Characterization of boiler ashes from sugarcane mill

Sugarcane mills produce sugar and ethanol and have always used bagasse as fuel to generate energy for self-consumption. Recently some mills have been also producing surplus electricity to sell in the market a third product from sugarcane. Although any boiler can be efficient, the sale of electricity has stimulated the improvement of the burning process. However, the investment in high-pressure boilers, much more expensive than any common boiler, is essential for the exportation of electricity. Among the 22 sugarcane mills from Mato Grosso do Sul, Brazil, only 12 power plants sell electricity to the grid. The power generation efficiency depends on the pyrolysis in boilers, which results in ashes that match the unburned mineral fraction of the fuel as oxide. Both the bagasse and the straw are composed predominantly of lignin, hemicellulose and cellulose with calorific power near to the wood at the same moisture content. However the bagasse leaves the mill with about 50% of moisture while the straw reaches the industry with about 15% of humidity. This paper characterize the ashes samples from burned bagasse from seven sugarcane mills at Mato Grosso do Sul Brazilian state, to compare the methodology available for use to measure the efficiency of the pyrolysis system. Among these sugarcane mills only two are highlighted by their higher burning efficiency, both of them selling electricity, while the others showed unburned portions characterizing an inefficient system. For these industries the ash content in the ashes showed values compatible with the Superior Calorific Value as an efficiency index for the combustion degree in boilers.

Composition and Physical Properties of the Natural Gas Supplied for Domestic Use through the Distribution Network

Aims: To assess the composition of the Natural Gas (NG) supplied for domestic consumption through the distribution network to correlate the physical properties linked to it were to be determined in order to investigate their fluctuations. Study Design: The samples were analyzed in accordance with the method described in the ISO 6974‑4 standard, “Natural Gas. Determination of Composition with Defined Uncertainty by Gas Chromatography”. Place and Duration of Study: Center of Technology Research, Fuels Laboratory, between January and December 2016. Methodology: Over the course of the year, a total of eighty-four samples of natural gas for domestic use were analyzed. These were collected at a rate of one per month in seven cities in the geographical zone under study (Galicia_Spain), in which the number of users is significant. Results and Conclusion: The protocols for technical management of the Gas System have a section on quality specifications for Natural Gas at entry points to the system. This sets limits for only three of the physical properties of natural gas: Wobbe index, superior calorific value and relative density. The figures obtained for Wobbe index, superior calorific value and relative density from the eighty-four samples studied showed that the quality of the Natural Gas distributed remained steadily within the acceptable limits throughout the whole year. The values for standard deviations bore witness to the fact that any variations did not significantly alter the quality of the Natural Gas supplied. The concentrations of the odorant, THT, were always above the recommended value of 18.0 mg/Nm3, the fluctuations noted over the course of the year were such as to make it possible to see them as excessive. In some instances, a high concentration of odorant may lead users to erroneous impressions, so that they come to think that there are leaks from the gas-pipes or even that the gas is not burning properly.

Development of combustion chamber of a reference calorimeter with numerical analysis

<p class="Abstract">The present work focuses on the numerical modeling of two combustion chambers to be used inside an isoperibolic calorimeter to measure the Superior Calorific Value (SCV) from natural gas. This work shows performance of both chambers working under isoperibolic principle, through simulations based on Computational Fluid Dynamics (CFD). The aim of the work is expose the performance of chamber combustion published in the literature versus another one proposed in this work, and show how was improved the performance of the chamber which proposed in this work by changing the geometry. And it is checked by analyzing temperature of burned gases at exit of combustion chamber.</p>