The purpose of this study is to investigate the catalytic effects of alkali and alkaline earth metallic species (AAEM) on char conversion during the gasification in steam and the changes in ex-situ char reactivity i...The purpose of this study is to investigate the catalytic effects of alkali and alkaline earth metallic species (AAEM) on char conversion during the gasification in steam and the changes in ex-situ char reactivity in oxygen after the gasification in steam using different forms (i.e. H-form, Na-form) of Shengli brown coal. The surface area, AAEM concentration and carbon crystallite of chars were obtained to understand the change in char reactivity. It was found that not only Na concentration and carbon structure were the main factors governing the char reactivity in the atmosphere of steam and oxygen, but also they interacted each other. The presence of Na could facilitate the formation of disordering carbon structure in char, and the amorphous carbon structure would in turn affect the distribution of Na and thus its catalytic performance. The surface area and pore volume had very little relationship with the char's reactivity. Addi- tionally, the morphology of chars from different forms of coals were observed using scanning electron microscope (SEM).展开更多
To optimize the technological parameter of underground coal gasification (UCG), the experimental results of air gasification, air-steam gasification, oxygen-enrichment steam gasification, pure oxygen steam gasificat...To optimize the technological parameter of underground coal gasification (UCG), the experimental results of air gasification, air-steam gasification, oxygen-enrichment steam gasification, pure oxygen steam gasification and two-stage gasification were studied contrastively based on field trial at the Huating UCG project. The results indicate that the average low heat value of gas from air experiment is the lowest (4.1 MJ/Nm3) and the water gas from two-stage gasification experiment is the highest (10.72 MJ/Nm3). The gas productivity of air gasification is the highest and the pure oxygen steam gasification is the lowest. The gasification efficiency of air gasification, air-steam gasification, oxygen-enriched steam gasification, pure oxygen steam gasification and two-stage gasification is listed in ascending order, ranging from 69.88% to 84.81%. Described a contract study on results of a field test using steam and various levels of oxygen enrichment of 21%, 32%, 42% and 100%. The results show that, with the increasing of O2 content in gasifying agents, the gas caloricity rises, and the optimal O2 concentration range to increase the gas caloricity is 30%-40%. Meanwhile, the consumption of O2 and steam increase, and the air consumption and steam decomposition efficiency fall.展开更多
The aim of this paper was preliminary design of the process for low-temperature coal tar hydrocrackmg m supercritical gasoline based on Aspen Plus with the concept of energy self-sustainability. In order to ensure the...The aim of this paper was preliminary design of the process for low-temperature coal tar hydrocrackmg m supercritical gasoline based on Aspen Plus with the concept of energy self-sustainability. In order to ensure the correct- ness and accuracy of the simulation, we did the following tasks: selecting reasonable model compounds for low-tem- perature coal tar; describing the nature of products gasoline and diesel accurately; and confirming the proper property study method for each block by means of experience and trial. The purpose of energy self-sustainability could be pos- sibly achieved, on one hand, by using hot stream to preheat cold stream and achieving temperature control of streams, and on the other hand, by utilizing gas (byproduct of the coal tar hydrocracking) combustion reaction to provide energy. Results showed that the whole process could provide a positive net power of about 609 kW-h for processing the low- temperature coal tar with a flowrate of 2 268 kg/h. The total heat recovery amounted to 2 229 kW-h, among which 845 kW'h was obtained from the gas combustion reaction, and 1 116 kW'h was provided by the reactor's outlet stream, with the rest furnished by hot streams of the products gasoline, diesel and residue. In addition, the process flow sheet could achieve products separation well, and specifically the purity of product gasoline and diesel reached 97.2% and 100%, respectively.展开更多
The coke plant of a steel plant corresponds to the area that transforms a blend of coal into coke for using in blast furnace and steam to power plant. The coking plant of ThyssenKrupp CSA uses the heat recovery techno...The coke plant of a steel plant corresponds to the area that transforms a blend of coal into coke for using in blast furnace and steam to power plant. The coking plant of ThyssenKrupp CSA uses the heat recovery technology with stamping charger for stamping and preparation a blend of coals for charging and coking. Stamping technology adds several benefits to the process, such as increased density, homogeneity and alignment of the coal cake charged into the oven, as well as provides better control of the coking process, improves parameters of coke quality and allows coal blending with lower coking power, thereby reducing the production cost of coke and power generation. Through the automation of stamping charger, it is possible to evaluate and calculate the stamped coal density charged and the productivity gains this system provides.展开更多
Combustion of biogas in gas turbines is an interesting option for provision of renewable combined heat and power from biomass. Due to an increasing share of fluctuating renewable energies in the power grid(especially ...Combustion of biogas in gas turbines is an interesting option for provision of renewable combined heat and power from biomass. Due to an increasing share of fluctuating renewable energies in the power grid(especially from wind and solar power), flexible power generation is of increasing importance. Additionally, with an increasing share of agricultural and municipal waste in biogas production, biogas composition is expected to be within a broader range. In this paper, the combustion of synthetic biogas(carbon dioxide and methane) in a combustion test rig with a swirl burner and a high pressure optical chamber is researched at different conditions. Results are compared to a CHEMKIN-PRO simulation using a detailed reaction mechanism. The results show that within the researched experimental matrix, stable biogas combustion for gas turbines can be achieved even with significantly changing gas composition and nominal power. Carbon dioxide concentration is varied from 0 to 60%. CO concentrations(normalized to 15% O_2) in the flue gas do not change significantly with increasing carbon dioxide in the fuel gas and, for the researched conditions, stayed below 10 ppm. NO_x concentration is below 10 ppm(normalized to 15% O_2) for pure methane, and is further decreasing with increasing carbon dioxide share in the fuel gas, which is mainly due to changing reaction paths as reaction analysis showed. Thermal load of the combustor is varied from 100% to 20% for the reference gas composition. With decreasing thermal load, normalized carbon monoxide flue gas concentration is further reduced, while NOx concentrations are remaining at a similar level around 5 ppm(normalized to 15% O_2).展开更多
文摘The purpose of this study is to investigate the catalytic effects of alkali and alkaline earth metallic species (AAEM) on char conversion during the gasification in steam and the changes in ex-situ char reactivity in oxygen after the gasification in steam using different forms (i.e. H-form, Na-form) of Shengli brown coal. The surface area, AAEM concentration and carbon crystallite of chars were obtained to understand the change in char reactivity. It was found that not only Na concentration and carbon structure were the main factors governing the char reactivity in the atmosphere of steam and oxygen, but also they interacted each other. The presence of Na could facilitate the formation of disordering carbon structure in char, and the amorphous carbon structure would in turn affect the distribution of Na and thus its catalytic performance. The surface area and pore volume had very little relationship with the char's reactivity. Addi- tionally, the morphology of chars from different forms of coals were observed using scanning electron microscope (SEM).
文摘To optimize the technological parameter of underground coal gasification (UCG), the experimental results of air gasification, air-steam gasification, oxygen-enrichment steam gasification, pure oxygen steam gasification and two-stage gasification were studied contrastively based on field trial at the Huating UCG project. The results indicate that the average low heat value of gas from air experiment is the lowest (4.1 MJ/Nm3) and the water gas from two-stage gasification experiment is the highest (10.72 MJ/Nm3). The gas productivity of air gasification is the highest and the pure oxygen steam gasification is the lowest. The gasification efficiency of air gasification, air-steam gasification, oxygen-enriched steam gasification, pure oxygen steam gasification and two-stage gasification is listed in ascending order, ranging from 69.88% to 84.81%. Described a contract study on results of a field test using steam and various levels of oxygen enrichment of 21%, 32%, 42% and 100%. The results show that, with the increasing of O2 content in gasifying agents, the gas caloricity rises, and the optimal O2 concentration range to increase the gas caloricity is 30%-40%. Meanwhile, the consumption of O2 and steam increase, and the air consumption and steam decomposition efficiency fall.
基金the financial support from the National Natural Science Foundation of China(No.2117619)the Shaanxi Province Major Project of Innovation of Science and Technology(No.2008zkc03205,No.2011KTZB03-03-01)
文摘The aim of this paper was preliminary design of the process for low-temperature coal tar hydrocrackmg m supercritical gasoline based on Aspen Plus with the concept of energy self-sustainability. In order to ensure the correct- ness and accuracy of the simulation, we did the following tasks: selecting reasonable model compounds for low-tem- perature coal tar; describing the nature of products gasoline and diesel accurately; and confirming the proper property study method for each block by means of experience and trial. The purpose of energy self-sustainability could be pos- sibly achieved, on one hand, by using hot stream to preheat cold stream and achieving temperature control of streams, and on the other hand, by utilizing gas (byproduct of the coal tar hydrocracking) combustion reaction to provide energy. Results showed that the whole process could provide a positive net power of about 609 kW-h for processing the low- temperature coal tar with a flowrate of 2 268 kg/h. The total heat recovery amounted to 2 229 kW-h, among which 845 kW'h was obtained from the gas combustion reaction, and 1 116 kW'h was provided by the reactor's outlet stream, with the rest furnished by hot streams of the products gasoline, diesel and residue. In addition, the process flow sheet could achieve products separation well, and specifically the purity of product gasoline and diesel reached 97.2% and 100%, respectively.
文摘The coke plant of a steel plant corresponds to the area that transforms a blend of coal into coke for using in blast furnace and steam to power plant. The coking plant of ThyssenKrupp CSA uses the heat recovery technology with stamping charger for stamping and preparation a blend of coals for charging and coking. Stamping technology adds several benefits to the process, such as increased density, homogeneity and alignment of the coal cake charged into the oven, as well as provides better control of the coking process, improves parameters of coke quality and allows coal blending with lower coking power, thereby reducing the production cost of coke and power generation. Through the automation of stamping charger, it is possible to evaluate and calculate the stamped coal density charged and the productivity gains this system provides.
基金the support from the Biofuels Research Infrastructure for Sharing Knowledge (BRISK) 7th Framework Programme to conduct this project (ref. CFU3-01-09-15)supported by funds of the Federal Ministry of Food and Agriculture (BMEL) based on a decision of the Parliament of the Federal Republic of Germany
文摘Combustion of biogas in gas turbines is an interesting option for provision of renewable combined heat and power from biomass. Due to an increasing share of fluctuating renewable energies in the power grid(especially from wind and solar power), flexible power generation is of increasing importance. Additionally, with an increasing share of agricultural and municipal waste in biogas production, biogas composition is expected to be within a broader range. In this paper, the combustion of synthetic biogas(carbon dioxide and methane) in a combustion test rig with a swirl burner and a high pressure optical chamber is researched at different conditions. Results are compared to a CHEMKIN-PRO simulation using a detailed reaction mechanism. The results show that within the researched experimental matrix, stable biogas combustion for gas turbines can be achieved even with significantly changing gas composition and nominal power. Carbon dioxide concentration is varied from 0 to 60%. CO concentrations(normalized to 15% O_2) in the flue gas do not change significantly with increasing carbon dioxide in the fuel gas and, for the researched conditions, stayed below 10 ppm. NO_x concentration is below 10 ppm(normalized to 15% O_2) for pure methane, and is further decreasing with increasing carbon dioxide share in the fuel gas, which is mainly due to changing reaction paths as reaction analysis showed. Thermal load of the combustor is varied from 100% to 20% for the reference gas composition. With decreasing thermal load, normalized carbon monoxide flue gas concentration is further reduced, while NOx concentrations are remaining at a similar level around 5 ppm(normalized to 15% O_2).