Hasancan Okutan

Effect of coal moisture on particulate emission in a fixed bed combustion appliance

Abstract Effect of moisture on particulate emissions of a young peaty (Agacli) coal from Turkey is investigated in a 93 kW, half cyclindirical hot water boiler. The boiler was operated under primary and secondary loading conditions. Sampling was realised using an EPA-approved Andersen Universal Sampling system. Experiments were carried out for 15.33%, 21.40% and 38.70% moisture coals of Agacli and 19.90% moisture Agacli–South African mixture coals. From the experimental results it is found that the medium moisture resulted in highest particulate emissions.

Application of the solution mining process to the Turkish trona deposit

Abstract This study was conducted to investigate the applicability of the solution mining technique to the Turkish trona deposit. For this purpose, sesquicarbonate and alkali extraction processes were applied to Turkish trona. Laboratory experiments were conducted to investigate the dissolution system and the crystallization parameters of these processes. The trona mineral used for this study was Turkish trona which had small amounts of sodium chloride and sodium sulphate compared with the Wyoming (USA) trona. Two crystallization methods were used to produce the crystals: cooling crystallization and evaporative crystallization. The crystals were calcined to produce soda ash.

Mechanism of the dissolution of Turkish trona

Abstract This study measures the rate of dissolution of Turkish trona as a function of the trona brine concentration and compares the results with a theoretical model of the rate of dissolution from a vertical wall under conditions of natural convection driven by the density gradient in the boundary layer caused by salt concentration differences. Laboratory dissolution experiments were conducted related to the solution mining of a Turkish trona deposit. The average rate of dissolution in water was measured to be 2.8 × 10−4 g/cm2 · sec−1 .

DETERMINATION OF DIFFUSION COEFFICIENT OF THE TURKISH TRONA IN WATER

Laboratory experiments were conducted to measure the diffusion coefficient of the Turkish trona in water. A rapid and inexpensive method was used for measuring the diffusion coefficient. The procedure consists essentially of soaking a porous disc in the solution of interest and then suspending the disc over a bath of pure water. The rate of diffusion of trona solution from the disc is then ascertained by measuring the apparent weight of the suspended disc at various times. The rate of change of the apparent weight is directly related to the loss of solute and hence to the diffusion coefficient of the trona. The diffusion coefficient of trona from solutions of various concentrations was measured and a linear relationship was found between diffusion coefficient and trona solution concentration. The average value of diffusion coefficient of trona was calculated to be 1.194 10−5 cm2/sec at 25°C.

Investigation of the pollution risk of residues from a laboratory-scale underground coal gasification of Malkara (Turkey) lignite

AbstractThe aim of this study was to examine the risk of heavy metal, ammonia and sulfate transition from underground coal gasification (UCG) chars and process water of Malkara lignite to the groundwater around the UCG cavity. The residues were collected during laboratory-scale underground coal gasification studies of Malkara lignite in ex situ gasification simulator. In order to compare gasification with combustion in terms of water pollution, ash samples were obtained by combustion of Malkara lignite. To determine the leaching behavior of the char and ash samples, two leaching tests (EPA TCLP and EN 12457-2 methods) were applied. The concentration of heavy metals in char, ash and process water samples was determined by ICP-OES. Additionally, ammonia and sulfate analyses were conducted for process water. Based on the results of this study, it has been found that the concentration of some elements, such as B, Sb and Al in char and ash eluates exceeded the maximum level of drinking water standards. However, there is no landfill concern about char samples according to EU Landfill Directive. A significant increase in B concentration was observed in ash samples. Considering B and some other elements combustion residues were identified with much higher water contamination ability, compared to gasification residues. Ammonia concentration was observed extremely high in process water of the gasification tests. UCG technique may be more environmentally applicable technology compared to combustion for Malkara lignite reserves. However, further detailed studies are necessary in the early stage of the UCG field test design and application.

Effect of Coal Moisture on Emissions in Fixed Bed Combustion Appliances

The water associated with coal is an important element in both the formation and utilization of coal deposit. The first stage of coal formation is the accumulation of vagetable matter in swamps. This is followed by consolidation and partial decay of the organic matter to form peat, which can have moisture contents of 80-90% in situ. Low-rank coals such as brown coals and lignite, which are formed in the next stage of coalification, can have moisture contents in range 30-70%. Hard or bituminous coals, which are formed in the final stages of coalification, have relatively low moisture contents of 10% or less. Thus the elimination of water is an integral part of the coalification process and it follows that the moisture content of coal is one of its most characteristic and important properties. Moisture is one of the most basic and important parameter defining coal structure but the data reported on its effect on combustion efficiency and emissions is rather limited. In this study we report effect of coal moisture on CO, NOx, SO2 and particulate emissions in a automatic-loaded boiler combustion. In this study, effects of moisture on particulate emissions of %37-38 moisture orijinal Yeniköy Ağaçlı (Y.A.), %24, %21, %17, %15 ve %10 moisture Yeniköy Ağaçlı, %6 moisture South African coal, %22 misture mixture coal (S.African ve Y.Ağaçlı) ve %13 moisture Soma are investigated in automatic-loaded boiler.

Energy and Enviromental Issues in Turkey

The current and future projections of energy utilisation and related environmental impact has been given. Due to the heavy dependance on low grade lignites and imported hard coal, Turkey is going to have problems in the control of CO2 emissions. Turkey was at first included as an Annex I country according to Kyoto Protocol. Later, it has been removed from the list which is justified considering the previous international environmental impact control applications and relatively much lower energy utilisation in Turkey, compared to Annex I countries. Therefore, Turkey has been removed from the Annex I list.Turkish power generation, industrial and transportation sector will be facing a difficult challenge over the coming 20 yr in complying with environmental impact levels. The developments in the liberalisation of Turkish energy sector since the 1980s is a positive step to overcome the problems.

APPLICATION OF SESQUICARBONATE PROCESS TO TURKISH TRONA DEPOSIT: COOLING CRYSTALLISATION

Sesquicarbonate process was applied to Beypazarý trona deposit. Laboratory experiments were conducted to find the dissolving system for this process. Dissolving temperature was chosen as 90° C and crystallisation temperature as 45° C. Cooling crystallisation was used to produce the sesquicarbonate crystals. The crystals were calcined at various temperatures and soda ash was produced with a yield of over 99%.

APPLICATION OF SESQUICARBONATE PROCESS TO BEYPAZARI TRONA DEPOSIT: EVAPORATIVE CRYSTALLISATION

Laboratory experiments were conducted to investigate the evaporative crystallisation parameters of sesquicarbonate process. Trona mineral used for the study is Turkish trona mineral, which has small amounts of sodium chloride and sodium sulphate salts compared with Wyoming (USA) trona mineral. Two evaporation temperatures (45° C and 90° C) were used and the results were discussed.