The global shift toward sustainable energy necessitates strategies that are not only technologically sound but also socially inclusive and equitable. Biomass co-firing presents a promising transitional technology for countries like Indonesia, yet its long-term viability often falters due to socioeconomic challenges in the supply chain. This qualitative case study investigates a pioneering biomass co-firing initiative in Indonesia that adopted a co-creation model, actively involving the local community as partners. Data collected through in-depth interviews, focus group discussions, and observation revealed that the co-creation process, built on structured dialogue, capacity-building symbiosis, and adaptive governance, successfully transformed a corporate-led project into a resilient community partnership. While tensions over pricing and scheduling marked the company–community interface, these were constructively navigated, reinforcing the partnership. Crucially, the model catalyzed local socioeconomic empowerment, creating circular income streams and enhancing community agency. The study concludes that co-creation is a critical mechanism for achieving a just and sustainable energy transition. However, for the model to be scalable and durable, it must be supported by strategies that ensure long-term biomass sustainability, financial independence for community enterprises, and stronger institutional embedding within corporate and policy frameworks.

The effect of KCl on the simultaneous removal of NO and toluene on CeO2-TiO2 catalyst: insights from experimental and DFT studies.

Numerical study on ignition of pulverized coal and biomass co-firing flames with detailed chemistry

Environment-dependent dual role of ammonia on the radiative characteristics of single-pellet biomass co-firing

The national energy transition encourages the application of biomass co-firing technology in Steam Power Plants (PLTU) as an effort to reduce greenhouse gas emissions and increase the renewable energy mix. The success of the implementation of co-firing is greatly influenced by the selection of the right biomass raw materials, considering the trade-off between benefits, costs, and operational risks. This study aims to determine the most optimal co-firing biomass raw materials in coal-fired power plants using the Benefit-Cost–Risk Analysis approach combined with the Analytical Hierarchy Process (AHP) method. The study was conducted on one of the coal-fired power plants in East Java by comparing three alternatives, namely sawdust, rice husks, and coal without co-firing. The weighting of criteria was carried out through expert assessment using AHP paired comparisons. The selected alternatives were then analyzed for their environmental impact using the Life Cycle Assessment (LCA) approach with the scope of cradle to gate. The results show that sawdust has the highest Benefit value, a Benefit–Cost (BCR) ratio above one, and a level of risk that can still be managed compared to other alternatives. The LCA analysis identified boiler units as the main hotspots of environmental impact, so operational improvements were recommended through water-steam system control. This research provides a basis for strategic decision-making in the selection of co-firing biomass that supports the energy transition and environmental sustainability.

Co-firing fibrous biomass with coal is a low-carbon option, but poor grindability and uncertain combustion limit its use. A mild embrittlement pretreatment at 230 °C was applied to upgrade fibrous biomass for efficient co-firing. The selective degradation of hemicellulose and part of cellulose turned the dense fibrous matrix into a brittle, porous solid. The grindability index increased nearly fivefold, and the higher heating value increased from 17.1 to 20.1 MJ kg−1, while energy yield remained above 75%. With 20% embrittled biomass, co-firing improved the combustion of two bituminous coals, Shitan (SC) and Wangbu (WB). Ignition and burnout temperatures decreased by 44 °C and 29 °C for SC, and by 38 °C and 25 °C for WB. Combustion indices, including the comprehensive combustion performance index S, increased by up to 40.4% for SC. Kinetic analysis revealed that activation energy during char oxidation decreased by up to 40.3% for SC and 28.2% for WB, due to enhanced volatile release and porosity that promoted oxygen transfer. Ash fusion temperatures remained stable across blending ratios, indicating minimal slagging risk and good ash compatibility. Embrittlement pretreatment offers an energy-efficient, practical route to enable large-scale biomass integration into coal-fired systems for cleaner power generationp.

Abstract Against the background of the low-carbon transformation of coal-fired power, biomass-coal co-firing has become an important approach to achieve low-carbonization. To formulate reasonable co-firing schemes, this study, based on the combustion characteristics of biomass and coal, proposes for the first time a Comprehensive Performance Index (CPI) model for biomass-coal co-firing to evaluate combustion safety, establishes a low-carbon index (L) based on CO 2 emissions, and develops an economic evaluation model for biomass-coal co-firing according to fuel costs. Furthermore, a multi-objective decision-making framework is constructed around low-carbon performance, safety, and economy, and the NSGA-II algorithm is employed to solve for the Pareto optimal solution set. Finally, the validity of the model is verified using data from typical units in Shaanxi. The results show that this model can effectively address the issue of biomass co-firing in coal-fired power units during the low-carbon transformation, providing a reference for the formulation of biomass-coal co-firing schemes and the selection of biomass.

Biomass–coal cofiring has emerged as a promising transitional strategy for low-carbon energy generation, yet uncertainties persist regarding its air-quality and health implications. This systematic literature review synthesizes evidence from 2000–2025 across 17 peer-reviewed studies to evaluate how fuel pretreatment, combustion modes, and control portfolios influence pollutant emissions, ambient PM₂. ₅, and population-level health outcomes. The review integrates combustion modeling, chemical transport analysis, and policy evaluation to bridge the knowledge gap between emission reductions and health co-benefits. The methodology followed PRISMA guidelines, incorporating studies from Scopus, Web of Science, PubMed, and ScienceDirect, with quality assessments using ROBIS and GRADE frameworks. Key findings reveal that torrefaction and hydrothermal carbonization (HTC) improve biomass quality, reducing NOx, SO₂, and PM₂.₅ by up to 40% under optimized conditions. Oxy-fuel and syngas reburn configurations demonstrate the most significant emission reductions, particularly when coupled with Selective Catalytic Reduction (SCR), Flue Gas Desulfurization (FGD), and Electrostatic Precipitators (ESP). However, regional inequities in health benefits persist, as uniform emission policies inadequately address high-exposure zones. Spatially explicit modeling using GIS and CMAQ demonstrates that integrating environmental justice (EJ) metrics and targeted retrofits can close up to 25% of the health gap between affluent and disadvantaged regions. Carbon pricing, renewable mandates, and subsidy frameworks, when aligned with spatial targeting, emerge as effective mechanisms for equitable decarbonization. This review concludes that cofiring’s health benefits are realized only under optimized technical and policy conditions that combine emission control, fuel innovation, and social inclusion. The study contributes a unified analytical framework linking combustion science, air-quality modeling, and policy equity, offering actionable insights for health-centered energy transitions. Keywords: Biomass cofiring; air quality; Environmental justice; emission control; health co-benefit

High-ratio biomass co-firing has emerged as a practical pathway for reducing emissions from small coal-fired power plants in remote island grids. This study evaluates the environmental performance of palm kernel shell (PKS) co-firing at 50%, 75%, and 100% blending ratios in a stoker-fired boiler at PLTU Tidore, Indonesia. Direct stack measurements and fuel characterisation were used to quantify the effects of PKS substitution on sulfur dioxide (SO₂), nitrogen oxides (NOx), particulate visibility, and ash characteristics, while also assessing the stabilizing role of a redundant baghouse filtration configuration. The strongly reduced sulfur and ash content of PKS, as detailed in the fuel analyses, led to substantial declines in SO₂ emissions. Concentrations decreased from 182.95 mg/Nm³ under coal-only operation to 16.53 mg/Nm³ during 100% PKS firing. NOx levels remained within an operationally stable range (303.87–452.14 mg/Nm³) despite non-linear fluctuations associated with fuel–temperature interactions. PKS firing also resulted in progressively lighter stack plumes and the production of finer, less clinker-forming ash. Throughout all tests, the redundant bag filter system maintained uninterrupted particulate control and prevented opacity excursions, ensuring the reliability of the environmental measurements. These results demonstrate that PKS co-firing, supported by robust filtration redundancy, provides a feasible and cost-effective approach for improving air quality performance in isolated coal-dominated grids. The findings highlight a replicable strategy for integrating biomass into small-scale thermal plants while maintaining emission stability and operational continuity.

Coal remains the dominant source of electricity generation in Indonesia, accounting for around 55% of installed capacity. As a fossil fuel, coal contributes significantly to greenhouse gas (GHG) emissions, posing a challenge to Indonesia’s commitment to the Paris Agreement. Biomass co-firing in coal power plants offers a promising pathway to reduce GHG emissions. However, sustainable biomass supply is a major challenge due to Indonesia’s archipelagic geography, which causes regional disparities in power capacity, fuel types, and biomass potential. This study assesses the potential of multi-regional biomass supply in relation to emission reduction targets, using secondary data for provincial biomass waste inventories is assessed. The Low Emissions Analysis Platform (LEAP) model projects coal demand from 2025 to 2045 under two scenarios: business as usual (BAU) and biomass co-firing (BCF) with biomass shares of 5%, 10%, and 15%. Findings show that municipal and industrial waste alone cannot sustain long-term co-firing at the national level. Therefore, multi-regional supply-demand analysis is essential. Provinces such as Riau, North Kalimantan, Central Kalimantan, West Kalimantan, Papua, Bangka Belitung Islands, and Jambi are identified as surplus regions. A 15% biomass co-firing scenario could reduce emissions by 108 Mt of CO₂ by 2045 and lower emission intensity nationwide.

This 47th volume of the International Journal of Sustainable Energy Planning and Management presents the most recent work on energy planning with a focus on storage in energy systems, cofiring of biomass in coal-fired power stations forecasting of electricity demand for better planning practise. Analyses demonstrate the potential resources for photo voltaics (PV) in Iraq, and barriers for its implementation in Indonesia, where perceived costs is a dominant barrier. Heat planning is a long-standing focus area of the journal – in this volume with a focus on stakeholder interests and the organisation of the heat planning process. Lastly, this volume presents analyses of links between energy and development in Africa.

To address the challenges of combustion stability and pollutant control during biomass co-combustion in coal-fired boilers under deep peak regulation, a numerical simulation study was conducted on a 660 MW front-and-rear wall opposed-fired pulverized coal boiler using computational fluid dynamics (CFD) technology. First, the reliability of the numerical model was validated under the Boiler Maximum Continuous Rating (BMCR) condition by comparing the simulated results of furnace outlet temperature and NO concentration with on-site operational data, with relative errors of 1.2% and 1.9%, respectively, both within the acceptable range of 5%. Subsequently, the effects of different biomass co-combustion ratios (0%, 5%, 10%, 15%, 20%) and injection positions (primary air nozzles of lower, middle, and upper burners) on the in-furnace velocity field, temperature field, component distribution (O2, CO, CO2), and NO emissions were systematically analyzed. The results indicate that increasing the biomass co-combustion ratio does not alter the overall variation trend of flue gas components but significantly affects their concentrations: the O2 content at the furnace outlet decreases gradually, while the CO2 content increases, and the NO emission concentration decreases continuously. A 20% co-combustion ratio is identified as the optimal choice, balancing combustion efficiency and NO reduction. Regarding injection positions, biomass injected at the middle burner’s primary air nozzle achieves the best NO control effect, reducing NO emissions by 22% compared to pure coal combustion. This is attributed to the formation of a stable reducing atmosphere in the main combustion zone, which facilitates NOx reduction. The research findings provide valuable theoretical references and technical support for the parameter optimization and safe, low-emission operation of biomass co-combustion in large-scale coal-fired boilers.

Elucidating ammonia's impact on non-gray radiation and thermometry during biomass co-firing via spectral guidance

Abstract The development of protective coatings against alkali-induced high-temperature corrosion is critical for extending the service life of components in aggressive environments such as boiler co-firing biomass. This study investigated the influence of Cr 3 C 2 -NiCr coating thickness on the corrosion performance of A516 carbon steel substrates exposed to alkali chloride vapor (NaCl + 55 wt% KCl) at 600 °C for 100 hours. Cr 3 C 2 -NiCr as the coating material was deposited by High Velocity Oxy Fuel (HVOF) spraying with approximate thicknesses of 150 µm and 20 µm. Their degradation behaviors were evaluated through mass change measurements, corrosion rate analysis, and detailed microstructural characterization using field emission-scanning electron microscopy (FE-SEM) equipped with electron dispersive spectroscopy (EDS), X-Ray Diffraction (XRD), and surface hardness testing. The thicker coating of 150 µm exhibited a significantly lower corrosion rate (0.15 mm/y during the first 20 hours) than the thinner coating of 20 µm, which experienced rapid degradation and visible spallation after 40 hours. XRD analysis revealed that the surface of the thicker coating was dominated by Cr 2 O 3 and NiCr 2 O 4 . In contrast, the thinner coating formed a more complex oxide mixture consisting of Cr 2 O 3 , NiCr 2 O 4 , Fe 3 O 4 , and NaCrO 2 , indicating a severe corrosion attack to the thinner coating and substrate. The underlying mechanisms of alkali salt vapor corrosion for both coating thicknesses are explained in this paper, offering understanding into microstructural of Cr 3 C 2 -NiCr coating on A516 carbon steel in corrosive high-temperature environments.

Numerical study and industrial application of coal co-firing biomass in a 600 MW opposed wall-fired boiler with feeding biomass through inner OFA nozzles

Coal-fired power plants (PLTUs) play a crucial role in the national electricity system due to their ability to generate electricity on a large scale. The 2x25 MW Anggrek Steam Power Plant in North Gorontalo Regency is one of the power plants that has implemented Lamtoro biomass cofiring technology. This study aims to analyze the thermodynamic performance of the 2x25 MW Anggrek Steam Power Plant (PLTUs) under two conditions: existing (100% coal) and cofiring (85% coal + 15% lamtoro biomass). The method employed in this study utilizes thermodynamic law analysis, supplemented by cycle tempo simulations, to evaluate boiler and power cycle efficiency. The results show boiler efficiency under cofiring conditions of 82.45% (direct method) and 87.04% (heat duty method). The power cycle efficiency decreased from 23.336% (existing) to 21.652% (cofiring) due to the lower heating value of the biomass. Therefore, despite the decrease in efficiency, cofiring lamtoro biomass remains a feasible alternative fuel in PLTUs because it can maintain operational stability and has the potential to reduce carbon emissions.

As Indonesia's population grows, the need for electrical energy increases. To meet this demand, the government is required to build power plants, one of which is a Steam Power Plant (PLTUs). However, PLTUs still rely on coal as their primary fuel, which contributes significantly to carbon emissions. One effort to reduce these emissions is the implementation of biomass cofiring technology as a more environmentally friendly alternative energy source. This study aims to model the thermal system of the Anggrek 2×25 MW PLTUs using Cycle Tempo 5.0 software and evaluate the system performance at varying cofiring ratios of coal with lamtoro biomass, specifically 10%, 15%, 20%, 25%, and 30%. The research method employed a cycle tempo simulation, utilizing input parameters derived from the actual operational data of the Anggrek PLTUs. The system model built was used to compare the performance of the PLTUs under existing conditions with various fuel mixture variations. The simulation results showed that the addition of lamtoro biomass to the fuel mixture reduced the efficiency of the thermal system due to the lower heating value of biomass compared to coal. The results based on existing conditions of 100% coal provided the highest efficiency, namely gross power of 23.23% and net power of 22.23%. At the same time, the 10% cofiring variation achieved a gross power efficiency of 21.98% and a net power of 21.02%. Meanwhile, a 15% variation yielded a gross power of 21.32% and a net power of 20.37%. Furthermore, a 20% variation yielded a gross power of 21.00% and a net power of 20.03%. A 25% variation yielded a gross power of 20.56% and a net power of 19.61%. Finally, a 30% variation yielded a gross power of 20.31% and a net power of 19.36%. Thus, this study demonstrates that cofiring lamtoro biomass can be a strategy to reduce dependence on coal and reduce carbon emissions, although system efficiency tends to decrease.

Combustion improvement and burnout enhancement by optimizing biomass nozzle position in a 600 MW opposed wall-fired boiler with coal co-firing biomass

PLN, Indonesia’s state-owned electricity company, continues to commit and innovate towards achieving the target of 23% new and renewable energy (NRE) mix by 2025 and net zero emissions by 2060. One of its programs is the Biomass Co-firing in Steam Power Plants (PLTU), a substitution technique in combustion that utilizes biomass as an alternative to partially and/or entirely replace coal as fuel. This study aims to analyze the impact of biomass quantity, biomass delivery, and power plant infrastructure on the productivity of biomass co-firing electricity production at steam power plants. This research employs a quantitative approach. The sampling technique used is purposive sampling, with a total of 100 respondents. Data analysis was conducted using the structural equation model (SEM) with the help of SmartPLS version 4 software. The results show that biomass quantity (X1) and power plant infrastructure (X3) have a positive and significant impact, while biomass delivery (X2) has a positive but not significant effect on the productivity of biomass co-firing electricity production at steam power plants (Y). The R-Square value is 0.355. The equation model is as follows: Y = 0.352 X1 + 0.035 X2 + 0.377 X3. Practical implications include establishing long-term partnerships with industrial/energy plantation forest managers, conducting stakeholder management, and conducting power plant readiness assessments.

Against the backdrop of the “dual-carbon” strategy and the ongoing energy transition, biomass co-firing in coal-fired boilers has gained wide attention due to its combined advantages of emission-reduction potential and engineering feasibility. However, the aerodynamic behavior of typical high-aspect-ratio straw particles during pre-furnace transport and mixing remains insufficiently understood, particularly the influence of particle–particle interactions on multidimensional force characteristics. This study examines a tandem configuration of two finite-length cylindrical particles and, for the first time, systematically incorporates variations in incidence angle (0° ≤ θ ≤ 90°) into particle-resolved direct numerical simulations (PR-DNS). Across a broad Reynolds number range (10 ≤ Re ≤ 2000) and multiple spacings (2 ≤ L/Deq ≤ 8), we comprehensively analyze the evolution of the drag (CD), lift (CL), and torque (CT) coefficients for Front and Back. The results reveal a characteristic “shielding–recovery” behavior of Back under different orientations and spacings and elucidate the mechanism by which increasing Reynolds number triggers three-dimensional wake instabilities and shifts force peaks. Furthermore, a lightweight surrogate model based on artificial neural networks (ANN) is developed, which demonstrates excellent robustness across the full parameter space. By training on PR-DNS datasets, the ANN achieves rapid predictions of CD, CL, and CT with deviations typically below 3%, even under highly nonlinear flow conditions where conventional correlations fail. Sensitivity analysis shows that ANN captures the coupled effects of Reynolds number, incidence angle, and spacing with superior accuracy, highlighting its capability to generalize beyond the sampled conditions. This work not only fills a gap in aerodynamic databases for non-spherical particles in tandem configurations but also proposes a hybrid modeling approach that couples physical mechanisms with data-driven learning. The combined insights from PR-DNS and ANN provide a scalable force-closure strategy for Eulerian–Lagrangian simulations of multiphase flows, enabling both physical interpretability and computational efficiency. The findings offer practical guidance for improving co-firing efficiency and emission reduction in coal-fired boilers.