Regarding the studies of other authors about energy performance of a reverse osmosis desalination plant operating with variable pressure; about desalination efficiency in their different recent articles, we continued ...Regarding the studies of other authors about energy performance of a reverse osmosis desalination plant operating with variable pressure; about desalination efficiency in their different recent articles, we continued working in this way researching in a real seawater reverse osmosis plant following the items below. The objectives of this test are to get the minimum electrical consumption and energy costs for the operation of a sea water desalination plant using membranes. We need to compare the performance of the different membranes manufacturer＇s and to determine, under this new thermal scenario, the optimal configuration to get the water quality and quantity needs with the minimum energy consumption.展开更多
The industrial energy diagnosis presented in this work occurred in a milk product cooperative, from an analysis of energy consumption in the main milk industrialization and a diagnosis of energy end uses of lighting a...The industrial energy diagnosis presented in this work occurred in a milk product cooperative, from an analysis of energy consumption in the main milk industrialization and a diagnosis of energy end uses of lighting and cooling systems. Almost all stages of milk industrialization are used hot water and steam generated in the boilers. The largest electricity consumption in this sector is by electric motors followed by cooling needed to maintain the quality of milk products. Because energy costs represent a significant portion of the monthly cost of the company, an analysis of the energy costs of the past two years to check the consumption of active and reactive energy and power demand contracted is performed. This paper presents the main results of an energy audit in a milk processing industry in southern Brazil.展开更多
Crop residues in agriculture pose disposal challenges and contribute to air pollution when burned.This study aims to use pigeonpea and maize stalks to produce biochar at different pyrolysis temperatures.Biochar can se...Crop residues in agriculture pose disposal challenges and contribute to air pollution when burned.This study aims to use pigeonpea and maize stalks to produce biochar at different pyrolysis temperatures.Biochar can serve in carbon sequestration,as a soil amendment,and as an alternative fuel source.Pyrolysis was conducted at 400,500,and 600°C to examine the effects on physicochemical properties,fuel,and energy related properties.Increase in temperatures resulted in decrease of biochar yield,volatile matter,and O/C and H/C atomic ratios,while ash content and essential nutrients increased.Yield was observed to be higher in pigeonpea stalks derived biochar compared to maize stalks derived biochar at same pyrolysis temperatures.The yields of pigeonpea stalks derived biochar at 400°C,500°C,and 600°C are 34,33 and 29%,respectively,and the yields of maize biomass-derived biochar at 400°C,500°C,and 600°C are 29,28,and 26%,respectively.The organic carbon content is found to be higher in the biochar samples prepared at 600°C,i.e.,10.44%,and 10.39%for pigeonpea and maize-derived biochar,respectively.The essential elements of biochar were increased with an increase in pyrolysis temperature except nitrogen which is conversely related to temperature.The biochar obtained through pyrolysis at 400°C demonstrated superior characteristics compared to biochar produced at other temperatures.It exhibited a higher biochar yield,with approximately 84.60%for pigeonpea and 64.85%for maize fixed carbon content.Additionally,the energy retention efficiency was higher,reaching 67.33%for pigeonpea and 42.70%for maize-derived biochar at a pyrolysis temperature of 400°C.The fixed carbon recovery efficiency was also notable at around 200.44%for PPS and 142.37%for maize biochar which is higher compared to biochar produced at other temperatures.Furthermore,the higher heating value(HHV)was approximately 30.75 MJ kg^(−1) for both the biochars,indicating their suitability as alternative solid fuels.A significant CO_(2) reduction potential of 84 CO_(2) eq kg^(−1) and 55 CO_(2) eq kg^(−1) was observed for pigeonpea and maize biochar,respectively.Hence,biochar is a promising and effective option for carbon sequestration,offering environmental benefits.展开更多
文摘Regarding the studies of other authors about energy performance of a reverse osmosis desalination plant operating with variable pressure; about desalination efficiency in their different recent articles, we continued working in this way researching in a real seawater reverse osmosis plant following the items below. The objectives of this test are to get the minimum electrical consumption and energy costs for the operation of a sea water desalination plant using membranes. We need to compare the performance of the different membranes manufacturer＇s and to determine, under this new thermal scenario, the optimal configuration to get the water quality and quantity needs with the minimum energy consumption.
基金This work was developed as a part of research activities on energy engineering at the Universidade Estadual do Rio Grande do Sul(UERGS)The authors acknowledge the support received by the institutionThe fourth author acknowledges the financial support received from CNPq for his research work(proc.n.309021/2014-6).
文摘The industrial energy diagnosis presented in this work occurred in a milk product cooperative, from an analysis of energy consumption in the main milk industrialization and a diagnosis of energy end uses of lighting and cooling systems. Almost all stages of milk industrialization are used hot water and steam generated in the boilers. The largest electricity consumption in this sector is by electric motors followed by cooling needed to maintain the quality of milk products. Because energy costs represent a significant portion of the monthly cost of the company, an analysis of the energy costs of the past two years to check the consumption of active and reactive energy and power demand contracted is performed. This paper presents the main results of an energy audit in a milk processing industry in southern Brazil.
文摘Crop residues in agriculture pose disposal challenges and contribute to air pollution when burned.This study aims to use pigeonpea and maize stalks to produce biochar at different pyrolysis temperatures.Biochar can serve in carbon sequestration,as a soil amendment,and as an alternative fuel source.Pyrolysis was conducted at 400,500,and 600°C to examine the effects on physicochemical properties,fuel,and energy related properties.Increase in temperatures resulted in decrease of biochar yield,volatile matter,and O/C and H/C atomic ratios,while ash content and essential nutrients increased.Yield was observed to be higher in pigeonpea stalks derived biochar compared to maize stalks derived biochar at same pyrolysis temperatures.The yields of pigeonpea stalks derived biochar at 400°C,500°C,and 600°C are 34,33 and 29%,respectively,and the yields of maize biomass-derived biochar at 400°C,500°C,and 600°C are 29,28,and 26%,respectively.The organic carbon content is found to be higher in the biochar samples prepared at 600°C,i.e.,10.44%,and 10.39%for pigeonpea and maize-derived biochar,respectively.The essential elements of biochar were increased with an increase in pyrolysis temperature except nitrogen which is conversely related to temperature.The biochar obtained through pyrolysis at 400°C demonstrated superior characteristics compared to biochar produced at other temperatures.It exhibited a higher biochar yield,with approximately 84.60%for pigeonpea and 64.85%for maize fixed carbon content.Additionally,the energy retention efficiency was higher,reaching 67.33%for pigeonpea and 42.70%for maize-derived biochar at a pyrolysis temperature of 400°C.The fixed carbon recovery efficiency was also notable at around 200.44%for PPS and 142.37%for maize biochar which is higher compared to biochar produced at other temperatures.Furthermore,the higher heating value(HHV)was approximately 30.75 MJ kg^(−1) for both the biochars,indicating their suitability as alternative solid fuels.A significant CO_(2) reduction potential of 84 CO_(2) eq kg^(−1) and 55 CO_(2) eq kg^(−1) was observed for pigeonpea and maize biochar,respectively.Hence,biochar is a promising and effective option for carbon sequestration,offering environmental benefits.
