Spherical and hollow fly ash particles having density < 1g/cm are known as cenospheres. Their concentration in coal combustion ash is typically << 1%; as a consequence, their value is relatively high (~$0.70/kg). However, cenospheres are really particles containing gas bubbles independent of their density. Hence, cenosphere densities can vary between 0.6 g/cm to near or greater than 2.0 g/cm. T...

Many leaching methods have been used for various purposes by research groups, industries and regulators, but there is still a need for a simple yet comprehensive approach to leaching coal utilization by-products (CUB) and other granular materials. A serial batch characterization method has been developed at the National Energy Technology Laboratory that can be completed in 2-3 days to serve as ...

Biomass is one of the most important sources renewable energy in industry. It assumed that by 2050 global deposit could be covered 33–50% biomass combustion. As with conventional fuels, combustion produces by-products, such as fly ash. Therefore, along growing interest use a source energy, production ash by-product increases every year. estimated approximately 476 million tons ashes per year ca...

Employing biomass as a feedstock to generate fuels or power has the advantage of being carbon neutral or even becoming carbon negative, if carbon is captured and sequestrated. However, there are challenges facing the effective utilization of biomass wastes: (a) biomass supply is limited and varies with the seasons, (b) biomass density is low and expensive for long-distance transportation, and (...

Four coals of different rank were gasified, using a steam/oxygen mixture as gasifying agent, at atmospheric and elevated pressure in a fixed bed reactor fitted with a solids feeding system in continuous mode. Independently of coal rank, an increase in gasification pressure led to a decrease in H(2) + CO production and carbon conversion. Gasification of the different rank coals revealed that the...

N2O emissions from coal fired fluidized-bed combustion are approximately 30–360 mg/Nm, much higher than that from pulverized coal combustion (less than 30 mg/Nm). One approach to reduce the N2O is to reburn the biomass gasification gas in the coal-fired fluidized bed. In this paper, the effects of gasified biomass reburning on the integrated boiler system were investigated by both simulation an...

In this paper, the promoting effects of ash and biomass gas reburning on N2O decomposition were investigated based on a fluidized bed reactor, with the assessment of the influence of O2 on N2O decomposition with circulating ashes. Experimental results show that different metal oxides contained in ash play distinct roles in the process of N2O decomposition with biomass gas reburning. Compared wi...