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[en] This paper describes the investigation of temperature characteristics of an in-furnace combustion using different coals in a 700 MW full scale boiler. Single mixture fraction approach is adopted for combustion model of both primary and secondary coals. The primary coal was based on the properties of Adaro which has been used as the design coal for the boiler under investigation. The secondary blend coal was selected based on sub-bituminous coal with higher calorific value. Both coals are simultaneously injected into the furnace at alternate coal burner elevations. The general prediction of the temperature contours at primary combustion zone shows identical pattern compared with conventional single coal combustion in similar furnace. Reasonable agreement was achieved by the prediction of the average temperature at furnace exit. The temperature distribution is at different furnace elevation is non-uniform with higher temperature predicted at circumferential 'ring-like' region at lower burner levels for both cases. The maximum flame temperature is higher at the elevation where coal of higher calorific value is injected. The temperature magnitude is within the accepTable limit and the variations does not differ much compared to the conventional single coal combustion.
[en] The paper considers the creation of optical sensors with given properties that allows measuring with sufficient truth the distribution of pressure fields in objects of a compound form for solving aerodynamic problems. The luminescence suppression by oxygen leads to decreasing persistent intensity. That is the base of the offered sensors of pressure. (author)
[en] Natural gas is the most rapid growing energy sources around the world. The presence of CO/sub 2/ in natural gas lowers its calorific value and purification of a natural gas by removing CO/sub 2/ is an essential process to increase its value. Several separation technologies are used to remove acidic gases like H2S and CO/sub 2/ from natural gas. Among these technologies, membrane process is a feasible energy saving alternate to CO/sub 2/ capture. The three types of membrane include polymeric, inorganic and mixed matrix membranes. Currently, polymer membranes and inorganic membranes were considered for gas separation, but inorganic membranes are too costly. Even mixed matrix membrane performance suffered defects caused by poor glassy polymer and particle interactions. Pure glassy and pure rubbery are problematic due to their instructive properties. The blending of glassy with rubbery polymers improve membrane properties for gas separation. To enhance the compatibility of the polymer blend, a third component is added such as alkanol amines. Although, the enhanced polymeric blend membranes have many advantages in terms of permeance, selectivity, thermal and chemical stability. Polymer blending also offers an effective technique to synthesize membranes with desirable properties. (author)
[en] The heat of combustion and sound speed of natural gas were studied as a function of random fluctuation of the gas fractions. A method of sound speed determination was developed and used for over 50,000 possible variants of component concentrations in four- and five- component mixtures. A test on binary (methane-ethane) and multicomponent (Gulf Coast) gas mixtures under standard pressure and moderate temperatures shows satisfactory predictability of sound speed on the basis of the binary virial coefficients, sound speeds and heat capacities of the pure components. Uncertainty in the obtained values does not exceed that of the pure component data. The results of comparison between two natural gas mixtures - with and without nonflammable components - are reported
[en] Since CO2 facilitates pipeline corrosion and contributes to a decrease of the calorific value of gaseous fuels, its removal has become an issue of significant economic importance. The present review discusses various types of traditional CO2 capture technologies in terms of their efficiency, complexity in system design, costs and environmental impact. The focus is hereby not only on conventional approaches but also on emerging 'green' solvents such as ionic liquids. The suitability of different ionic liquids as gas separation solvents is discussed in the present review and a description on their synthesis and properties in terms of CO2 capture is provided. The bibliography includes 136 references.
[en] In the article the issue on methodology of hydrocarbons calorific value detecting is presented. The selection of method for creating the automated device for calorific value measuring of natural gas has been substantiated. The chosen method is based on measuring the conductivity of gas mixture combustion. The hardware algorithm has been suggested for calorific value detection of the fuel and testing result has been shown. (author)
[en] Highlights: • NRP data as the real plastic waste amount is used to pyrolyze. • The source of PS for additional feed can be taken from RPS in recycle stream. • Liquid, gas and tar produced contain high energy and can be used as source of fuel. • Energy from Malaysia’s NRP pyrolysis is equal to 4,264,167 barrels of oil/year. - Abstract: Oil produced from pyrolysis of plastics have been known for its higher calorific value than wood-based oil, in which comparable to conventional diesel. Even though many studies have been conducted on pyrolysis of plastics, the findings of those studies are not applied and reported yet according to the real portion of plastic waste. The real amount of plastic waste available is mainly derived from non-recycled plastics (NRP). NRP is defined as the plastic waste that remain in the recycling centers, which unable to be processed due to the certain restrictions. The amounts of NRP vary for each country based on daily applications. In this study, data of NRP in Malaysia, US, UK, as well as global were used to investigate the potential production of liquid fuel based on their different composition of plastic waste. Pyrolysis was conducted in a fixed bed reactor at 500 °C with nitrogen flow of 200 ml/min for 30 min reaction time. The addition of polystyrene (PS) into the NRP composition was also studied to evaluate the improvement of the liquid quality. Several important findings were discussed in this paper including some technical problems, features of the liquid product, characteristics of the by-products and potential energy recovery from NRP. The liquid product was analyzed by various methods such as FTIR, GCMS, elemental analysis and water content.
[en] A generalized thermodynamic theory of giant-caloric effects in coupled multiferroic solids is introduced. The generalized theory allows analytical derivation of any caloric effect in solids displaying any type of cross coupling. In the particular cases of the non-coupled ferroic materials, the theory reproduces the well-known formulae describing magnetocaloric, electrocaloric or elastocaloric effects. This work facilitates adequate modeling tools and analytical relations capable of predicting caloric effects in complex coupled multiferroic materials, which is very beneficial to future developments in solid-state cooling technologies. (paper)