A kinetic investigation on the pyrolysis of Seguruk asphaltite

The pyrolysis of Seguruk asphaltite has been investigated using thermogravimetric analysis at atmospheric pressure between 293 to 1223 K at different linear heating rates of 5, 10 and 20 K min(-1) under nitrogen as ambient gas. There was a two-stage thermal decomposition. Thermal decomposition started around 630 K for stage 1 for the slowest heating rate. On the other hand, for the same heating rate and stage 2, thermal decomposition started around 950 K. These values were shifted to higher temperatures with increasing heating rate. In this study, two different Coats-Redfern methods were applied to thermal degradation of Seguruk asphaltite

Use of sequential extraction with UV/Vis spectrophotometer to assess phosphorus species in surface sediments (NE Mediterranean Sea)

The speciation of total phosphorus in different forms is necessary to understand the phosphate exchange mechanisms In sediments, its potential removal from the water column, and the availability of phosphorus for primary producers. This paper presents the phosphorus (P) distribution (total phosphorus, organic phosphorus, and forms of inorganic phosphorus; loosely adsorbed phosphorus and phosphorus bound to aluminium, phosphorus bound to calcium, and phosphorus bound to iron, as well as total inorganic phosphorus) in surface sediments collected from two coasts (each under different anthropogenic pressures) in the eastern Mediterranean Sea in April 2007. The sampling stations are located at on the south-eastern Mediterranean coast of Turkey, adjacent to the Cillcian Basin. The most abundant phosphorus in studied surface sediments was found as calcium-bound phosphorus. Relative abundances of the remaining phosphorus forms follow the order: P-Al > loosely bound-P > P-Fe. The concentration of total phosphorus in the surface sediments taken from Tasucu was found to be higher than the sediments from Erdemli. Accuracy of the method was checked by using NCS DC 73316 certified reference material and the results found were found to be in good agreement with the certified value. Maximum values of total P in Erdemli and Tasucu were 220.35 and 321.42 µg g-1, respectively

Effect of homogeneous alkaline catalyst type on biodiesel production from soybean [<i>Glycine max</i> (L.) Merrill] oil

596-600Transesterification or alcoholysis is the most commonly applied method for biodiesel production. A catalyst is needed to improve the transesterification reaction and yield. The present study used soybean oil as the raw oil to mix with methanol and four strong alkali catalysts (NaOH, KOH, CH3ONa &amp; CH3OK) to undergo a transesterification reaction. Transesterification was carried out using 100% excess alcohol, i.e., molar ratio of alcohol to soybean oil was 6:1, and catalyst concentration of 1% at 60oC. Alkali metal alkoxides were found to be more effective transesterification catalysts compared to hydroxides. Sodium methoxide was the most efficient catalyst, although KOH and NaOH could also be used because they are cheaper and are used widely in large scale processing

Effect of molten caustic leaching on demineralization and desulfurization of asphaltite

Molten caustic leaching process is effective in reducing significant amounts of ash-forming minerals, pyritic sulfur, and organic sulfur from solid fossil fuels. The effect of leaching asphaltite samples from Seguruk and Harbul collieries of Sirnak and Silopi asphaltite fields (situated in the Southeast Anatolia region of Turkey) with molten sodium hydroxide and followed by mild acid on demineralization and desulfurization was investigated. The effects of alkali/asphaltite ratio, time, and temperature on the leaching efficiency were detailed, and the experimental results are presented here. Chemical demineralization and desulfurization of asphaltite samples using molten sodium hydroxide were investigated in the temperature range of 200 degrees C-400 degrees C. The percentage of demineralization and desulfurization increased with the increase in alkali/asphaltite ratio. The removal of total sulfur and ash increased with increasing leaching temperature and time. Most of the inorganic sulfur and a significant portion of the organic sulfur were removed

A kinetic investigation on the pyrolysis of Seguruk asphaltite

The pyrolysis of Seguruk asphaltite has been investigated using thermogravimetric analysis at atmospheric pressure between 293 to 1223 K at different linear heating rates of 5, 10 and 20 K min(-1) under nitrogen as ambient gas. There was a two-stage thermal decomposition. Thermal decomposition started around 630 K for stage 1 for the slowest heating rate. On the other hand, for the same heating rate and stage 2, thermal decomposition started around 950 K. These values were shifted to higher temperatures with increasing heating rate. In this study, two different Coats-Redfern methods were applied to thermal degradation of Seguruk asphaltite