Zirconia-Based Electrochemical Oxygen Sensor to Infer Fuel Ethanol Content in Flex Fuel Vehicles

2015 ◽  
Keyword(s):  
Oxygen Sensor ◽  
Fuel Ethanol ◽  
Ethanol Content ◽  
Flex Fuel ◽  
Electrochemical Oxygen

AFR-Based Fuel Ethanol Content Estimation in Flex-Fuel Engines Tolerant to MAF Sensor Drifts

2013 ◽  
Vol 21 (3) ◽  
pp. 590-603 ◽  
Author(s):  
Kyung-ho Ahn ◽  
Anna G. Stefanopoulou ◽  
Mrdjan Jankovic
Keyword(s):  
Fuel Ethanol ◽  
Ethanol Content ◽  
Flex Fuel

Tolerant Ethanol Estimation in Flex-Fuel Vehicles During MAF Sensor Drifts

2009 ◽  
Author(s):  
Kyung-ho Ahn ◽  
Anna G. Stefanopoulou ◽  
Mrdjan Jankovic
Keyword(s):  
Oxygen Sensor ◽  
Air Flow ◽  
Intake Manifold ◽  
Absolute Pressure ◽  
Exhaust Gas ◽  
Fuel Ratio ◽  
Ethanol Content ◽  
Sensor Drift ◽  
Flex Fuel ◽  
The Difference

Flexible fuel vehicles (FFVs) can operate on a blend of ethanol and gasoline in any volumetric concentration of up to 85% ethanol (93% in Brazil). Existing FFVs rely on ethanol sensor installed in the vehicle fueling system, or on the ethanol-dependent air-to-fuel ratio (AFR) estimated via an exhaust gas oxygen (EGO) or λ sensor. The EGO-based ethanol detection is desirable from cost and maintenance perspectives but has been shown to be prone to large errors during mass air flow sensor drifts [1, 2]. Ethanol content estimation can be realized by a feedback-based fuel correction of the feedforward-based fuel calculation using an exhaust gas oxygen sensor. When the fuel correction is attributed to the difference in stoichiometric air-to-fuel ratio (AFR) between ethanol and gasoline, it can be used for ethanol estimation. When the fuel correction is attributed to a mass air flow (MAF) sensor error, it can be used for sensor drift estimation and correction. Deciding under which condition to blame (and detect) ethanol and when to switch to sensor correction burdens the calibration of FFV engine controllers. Moreover, erroneous decisions can lead to error accumulation in ethanol estimation and in MAF sensor correction. In this paper, we present a cylinder air flow estimation scheme that accounts for MAF sensor drift or bias using an intake manifold absolute pressure (MAP) sensor. The proposed fusion of the MAF, MAP and λ sensor measurements prevents severe mis-estimation of ethanol content in flex fuel vehicles.

scholarly journals Influence of fuel ethanol content on primary emissions and secondary aerosol formation potential for a modern flex-fuel gasoline vehicle

2016 ◽  
Author(s):  
Hilkka Timonen ◽  
Panu Karjalainen ◽  
Erkka Saukko ◽  
Sanna Saarikoski ◽  
Päivi Aakko-Saksa ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Organic Compounds ◽  
Fuel Ethanol ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
Formation Potential ◽  
Aerosol Mass ◽  
Ethanol Content ◽  
Flex Fuel ◽  
Primary Emissions

Abstract. The effect of fuel ethanol content (10 %, 85 %, 100 %) on primary emissions and on subsequent secondary aerosol formation was investigated for a EURO5 flex-fuel gasoline vehicle. Emissions were characterized during the New European Driving Cycle (NEDC) using a comprehensive setup of high time resolution instruments. Detailed chemical composition of exhaust particulate matter (PM) was studied using a soot particle aerosol mass spectrometer (SP-AMS) and secondary aerosol formation using a potential aerosol mass (PAM) chamber. For the primary gaseous compounds, an increase in total hydrocarbon emissions and a decrease of aromatic BTEX (benzene, toluene, ethylbenzene and xylenes) compounds was observed when the amount of ethanol in fuel increased. In regard to particles, largest primary particulate matter concentrations and potential to form secondary particles were measured for the E10 fuel (10 % ethanol). As the ethanol content of the fuel increased, a significant decrease in average primary particulate matter concentrations over the NEDC cycle was found, PM emissions being 0.45, 0.25 and 0.15 mg m−3 for E10, E85 and E100, respectively. Similarly, a clear decrease in secondary aerosol formation potential was observed with larger contribution of ethanol in fuel. Secondary to primary PM ratios were 13.4, and 1.5 for E10 and E85, respectively. For E100 a slight decrease in PM mass was observed after the PAM chamber, indicating that the PM produced by secondary aerosol formation was less than the PM lost via e.g. wall losses or degradation of POA in the chamber. For all fuel blends, the formed secondary aerosol consisted mostly of organic compounds. For E10 the contribution of organic compounds containing oxygen increased from 35 %, measured for primary organics, to 62 % after the PAM chamber. For E85 the contribution of organic compounds containing oxygen increased from 42 % (primary) to 57 % (after the PAM chamber), whereas for E100 the amount of oxidized organics remained the same (approximately 62 %) with the PAM chamber when compared to the primary emissions.

scholarly journals Influence of fuel ethanol content on primary emissions and secondary aerosol formation potential for a modern flex-fuel gasoline vehicle

2017 ◽  
Vol 17 (8) ◽  
pp. 5311-5329 ◽  
Author(s):  
Hilkka Timonen ◽  
Panu Karjalainen ◽  
Erkka Saukko ◽  
Sanna Saarikoski ◽  
Päivi Aakko-Saksa ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Organic Compounds ◽  
Fuel Ethanol ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
Formation Potential ◽  
Aerosol Mass ◽  
Ethanol Content ◽  
Flex Fuel ◽  
Primary Emissions

Abstract. The effect of fuel ethanol content (10, 85 and 100 %) on primary emissions and on subsequent secondary aerosol formation was investigated for a Euro 5 flex-fuel gasoline vehicle. Emissions were characterized during a New European Driving Cycle (NEDC) using a comprehensive set-up of high time-resolution instruments. A detailed chemical composition of the exhaust particulate matter (PM) was studied using a soot particle aerosol mass spectrometer (SP-AMS), and secondary aerosol formation was studied using a potential aerosol mass (PAM) chamber. For the primary gaseous compounds, an increase in total hydrocarbon emissions and a decrease in aromatic BTEX (benzene, toluene, ethylbenzene and xylenes) compounds was observed when the amount of ethanol in the fuel increased. In regard to particles, the largest primary particulate matter concentrations and potential for secondary particle formation was measured for the E10 fuel (10 % ethanol). As the ethanol content of the fuel increased, a significant decrease in the average primary particulate matter concentrations over the NEDC was found. The PM emissions were 0.45, 0.25 and 0.15 mg m−3 for E10, E85 and E100, respectively. Similarly, a clear decrease in secondary aerosol formation potential was observed with a larger contribution of ethanol in the fuel. The secondary-to-primary PM ratios were 13.4 and 1.5 for E10 and E85, respectively. For E100, a slight decrease in PM mass was observed after the PAM chamber, indicating that the PM produced by secondary aerosol formation was less than the PM lost through wall losses or the degradation of the primary organic aerosol (POA) in the chamber. For all fuel blends, the formed secondary aerosol consisted mostly of organic compounds. For E10, the contribution of organic compounds containing oxygen increased from 35 %, measured for primary organics, to 62 % after the PAM chamber. For E85, the contribution of organic compounds containing oxygen increased from 42 % (primary) to 57 % (after the PAM chamber), whereas for E100 the amount of oxidized organics remained the same (approximately 62 %) with the PAM chamber when compared to the primary emissions.

scholarly journals The Influence of Pretreatment on the Preparation of Fuel Ethanol from Corn Stalk

2018 ◽  
Vol 228 ◽  
pp. 04002
Author(s):  
Yanfei Wang ◽  
Rui Xu ◽  
Yuanyuan Heng ◽  
Xiao Lu ◽  
Gaofei Liang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Conversion Rate ◽  
Sugar Content ◽  
Fuel Ethanol ◽  
Reducing Sugar ◽  
Corn Stalk ◽  
Corn Straw ◽  
Ethanol Content ◽  
Maize Straw

In this research, the effects of three different pretreatment methods, physical pulverizing, steam blasting and hydrogen peroxide oxidizing, on ethanol preparation from corn straw were compared. The results showed that the content of reducing sugar in corn straw briquette with grinding and steam blasting pretreatment were 2 and 1.5 times higher than that without pretreatment. In the final product, the concentration of ethanol and rate of alcohol increased about 3.8 and 2 times, respectively. Besides, the reducing sugar content, ethanol content and alcohol yield in corn stalks soaked in hydrogen peroxide were 7 times higher than the untreated. The cellulose can be effectively isolated after being soaked in hydrogen peroxide with a concentration of 2.5% for 72 hours, as well as better degradation of lignin and hemicellulose. The amount of ethanol and the yield of alcohol were 1.9 and 3.3 times higher than physical pulverization and steam blasting. In brief, it is declared that hydrogen peroxide pretreatment can easily destroy the lignocellulosic cellulose of maize straw and improve the conversion rate of cellulose, which might be beneficial for the production of fuel ethanol.

Emissions from a flex fuel GDI vehicle operating on ethanol fuels show marked contrasts in chemical, physical and toxicological characteristics as a function of ethanol content

2019 ◽  
Vol 683 ◽  
pp. 749-761 ◽  
Author(s):  
Jiacheng Yang ◽  
Patrick Roth ◽  
Thomas D. Durbin ◽  
Martin M. Shafer ◽  
Jocelyn Hemming ◽  
...  
Keyword(s):  
Ethanol Content ◽  
Flex Fuel

Estimation of Ethanol Content in Flex-Fuel Vehicles Using an Exhaust Gas Oxygen Sensor: Model, Tuning and Sensitivity

2008 ◽  
Author(s):  
Kyung-Ho Ahn ◽  
Anna G. Stefanopoulou ◽  
Mrdjan Jankovic
Keyword(s):  
Oxygen Sensor ◽  
Control Process ◽  
Engine Management System ◽  
Exhaust Gas ◽  
Fuel Blend ◽  
Analysis And Design ◽  
Sensor Model ◽  
Ethanol Content ◽  
Model Tuning ◽  
Adaptation Law

Throughout the history of the automobile there have been periods of intense interest in using ethanol as an alternative fuel to petroleum-based gasoline and diesel derivatives. Currently available flexible fuel vehicles (FFVs) can operate on a blend of gasoline and ethanol in any concentration of up to 85% ethanol. In all these FFVs, the engine management system relies on the estimation of the ethanol content in the fuel blend, which typically depends on the estimated changes in stoichiometry through an Exhaust Gas Oxygen (EGO) sensor. Since the output of the EGO sensor is used for the air-to-fuel ratio (AFR) regulation and the ethanol content estimation, several tuning and sensitivity problems arise. In this paper, we develop a simple phenomenological model of the AFR control process and a simple ethanol estimation law which can be representative of the currently practiced system in FFVs. Tuning difficulties and interactions of the two learning loops are then elucidated using classical control techniques. The sensitivity of the ethanol content estimation with respect to sensor and modeling errors is also demonstrated via simulations. The results point to an urgent need for model-based analysis and design of the AFR controller, the ethanol adaptation law and the fault detection issues in FFVs. Tuning and sensitivity issues are demonstrated via simulations and limitations are also discussed.

Sign in / Sign up

Export Citation Format

Share Document