The Ministry of the Environment of Government of Japan and the Ministry of Environment and Forestry of the Republic of Indonesia concluded a memorandum of environmental cooperation between both countries in 2017. This memorandum used a co-benefit approach addressed at the atmospheric field and the diagnoses of measures related to energy conservation and exhaust gas reduction of coal-fired industrial boiler and its steam system and also how to conduct them.
The co-benefit approach is a series of activities to obtain two outcomes by means of one method or technology. The co-benefit approach in this project refers to an approach to reduce greenhouse gas emissions and air pollutants by improving the operation of boilers with focusing on energy conservation and energy cost reduction.
Ministry of Environment of Government of Japan (MOEJ) collaborated with Mitsubishi UFJ Research and Consulting (MURC) and Center for Pulp and Paper (CPP) of Indonesia conducted a Co-Benefit Project for Coal Boiler Utilization in Paper Sector Programme in 2018 – 2019 at one of paper mill in Indonesia as a model.
In this project, CPP had a role to support MURC in diagnosis and implementation of co-benefit approach, including sampling and analysis of exhaust gas, and training on co-benefit practice for engineers/operators. The results obtained in this activity including a diagnosis for cost reduction and air polution reduction rate, such as heat efficiency of boilers, improvement of combustion air ratio, contribution of moistures to calorific value of coal, boiler blow water, and also the potential of RPF for steam boiler fuel.
The methodology employed including the diagnosis of moistures contribution on calorific value of coals, the quality of water used for boiler, boiler blow water, condensed water and make-up water, heat insulation measurements, management of air ratio, and operation control of multiple boilers, and other examples of energy conservation measures such as the potential utilization of Refuse derived paper and plastics densified Fuel (RPF) and generator which using steam pressure difference.
From the energy conservation point of view, there are the following issues in this project:
1. Coals with high moisture content were used.
2. The boilers are stopped during the time of playback of the bag filters.
3. Insulation measures such as ducts, which are accessory devices, are not implemented.
4. Other problems such as too much blowdown water, oxygen concentration readings are not recorded and stored in electronic media, etc.
Suggested measures and reduction potential including: contribution of moistures to calorific value of coal, improvement of combustion air ratio, improvement of blowdown water, improvement of condensed water recovery rate, heat insulation measures for steam piping, condensed water piping, papermaking machine, ducts heat insulation to preheat boiler air inlet, operation control of multiple boiler, use of RPF for boiler fuel, and generator using steam pressure difference. Theoretically, the maximum of CO2 emission reduction if all proposed improvement suggestions are implemented may reaches 48.6％.
Suggested measures and reduction potential
|Energy-saving measures||Ratio of Coal reduction||Coal reduction||CO2 reduction||Cost reduction||Ratio of Pollution reduction|
|Decrement of water moisture on Coal (25.8% to10.0%)||19.4||6,561||1,278||4,789||19.4|
|Improvement of Combustion Air Ratio (13,0% to 8,0%)||5.0||1,690||2,841||1,234||5.0|
|Optimalization of Blowdown Water (blowdown: 3,6% to 1,0%)||3.4||2,281||2,841||834||3.4|
|Improvement of recovery rate of condensed water (43% to 60%)||1.4||486||969||355||1.4|
|Heat insulation measures for steam piping (134,1 m2, around 570 locations)||0.9||315||628||230||0.9|
|Heat insulation measures such as condensed water piping (263,5 m2)||1.1||387||772||282||1.1|
|Heat insulation measures of duct to preheat boiler inlet air (inlet: 40oC to 76,6oC)||2.6||865||1,726||631||2.6|
|Heat insulation measures for papermaking machine (production line 1: 34,1oC to 30,6oC; production line 2: 33,9oC to 30,6oC)||6.5||2,205||4,400||1,610||6.5|
|Optimalization of multiple boilers (operational priority on 20t boiler + emergency boiler)||8.3||2,793||4,694||2,039||8.3|