Pavel Kolat

Co-Combustion of Coal and Alternative Fuels

Energy utilization of alternative fuels including biofuels is one of the main tasks for development of recoverable sources in the world. The research consists of combustion tests in the large CFB boilers and measuring data inside the combustor. Since 1995, 29 large CFB boilers of different designs and power outputs have been in operation in the Czech Republic as shown in the Table 4. Construction of the boilers, technical documentation, licensing and engineering has been based on foreign experience. Every large power project is always preceded by trial measurements and tests on smaller pilot, trial or if need be model equipment. Due to the great difference in scale, some unexpected measuring equipment behavior or problems must be taken into consideration for cocombustion of coal and alternative fuels.

Exergy in chemical reactions of combustion and gasification part 2: some numerical examples

The exergy concept applied to chemical reactions of combustion and gasification has been presented and discussed in detail. All the essential cases will be taken into account, namely the equimolar and non–equimolar — homogeneous and heterogeneous — stoichiometric processes, but also the non–stoichiometric ones. The numerical examples show the expected correctness of the theoretical approach which means, the method can be applied to the complex system analysis containing combustion and gasification processes. The analysis makes it clear that the method can be also used for all the chemical conversion processes in the chemical and process engineering. Abstrakt Exergeticka koncepce byla aplikovana na chemicke reakce spalovani a zplyňovani a byla předložena a projednana detailně. Vsechny zakladni připady budou brany v uvahu, a sice equimolarni a ne-equimolarni , homogenni a heterogenni stechiometricke procesy, ale take i ne-stechiometricke procesy. Numericke přiklady ukazuji na ocekavanou spravnost teoretickeho přistupu, což znamena, že metodu lze použit na komplexni systemove analýzy, ktere obsahuji spalovaci a zplyňovaci procesy. Z analýz je zřejme, že metoda může být take použita pro vsechny chemicke konverzni procesy v chemickem a procesnim inženýrstvi.

Determining start parameters for oxygen–water steam gasification with and without recirculation

The analytical, unified selection method of the converting medium composition is presented as to apply for the oxygen – water steam gasification the recirculation of reaction products. The selected molar fractions of the converting medium components should give the assumed (needed) CO/H2– ratio of the synthetic gas by the chosen process pressure and temperature. The graphical selection methods applying the MOLLIER–HOFFMANN diagram are used for the parameters preselecting of the air – water steam gasification, e.g. if there is any contents of nitrogen from the atmosphere. The presented analytical method refers to the oxygen – water steam without and with gas recirculation. The last assumption allows the presence of CO, H2, CO2 and CH4 in the converting medium — new gasifying technologies need the permanent presence of carbon monoxide and hydrogen because of the iron catalyst. The determined values of its molar fractions help to choose the suitable process calculation iterative method. Abstrakt Analyticka unifikovana selektivni metoda přeměny středniho složeni je prezentovana a aplikovana pro recirkulaci reakcnich produktů zplyňovaciho procesu kyslik–vodni para. Vybrane molarni frakce přeměněných produktů davaji potřebný předpoklad urceni poměru CO/H2 syntetickeho plynu podle tlaku a teploty V danem procesu. Graficka unifikovana metoda použiva MOLLIER–HOFFMANN diagram pro předběžne urceni parametrů vzduch–vodni para U zplyňovaciho procesu, jestliže je zde obsažen dusik Z atmosfery. Prezentovana analyticka metoda se odkazuje na proces kyslik–vodni para bez a S recirkulaci. Posledni předpoklad dovoluje přitomnost CO, H2, CO2 a CH4 V přeměňujicim se mediu – nove zplyňovaci technologie potřebuji S ohledem na katalyzator – železo, stalou přitomnost CO, H2. Urcene hodnoty těchto molarnich frakci pomahaji vybrat vhodnou výpoctovou iteracni metodu.

Co-combustion coal and waste alternative fuel: thermogravimetric analysis

Spalovani uhli s relativně malým procentem alternativniho paliva představuje možnost pro nakladani s těmito odpady. Spoluspalovani uhli a jejich směsi 5%, 10% a 50% (hm%) s alternativnim palivem bylo hodnoceno termogravimetrickým analyzatorem v teplotnim rozsahu do 1,000oC a rychlosti ohřevu 10oC min-1. Spalovaci charakteristiky jako těkani, vzniceni a zapaleni byly take studovany u směsi paliva. Pomoci metody přime nelinearni regrese (PNR) byly stanoveny formalni kineticke parametry (aktivacni energie, frekvencni faktor) oxidace z TG křivek pro řad reakce roven jedne. Studie byla provedena za ucelem rozsiřeni spektra paliv pro spoluspalovani.