In this study, a five-year (2010-2014) production and energy utilisation data in a sausage producing company in Nigeria was analysed for energy consumption, energy intensity, energy productivity, cost of energy per un...In this study, a five-year (2010-2014) production and energy utilisation data in a sausage producing company in Nigeria was analysed for energy consumption, energy intensity, energy productivity, cost of energy per unit product and Normalized Performance Indicator (NPI). The average annual energy consumption was 15,853.22 GJ. The energy consumption mix was 27.66% PHCN main, 32.06% diesel generators and 40.28% oven gas. Main electricity supply from utility company contributed to 25.04% of the total energy cost while diesel was 44.24% and oven gas was 30.71% of the total cost. The average production output from the factory was 595,700 tonnes and the average cost of energy input was 6.71 kobo/kg for the five-year period. The values of cost of energy input per unit product showed a decreasing trend for the five years. The energy intensity also increased through the study years with an average of 1.67 GJ/m2 while the energy productivity decreased throughout the years with an average of 28.3 kJ/kg. The Normalized Performance Indicator (NPI) values calculated for the five years showed steady increment with an average of 1.61 GJ/m2. This indicated a “very poor” range which implies an excessive energy usage, immediate action should be taken to investigate and remedy this.展开更多
Energy security, cost of production and environmental constraints have necessitated the need for proper energy utilisation in the manufacturing industries. This work analysed energy and production data from an alumini...Energy security, cost of production and environmental constraints have necessitated the need for proper energy utilisation in the manufacturing industries. This work analysed energy and production data from an aluminium extrusion plant in Lagos, Nigeria for energy efficiency, exergy efficiency (or process?efficiency), energy cost per unit of production, CO2 emission and pollution?rate?index. The input-output energy analysis method was used to estimate the?embodied energy intensity. The pollution rate, energetic and exergetic efficiencies were estimated from the exergy analysis. The CO2 emission was estimated?from IPCC guideline on greenhouse inventories and the energy cost of unit?produce was estimated from energy cost accounting method. The five-year average thermal and electrical utilisation ratio was 45/55, which deviated from the 70:30 of the global best practices. The embodied energy intensity for the five years’ ranges between 2.31 - 162.3 GJ/t which is in excess of the recommended?range of (2.9 - 3.2 GJ/t). The mean energy efficiency for the five year was 79.4% and the mean exergetic efficiency was 57.8% indicating that production was well?managed (>50%) with energy wastages very high in boiler energy conversion. The total energy used was 16 MJ and CO2 emitted is 1.01 × 1011 g during the study period. The average pollution rate index for the plant was 0.8695 indicating that the plant is negatively impacting the environment due to technological limitation of the energy conversion process employed in the manufacturing plant. The study reveals a distortion of the recommended best practice in energy balance ratio which accounted for the high average cost of production (N 4418.3/t);process efficiency was generally low thereby negatively affecting industrial output for the company.展开更多
文摘In this study, a five-year (2010-2014) production and energy utilisation data in a sausage producing company in Nigeria was analysed for energy consumption, energy intensity, energy productivity, cost of energy per unit product and Normalized Performance Indicator (NPI). The average annual energy consumption was 15,853.22 GJ. The energy consumption mix was 27.66% PHCN main, 32.06% diesel generators and 40.28% oven gas. Main electricity supply from utility company contributed to 25.04% of the total energy cost while diesel was 44.24% and oven gas was 30.71% of the total cost. The average production output from the factory was 595,700 tonnes and the average cost of energy input was 6.71 kobo/kg for the five-year period. The values of cost of energy input per unit product showed a decreasing trend for the five years. The energy intensity also increased through the study years with an average of 1.67 GJ/m2 while the energy productivity decreased throughout the years with an average of 28.3 kJ/kg. The Normalized Performance Indicator (NPI) values calculated for the five years showed steady increment with an average of 1.61 GJ/m2. This indicated a “very poor” range which implies an excessive energy usage, immediate action should be taken to investigate and remedy this.
文摘Energy security, cost of production and environmental constraints have necessitated the need for proper energy utilisation in the manufacturing industries. This work analysed energy and production data from an aluminium extrusion plant in Lagos, Nigeria for energy efficiency, exergy efficiency (or process?efficiency), energy cost per unit of production, CO2 emission and pollution?rate?index. The input-output energy analysis method was used to estimate the?embodied energy intensity. The pollution rate, energetic and exergetic efficiencies were estimated from the exergy analysis. The CO2 emission was estimated?from IPCC guideline on greenhouse inventories and the energy cost of unit?produce was estimated from energy cost accounting method. The five-year average thermal and electrical utilisation ratio was 45/55, which deviated from the 70:30 of the global best practices. The embodied energy intensity for the five years’ ranges between 2.31 - 162.3 GJ/t which is in excess of the recommended?range of (2.9 - 3.2 GJ/t). The mean energy efficiency for the five year was 79.4% and the mean exergetic efficiency was 57.8% indicating that production was well?managed (>50%) with energy wastages very high in boiler energy conversion. The total energy used was 16 MJ and CO2 emitted is 1.01 × 1011 g during the study period. The average pollution rate index for the plant was 0.8695 indicating that the plant is negatively impacting the environment due to technological limitation of the energy conversion process employed in the manufacturing plant. The study reveals a distortion of the recommended best practice in energy balance ratio which accounted for the high average cost of production (N 4418.3/t);process efficiency was generally low thereby negatively affecting industrial output for the company.
