– Er. Sudan Neupane
Energy accounts for a significant share of the manufacturing cost in different industries. The efficient use along with conservation of energy is considered vital not just to avoid wastage of a precious resource, but also to slow down the rapid depletion of coal, oil, and natural gas resources. Nepalese industries are found to be using both electrical and thermal energy inefficiently. So there is a huge possibility of improvements in consumption of energy pattern in industrial sectors. There is a huge demand of energy (electricity) in the industrial sector of Nepal but due to the crisis, the demand has not been fulfilled. Industrial sectors account for 7.9% share of energy (WECS, 2013). Their GDP share is 15.2% and the growth rate is 2.7% from 2000 to 2014 A.D. (Central Bureau of Statistics, CBS). In this context steel rolling industries, being energy intensive industries, have numerous areas for increasing energy efficiency and reducing emission of CO2. The focus on energy efficiency is not only good for the environment but also profitable for industries, as it increases competiveness and productivity. Therefore, by calculating the present potential energy saving and developing future energy demand using Long range Energy Alternative Planning (LEAP) modelling tool for the steel rolling mills of Nepal, assuming planning period of 2015-2030, we will see some eye pleasing pictures. For this, the demand of TMT steel, its energy consumption and CO2 emission are taken under consideration.
The demand scenario of TMT steel is classified as Business-as-usual (BAU), Medium growth (MG) and Higher growth (HG), and they are assumed 4.45%, 5.4% and 6.5% respectively.
Result of growth of energy and CO2 emission as per different demand scenarios:
The energy demand for the base year 2015 in BAU, MG, and HG is 906.5Tera Joule (TJ). The final energy would increase to 2906.4, 3703.4 and 4889.3 TJ respectively in 2030. The cumulative energy demand for BAU,MG and HG scenario would be respectively 33.14PJ, 40.289PJ and 50.85PJ. compared to the BAU scenario, the cumulative energy demand rise would be 21.5% for MG and 53.4% for HG scenario.
The CO2 emission for the base year 2015 in BAU, MG and HG is 63.8 thousand MT. The final CO2 emission would increase to 273.7, 370.5 and 524.4 thousand MT in 2030. The cumulative emission for BAU, MG and HG scenario would be respectively 2.33, 2.83 and 3.57 million MT. Compared to BAU scenario, the cumulative scenario would rise by 21.5% for MG and 53.4% for HG scenario.
| Fig: CO2 Emission forecasted
under different growth scenario
|
| Fig: Final Energy Demand forecasted under different growth scenario |
Now through LEAP modelling tool, we will be considering three energy fulfilling scenarios viz. Business-as-Usual Scenario (BAU), Efficient scenario (EF) and Fuel switching scenario (FS) with their impacts on fuel consumption and total emissions of CO2 in the rolling mill sector of Nepal. In Business-as-Usual Scenario (BAU), we deal energy in the usual way in which we are currently using where as in Efficient scenario (EF), the objective is to observe the energy consumption pattern on decreasing the energy intensity determined by benchmarking the international standard. In Fuel switching scenario (FS), we observe the effects on the environmental emission due to alternative fuel penetration.
Results of Efficient and Fuel switching Scenarios:
The efficient scenario is constructed as an efficiency improvement in the technology employed and accordingly decreases in the fuel intensity in steel rolling mill. The efficient scenario studies the effects of technological improvement in BAU, MG and HG scenario. The EF BAU, EF MG and EF HG scenario projects the total cumulative final energy demand to be 25.34 PJ, 30.52PJ and 38.14PJ respectively. Compared to BAU scenario, with EF BAU scenario 23.5% of total cumulative energy consumption can be reduced. Similarly in MG scenario and EF MG scenario, 24.25% of total cumulative energy can be saved. Again comparing HG scenario with EF HG scenario, 25.1% can be saved.
The result of fuel switching is considered only for emission reduction assuming that the penetration of alternative fuel in long run substitute the use of furnace oil and bituminous coal from the base year till the planning period (2015-2030). With switching of fuel, its effect can be summarized in emission reduction in different growth scenario viz. FS BAU, FS MG and FS HG. The FS BAU, FS MG and FS HG scenario projects the total CO2 emission to be at 1.2 million MT, 1.74 million MT and 1.45 Million MT respectively. Compared to BAU scenario, in FS BAU scenario 46% of total cumulative emission can be reduced. Similarly, in FS MG and MG scenario, 38.3% of emission can be reduced. Again comparing HG scenario with FS HG scenario, 59.3% of emission can be reduced.
The result shows that with the introduction of energy efficient methods we will be able to improvise our energy consumption pattern and reduce CO2 emission. The adaptation will not only set up a good culture in energy consumption pattern but it will also be a path leading us to prosperity. The sooner we walk in this path the quicker we will catch the pace of modernization.
Sudan Neupane is an industrial engineer, and works as Head of Department, Department of Industrial Engineering, Thapathali Campus. He can be reached at neupanesudan@ioe.edu.np.