Strategies for targeted emission reductions from the Indonesian coal fleet


DAY 1 – Tuesday 11 July 2023


Opening welcome from USDOS and US Embassy
Cara Rose, US Embassy


Opening welcome
Ministry of the Environment and Forestry (MOEF)


Opening welcome 
Ministry of Energy and Mineral Resources (MEMR)


Welcome from BCBC-Asia
Anton Purnomo


International scene setting
Lesley Sloss, ICSC


Coal and the Minamata Convention
Alexander Romanov, UNEP
Introduction to the Minamata Convention and what it means for the coal sector internationally


OECD’s project on Best-Available-Techniques (BAT) to prevent and control industrial pollution
Berrak Eryasa OECD

Best-Available-Techniques (BAT)

An increasing number of countries use BAT as a tool to establish evidence-based environmental permit conditions for industrial installations, to prevent and control industrial pollution, and thus ensure a high level of human health and environmental protection. BAT are state-of-the-art techniques that are developed at a scale that enables implementation under economically and technically viable conditions.

Countries spend significant resources on designing, developing, and implementing policies for BAT-based permitting. The OECD’s BAT project aims to exchange best practices across countries that already have BAT-based policies and provide assistance to governments that seek to adopt BAT-based permitting. The project is overseen by the OECD’s Expert Group on BAT. The project is in its third phase (2022-2024) with three publications planned;

  • Activity 7, a cross country analysis of BAT Reference Documents (BREFs) and BAT- associated emission levels for Iron & Steel production, Paper & Pulp production and Waste Incineration
  • Activity 8, capacity building workshops on BAT policies
  • Activity 9, a study on identifying emerging technologies for potential BAT determination


The USDOS project
Lesley Sloss, ICSC

A summary of the ICSC work, under the US Department of State Project, to assist with accelerated mercury emission reduction from the coal sector in Indonesia


Unveiling the future: exploring strategies to reduce mercury emissions in Indonesia
Edward Archer, Peter F Nelson
Macquarie University

The presentation will provide an overview of an ongoing project funded by the UN Environment Program (UNEP) and the Global Environment Facility (GEF) that aims to assess future global mercury emissions from coal-fired power plants. One of the project’s main objectives is to explore scenarios for reducing mercury emissions in the coal-fired power plant sector by considering current energy development plans and commitments under the Paris Agreement and Minamata Convention.

The discussion will be focused on the potential of implementing a set of best available technologies and best environmental practices (BAT/BEP) in Indonesia’s coal-fired power plant sector to mitigate mercury emissions, especially through multi-pollutant control strategies. Finally, the presentation will examine the potential impact of actions by the Just Energy Transition Partnership (JETP) and Energy Transition Mechanism (ETM) on reducing future mercury emissions from the country’s coal-
fired power plant sector.


Maximising plant flexibility while controlling emissions
Stephen Storm, EPRI

An introduction to the Flexibility toolkit and how it can improve plant performance whilst keeping emissions low


Balancing fuel-air distribution at Ombilin power station, Indonesia
Dr. Vivek Savarianadam,  Ammegen part of Greenbank Group

Tangential coal boiler firing systems are designed to have one mill feeding all corner burners for the same elevation. With this arrangement, differential lengths, configuration and degree of wear in the pipework conveying pulverised fuel (PF) generates different pressure drop resulting in non-uniform fuel distribution. This non-uniform fuel distribution leads to high CO for rich fuel burners and high NOx for lean fuel burners, thereby reducing the combustion efficiency. This case study outlines the process of balancing PF distribution, leading to improved boiler efficiency and marketable fly ash.

Ammegen Greenbank’s PF balancing system consisting of electrical actuated CoalFlo® dampers, Pulverised Fuel Monitoring System (PFMS) was implemented in Ombline Power Station located in Sawahlunto, West Sumatra, Indonesia. The plant, one of the two is rated at 100MWe at maximum continuous operation but was limited to 70MWe due to high Carbon in Ash (CIA) levels of over 12%. An analysis of the plant’s pipework revealed non-uniform fuel distribution of over 15%, one of the main causes contributing to the high CIA levels. With large mounds of ash surrounding the power plant.

A Computational Fluid Dynamics (CFD) study demonstrated the improved performance achievable by installing CoalFlo® damper to maintain PF distribution within ±4% across the PF pipes. The CoalFlo® damper and PFMS were subsequently installed in Unit along with optimised bends and aluminium tiles to reduce turbulence and erosion and to maintain primary heated air temperature. A closed loop control system was implemented to balance PF distribution. This effectively measures relative PF distribution using the PFMS and actuates the CoalFlo® dampers to maintain uniform flow.

After implementing the PF distribution system, the plant can operate at 100MWe without constraints. Actual PF distribution of ±3% across the PF pipework was achieved. Further, by maintaining balanced PF distribution levels, CIA levels reduced to less than 6% which improved boiler efficiency and improved the plant’s fly ash resale value.


Innovative cost-effective high-impact emissions and cost reduction solutions for Suralaya coal power plant, Indonesia
Zeljko Warga, Zellol Power Holdings Ltd.

Coal power will remain in service for decades, although its use will decline more quickly in Western countries than in the rest of the world. This extended service life is expected across Asian and African countries. In 2022, 2.067 mil MW of coal generating capacity was in place globally, with 184.500 MW under construction and 297.000 MW of future capacity. After the USA and EU depart from coal power, the effect on global emissions will be marginal. Emissions from coal fired power plants therefore remain a global problem, in particular CO2 emissions.

The Plant Efficiency Toolbox (PET) is a cost-effective solution for coal power plants to reduce emissions while generating economic gain. Outstanding results across two projects prove the concept:

  1. Innovative boiler combustion tuning in Indonesia at Suralaya Power Station under UNIDO ( sponsorship in 2016 displaying potential for the plant to reduce coal usage of around 225.000 tons a year, CO2 emissions by around 420.000 tons and the potential for significant further reduction was detected;
  2. An online chemical treatment, demonstrated under a UN agreement between Danish and Romanian governments, successfully reduced CO2 emissions and coal usage by an average of more than 10% over a four-year period by reducing wall deposition in the boiler. This innovative chemical substantially limits deposition throughout a boiler and either allows maintenance of high thermal efficiencies or capacity recovery where limitations by deposition existed. The impact of this chemical can be tracked by plant operators using a new dedicated online interface that measures the true extent of deposition on coal usage.

Unusually in both cases, the boilers were already properly set-up and maintained, which indicates larger tuning potential at other less well-maintained locations. The payback period for both the boiler tuning and the chemical can be as low as a few months.
It is proposed to run a demonstration on the same Suralaya 600MW unit boiler to reverify and rectify the previously identified reduction potential for both coal usage and emissions, and to check on the settings from the initial tuning process.

Additionally, trials with the chemical are proposed as data obtained during the boiler tuning process indicated a significant wall deposit removal and associated coal usage and CO2 emissions reduction potential. The plant would serve as an example of a good practice to be adopted by other power plants.


Sootaway: a combustion catalyst and its potential for success in plants such as Suralaya
Leif Vebenstad, Johnsen Chemicals

Sootway is a non-hazardous combustion catalyst which reduce air pollution by improving the efficiency of the combustion of solid fuels like coal, biomass and waste.

Older thermal power plants are often ineffective with incomplete combustion leading to high consumption of fuel per MW power produced, slagging and high emission of polluting gases like CO, NOx, SOx, HCN and PM. We have developed a combustion catalyst that enable a complete combustion at a lower level of Oxygen. Our active ingredient is a Manganese-complex that work as an Oxygen scavenger which attract all available Oxygen in the combustion environment to the surface of the solid fuel.

This will reduce the emission of CO, reduce the content of unburned C in the flyash/bottomash and reduce the unburned C in the sedimentation. This C will be utilized to increase creation of CO2 and will thereby increase power production per unit fuel.

The reduced building of sedimentation will also increase the boiler efficiency as sedimentation is a very good insulator. If you have 1 mm of sedimentation on the heat exchanger, you loose 8% in the heat transfer.

As creation of CO2 use twice the amount of O as creation of CO, the level of O in the boiler will be reduce unless you choose to increase the airflow.
And with less O available in the combustion environment, the creation of pollution like CO, NOx and SOx containing O will be reduced. As we apply our combustion catalyst on the fuel before entering the combustion, it can easy be retrofitted on existing installations. The investments necessary to install our technology are low. The time from decision to operation is short. As our combustion catalyst work in the front end of the boiler, it can easy be combined with emission control technologies like SCR, SNCR and scrubbers.Based on the lab report from GeoCoal in India and technical data received from ICSC, we estimate that we, with unchanged airflow, can do the following for unit 6 at Suralaya :

  • 3% reduction in fuel consumption per MW
  • 57% reduction in emission of SO2
  • 39% reduction in emission of NOx
  • 20% reduction in emission of PM

If combined with a smaller reduction in airflow, we estimate we can do the following for unit 6 at Suralaya:

  • 2% reduction in fuel consumption per MW
  • 69% reduction in emission of SO2
  • 56% reduction in emission of NOx
  • 35% reduction in emission of PM

All these reductions can be done without increasing the emission of CO above the reference level before using our technology


Retrofit potential for Indonesia’s coal-fired fleet – 21st century high-efficiency coal-fired steam generator with integral emissions control 
Keith Moore, Castlelight Energy

CastleLight Energy Corp, a technology management firm located in Oxnard, California, USA propose retrofit programs for Indonesia’s fleet (~46 GW) of coal-fired electric generation plants with the Clean Combustion System™ (CCS).

The CCS program’s objective is to update to the 21st century, Indonesia’s large >100 MW coal-fired (Wall, Tangential and Cyclone) electric generation fleet with significant (+10%) efficiency improvements (reduce CO2 emissions and operating costs) and meet Indonesia’s new tighter (550 ng/m3) pollutant emission standards for SO2 and NOx.

The CCS technology evolved from advanced combustion modeling developed for the U.S Apollo moon rocket engines.

The field-demonstrated CCS technology replaces the existing plant’s coal burners. Firing pulverized coal with powdered limestone added in a “Hybrid-of-Coal-Gasification”, the CCS controls both SO2 and NOx pollutant emissions right within the Steam Generator. Fly ash particulates (and mercury) are captured with the plants existing electrostatic precipitators (ESP). No Flue Gas (SO2) Scrubber (FGD) or Selective Catalytic (NOx) Reduction (SCR) systems are required.

A CCS Coal-fired Steam Generator© (100 MW to 600 MW) operates the same as before with load-following (25% to 100%) operation and near super-critical heat-rate (< 9500 Btu/kW-h) performance.

Firing Wyoming Powder River Basin (PRB) sub bituminous coals, the CCS has demonstrated meeting strict U.S. EPA air quality regulations: i.e. SO2 emissions (< 0.2 Lb. / MMBtu (250 mg/m3) and NOx emissions (< 0.15 Lb. / MMBtu (184 mg/m3).



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DAY 2 – Wednesday 12 July 2023


Evaluating the viability of co-firing biomass waste to mitigate coal plant emissions in Indonesia
Claire Squire
University of Maryland

An effective emissions control strategy in Indonesia’s energy sector requires both mitigating emissions from coal plants and ensuring that a sustainable low-carbon energy pathway does not exacerbate land degradation and land use change emissions. Co-firing biomass presents a promising approach for reducing carbon emissions in Indonesia due to its abundant biomass resources, especially from agricultural residues, forestry waste, and municipal solid waste.

By incorporating biomass waste feedstocks, power plants can reduce their carbon footprint and contribute to the country’s renewable energy targets. In this paper, we assess the potential of biomass waste by addressing the following two questions:

Is the available biomass waste sufficient to meet the current and future feedstock requirements needed to co-fire at coal plants without additional land use emissions?
Can Indonesia’s existing waste processing capacity consistently meet the demand for biomass used in these plants? Estimating the country’s biomass demand and existing waste supply is challenging due to limited data availability.

For this study, we therefore undertook a comprehensive data collection effort and conducted an extensive literature review to quantify the demand for and supply of biomass for co-firing in Indonesia. On the demand side, we conducted a feasibility study for each coal power plant in the country, considering both captive and non-captive plants. On the supply side, we evaluated various potential biomass waste feedstocks suitable for Indonesia, including wood waste (both forest residues and by-products from industrial processing), rubber, sugarcane, oil palm (kernel shell and empty fruit bunches), rice husk and straw, and municipal solid waste (MSW) in major cities. Our preliminary results indicate that existing biomass waste is sufficient to meet co-firing demand, although competition with alternative domestic uses and a changing export market may significantly impact the ability to meet demand. Our study provides insights into the seasonal and spatial nature of waste availability across the archipelago, potential land use impacts, and plant-level implications for meeting co-firing demand.


Implementation of co-firing in a coal power plant: utilizing biomass residue and coal fines with TOSS, experience in Indonesia 
Indradjaja M Brunner

Co-firing activities have been conducted at Ropa Coal Power Plant, Ende Regency, East Nusa Tenggara, Indonesia. The raw materials come from a mixture of biomass residues and coal fines. Residual biomass comes from various waste sources including agricultural/plantation production (rice husks, candlenut shells, corn husks), tree debris and garden maintenance (grass, leaves). Coal fines are fine-sized coal waste from coal transportation and stockpiling.

Approximately 45 tons/day of biomass residue generated in Ende Regency is generally disposed of through solid waste landfill, illegal burning or ends up in waterways and beaches. Biomass residue is processed using the Technology of Onsite Solid Waste Sources (TOSS) method which consists of chopping, drying with a bioactivator in a bamboo box, pelletizing, drying and storage. Chopping aims to uniform the size of materials and remove water. The bioactivator is locally sourced and functions to reduce water content and homogenize heterogeneous materials. Biological drying with microbes reduces the moisture content of residual biomass from 80% to 40% within 5 to 7 days.

The materials are mixed with coal fines and compacted into pellets with diameter of 1.2cm and length of 3-7cm, with moisture content of 15%. The final process is sun drying to remove moisture from the compaction process and maintain a moisture content of around 10%. The results of pellet analysis have a calorific value of ±3800 KKal/kg, moisture ±11%, volatile matter ±55%, fixed carbon ±25%, sulfur ±0.3% and ash content ±19%.

In 2020-2021, a collaboration between the Government of Ende Regency, the State Electricity Company (PLN) of Flores and the start-up company held systematic trials by conducting performance tests, reliability runs, and continuous runs with 200 tons of pellets. In 2021–2022, the collaboration continued commercially with a commitment to supply pellets of 1,700 tons/year. Based on theoretical calculations, every 10 tons/day of managed biomass residue can reduce 16,000 tons of CO2eq/year.

The calculation is based on reducing the release of methane gas at landfills, transportation using fossil fuels to the landfill and reducing the use of coal in the power plant. Utilization of biomass residue reduces the potential for agricultural/plantation land fires because communities can process biomass into renewable solid fuels with economic value. The potential for coal fines carried by rainwater to pollute the oceans and contaminate groundwater can also be prevented.


Reclamation of coal mining land in Indonesia using ashes from co-firing activities
Arief Noerhidayat

The co-firing program has had a significant impact on determining the direction of the policy on the use of coal as fuel for power generation. However, at the same time there are demands to terminate the use of the coal powered power plant, and that miners must carry out reclamation of their ex-mining land. The termination of coal powered power plant operations is related to greenhouse gas emissions, as well as supporting the Renewable Energy and Net Zero Emission programs.

Comestoarra is a start-up company engaged in the supply chain and value chain management of organic waste and biomass residue into solid renewable fuels. Co-firing activities at coal powered power plant provide an opportunity to continue to produce energy that is more environmentally friendly than the use of coal. The fuel used in co-firing activities comes from organic waste and biomass residue, as well as Fly Ash Bottom Ash (FABA) from burning coal.

Based on research in Berau District, data was obtained that FABA still has a calorific value of around 4000 kcal/kg. Organic waste and biomass residue are used as FABA binding materials so that they can be compacted and reused for co-firing activities. The ash resulting from burning the mixture tends to be more than the use of coal. This is because the ash content of the mixed material is around 22.5% compared to coal which is only 4.8%. The large volume generation of ash opens up opportunities to be used as a medium for reclamation of ex-mining land. FABA can neutralize acids in ex-mining land, while ash from burning organic waste and biomass residue contains soil nutrients.

The use of mixed ashes for reclamation media can make ex-mining land more suitable for replanting. Plant maintenance on the reclamation land can be a source of biomass material for co-firing activities which provides net zero carbon emissions.


Advanced and high value uses for fly ash
Wojciech Jozewicz


CEMS for compliance – challenges
Sanjeev Kanchan, CEEW


Status Report for Tekran / Alfa Pegasus Model 3400 HgCEMS in Indonesia
Michael Ricci
Tekran Instruments

Tekran Mercury Continuous Emissions Monitoring Systems (HgCEMS) are currently operating at over 130 North American locations to comply with strict US EPA regulations. Tekran has installed over 200 HgCEMS for coal-fired power plants, cement plants, steel refineries, waste incinerators, air pollution control testing, and research in North America, Europe, and Asia.

The US National Institute of Standard and Technology (NIST) selected the Tekran 3310 Elemental Mercury Calibration Source as the “NIST Prime”, which is used to certify all other HgCEM calibration sources.
The Tekran Series 3400 HgCEM is designed to measure total gaseous mercury emissions, with optional components to measure elemental and ionic mercury in virtually any combustion source, with NIST traceability. The system is sensitive enough to measure Hg levels at any coal fired power plant and is immune to the interferences that plague conventional mercury CEMS.
In 2020/2021, Alfa Pegasus installed four (4) Tekran Model 3400 HgCEMS at Sumitomo Corporation’s PT Central Java Power (PT CJP), near Japara, Central Java Province:

  • HgCEMS #1 & #2: Tanjung Jati B (TJB) Unit 1 & 2
  • HgCEMS #3 & #4: Tanjung Jati B (TJB) Unit 3 & 4

In 2023 Alfa Pegasus installed two (2) Tekran Model 3400 HgCEMS at PT Freeport’s 195 MW coal-fired power plant, located in Portsite. The coal fired power plant produces electricity for PT Freeport’s Copper Smelter in the Sudirman Mountain Range in Papua Province, Indonesia.

    • HgCEMS #1: Unit 1 (65 MW)
  • HgCEMS #2: Unit 2 (65 MW)

In 2023, Asia Pulp & Paper (APP) Sinar Mas purchased twelve (12) Tekran Model 3400 HgCEMS for coal-fired power plants producing electricity for pulp & paper plants in the following locations:

  • HgCEMS #1, #2, #3: Indah Kiat Pulp & Paper (IKPP) Perawang Mill, Riau Province, Sumatra Island
  • HgCEMS #4, #5, #6: Indah Kiat Pulp & Paper (IKPP) Serang Mill, Banten Province, Java Island
  • HgCEMS #7, #8: Lontar Papyrus , Jambi Province, Sumatra Island
  • HgCEMS #9, #10, #11: Pindo Deli Karawang, West Java Province, Java Island
  • HgCEMS #12: Tjiwi Kimia Mojokerto, East Java Province, Java Island

Tekran, and their exclusive distributor Alfa Pegasus, have installed six (6) HgCEMS at coal fired power plants and sold another twelve (12), for a total of eighteen (18) Model 3400 HgCEMS sold in Indonesia for mercury emissions monitoring and control. This presentation will provide a status report for these installations.”


Simple Low Operating Cost Multi-Pollutant Control System utilizing Sorbent/Catalyst Modules
Yuji Takeshita
Japan Coal Frontier Organization


Gore Mercury & SO2 control system
Naoki Moriuchi
WL Gore

Operators of coal fired power plants in Indonesia are facing future tighter emissions limits including Mercury and SO2, while maintaining a desire to minimize operating cost and simplify operation. The GORE™ Mercury and SO2 Control System (GMSCS) is ideally suited for this market as a multi-pollutant control system.

The GMSCS is based on catalyst/sorbent composite material configured into low pressure drop modules. Placed directly in the flue gas, these modules continuously capture gas phase mercury without requiring any reagent – and due to the high capacity for mercury capture, the modules are often projected to last over 10 years before needing to be replaced.

In addition, the modules contain catalyst which converts SO2 into sulfuric acid where it is collected as a liquid for potential beneficial use. For power plants that have wet flue gas desulfurizers (FGD) already installed (limestone or seawater), the GMSCS modules can be installed inside existing absorber vessels in a zero-footprint installation approach. In this case, there are no moving parts, operating is exceedingly simple, as the passive modules will control mercury emissions and provide additional SO2 polishing.

For plants without FGD controls, the GMSCS can be installed as a stand-alone unit, where the system will reduce SO2 emissions to the required limits while simultaneously capturing gas phase mercury. In this configuration, there can be significant revenue generated from the sulfuric acid byproduct generated, which has uses in many industries such as fertilizer production. This byproduct combined with the fact that no reagents are required results in the lowest operating cost solution for this market. Additional benefits including low parasitic power consumption and lack of solid waste generation.

Furthermore, the catalytic reaction of SO2 to sulfuric acid doesn’t involve additional CO2 generation. When considering GMSCS as an alternative to a wet limestone FGD for SO2 control and activated carbon injection for mercury control, the reduction in overall CO2 creation can be quite significant. GMSCS has been successfully deployed in over 30 installations around the world since 2013, in applications including coal fired power, incineration, and metals/minerals applications.


Bromine for mercury control at coal-fired power plants
Bernhard Vosteen
Vosteen Consulting

Since 2001 Vosteen’s Bromine-Enhanced-Mercury-Oxidation-technology (BEMOtechnology) has been successfully applied at a multitude of coal- and lignite-fired power plants as well as at waste-to-energy plants proving to be a most effective, though simple and inexpensive retrofit method to promote dry and/or wet mercury removal from flue gases.

Large scale tests over 8 months in 2021 of the BEMO-technology at the huge
Belchatow site in Poland (12 Units, summing up to in total 5100 MWe) and it’s
subsequent commercial application since 2022 will be reported. Many of the Polish
experiences might be transferred to comparable Indonesian sites as e.g. Suralaya on
Java (8 Units, summing up to in total 4025 MWe). Of interest is the fact that the fired
subbituminous coals from the neighbouring isle Sumatra are of only limited sulfur
content (about 0.5 weight % – comparable to former Ruhr-coals), and also of low
chlorine content and mean mercury content (comparable to subbituminous coals
from USA, Columbia, Southafrica). This may be the reason for the fact that most
Indonesian power plants have no sophisticated APCs, operating “with ESP only”.
All old Units 2 – 12 at the Belchatow site are applying staged combustion to minimize
NOx-production. The staged combustion of the Belchatow lignite induces enlarged
unburnt carbon levels in the fly ashes, serving as “self-produced activated carbon”
for the sorptive capture of mercury by the ESP-fly ash, getting improved by the
BEMO-technology as well. Experimental results will be reported.


Potential for mercury reduction in Indonesia
Wojciech Jozewicz AEA LLC
Using the iPOG emission estimation tool to project potential mercury reductions from the Indonesian coal sector