Experimental study on particulate control of turbo gasoline engine

This study takes light-passenger vehicles with 1.5L port fuel injection turbocharged engine as the research object, based on the WLTC test cycle about the China 6b emissions regulations, including some influence of several key technologies, such as fuel injector selection, intake VVT opening, fuel control and gear shift point matching, what can affect the particulate emissions from light-passenger vehicles. The results show that without particulate filter (GPF) technology, Using the original 4-hole fuel injector, the opened intake air VVT in catalyst light off, the optimized fuel control and gearbox shift point, the emission test results of the light-passenger vehicle can reach the development target of China 6b, what can avoid GPF blockage and regeneration problems in the market. Meanwhile, the cost of mass production and development cycle about vehicle is effectively reduced.

Behavior of Cd during Coal Combustion: An Overview

Due to the unfavorable combination of its toxicity and high volatility, Cd is contained in most lists of potentially hazardous air pollutants with the greatest environmental and human-health concerns. The review paper evaluates the behavior of Cd during combustion (incineration) processes and its redistribution among condensed fractions (bottom ash/slag, fly ash) and volatilized fractions (that passes through most particulate control devices). The paper addresses all important effects of Cd interactions, such as presence of organic or inorganic chlorides, moisture levels, S, P and Na concentrations, flue gas composition etc. Possibilities of using various adsorbents (either within in-furnace regime or applied in post-combustion zone) are evaluated as well. Special attention is paid to mitigating its emissions factors; decreasing Cd volatility and facilitating Cd retention are discussed with the view of various combustion (incineration) conditions and the feed fuel composition.

Experimental Investigation of the Electrical Resistivity of Cement Dust

Electrical resistivity is one of the important particle–based factors influencing the performance of an Electrostatic Precipitator (ESP), a particulate control device commonly employed in most cement industries in Nigeria. Therefore, this study investigated the electrical resistivity of Cement Kiln Dust (CKD) across nine locally-operated cement manufacturing plants in Nigeria with the aim of tracing causes of performance problems associated with the ESP used for dust control in the plants. Samples of CKD were collected from the ESPs of these plants and tested for their resistance using the two probe method. The measured electrical resistivities were in the range of 108 – 1011 Ω·cm and showed strong dependence on temperature and slight variation with particle size. The CKD’s resistivity increases as temperature rises from ambient to about 250℃ and declines as temperature rises above 300℃; Nevertheless, the resistivities are adaptable for efficient ESP performance in the collection of cement dust.

Behavior of Pb During Coal Combustion: An Overview

Despite the progress in understanding heavy metals behavior during coal combustion, mitigation of heavy metals emissions is still a tough challenge due to a complex character of this phenomenon. Several lists of potentially toxic elements have been presented; in most cases, Pb belongs to the elements with the greatest environmental and human-health concern. The review paper is focused upon the behavior of Pb during coal combustion. with particular attention paid to decreasing its emissions. It summarizes the dominant parameters affecting its redistribution among coal combustion streams. As gaseous emissions can quite easily pass through the particulate control device, attention was paid primarily to Pb distribution between condensed and volatilized phases. A crucial factor enhancing Pb volatility is the presence of organic or inorganic chlorides, which is discussed in detail, including their chlorination mechanisms and interactions with other fuel/flue gas species. Components decreasing Pb volatility and promoting the formation of condensed phases are also discussed (higher levels of moisture, Na, O2 etc.). Factors enhancing Pb volatility, as well as factors facilitating Pb retention, are discussed with the view of fluidized-bed combustion, pulverized-fuel combustion, or co-combustion of coal with wastes.