the original fuel. It can be briquetted to form an excellent fuel for wood stoves or can be used as a soil conditioner. After successful laboratory trial, the system was also tested at a metallurgical company, where it was retrofitted to an oil-fired furnace for baking speciality ceramics. The furnace was operated exclusively on the gasification system and the product quality was on a par with, if not better than, that obtained during oil-fired operation. The economics of the system are also presented.
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Suitability of different investigation methods for determining the combustion behavior of biofuels in the parameter region of fluidized-bed combustion Kleindienst, M. VDI-Eer., 1997, 1313, 531-536. (In German) Fossil fuel-derived coke and biomass-derived coke were compared with three experimental methods to investigate their combustion behaviour. The methods used were an atmospheric-pressure drop-tube reactor, a laboratory-scale fluidized bed reactor, and gas-patentiometric combustion apparatus. Two bituminous coal-derived cokes, a brown coal-derived coke and a biomass-derived coke were examined. The three methods cannot be directly compared with each other; the drop-tube method is both more time-consuming and more labour-consuming compared with the gaspotentiometric combustion method.
Geothermal Energy 98100448 A closely-spaced magnetotelluric study of the Ahuachapan-Chipilapa geothermal field, El Salvador Romo, J. M. et al. Geothermics, 1997, 26, (516) 627-656. Using 2-D models based on 126 closely-spaced magnetotelluric (MT) measurements, the distribution of electrical conductivity beneath the Ahuachapan-Chipilapa geothermal area was simulated. The MT response was interpreted as resulting from the superposition of two orthogonal geological structural systems.
An approximately E-W regional trend associated with the Central Graben structure, which affects the longer period response, and a local and younger N-S fault system that is responsible for the short-to-intermediate period data were determined. The MT response in the 0.02-10 s range period was used to simulate the conductivity structure within the first 2 km depth. By correlating the lowresistivity zones between 12 2-D models, maps of the spatial distribution of conductors at three different depth levels were constructed.
Three deep conductors were identified, one of them associated with the Ahuachapan reservoir, another apparently related to the Laguna Verde volcano, and a third one controlled by El Tortuguero Graben. The large number of drillholes and the dense MT site coverage allowed the definition of important correlations between high temperature and high conductivity, as well as between deep conductivity anomalies and productive wells. Two areas for future drilling are proposed.