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The article discusses the possibility of using glycerol as an additive to the engine fuel in order to reduce the tendency of combustion knock, and thus to increase the octane number of a given fuel. Experimental tests were carried out on the UIT-85 research engine with a variable compression ratio from eight to eleven to test the intensity of the knock. The completely renewable fuel—the blend of glycerol with butanol in the ratio of 25 and 75%, respectively—was tested. A comparative analysis of the knock intensity was conducted with gasoline 95 and N-butanol tested as reference fuels. The developed method for knock analysis using the proposed knock indicator was also presented. The experimental results proved the proposed blend of N-butanol and glycerol reduces the knock intensity by more than 50% in the spark-ignition engine at a compression ratio of 10, maintaining engine performance at a similar level as it was for a gasoline-fueled engine. The results confirmed the thesis on the reduction of knock intensity when adding glycerol to N-butanol. [ABSTRACT FROM AUTHOR]

The article discusses the results of experimental studies on the course of pyrolysis oil injection through the high-pressure injector of a direct-injection engine. The pyrolysis oil used for the tests was derived from waste plastics (mainly high-density polyethylene—HDPE). This oil was then distilled. The article also describes the production technology of this pyrolysis oil on a laboratory scale. It presents the results of the chemical composition of the raw pyrolysis oil and the oil after the distillation process using GC-MS analysis. Fuel injection tests were carried out for the distilled pyrolysis oil and a 91 RON gasoline in order to perform a comparative analysis with the tested pyrolysis oil. In this case, the research was focused on the injected spray cloud analysis. The essential tested parameter was the Sauter Mean Diameter (SMD) of fuel droplets measured at the injection pressure of 400 bar. The analysis showed that the oil after distillation contained a significant proportion of light hydrocarbons similar to gasoline, and that the SMDs for distilled pyrolysis oil and gasoline were similar in the 7–9 µm range. In conclusion, it can be considered that distilled pyrolysis oil from HDPE can be used both as an additive for blending with gasoline in a spark-ignition engine or as a single fuel for a gasoline compression-ignition direct injection engine. [ABSTRACT FROM AUTHOR]

The paper presents results from investigation on a new type of fuel which can be implemented for the both automotive and power industry. The proposed fuel is of a completely renewable origin based on ethanol and glycerol at the ratio of 3:1 (75% and 25%), respectively. Hence, it does not contribute to unsustainable CO 2 emissions to the atmosphere. The analysis of combusting the ethanol-glycerol blend in the spark-ignited reciprocating engine was focused on engine performance, combustion thermodynamics, and toxicity content in the exhaust gases. The analysis was conducted as a comparative analysis for gasoline and ethanol, which were treated as reference fuels. The toxic emissions of CO, NOx, and unburnt hydrocarbons (UHC) did not differ remarkably from the gasoline emissions tests. The engine performance expressed by the indicated mean effective pressure deteriorated less than 3%. It was found that the ethanol-glycerol blend at the ratio of 3:1 (75/25%) can be directly applied as a substitute fuel for either gasoline or ethanol in internal combustion engines in the automotive and power industry. [Display omitted] • Investigation of ethanol-glycerol blend (3,1) for the internal combustion engine. • The engine performance (IMEP) deteriorated less than 3%. • Exhaust emissions of the blend are at similar level of gasoline 95 emissions tests. • Ethanol-glycerol blend can be applied as fuel for the spark-ignited engine. • Glycerol blended ethanol - considered an economic and energy-effective technology. [ABSTRACT FROM AUTHOR]

Abstract: The paper mainly focuses on applying the two-stage combustion system with a pre-chamber into the stationary internal combustion spark ignited engine. It especially concentrates on applying throttle less operation at partial load and reduction of the NO x emission. Considerations conducted in the paper are based on the in-cylinder combustion progress analysis. Additionally, analysis of tailpipe toxic emission, with particular focus on the NO x formation in the engine equipped with the pre-chamber, is also performed. The paper presents both results of 3-D combustion modeling in the SI engine and results conducted on a test SI engine. The 3-D modeling was performed in the KIVA-3V code. Next, results from modeling were compared with results obtained from tests. Finally, satisfactory good consistency between modeled and experimental courses of both pressure, temperature and NO x were obtained. Thus, the engine model with the proposed two-stage combustion system properly simulates engine working conditions on the test bed. Results from both analyses confirmed that the two-stage combustion system significantly shortens combustion duration of an ultra lean gasoline–air mixture and contributes to reduction in NO x . [Copyright &y& Elsevier]

Investigation of a new type of fuel for the internal combustion engine, which can be successfully used in both the power generation and the automotive industries, is presented in this article. The proposed fuel is a blend of 75% n-butanol and 25% glycerol. The engine tests conducted with this glycerol–butanol blend were focused on the performance, combustion thermodynamics, and exhaust emissions of a spark-ignition engine. A comparative analysis was performed to find potential similarities and differences in the engine fueled with gasoline 95 and the proposed glycerol–butanol blend. As measured, CO exhaust emissions increased, NOx emissions decreased, and UHC emissions were unchanged for the glycerol–butanol blend when compared to the test with sole gasoline. As regards the engine performance and combustion progress, no significant differences were observed. Exhaust temperature remarkably decreased by 3.4%, which contributed to an increase in the indicated mean effective pressure by approximately 4% compared to gasoline 95. To summarize, the proposed glycerol–butanol blend can be directly used as a replacement for gasoline in internal combustion spark-ignition engines. [ABSTRACT FROM AUTHOR]