Vplivi aditivov na emisije motorjev z notranjim izgorevanjem

Rešetič, Kristjan (author), Novosel, Barbara (mentor)

Diplomsko delo opisuje različne vrste aditivov in njihove načine delovanja za namene zmanjševanja emisij pri motorjih z notranjim izgorevanjem in tako posledičnega zmanjšanja škodljivih učinkov na okolje. S tem je doseženo manj onesnaženo okolje, v katerem živimo in ki je neposredno povezano z našim zdravjem. Za boljše razumevanje in praktične namene so v diplomskem delu medsebojno primerjani trije različni aditivi: 2-etilheksil nitrat (2-EHN), dietil eter (DEE) in dimetil karbonat (DMC). Primerjal sem vplive na emisije dušikovih oksidov NOx, ogljikovega monoksida CO, ogljikovodikov HC in v nekaterih primerih tudi emisije trdnih delcev PM. Pri tem sem podatke črpal iz dostopnih strokovnih in znanstvenih virov. Vsak aditiv sem opisal s kemijskimi, fizikalnimi in toksikološkimi lastnostmi. Predstavil sem način delovanja aditiva, obrazložil potek razpada na radikale v začetnih fazah izgorevanja in vplive na sestavo zgorevalnih plinov goriva z dodatkom aditiva. Učinek dodatka aditivov je pokazal, da so se emisije spremenile le v primerih za NOx, pri dodatku 2-EHN so se povišale za 7-94 ppm, pri dodatku DMC pa znižale za 148 ppm. Pri emisijah CO je aditiv 2-EHN izboljšal vrednosti za 61 ppm, DEE za 39 ppm in DMC za 74 ppm. Poslabšanje emisij je bilo zgolj pri HC, kjer je dodatek DEE zvišal emisije za 53 ppm in dodatek 15 % DMC-ja povišal emisije za 92 %. Iz dobljenih podatkov sem lahko določil vzroke za take rezultate, kot je na primer energijska bilanca, ustvarjena z aditivom v sistemu. To pomeni, da večji kot je prispevek energije, manj je CO zaradi popolnejšega izgorevanja, hkrati pa je več emisij NOx zaradi višje temperature. Ugotovil sem tudi, da je razpad na določene radikale ena izmed pomembnejših lastnosti, ki jih ima aditiv za zniževanje emisij. Iz vseh zbranih informacij sem na koncu od treh primerjanih aditivov določil tistega, ki najučinkoviteje zmanjšuje škodljive emisije in s tem izboljšuje življenjske razmere in zdravje ljudi.

• Language: Slovenian
• Keywords: motor z notranjim izgorevanjem, aditivi, emisije, 2-etilheksil nitrat, dietil eter, dimetil karbonat
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2020
• PID: 20.500.12556/RUL-120696
• COBISS.SI-ID: 34363139
• Publication date in RUL: 24.09.2020

Secondary language

• Language: English
• Title: The effects of additives on emission of internal combustion engines

Abstract

The thesis describes different types of additives and their modes of operation for the purpose of reducing emissions in internal combustion engines. The main use of additives lies in improving the emissions and consequently the air we breathe. With this kind of use of additives we achieve a less polluted environment in which we live in, which is directly related to our health. For better understanding and practical purposes, the thesis compares three different additives 2-ethylhexyl nitrate (2-EHN), diethyl ether (DEE) and dimethyl carbonate (DMC). To compare the effectiveness of additives, I compared their effects on emissions of nitrogen oxides NOx, carbon monoxide CO, hydrocarbons HC and to a lesser extent also emissions of particulate matter PM. In doing so, I drew data from other sources and researches. To make it easier to understand how the additive affects emissions, I firstly described each additive with chemical, physical, and toxicological properties. After that I have also described how additives decompose into radicals in the initial stages of combustion and in the end present the effects on the emission composition after their addition. The effect of adding additives showed that emissions changed only in cases of NOx at 2-EHN which increased by 7-94 ppm, and DMC values decreased by 148 ppm With CO emissions 2-EHN improved values by 61 ppm, DEE by 39 ppm and DMC for 74 ppm. Worse values were observed with HC emissions, where the addition of DEE increased emissions by 53 ppm and with an addition of 15% DMC, base emission value increased by 92%. From the obtained data, I was also able to determine the reasons for such results, such as the energy balance created with adding additive to the system. This means that the higher the energy contribution is from adding additive, the less CO there is due to more complete combustion, and at the same time there is more NOx emissions due to higher temperature created. I have also found that decomposition to certain radicals is one of the more important properties that an additive has to reduce emissions. With the help from all the gathered information on the three compared additives, in the end, I determined the one that most effectively reduces harmful emissions and thus improves living conditions and human health.

• Keywords: engines with internal combustion, additives, emissions, 2-ethylhexyl nitrate, diethyl ether, dimethyl carbonate