Vpliv katalitične oksidacije SO2 na moker kalcitni postopek

magistrsko delo

Zdenko Kolarič (Avtor), Aleksandra Lobnik (Mentor), Niko Samec (Komentor)

Povzetek

Premog predstavlja pomemben energijski vir. V termoelektrarnah zgoreva premogov prah, preko pretvorbe pridobivajo električni tok. Kot negativni vplivi pa nastajajo prašni delci, odpadna toplota in različne kemijske spojine. Med njimi so po škodljivosti najbolj pomembni dušikovi oksidi in žveplov dioksid. Žveplov dioksid je plin. Škodljivo deluje na ljudi in živali s poškodbami dihalnih poti, povzroča sušenje rastlin, posebej je to vidno pri izumiranju iglavcev. Uničujoče deluje še na predmete, zgradbe, spomenike in tla, neposredno in še posredno preko kislega dežja. Zato je pri pridobivanju električne energije iz premoga pomembno, da žveplov dioksid odstranjujejo iz dimnih plinov. V svetu se pri tem največ uporablja mokri kalcitni postopek, ki zagotavlja do 95 % učinkovitost, absorpcijsko sredstvo je apnenec, ki je poceni in lahko dosegljiv. Produkt razžveplanja je mavec, ki ga lahko koristno izrabijo po predelavi v gradbeništvu, ali pomešano s pepelom odvažajo na deponije, ali zapolnjujejo opuščene rudniške jaške. V magistrskem delu je obravnavan moker kalcitni postopek z vidika različnih pogojev njegove katalize. Eksperimentalno delo je obsegalo simulacijo postopka odstranjevanja žveplovega dioksida (SO2) med njegovim uvajanjem v prenasičeno raztopino (suspenzijo) kalcijevega karbonata (CaCO3). Opravljenih je bilo več serij eksperimentov brez in s katalizatorjem. Katalizirane reakcije so potekale pri sobni temperaturi (homogena kataliza) in pri 200 °C (heterogena kataliza). Razlikovale so se glede na vrsto (železove in manganove soli pri homogeni katalizi ter železovi oksidi in rude pri heterogeni katalizi) in obliko katalizatorja (prah, peleti) ter tip reakcije: (I) katalizator v raztopini CaCO3 - homogena kataliza in (II) katalizator v koloni izven raztopine - heterogena kataliza. Učinkovitost postopka odstranjevanja SO2 je bila ovrednotena glede na koncentracijo nastalega kalcijevega sulfata (CaSO4), ki smo ga določili v različnih časovnih intervalih eksperimenta. Rezultati kažejo na izboljšanje izkoristka reakcije, pri čemer je bil najboljši rezultat dosežen ob prisotnosti manganovega sulfata v postopku homogene katalize (66,31 % delež SO4 glede na SO2).

Ključne besede

žveplov dioksid;moker kalcitni postopek;onesnaženje;razžvepljevanje dimnih plinov;homogena kataliza;heterogena kataliza;magistrske naloge;

Podatki

Jezik:	Slovenski jezik
Leto izida:	2014
Tipologija:	2.09 - Magistrsko delo
Organizacija:	UM FS - Fakulteta za strojništvo
Založnik:	[Z. Kolarič]
UDK:	543.272.51(043.2)
COBISS:	18049046
Št. ogledov:	1895
Št. prenosov:	231
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	Influence of catalytic oxidation SO2 on Wet Calcite Flue Gas Desulphurisation process
Sekundarni povzetek:	Coal is one of the most important sources of energy. In thermal power plants coal dust is being burnt to produce electricity through transformation. However, simultaneously dust particles, waste temperature and various chemical compounds are side products in the process. The most harmful and important among them are nitrogen oxides and sulphur dioxide. Sulphur dioxide is a gas. It has a harmful effect on people and animals by harming their breathing paths, on plants causing them to dry, which is particularly noticeable with pine trees. In addition, its devastating effect spreads to objects, buildings, monuments and also to the soil, directly or indirectly through acid rain. Therefore it is important that in the production of electricity to eliminate sulphur dioxide from flue gases. The most widely used procedure in this is the wet calcite process, which ensures a 95% level of effectiveness, with limestone acting as the absorptive element, being the cheapest and the most accessible. A side product of desulphurisation in this case is gypsum, which can, after processing, be used in construction, mixed with ash and stored at dump sites, or, be used to fill up abandoned mineshafts. The thesis deals with the Wet Calcite Flue Gas Desulphurisation process from the viewpoint of various conditions of its catalysis. The experimental part of the thesis consists of the simulation of the procedure of the elimination of sulphure dioxide (SO2) during its insertion into a supersaturated suspension of calcium carbonate (CaCO3). Several series of experiments have been performed with and without presence of a catalyst. The catalytic reactions took place at room temperature (homogeneous catalysis) and at the temperature of 200 0C (heterogeonous catalysis) and they both varied according to its kind (iron or manganese salts at homogenous catalysis, iron oxides and ores in heterogeneous catalysis), as well as to the form of the catalyst (dust, pelets) and the type of reaction: (I) catalyst in a CaCO3 solution - homogenous catalysis, and (II) catalyst in a column outside of a solution - heterogeneous catalysis. The effectiveness of the process of desulphurisation was measured with regard to the concentration of the produced calcium sulphate (CaSO4), which was determined at various time intervals. The results show an increase in the yield of the reaction, with the best result reached at the presence of manganese sulphate in the process of homogenous catalysis (66.31 % share of SO4 with regard to SO2).
Sekundarne ključne besede:	sulfur dioxide;wet limestone scrubbing;pollution;flue-gas desulfurization;homogeneous catalysis;heterogeneous catalysis;
URN:	URN:SI:UM:
Vrsta dela (COBISS):	Magistrsko delo
Komentar na gradivo:	Univ. v Mariboru, Fak. za strojništvo
Strani:	XI, 90 f.
ID:	8729115