Author: Tia M. MitchellPublisher:
ISBN:
Category : Coal
Languages : en
Pages : 91
Book Description
Studies of Spontaneous Combustion of Low Rank Coals and Lignites
Author: Tia M. MitchellSTUDIES OF THE SPONTANEOUS COMBUSTION OF LOW RANK COALS AND LIGNITES.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Spontaneous combustion has always been a problem in coal utilization especially in the storage and transportation of coal. In the United States, approximately 11% of underground coal mine fires are attributed to spontaneous coal combustion. The incidence of such fires is expected to increase with increased consumption of lower rank coals. The cause is usually suspected to be the reabsorption of moisture and oxidation. To understand the mechanisms of spontaneous combustion this study was conducted to (1) define the initial and final products during the low temperature (10 to 60 C) oxidation of coal at different partial pressures of O2, (2) determine the rate of oxidation, and (3) measure the reaction enthalpy. The reaction rate (R) and propensity towards spontaneous combustion were evaluated in terms of the initial rate method for the mass gained due to adsorbed O2. Equipment that was used consisted of a FT-IR (Fourier Transform-Infrared Spectrometer, Perkin Elmer), an accelerated surface area porosimeter (ASAP, Micromeritics model 2010), thermogravimetric analyzer (TGA, Cahn Microbalance TG 121) and a differential scanning calorimeter (DSC, Q1000, thermal analysis instruments). Their combination yielded data that established a relation between adsorption of oxygen and reaction enthalpy. The head space/ gas chromatograph/ mass spectrometer system (HS/GC/MS) was used to identify volatiles evolved during oxidation. The coal samples used were Beulah lignite and Wyodak (sub-bituminous). Oxygen (O2) absorption rates ranged from 0.202 mg O2/mg coal hr for coal sample No. 20 (Beulah pyrolyzed at 300 C) to 6.05 mg O2/mg coal hr for coal sample No. 8 (wyodak aged and pyrolyzed at 300 C). Aging of coal followed by pyrolysis was observed to contribute to higher reaction rates. Reaction enthalpies ranged from 0.42 to 1580 kcal/gm/mol O2.
Spontaneous Combustion of Coal
Author: Xinyang WangPublisher: Springer Nature
ISBN: 3030336913
Category : Science
Languages : en
Pages : 240
Book Description
This book aims to understand, analyze and mitigate the harmful impacts of spontaneous coal combustion in underground mines, a thermal phenomenon that triggers fires and explosions threatening the safety of mine workers globally. Based on experimental and theoretical research findings, the book emphasizes three essential questions that are fundamental to understand spontaneous coal combustion: What are the root causes? How to evaluate the causative factors to determine the activity of coal? and How to bring this issue under control in real longwall panel? Readers are introduced to experimental techniques applied to investigate the basic molecular structure of coal and evaluate chemical properties that induce self-heating behavior, theoretical analyses to predict the extrinsic effect on low temperature oxidation of coal in experimental scale and full-size longwall panel, and preventive measures to mitigate this issue using methods for retardant screening, numerical simulations for optimal grouting and nitrogen injections, and case studies analyzing thermal events using mine atmosphere gas monitoring data. The book will be of interest to students and researchers studying mining engineering and chemistry, as well as engineers and practitioners involved in coal mine development and risk assessment.
Spontaneous Combustion Studies of U.S. Coals
Author: Alex C. SmithLow-rank Coals for Power Generation, Fuel and Chemical Production
Author: Zhongyang LuoPublisher: Woodhead Publishing
ISBN: 0081009291
Category : Technology & Engineering
Languages : en
Pages : 367
Book Description
Low-Rank Coals for Power Generation, Fuel and Chemical Production provides a thorough introduction to lignite (brown coal) and subbituminous coals and explores how they can be used efficiently and economically in place of hard coal. The book examines the undesirable characteristics of low-quality coals, such as high moisture content, low calorific value, and aggressive ash characteristics, and the resulting refinements to standard technologies and practices required for successful combustion, gasification, and pyrolysis.The first part of this book provides a comprehensive and systematic review of the properties of low-rank coals and corresponding preparation methods, such as drying, cleaning, and upgrading. Power generation from low-rank coals is the focus of Part 2, with chapter topics ranging from high efficiency pulverized coal combustion and circulatingfluidized bed combustion to emerging areas such as chemical looping and oxyfuel combustion. The final contributions address the important subjects of coal-to-liquids,polygeneration and coke production using low-rank coals, as well as the critical issue of carbon capture and storage.This book is a valuable resource for power generation engineers and researchers seeking to maximize the opportunities provided by these cheaper coal feedstocks for efficient and environmentally compatible power generation. Presents the most in-depth treatment of low-rank coals available Addresses both power generation and fuel production Includes coverage that spans pulverized coal combustion and emerging technologies, such as CFBC, UCG, CLC, and oxyfuel combustion
Detailed Study of the Reaction Mechanism of Spontaneous Combustion of Coal with Particular Emphasis on Western Canadian Low-rank Coals
Author: Amitabha MajumdarPublisher:
ISBN:
Category : Coal
Languages : en
Pages : 169
Book Description
Detailed Study of the Reaction Mechanism of Spontaneous Combustion of Coal with Particular Emphasis on Western Canadian Low Rank Coals, Phase II.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 93
Book Description
Western Canada contains abundant quantities of low sulfur, low to medium rank coals, representing a good potential for sales to Eastern and overseas markets, particularly for power plants. For most of these coals, their only drawback is their tendency to spontaneous combustion, especially for those coals which have undergone a preliminary drying treatment before shipment. This report continues work begun in October 1983 and includes an update on this work. The major part of the report deals with studies on the progressive drying of 6 selected Alberta coal samples (3 high volatile bituminous and 3 subbituminous) and their adiabatic response to the passage of a controlled humidity flowing gas. Changes in porosity, free radicals and peroxides were measured on samples to examine the effect of this drying and subsequent moist air treatment to see if any correlation could be made between these parameters.
Large-scale Studies of Spontaneous Combustion of Coal
Author: Alex C. SmithGeology of Coal Fires
Author: Glenn B. StracherPublisher: Geological Society of America
ISBN: 0813741181
Category : Science
Languages : en
Pages : 304
Book Description
Naturally burning coal fires and those ignited by human activities receive little attention from the media compared to other environmental hazards, but their study is gaining ground. Here, the world's leading experts present their research findings covering topics such as the gases generated in underground coal fires, the origin of gas-vent minerals and land-cover changes due to coal fires.
Mine Planning and Equipment Selection
Author: Carsten DrebenstedtPublisher: Springer Science & Business Media
ISBN: 331902678X
Category : Technology & Engineering
Languages : en
Pages : 1464
Book Description
This edited volume includes all papers presented at the 22nd International Conference on Mine Planning and Equipment Selection (MPES), Dresden, Germany, 2013. Mineral Resources are needed for almost all processes of modern life, whilst the mining industry is facing strict requirements regarding efficiency and sustainability. The research papers in this volume deal with the latest developments and research results in the fields of mining, machinery, automatization and environment protection.