Coal and plastic waste co-pyrolysis by thermal analysis–mass spectrometry

Simultaneous thermogravimetry–mass spectrometry studies of a pyrolytic decomposition of mixtures of different plastic wastes/coking coal were carried out. The investigation was performed at temperatures up to 1000 °C in a helium atmosphere under dynamic conditions at a heating rate of 25 °C/min. Five thermoplastics, commonly found in municipal wastes: low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and a plastic mixture rich in polyolefins were selected. Thermogravimetric parameters, together with different characteristic ion fragments from selected libraries of evolving products during the co-pyrolysis process were monitored, such as hydrogen, CO2 and aliphatic and aromatic hydrocarbons. Based on the results obtained, a synergistic effect between coal and individual residues has been found. The maximum interaction occurs at temperatures close to the maximum release of volatile matter of the plastic waste. There is a delay in the decomposition of the plastics that together with the changes in the composition of the volatile matter evolved, promote interactions between the components and have negative effects on coal fluidity. The polyolefinic wastes (HDPE, LDPE and PP) degrade at temperatures close to that of maximum coal degradation, modifying the thermal behaviour of the coal to a lesser degree. However, PS and PET, that release their volatile matter mostly in the early stage of the coal decomposition, show a more pronounced influence on the thermal behaviour. Moreover, the kinetic data demonstrates that the addition of polyolefins increases the energy required to initiate pyrolysis compared to PS and PET. All of these results agree with the fact that polyolefins reduce coal fluidity in a more moderate way than PET and PS

Выбор участка эксплуатационного объекта для применения гидродинамических методов увеличения нефтеотдачи в процессе разработки месторождений

Объектом исследования являются технологии гидродинамических методов увеличения нефтеотдачи. Цель исследования – обоснование применения гидродинамических методов увеличения нефтеотдачи на эксплуатационных объектах нефтяных месторождений. В процессе исследования были подробно рассмотрены технологии гидродинамических методов нефтеотдачи, применяемых на нефтяных месторождениях, а также рассмотрена эффективность применения от внедрения технологий в процесс эксплуатации месторождения. Проведен обзор применения различных методов и анализ их эффективности применения. Проанализирован метод комбинированного нестационарного заводнения.The object of the research is the technologies of hydrodynamic methods of increasing oil recovery. The purpose of the study is to substantiate the use of hydrodynamic methods for enhancing oil recovery at production facilities of oil fields. In the course of the study, the technologies of hydrodynamic methods of oil recovery used in oil fields were considered in detail, and the effectiveness of the application from the introduction of technologies into the process of operating the field was considered. A review of the application of various methods and an analysis of their effectiveness are carried out. The method of combined non-stationary waterflooding is analyzed

Effect of maceral composition and coal rank on gas diffusion in Australian coals

Abstract not availableAlireza Keshavarz, Richard Sakurovs, Mihaela Grigore, Mohammad Sayyafzade

Study of gasification reaction of cokes excavated from pilot blast furnace

Fundamental understanding of coke reactions with gas, metal and slag phases is essential for ensuring smooth operation and optimisation of coke performance in existing and advanced blast furnace process, and is dictated by coke properties and blast furnace process conditions. In this study, coke samples excavated from LKAB's Experimental Blast Furnace (EBF) at MEFOS in Luleå, Sweden were collected. The centreline quenched coke samples from different zones of this EBF were used to observe the influence of in-furnace reactions on the evolution of coke properties and their associations with CO2 reactivity. Carbon structure of coke was found to increasingly ordered, silicon and iron concentration in the coke samples decreased, while alkali concentration particularly potassium and sodium were found to increase as the coke descended towards lower part of the EBF. Both isothermal and non-isothermal reactivity based on TGA measurements showed that coke reactivity towards CO2 is increased as coke descends towards cohesive zone despite increasing order of carbon structures. Increased reactivity of cokes at lower parts of EBF was related to alkali enrichments of cokes. The study further shows that increased alkali components in cokes have a strong impact on CO2 gasification in EBF such that influence of coke graphitisation could be compensated by catalytic influence of alkalis. To further assist with development of understanding of reactivity of coke, gasification studies were also conducted in a fixed bed reactor at 900ºC using a series of cokes made from Australian coals (varying in rank, maceral and mineral matter). The CO2 reactivity of cokes in a fixed bed reactor was also found to be strongly influenced by the coke minerals compared to carbon structure. Further studies are required to provide a critical insight into the influence of key parameters such as coke graphitisation and mineral reactions on coke gasification particularly at higher temperatures.Godkänd; 2004; 20061210 (ysko