The 40kt/a sulfur recovery unit for tail gas treating applying the reduction-absorption-recycling (RAR) technology is aimed at regeneration of the rich amine solution and recovery of sulfur to operate in tandem with t...The 40kt/a sulfur recovery unit for tail gas treating applying the reduction-absorption-recycling (RAR) technology is aimed at regeneration of the rich amine solution and recovery of sulfur to operate in tandem with the 1.2Mt/a diesel hydrofining unit. The process unit calibration data have revealed that the recovery of total sulfur reaches 99.86%, which is 6.65 percentage points higher than that before application of the RAR technology. The SO2 content in vented tail gas is 0.27 t/d, which is much less than the latest emission standard prescribed by the State. The factors that can affect the unit operation have been analyzed and corresponding measures have been suggested including the necessity to improve the control over the reaction temperature in the tail gas hydrogenation unit.展开更多
The main technologies for reducing flue gas heat loss of pulverized coal-fired boilers are introduced, and the suitability of these technologies for boiler operation and the principles for selection of these technolog...The main technologies for reducing flue gas heat loss of pulverized coal-fired boilers are introduced, and the suitability of these technologies for boiler operation and the principles for selection of these technologies are explored. The main conclusions are： 1） the non-equilibrium control over flue gas flow rates at the inlet of the air heater and the reversal rotation of the air heater rotator should be popularized as regular technologies in large boilers; 2） increasing the area of the air heater to reduce the flue gas heat loss in pulverized coal-fired boilers should be the top option and increasing the area of the economizer be the next choice; 3） low- pressure economizer technology could save energy under special conditions and should be compared with the technology of increasing economizer area in terms of technical economics when the latter is feasible; 4） the hot primary air heater is only suitable to the pnlvefizing system with a large amount of cold air mixed.展开更多
The experiment was conducted to investigate the heat transfer performance of wet flue gas in a vertical tube. The factors influencing the convective condensation of wet flue gas were experimentally investigated. The m...The experiment was conducted to investigate the heat transfer performance of wet flue gas in a vertical tube. The factors influencing the convective condensation of wet flue gas were experimentally investigated. The measured results indicate that the convective heat transfer of bulk flow and condensation heat transfer of vapor have significant contribution to the total heat transfer and the dominant transport mechanism is dependent upon the vapor fraction in mixture.展开更多
In a modern day sulfur recovery unit(SRU),hydrogen sulfide(H_(2)S)is converted to elemental sulfur using a modified Claus unit.A process simulator called TSWEET has been used to consider the Claus process.The effect o...In a modern day sulfur recovery unit(SRU),hydrogen sulfide(H_(2)S)is converted to elemental sulfur using a modified Claus unit.A process simulator called TSWEET has been used to consider the Claus process.The effect of the H_(2)S concentration,the H_(2)S/CO_(2) ratio,the input airflow rate,the acid gasflow of the acid gas(AG)splitter and the temperature of the acid gas feed at three different oxygen concentrations(in the air input)on the main burner temperature have been studied.Also the effects of the tail gas ratio and the catalytic bed type on the sulfur recovery were studied.The bed temperatures were optimized in order to enhance the sulfur recovery for a given acid gas feed and air input.Initially when the fraction of AG splitterflow to the main burner was increased,the temperature of the main burner increased to a maximum but then decreased sharply when theflow fraction was further increased;this was true for all three concentrations of oxygen.However,if three other parameters(the concentration of H_(2)S,the ratio H_(2)S/CO_(2) and theflow rate of air)were increased,the temperature of the main burner increased monotonically.This increase had differ-ent slopes depending on the oxygen concentration in the input air.But,by increasing the temperature of the acid gas feed,the temperature of the main burner decreased.In general,the concentration of oxygen in the input air into the Claus unit had little effect on the temperature of the main burner(This is true for all parameters).The optimal catalytic bed temperature,tail gas ratio and type of catalytic bed were also determined and these conditions are a minimum temperature of 300°C,a ratio of 2.0 and a hydrolysing Claus bed.展开更多
文摘The 40kt/a sulfur recovery unit for tail gas treating applying the reduction-absorption-recycling (RAR) technology is aimed at regeneration of the rich amine solution and recovery of sulfur to operate in tandem with the 1.2Mt/a diesel hydrofining unit. The process unit calibration data have revealed that the recovery of total sulfur reaches 99.86%, which is 6.65 percentage points higher than that before application of the RAR technology. The SO2 content in vented tail gas is 0.27 t/d, which is much less than the latest emission standard prescribed by the State. The factors that can affect the unit operation have been analyzed and corresponding measures have been suggested including the necessity to improve the control over the reaction temperature in the tail gas hydrogenation unit.
文摘The main technologies for reducing flue gas heat loss of pulverized coal-fired boilers are introduced, and the suitability of these technologies for boiler operation and the principles for selection of these technologies are explored. The main conclusions are： 1） the non-equilibrium control over flue gas flow rates at the inlet of the air heater and the reversal rotation of the air heater rotator should be popularized as regular technologies in large boilers; 2） increasing the area of the air heater to reduce the flue gas heat loss in pulverized coal-fired boilers should be the top option and increasing the area of the economizer be the next choice; 3） low- pressure economizer technology could save energy under special conditions and should be compared with the technology of increasing economizer area in terms of technical economics when the latter is feasible; 4） the hot primary air heater is only suitable to the pnlvefizing system with a large amount of cold air mixed.
基金This work was supported by science and technology key project of Ministry of Education (Contract No.00129) National 973 Program (Contract No.2000026301).
文摘The experiment was conducted to investigate the heat transfer performance of wet flue gas in a vertical tube. The factors influencing the convective condensation of wet flue gas were experimentally investigated. The measured results indicate that the convective heat transfer of bulk flow and condensation heat transfer of vapor have significant contribution to the total heat transfer and the dominant transport mechanism is dependent upon the vapor fraction in mixture.
基金the National Iranian Gas Company(NIGC)for their financial support to this study.
文摘In a modern day sulfur recovery unit(SRU),hydrogen sulfide(H_(2)S)is converted to elemental sulfur using a modified Claus unit.A process simulator called TSWEET has been used to consider the Claus process.The effect of the H_(2)S concentration,the H_(2)S/CO_(2) ratio,the input airflow rate,the acid gasflow of the acid gas(AG)splitter and the temperature of the acid gas feed at three different oxygen concentrations(in the air input)on the main burner temperature have been studied.Also the effects of the tail gas ratio and the catalytic bed type on the sulfur recovery were studied.The bed temperatures were optimized in order to enhance the sulfur recovery for a given acid gas feed and air input.Initially when the fraction of AG splitterflow to the main burner was increased,the temperature of the main burner increased to a maximum but then decreased sharply when theflow fraction was further increased;this was true for all three concentrations of oxygen.However,if three other parameters(the concentration of H_(2)S,the ratio H_(2)S/CO_(2) and theflow rate of air)were increased,the temperature of the main burner increased monotonically.This increase had differ-ent slopes depending on the oxygen concentration in the input air.But,by increasing the temperature of the acid gas feed,the temperature of the main burner decreased.In general,the concentration of oxygen in the input air into the Claus unit had little effect on the temperature of the main burner(This is true for all parameters).The optimal catalytic bed temperature,tail gas ratio and type of catalytic bed were also determined and these conditions are a minimum temperature of 300°C,a ratio of 2.0 and a hydrolysing Claus bed.
