration characteristics in this area.The CBM enrichment patterns and the geological impacts on gas well production characteristics were revealed.The optimal area for CBM development and CO_(2)geological storage in the study area were also proposed.Dominated by the Xueguan reverse fault zone,the hydraulic unit in this area can be divided into two parts(i.e.,the recharge-runoff zone in the east and the weak runoff-stagnation zone in the west).The thermogenic gas is dominating CBM genesis in this area.Secondary biogenic gas replenishment is only distributed in the eastern margin area,where theδ13C1 value is less than the thermal simulation results as an influence of hydrodynamic fractionation.Finally,two models of CBM formation and accumulation were proposed,1)thermogenic CBM migrated by hydrodynamic and resorbed for preservation at impermeable fault boundaries;2)thermogenic CBM trapped by fault and accumulated by hydrodynamic in slope zone.The gas production performance,generally increased from east to west,is mainly dominated by hydrogeological conditions.Generally,the west side of the fault zone is the enrichment and high-yield area for ECBM development and CO_(2)geological storage in the study area.
基金Supported by the National Natural Science Foundation of China(41472120)
文摘The core of coal-derived gas theory is that coal measure is the gas source, and the hydrocarbon generation of coal measure is dominated by gas and supplemented by oil, so discoveries in related basins are dominated by gas fields. Discovering and developing giant gas fields, especially those super giant gas fields with recoverable reserves more than 1×10^12 m^3, plays a key role in determining whether a country can be a major gas producing country with annual output over 500×10^8 m^3. The coal resource and coal-derived gas reserves are abundant and widespread in the world, and coal-derived gas makes a major contribution to the gas reserves and gas production in the world. By the end of 2017, 13 super giant coal-derived gas fields have been discovered in the world. The total initial recoverable reserves were 49.995 28×10^12 m^3, accounting for 25.8% of the total remaining recoverable reserves (193.5×10^12 m^3) in that year in the world. In 2017, there were 15 giant gas producing countries in the world, with a total gas yield of 28 567×10^8 m^3. Among them, six major coal-derived gas producing countries had a total gas yield of 11 369×10^8 m^3, accounting for 39.8% of total gas yield of major gas producing countries. The Urengoi gas field is a super giant coal-derived gas field with the most cumulative gas production in the world. By the end of 2015, the Urengoi gas field had cumulative gas production of 63 043.96×10^8 m^3, with the highest annual gas yield in the world. Its gas output was 3 300×10^8 m^3 in 1989, accounting for 41.4% and 15.7% of the gas output of Russia and the world, respectively. This study introduces the gas source rocks of the basins with super giant coal-derived gas fields in Russia, Turkmenistan, Netherlands, Mozambique and China, and their significances for these countries becoming giant gas producing countries in the world.
文摘Biomass gasification is a well-developed technology with the potential to convert agricultural residues to value-added products. The availability of on-farm gasifiers that can handle low-density agricultural wastes such as soybean residue, an underutilized feedstock, is limited. Therefore, the goal of this research was to install and assess an allothermal, externally heated, auger gasifier capable of converting agricultural wastes to combustible gas for on-farm grain drying. The system was used to convert soybean residues under different reactor temperature, i.e., 700°C, 750°C, 800°C, and 850°C. The results showed that increasing the reactor temperature from 700°C to 850°C increased the producer gas molar fractions of H2, CO, and CH4, from 1.1% to 1.5%, from 15.0% to 23.8%, and from 5.1% to 7.7%, respectively. The higher heating value of the producer gas reached 6.3 MJ/m3 at reactor temperature of 850°C. Specific gas yield increased from 0.32 to 0.58 m3/kgbiomass while char and particulate yield decreased from 41.7% to 33.6% by increasing the reactor temperature from 700°C to 850°C. Maximum carbon sequestration achieved, in the form of biochar-carbon, was 32% of the raw feedstock carbon. Gasification of collectable soybean residues from 1 acre would be sufficient to dry 1132 kg of soybean seeds (the average yield from one acre)
文摘Sawdust which is basically considered as?a timber-industrial waste?that pollutes the environment can become a valuable commodity which is considered in three ways: Manufacturing, Energy and Agricultural utilization. The sawdust is burnt in an updraft gasifier under a limited supply of air to obtain?producer gas which is carbon II oxide and hydrogen as main components. The sawdust and other biomass materials are mixed in certain proportions, then bound together and palletized to a small blocks called briquettes. The material?was also considered to be composted by mixing it with animal digestion or?wood ashes and calcium carbonate to form fertilizers. The sawdust and wood shavings can be used for particle board as well as oil production.
文摘During the last years many authors have char-acterized the produced formation waters (PFWs) with respect to chemical compounds and toxic-ity. Most of data are related to PFWs collected on offshore platform after treatment process. The available results showed that the particulate phase had an influence on PFW toxicity. As-suming the toxicity of PFWs treated on platform, the aim of this paper is to study the toxicity of these PFWs after a further filtration treatment carried out in laboratory. For this purpose PFWs were sampled from three natural gas platforms located in the Adriatic Sea (Italy) below treat-ment system. The eco-toxicological bioassays have been conducted on test-organisms be-longing to different trophic levels such as bac-teria, algae, crustaceans and fishes. The PFWs resulted toxic according to an overall assess-ment obtained through the bioassays. Further-more, it has been possible to identify the spe-cies that were more sensitive to the tested PFWs, namely Tigriopus fulvus, Dicentrarchus labrax and Vibrio fischeri. Besides, a chemical char-acterization was reported related to the con-taminants present in the PFWs to go with eco-toxicological assessment. Barium, zinc and manganese showed the most concentrations among the metals and the lower molecular weight components were common among the organic compounds. Some differences among PFWs were observed both for toxicity and chemical composition. The highest toxicity was recorded in PFWs (PFW1 and PFW2) containing the highest concentrations of some metals (Ba, Mn and Zn) and/or BTEX.
文摘The most important waste stream created during oil and gas production is oilfield-produced water.When discharged without treatment,it poses a significant risk of pollution of marine ecosystems.While adequate treatment before disposal is acceptable,achieving authorized discharge criteria continues to be a problem for the petroleum sector.This research examined the physicochemical characteristics of produced water at various month intervals before and after treatment.Heavy metal and organic component concentrations in water samples were determined using atomic absorption spectroscopy and gas chromatography.The results indicate that produced water from a certain Niger Delta oilfield contains significant amounts of heavy metals and some organic compounds after treatment.The present laws,as well as the measurement of dispersed oil and grease content,have been in place for a long period of time without considerable change,even though most dangerous components in produced water are dissolved.It is recommendable for the prospective field developers/operators to consider the dissolved components of produced water and consider the economic consequences of adopting tertiary produced water polishing technologies.
