Measurement Of Calorific Value Research Articles

Coal property analysis using laser-induced breakdown spectroscopy

Fast or online coal property analysis would greatly improve coal pricing reliability and combustion optimization for power generation, especially in China. A non-linearized multivariate dominant factor based partial least square (PLS) model was applied to analyze coal properties through laser-induced breakdown spectroscopy (LIBS). The dominant factor explicitly modeled the direct correlation between coal property and spectral line intensities, whereas residual errors were corrected by PLS method with full spectral information. The results demonstrated an overall improvement over conventional PLS method for ash content, volatile content, and calorific value measurement. For example, the root mean square error of prediction of calorific value was decreased from 1.63 MJ kg−1 to 1.33 MJ kg−1; and the average relative error of all samples was reduced from 3.55% to 2.71%. Although current LIBS application results for coal proximate analysis have not met the national standard, LIBS is shown to be fully capable of providing useful information for coal combustion optimization and reliable references for coal pricing, showing LIBS has great potential for coal property analysis for the power generation industry.

Interpolation algorithm ranking using cross-validation and the role of smoothing effect. A coal zone example

For a property measured at several locations, interpolation algorithms provide a unique and smooth function yielding a locally realistic estimation at any point within the sampled region. Previous studies searching for optimal interpolation strategies by measuring cross-validation error have not found consistent rankings; this fact was traditionally explained by differences in the distribution, spatial variability and sampling patterns of the datasets. This article demonstrates that ranking differences are also related to interpolation smoothing, an important factor controlling cross-validation errors that was not considered previously. Indeed, smoothing in average-based interpolation algorithms depends on the number of neighbouring data points used to obtain each interpolated value, among other algorithm parameters. A 3D dataset of calorific value measurements from a coal zone is used to demonstrate that different algorithm rankings can be obtained solely by varying the number of neighbouring points considered (i.e. whilst maintaining the distribution, spatial variability and sampling pattern of the dataset). These results suggest that cross-validation error cannot be used as a unique criterion to compare the performance of interpolation algorithms, as has been done in the past, and indicate that smoothing should be also coupled to search for optimum and geologically realistic interpolation algorithms.

The measurement of calorific value and the applied product of the new thermogenic composition

The measurement of calorific value and the applied product of the new thermogenic composition

Metrological issues in energy measurement on biogas

The use of biogas as regenerative energy can be achieved more efficiently by injecting the treated biogas into natural gas grids since the localisation of the biogas CHP (combined heat and power) plant is made independent from the site of the biogas production. Thus, the utilisation of the heat generated in the CHP plant may be optimised. For that reason, the National and European regulations support injection into the natural gas grid. This paper deals with the general metrological issues concerning injection from the specific aspects of measurement technology. The issues discussed include the adjustment of biogas to the characteristics of natural gas (treatment to produce biomethane) and the measurement of biomethane calorific value. Measuring the calorific value of natural gas today is almost always based on the use of process gas chromatographs specifically designed for the analysis of typical natural gases. Natural gas chromatographs are only suitable under minted conditions for use with biomethane due to differences in the composition of natural gas and biomethane. This paper explains the specific issues and solutions for the measurement of the calorific value of biomethane and their implementation in current plants equipped with injection facilities.

New French reference calorimeter for gas calorific value measurements

The direct measurement of gross calorific value (GCV) of gas with the lowest possible uncertainty can be performed with a reference gas calorimeter. LNE is currently developing an isoperibolic reference gas calorimeter. An exhaustive description of this calorimeter (set up and raw data analysis) for natural gas calorific value measurements is here described. A repeatability study of GCV of methane performed with a prototype version and first tests to reduce the unburned methane dragged with the burned gases are also presented. Calculation method of GCV is detailed and the improvements carried out on the different parts of the calorimeter (burner, vessels, sensors, etc …) are highlighted.

Waste management options in southern Europe using field and experimental data

The applicability of the Waste Management Hierarchy concept that appeared to be an essential element in current national environmental policies was investigated in the case of a region in Southern Europe. The waste generation profile that determines the appropriateness of different waste management options was created after a 1-year municipal waste sampling investigation conducted in the Municipality of Pilea in Northern Greece. The paper describes the results of (1) the sampling method, which was conducted four times during 1 year (once per season) in selected areas of the city, (2) the qualitative analysis of the collected samples and (3) the waste treatment, which consisted of drying, grinding, calorific value measurement, incineration and chemical analysis of the collected samples. Comparative analysis between the above mentioned data and on past data derived from investigations conducted in other Greek regions with similar characteristics to those of Pilea were used to identify and discuss future trends in the composition of generated waste over time. An analysis of the current waste management status in Greece as well as the feasibility of implementing a comprehensive management approach is assessed taking into account guidelines set worldwide to promote renewable energy sources use. It is concluded that recycling, perhaps the most positively received of all waste management practices, is going to be an essential part of contemporary waste management strategies, composting can play an important role, while incineration seems to be a conditionally feasible solution.

Measurement of Calorific Value Containing Organic Matter with a Large Amount of Water

It has been known that the pyrolysis liquor obtained from pyrolysis of municipal wastes or biomass can be used as new liquid fuel.The pyrolysis liquor from cellulosic matter generally contains a large amount of water, which has an evil effect on ignition or combustion and makes it difficult to obtain its precise calorific value by traditional measuring methods.We studied a method which enables us to measure the calorific value precisely, using methyl alcohol aqueous solution with moisture up to 100% as a sample. As a result, the measurement of the precise value could be taken by adding nearly the same amount of benzoic acid as that of the sample.By this method, the calorific value of the pyrolysis liquor from wood or municipal wastes was measured, and it was found that the value is in inverse proportion ratio to the water content of the liquor.