Study of energy efficiency and greenhouse gas emissions of industrial thermal systems

Abstract

Due to rising energy costs, efficient use of available resources has become very important not only in Bangladesh but also worldwide. Bangladesh is one of the lowest energy consuming countries in the world with energy production of 24,872 ktoe and energy use of 27,187 ktoe, including imported fuel. The energy uses per GDP ($1000) in Bangladesh was 238 kgOE in the year 2012. More than 31% of the total energy were consumed by industries during the FY 2012-13. It is forecasted that the demand will greatly exceed the supply in 2021, which indicates that a potential severe crisis will emerge if new domestic production or access to imported gas is not ensured in a sustainable way. Most of the country’s industries are inefficient in their energy consumption compared to international benchmarks because of old and badly maintained equipment and machinery and poor energy management. The total Energy Efficiency and Conservation (EE&C) potential in industrial sub-sectors is estimated by master plan at around 30%. The core equipment of the thermal system of any factory for steam generation is the boiler, which is fired by Natural Gas (NG), Liquefied Petroleum Gas (LPG), Furnace Oil (FO) and Fuel Oil. Inefficient boilers (55-75% efficient) are one of the major energy consuming units. Ten (10) industrial survey data sets on Boilers were collected from consultancy firm and industries. Boiler efficiency is obtained by measuring the working temperature, pressure, air velocity and flue gas analysis at boiler operating conditions. The problems and limitations in the available literature are identified and listed. There are different methods that can be used to improve boilers’ energy efficiency, such as maintaining proper air-fuel ratio, using variable speed drive (VSD) and improving the heating system. Attempting these steps reduction of fuel (NG and FO) consumption is 6 to 14 percent based on factory status. The possible scopes of further research that can be done to overcome the limitations of existing research are identified.