Ash-Related Operational Challenges in Energy Utilization of Sustainable Fuels

Technical University of Denmark (DTU) via Coursera

Go to Course: https://www.coursera.org/learn/sustainability-fuels-ash-chemistry-deposits-corrosion-additives

Introduction

**Course Review: Ash-Related Operational Challenges in Energy Utilization of Sustainable Fuels** In today's rapidly evolving energy landscape, the pursuit of sustainable fueling solutions has never been more critical. With increasing governmental pressure to reduce emissions and reliance on fossil fuels, knowledge around sustainable fuels is essential for both industry professionals and students alike. Through Coursera, the course titled "Ash-Related Operational Challenges in Energy Utilization of Sustainable Fuels" offers a comprehensive overview of the subject, focusing on the intricate relationship between fuel characterization, ash formation, and the operational challenges posed within this space. ### Course Overview This Massive Open Online Course (MOOC) is a collaborative effort led by the research group at the Technical University of Denmark (DTU), geared towards individuals who want to deepen their understanding of ash-related operational challenges in sustainable fuel utilization. Ranging from advanced fuel characterization to hands-on case studies, the curriculum is meticulously structured to offer insights that are both theoretical and practically applicable. ### Detailed Syllabus Breakdown **Module 1: Brief MOOC Introduction and Incitement for Following This** The course kicks off with a compelling introduction that lays the groundwork for what participants can expect. It not only piques interest but also instills a sense of purpose in understanding the relevance of ash-related challenges in sustainable fuels. **Module 2: Fuel and Ash Chemistry and Characterization** Delving into the properties of various fuels and ashes, this module takes students through both fundamental and advanced analytical techniques. The diversity of methodologies presented—ranging from proximate and ultimate analyses to cutting-edge techniques such as Simultaneous Thermal Analysis (STA) and Scanning Electron Microscopy (SEM)—equips learners with a solid skill set necessary for effective fuel analysis. **Module 3: Release of Critical Ash-Forming Elements** Understanding how critical elements like potassium (K), sulfur (S), and chlorine (Cl) are released during the thermal conversion is vital. This module offers insight into important processes associated with both fixed-bed and entrained flow systems, enabling learners to comprehend the foundational chemistry behind ash behavior. **Module 4: Formation of Fly Ash and Aerosols** The journey continues as students explore how these critical elements transition into fly ash and aerosols post-combustion. This module balances technical detail with health implications, helping students grasp the dualities of energy production and environmental responsibility. **Module 5: Transport and Adhesion of Ash Particles** Through an exploration of transport mechanisms like thermophoresis and inertial impaction, students will understand how ash particles adhere to surfaces. This foundational understanding is crucial, given the operational challenges that arise in energy systems. **Module 6: Deposit Build-Up, Consolidation, and Shedding** Complex interactions between ash and surfaces are examined here, with practical experiences in measuring deposit formations shared. Participants are urged to consider the implications of deposit dynamics on operational efficiency. **Module 7: High-Temperature Cl-Corrosion** The challenges of corrosion from deposits are dissected, tying together research findings from years of studies at DTU. Understanding these issues is essential for designing robust energy systems that withstand operational stresses. **Module 8: Use of Additives to Minimize Deposit Formation** This module explores innovative solutions for minimizing adverse effects through various additives, bridging the gap between theoretical research and practical application in boiler systems. **Module 9: Danish Case Studies on Ash and Deposit Formation** Concluding the course, this module integrates real-world case studies from Danish utilities, presenting tangible examples of ash formation challenges. By exploring scenarios involving straw-firing, students are equipped with applied knowledge that ensures relevance to current market needs. ### Recommendation The course “Ash-Related Operational Challenges in Energy Utilization of Sustainable Fuels” is a vital resource for individuals engaged in energy production, environmental engineering, or fuel technology. Its well-rounded content balances theory with practical insights, fostering an understanding that extends beyond academic boundaries. Whether you’re a student eager to explore the cutting-edge of energy technologies, or an industry professional seeking to enhance your operational knowledge and tackle today’s sustainability challenges, this course is highly recommended. The rich content and the engagement with ongoing academic research make it a unique platform fostering the vital bridge between industry and academia, and ultimately advancing the future of sustainable energy solutions. Embrace this opportunity to elevate your knowledge and contribute meaningfully to the conversation around sustainable energy.

Syllabus

Brief MOOC Introduction and Incitement for Following This

This module will introduce the basic content of the course to the student.

Fuel and Ash Chemistry and Characterization

Module 2 (Fuel and Ash Chemistry and Characterization) is subdivided into 7 lessons, dealing with fuel and ash characterization, and is meant as an introduction to different techniques, applied to characterize fuels or ash samples. Both simple techniques like proximate and ultimate analyses, but also advanced techniques like Simultaneous Thermal Analysis (STA) analysis of ash fusion and Scanning Electron Microcospy (SEM), are introduced. There is also included an introduction to online fuel databases.

Release of Critical Ash-Forming Elements

This module gives an introduction to how critical ash-forming elements like K, S, and Cl, but also Na, Zn and Pb, are released from fuels, during thermal conversion.Module 3 (Release of Critical Ash-Forming Elements) deals with release of critical ash-forming elements, mainly K, S and Cl, but also Na, Zn, and Pb. The module has four lessons and deal with both fixed-bed and entrained flow release quantification. Further, there is a thorough introduction to K-release from K-Ca-P-rich ashes.

Formation of Fly Ash and Aerosols

As soon as the critical ash-forming elements have been released to the gas, formation of fly ash and aerosols begin, which is the subject of Module 4 (Formation of Fly Ash and Aerosols). This module is subdivided into 5 lessons, introducing both fundamental and detailed physical aspects of residual fly ash formation, as well as formation of and harmful health effects of combustion-derived aerosols. Finally, there is a thorough introduction to the pioneering Danish full.scale aerosol formation studies at Haslev respectively Slagelse CHP.

Transport and Adhesion of Ash Particles

Next natural step in the chain of events leading to troublesome deposit formation is the transport and adhesion of ash species (gases, aerosols and particles), which is the subject of Module 5 (Transport and Adhesion of Ash Particles), thoroughly addressing both important transport mechanisms like diffusion, thermophoresis and inertial impaction, as well as mechanisms of adhesion and different criteria for sticking of ash species.

Deposit Build-Up, Consolidation and Shedding

As soon as the ash species stick to the surface of the deposit, a build-up, consolidation and shedding of deposit begins. These are extremely complex, interaction phenomena, involving both physical and chemical aspects. This is the subject of Module 6 (Deposit Build-Up, Consolidation and Shedding), which also covers practical experiences in performing deposit measurements in full-scale.

High-Temperature Cl-Corrosion

One of the consequences of deposit formation is the possible chemical interaction between the deposit and the heat transfer tube, better known as corrosion, which is outlined in Module 7 (High-Temperature Cl-Corrosion), based on several years of research in this field at our Department at DTU. Aspects of corrosion underneath deposits formed in biomass- as well as waste-fired units are covered in details.

Use of additives to Minimize Deposit Formation and High-Temperature Corrosion

There are a number of ways to minimize corrosion, aerosol and ash deposit formation in boilers, one of them being the use of additives to affect the chemistry in the freeboard of the boiler, thereby minimizing e.g. the concentration of Cl in the inner layers of the deposit, or, minimizing the mass loading of aerosols and thereby the environmental impact of these. This has for years been a major research activity at DTU and Module 8 (Use of additives to Minimize Deposit Formation and High-Temperature Corrosion) therefore deals with the application of additives, both the classical Al-Si- and the more sophisticated S-based additives.

Danish Case-Studies on Ash and Deposit Formation

Finally, Module 9 (Danish Case-Studies on Ash and Deposit Formation) in this MOOC deals with Danish case studies of ash and deposit formation in utility boilers. The module covers three classical cases from dedicated straw-fired grate units: the Haslev/Slagelse, Rudkøbing and Masnedø CHPs. After this, an introduction to the MKS1 demoprogramme on co-firing of coal and straw in pc-fired units follow, this campaign marked a progressive step toward the ultimative shift from pure biomass-firing in grate units, to biodust-firing in pf-units. The last two lessons in this module covers biodust-firing at the Avedøre Power Station, with special focus on aerosol and deposit formation and chemistry, with and without the use of coal fly ash as an additive.