Analysis of Flue Gas Emissions Using a Semi-industrial Boiler Fueled by Biodiesel Produced from Two-stage Transesterification of Waste Cooking Oil

In this work, waste cooking oil and methanol as feedstock together with sulfuric acid and potassium hydroxide as catalysts were used to produce biodiesel. The physical properties of the waste cooking oil, the produced biodiesel and the purchased petrodiesel were measured using specified ASTM standards. To examine their performance and their flue gases emissions, biodiesel and petrodiesel were burnt in a wet base semi-industrial boiler. The emitted combustion gases, including CO, NOx, SO2 and CO2, were measured with a flue-gas analyzer at a wide range of air-to-fuel ratios and two levels of energy. For better reliability, all tests were repeated five times and almost no measurable differences were found in the repeat tests. The results show that produced biodiesel meets ASTM standards for flash point, heating value, specific gravity, kinematic viscosity, copper corrosion, acid number, cetane number, carbon residue, and total sulfur. These properties of biodiesel are also comparable with the petrodiesel properties. The trends of exhaust temperature and combustion efficiency of biodiesel are the same as petrodiesel at different air-to-fuel ratio. However, they are slightly lower. The CO, NOx, SO2 and CO2 emissions of biodiesel are lower than those of petrodiesel at different air-to-fuel ratios and two levels of energy

COMMON ETIOLOGIES OF ADULT ONSET EPILEPSIES IN NORTHWEST OF IRAN

Frequency of common etiologies of adult onset epilepsy is different in various studies. The aim of this study is to evaluate the frequency of common ‎etiologies of late adult onset epilepsies. ‎ All patients referred to Razi and Imam Khomeini Hospitals ‎in the year 2003 with at least two seizure attacks beginning after age of 50 were evaluated. In the majority of cases neuroimaging, electroencephalography and ‎echocardiography were done and risk factors for atherosclerosis and cerebrovascular ‎diseases were investigated. All medical records and previous medical histories ‎were reviewed. ‎A total of 97 patients were included. We found hemorrhagic stroke in 10 (10.3%), ‎ischemic stroke in 43 (44.3%) and space-occupying lesion (all of them were ‎tumors) in 19 patients (19.6%). In 24 (24.7%) cases we could not find a clear ‎cause for seizure attacks. ‎In conclusion, since seizures were associated with a central nervous system ‎disease in about 75% of the patients, careful investigation is necessary. We ‎also recommend better control of risk factors for cerebrovascular diseases in our country

Calorific value, flash point and cetane number of biodiesel from cotton, jatropha and neem binary and multi-blends with diesel

The calorific value, flash point and cetane number were investigated for binary and multi-blends of biodiesel from cotton, jatropha and neem with diesel. A binary blend is a fuel mixture comprising biodiesel from one feedstock and diesel, while a multi-blend consists of biodiesel from two or more feedstocks and diesel fuel. Blends were made of B5, B10, B15, B20, B25 and B30 for binary blends of each biodiesel, and a replication of those blend levels for the mixed blends of cotton, neem and jatropha with fossil diesel. The calorific value of the biodiesel/diesel samples was measured using a bomb calorimeter, the flash point was determined by the ASTMD93 method using a Pensky–Martens closed cup tester and the cetane number was determined using a portable cetane/octane meter. It was established that most of the fuel samples have heating values above the American Society for Testing and Materials (ASTM) minimum and close to that of petro-diesel. All 28 fuel samples are consistent with the ASTM standards for flash point and cetane number, they are devoid of carbon deposits and inferior cooking in the CI engines, and they have the shortest ignition delay when burned in the CI engines; hence, they are suitable for use in CI engine operations. Statistical analyses of the experimental data carried out using SPSS software indicate that the data contributed equally in each category to all of the properties, and there are no significant differences between the experimental values