Exhaust Gas Analysis Research Articles

Desulfurization of diesel-like fuel produced from waste lubrication oil and its utilization on engine performance and exhaust emission

In this study, desulfurization of diesel-like fuel (DLF) produced from waste lubrication oil, and the effects of desulfurized fuel on engine performance and emissions were investigated experimentally. Firstly, the DLF was produced by using a fuel production system and applying pyrolitic distillation method. After producing the DLF, oxidative desulfurization (ODS) method was applied at a temperature of 50 °C in order to decrease the amount of sulfur in the DLF. The sulfur level of the DLF was decreased from 3500 to 420 ppm after the application of ODS method. It was observed that temperature had an important effect on decrement of sulfur content of the DLF. Secondly, characteristic tests such as density, kinematic viscosity, heating value and flash point, sulfur content and distillation tests for the desulfurized fuel named as low sulfur diesel-like fuel (LSDLF) are performed. Finally, the LSDLF and a commercial diesel fuel were used in a diesel test engine to examine their effects on engine performance and emission parameters. In each test, performance and emission parameters for the fuels were measured using the test engine and exhaust gas analyzer. The performance and emission test results indicated that torque, mean effective pressure and brake thermal efficiency for the LSDLF were slightly higher while brake specific fuel consumption, exhaust temperature and emissions of SO2, CO and NOx appeared to be lower than those of the commercial diesel fuel. It was concluded that the LSDLF could be used in diesel engine without any problems in terms of physico-chemical parameters, distillation and performance tests.

Carbon Dioxide Decomposition and Oxygen Generation Via SOEC

Oxygen-Deficient Ferrite (ODF) or nickelate-based materials are mixed with YSZ powder via Mechano-Chemical Bonding (MCB) process. The Solid Oxide Electrolyzer Cell (SOEC) with ODF/YSZ or nickelate/YSZ electrodes and YSZ electrolyte is utilized to decompose carbon dioxide (CO2) into solid carbon (C) or carbon monoxide (CO) and generate oxygen (O2) in a continuous process. The cells are tested in a NexTech ProbostateTM apparatus combined with EIS/potentiostate and gas chromatography (GC). In our preliminary tests, CO or solid carbon at cathode side and O2 at anode side were detected, when CO2 was fed to the cathode side and a small potential bias applied across the electrode. Depending on the applied potential, the system is capable of decomposing CO2 into CO or C. Through in-situ EIS and exhaust gas analyses as well as post mortem microstructural analyses using SEM, XRD, and XPS, the capability and efficiency of CO2 decomposition are evaluated. An energy assessment shows that the net energy input in this process is smaller compared to CCS (carbon capture and sequestration).

Estimation of soot oxidation rate in DPF under carbon and non-carbon based particulate matter accumulated condition

By high particulate matter(PM) reduction performance, diesel particulate filter(DPF) is applied to almost all of modern HSDI diesel engine. PM emitted from diesel engine is consist of carbon based and non-carbon based material. Representative carbon based PM is soot. Non-carbon based PM is produced by wear of engine and exhaust component, combustion of lubrication oil and sulphur in fuel. Accumulation of non-carbon based PM affects pressure difference of DPF and thus accuracy of soot mass estimation in DPF can be lowered during normal and regeneration condition when the pressure difference caused by non-carbon based PM is not recognized correctly. Also unevenly accumulated PM inside of DPF can produce locally different exhaust gas temperature and thus it can lower accuracy of soot mass estimation during regeneration. This study focuses on estimation of soot oxidation rate not by conventional pressure difference but by exhaust gas analysis at up and downstream of DPF. Results, strong correlations between CO2 -fuel mass ratio and soot oxidation was observed.

Decomposition of CO2 Gas in CaCl2-CaO and LiCl-Li2O Molten Salts

The electrochemical decomposition of CO2 gas to form carbon and oxygen gas was studied in CaCl2-CaO and LiCl-Li2O molten salts. A constant voltage was applied at 1173K and 923K, respectively. This process consists of (1)electrochemical reduction of oxide (formation of reductant), (2)thermal reduction of CO2 gas by reaction with the metal dissolved in the molten salt, and (3)ZrO2 anodic electrode worked as an oxygen ions conductor to remove oxygen ions from the molten salt. When 9.7 %CO2-Ar mixed gas was blown into CaCl2-CaO and LiCl-Li2O molten salts, the current efficiency was evaluated to be 78.5 % and 89.7 %, respectively, judged by the exhaust gas analysis and the supplied charge. After electrolysis, the aggregations of carbon nano-tubes and amorphous carbon particles were observed by transmission electron microscope.

CO2 gas decomposition to carbon by electro-reduction in molten salts

The electrochemical decomposition of CO2 gas in LiCl–Li2O or CaCl2–CaO molten salt was studied to produce carbon. This process consists of the electrochemical reduction of the oxide, Li2O or CaO, and the thermal reduction of CO2 gas by metallic Li or Ca. Two kinds of ZrO2 solid electrolytes were tested as an oxygen ions conductor and removed oxygen ions from the molten salts to the outside of reactor. After the electrolysis in the both salts, the aggregations of nanometer-scale amorphous carbon and rod-like graphite crystals were observed by transmission electron microscope. When 9.7% CO2–Ar mixed gas was blown into LiCl–Li2O or CaCl2–CaO molten salt, the current efficiency was evaluated to be 89.7% or 78.5%, respectively, by the exhaust gas analysis and the supplied charge. When the solid electrolyte with the better ionic conductivity was used, the current and the carbon production became larger. The rate determining step of this proposal was diffusion of oxygen ions in ZrO2 solid electrolyte.

Respiratory Quotient (Rq), Exhaust Gas Analyses, CO2 Emission and Applications in Automobile Engineering

Respiratory Quotient (Rq), Exhaust Gas Analyses, CO2 Emission and Applications in Automobile Engineering

Effects of Errors on Vehicle Emission Rates from Portable Emissions Measurement Systems

Portable emissions measurement systems (PEMS) are useful for quantification of real-world vehicle activity, energy use, and emissions. However, there is no standard methodology for processing PEMS data; this can lead to errors in reported results. PEMS typically include tailpipe exhaust gas and particle analyzers, Global Positioning System (GPS) receivers, engine sensors, and electronic control unit (ECU) data loggers. The sensitivity of estimated emission rates to random errors in measurements is quantified. Methods are evaluated for identification and correction of improper synchronization of PEMS, ECU, and GPS data streams and for road grade estimation. Estimated fuel use and emission rates for light- and heavy-duty vehicles are sensitive to errors in intake manifold absolute pressure and engine revolutions per minute values and in indicators of air-to-fuel ratio including carbon dioxide and oxygen concentrations. Synchronization can be aided by maximizing the Pearson correlation coefficient between two indicator variables and confirming the result by matching concurrent increases in indicator variables. The effect of improper synchronization on estimated modal emission rates is quantified. Modal average emission rates based on vehicle-specific power (VSP) are more sensitive to improperly synchronized engine versus GPS data. Improperly synchronized data streams result in decreased variability between the lowest and highest modal average emission rates. Estimation of road grade from a linear least squares slope of elevation over a specified distance is demonstrated. VSP-based modal fuel use and pollutant emission rates are less sensitive to differences in road grade than to errors in synchronization.

Effects of Travel Routes on Vehicular Emissions in Urban Driving

This study measured the concentration of pollutants in a passenger car Golf 3, Volkswagen model, popularly used as Taxi in Nigeria was done on three different travel routes of state routes in the Federal Capital Territory, Abuja, in the bid to compare the emission level of regulated and non-regulated gasses of Carbon monoxide (CO), Carbon dioxide (CO2), Nitrogen oxide (NO), and Non-Methane Hydro Carbon (NMHC) propane using SV -5Q Automobile Exhaust Gas Analyzer connected to the exhaust port with measurement conducted at intervals over traveled distance. The Route C ( Berger- Area1) gave the lowest average emissions value of 0.45%, 87.69%, 320.72ppm and 590.86 ppm for CO, CO2, HC and NO, Route B (Nyanya- AYA) gave the highest value of 0.53% CO, 8.99% CO2, 374.06ppm HC and 691.52ppm NO . In percentage analysis the average emission value for CO in route B was 6% higher while Route A (Jikwoyi- Kurudu) 3% higher than the value in Route C. Also the CO2 average emission was 6% higher in Route B than Route C similar to observation in CO but in Route A the CO2 value was 5% lower than Route C. The road grade should be taken into account for localized emissions estimation Keyword: Altitude, Average Speed, Emissions, Travel Routes,

Dynamic modeling of methylotrophic Pichia pastoris culture with exhaust gas analysis: From cellular metabolism to process simulation

A systematic approach to establish a dynamic model of methylotrophic Pichia pastoris culture in bioreactor is presented on the basis of biomass compartmentalization and metabolic stoichiometry simplification. Besides direct state variables (i.e., biomass, glycerol, methanol, and ammonia), CER and OUR calculated from on-line exhaust gas analysis are included in the model. The model is directly and crossly validated with five experimental cultures involving glycerol growth and methanol feeding phases. Model parameters are identified with confidence intervals. Meanwhile, data consistency is straightforward checked between predicted CERs and measured CTRs. In addition, in the light of the model structure, the results of parameter sensitivity analysis verifies the relative “freedom” of biomass initial compartmentalization and the high output sensitivity when the substrate (glycerol or methanol) concentration is close to the affinity constant (KGly or KMeth). With the proposed model, a process control strategy can be accordingly developed, which is based on real-time monitoring and regulating of cellular metabolic state during culture.

Influence of CO2 dissolution into anion exchange membrane on fuel cell performance

Influence of CO2 dissolution into anion exchange membranes (AEMs) on fuel cell performance was investigated. The conductivity of AEM decreased with an increase in carbonate ion species. For the power generation test with a supply of humidified H2/O2, the IR–free cell potential difference for the membrane electrode assembly (MEA) with the HCO3− form membrane was lower than that with the OH-form membrane. This low cell potential difference became noticeable by the supply of CO2 to either anode or cathode. The increment of ohmic resistance was confirmed by the supply of CO2 to cathode, but no obvious change in ohmic resistance was observed by the supply of CO2 to anode. Then, a CO2 permeation flux was determined by a gas chromatograph analysis of exhaust gas, and the correlation between the AEM fuel cell performance and the composition of ion species in the membrane was discussed.

Experiments and zero D modeling studies using specific Wiebe coefficients for producer gas as fuel in spark-ignited engines

The paper addresses experiments and modeling studies on the use of producer gas, a bio-derived low energy content fuel in a spark-ignited engine. Producer gas, generated in situ, has thermo-physical properties different from those of fossil fuel(s). Experiments on naturally aspirated and turbo-charged engine operation and subsequent analysis of the cylinder pressure traces reveal significant differences in the heat release pattern within the cylinder compared with a typical fossil fuel. The heat release patterns for gasoline and producer gas compare well in the initial 50% but beyond this, producer gas combustion tends to be sluggish leading to an overall increase in the combustion duration. This is rather unexpected considering that producer gas with nearly 20% hydrogen has higher flame speeds than gasoline. The influence of hydrogen on the initial flame kernel development period and the combustion duration and hence on the overall heat release pattern is addressed. The significant deviations in the heat release profiles between conventional fuels and producer gas necessitates the estimation of producer gas-specific Wiebe coefficients. The experimental heat release profiles are used for estimating the Wiebe coefficients. Experimental evidence of lower fuel conversion efficiency based on the chemical and thermal analysis of the engine exhaust gas is used to arrive at the Wiebe coefficients. The efficiency factor a is found to be 2.4 while the shape factor m is estimated at 0.7 for 2% to 90% burn duration. The standard Wiebe coefficients for conventional fuels and fuel-specific coefficients for producer gas are used in a zero D model to predict the performance of a 6-cylinder gas engine under naturally aspirated and turbo-charged conditions. While simulation results with standard Wiebe coefficients result in excessive deviations from the experimental results, excellent match is observed when producer gas-specific coefficients are used. Predictions using the same coefficients on a 3-cylinder gas engine having different geometry and compression ratio(s) indicate close match with the experimental traces highlighting the versatility of the coefficients.

On the formation of spinning flames and combustion completeness for premixed fuel–air mixtures in stepped tube microcombustors

Various premixed fuel–air mixtures are introduced in stepped tube microcombustors. The experimental investigations show the formation of various steady and unsteady spinning flame propagation modes for a range of flow rates and mixture ratio conditions due to thermal-wall coupling. The spinning flames of very high frequency, ∼150 Hz have been observed for the first time with various fuel–air mixtures. The spinning frequency of these flames is almost twice that of flames observed in earlier work. The spinning flames were observed for both lean and rich mixtures of methane-, LPG- and propane–air mixtures. The formation of these spinning flames depends on the mixture flow rate, equivalence ratio and number of steps in the microcombustor. Exhaust gas analysis was carried out for different operating conditions. It was observed that contrary to general perception of low combustion efficiency and high CO emissions associated with such rotating and spinning flames, these high frequency spinning flames led to complete combustion with almost zero CO emissions.

CRDI시스템을 갖는 천연가스/디젤 혼소차량의 개발에 대한 연구

This research is about the exhaust gas and driving performance test which are for CNG-Diesel dual fuel engine. The CNG-Diesel dual fuel engine converted from 2500cc diesel has two steps of injection systems; small amount of diesel is injected to mixture CNG in cylinder to ignite before CNG is injected into each intake manifold to form mixture. The amounts of output power and emission in duel fuel consumption were measured by engine dynamometer and exhaust gas analyzer. Over 90% of diesel consumption reduction, similar driving performance to current diesel engine and reduced emission on <TEX>$CO_2$</TEX> and PM, respectively, were indicated through the measurements. The two steps of system were applied to vehicle to investigate exhaust gas characteristics and driving performance via NEDC mode and real driving test. Additional oxidation catalyst was applied to reduce emission on the test vehicle and the NEDC mode test showed the reduction of Co, <TEX>$CO_2$</TEX>, Pm and THC.

가스화용융(熔融) 실증 시스템에서 HFC-134a 냉매분해(冷媒分解) 특성(特性) 연구(硏究)

본 연구는 가스화용융 시스템을 활용한 폐차 냉매의 친환경 파괴 기술개발을 목표로 하였다. 실증규모(생활폐기물 100톤/일) 가스화용융 시스템내 냉매를 주입할 수 있는 주입장치를 개발 및 제작하였으며, HFC-134a 주입량에 따른 냉매 분해효율 및 유해가스 특성을 고찰하였다. 분해효율은 3 kg/hr 냉매 주입시 99.995%이었고, 18시간 동안 유해가스 연속 측정 및 샘플링 측정결과, CO, SOx, NOx, HCl, HF 등의 유해가스는 환경법규를 만족하였고, 특히 냉매파괴 발생 HF는 0.1 ppm으로 법적 기준치 2ppm에 비해 미량으로 검출되었다. Destruction of HFC-134a from ELV (End of Life Vehicle) were determined in a gasification-melting demonstration system of municipal solid waste (100ton/day). The injection system has been developed for the uniform injection of HFC-134a to the gasification-melting system. The destruction characteristics of HFC-134a and analysis of exhaust gases have been performed. The destruction efficiency was 99.995% for HFC-134a feeding of 3 kg/hr and the exhaust gases such as CO, SOx, NOx, HCl and HF satisfied the environmental standards.

CO2 decomposition using electrochemical process in molten salts

The electrochemical decomposition of CO2 gas to carbon and oxygen gas in LiCl-Li2O and CaCl2-CaO molten salts was studied. This process consists of electrochemical reduction of Li2O and CaO, as well as the thermal reduction of CO2 gas by the respective metallic Li and Ca. Two kinds of ZrO2 solid electrolytes were tested as an oxygen ion conductor, and the electrolytes removed oxygen ions from the molten salts to the outside of the reactor. After electrolysis in both salts, the aggregations of nanometer-scale amorphous carbon and rod-like graphite crystals were observed by transmission electron microscopy. When 9.7 %CO2-Ar mixed gas was blown into LiCl-Li2O and CaCl2-CaO molten salts, the current efficiency was evaluated to be 89.7 % and 78.5 %, respectively, by the exhaust gas analysis and the supplied charge. When a solid electrolyte with higher ionic conductivity was used, the current and carbon production became larger. It was found that the rate determining step is the diffusion of oxygen ions into the ZrO2 solid electrolyte.

정적연소기내 H2-LPG 연료의 혼합 비율에 따른 연소 및 배출가스 특성에 관한 실험적 연구

Finding an alternative fuel and reducing environmental pollution are the main goals for future internal combustion engines. The purpose of this study is to obtain low-emission and high-efficiency by hydrogen enriched LPG fuel in constant volume chamber. An experimental study was carried out to obtain fundamental data for the combustion and emission characteristics of pre-mixed hydrogen and LPG in a constant volume chamber (CVC) with various fractions of hydrogen-LPG blends. To maintain equal heating value of fuel blend, the amount of LPG was decreased as hydrogen was gradually added. Exhaust emissions were measured using a HORIBA exhaust gas analyzer for various fractions of hydrogen-LPG blends. The results showed that the rapid combustion duration was shortened, and the rate of heat release elevated as the hydrogen fraction in the fuel blend was increased. Moreover, the maximum rate of pressure rise also increased. These phenomena were attributed to the burning velocity which increased exponentially with the increased hydrogen fraction in the <TEX>$H_2$</TEX>-LPG fuel blend. Exhaust HC and <TEX>$CO_2$</TEX> concentrations decreased, while NOX emission increased with an increase in the hydrogen fraction in the fuel blend. Our results could facilitate the application of hydrogen and LPG as a fuel in the current fossil hydrocarbon-based economy and the strict emission regulations in internal combustion engines.

Performance and characteristics of platinum, palladium/rhodium and palladium automotive catalysts when subjected to ethanol, acetaldehyde and a synthetic E85 exhaust gas mixture

The performance optimization of automotive catalysts has been the focus of in-depth research for many years as the automotive industry has endeavoured to reduce the emission of toxic and pollutant gases generated from internal combustion engines. Just as the emissions from diesel and gasoline combustion vary, so do the emissions from the combustion of alternative fuels such as ethanol, with variation in both quantity and chemical composition. In particular, when ethanol is contained in the fuel, ethanol and acetaldehyde are present in the exhaust gas stream, and these are two compounds which the catalytic converter has not traditionally been designed to manage. The aim of the study outlined in this paper was to assess the performance of various catalyst formulations when subjected to a representative ethanol exhaust gas mixture. Three automotive catalytic converter formulations were tested, including a fully platinum sample, a palladium/rhodium three-way catalyst sample and a fully palladium sample. Initially the samples were tested using single component hydrocarbon light-off tests followed by a set of tests with carbon monoxide included as an inlet gas to observe its effect on each individual hydrocarbon oxidation. Finally, each formulation was tested using a full E85 exhaust gas mixture. The study was carried out using a synthetic gas reactor along with Fourier transform infrared spectroscopy and flame ionization detector exhaust gas analysers. All formulations showed selectivity toward acetaldehyde formation from ethanol dehydrogenation which resulted in negative acetaldehyde conversion across each of the samples during the mixture tests. The fully platinum sample was the most detrimentally affected by the introduction of carbon monoxide into the gas feed. The palladium and palladium/rhodium samples exhibited a tendency toward acetaldehyde decomposition resulting in methane and carbon monoxide formation. The platinum sample did not form methane but did form ethylene as a result of ethanol dehydration.

Research on Vehicle Emissions of Typical Intersection in City

Investigated at the intersection of zhongshan east road and xilin road in Hohhot, the total quantity of vehicle in morning, noon and evening peak hours is 19,793. Pollutant concentrations and weather parameters are investigated, vehicular emission density in the intersection is calculated by the Nichoson box model, and each pollutant concentration in the intersection is measured by the exhaust gas analyzer. The result shows that the concentration of CO in the intersection is still lower than the limit value, but the concentration of NOX is far higher than the limit value. Pollution is very serious.

GC-MS/FID analysis of aldehyde and hydrocarbon emissions from exhaust gases of a spark ignition engine fueled with different ethanol-gasoline blends

In this paper the influence of changes in ethanol concentration in gasoline-alcohol blend on the concentrations of aldehydes and hydrocarbons emitted from a spark-ignition automotive engine is described. Results of the exhaust gas analysis with E0, E5, E10, E25 and E50 blends tested in a car meeting the Euro 5 emission standard are presented. It was found that an increase of the ethanol concentration in the fuel blend leads to an increase in the acetaldehyde concentration in the exhaust gas. TD-GC-FID/MS analysis of exhaust gases collected on two different, complementary sorbents (Carbograph 1TD, Tenax TA) allowed for identification of the large number of hydrocarbons.

대형 DME버스의 연비 및 배기가스 특성에 관한 연구

본 연구에서는 대형버스 배기가스 테스트 모드인 JE-05 에서 DME와 디젤을 연료로 사용하는 대형 DME버스를 차대동력계, 배기가스 분석기 그리고 PM 측정시스템을 이용하여 대형 DME버스의 연비, 배기가스특성 그리고 동적 특성에 대해 알아보았다. 대형 DME버스에는 6기통 8,071cc 디젤엔진이 장착되었으며, 현재 운행되고 있는 상용 디젤버스와는 달리 DOC, DPF와 같은 후처리 장치가 없다. 실험 결과, 각 부하에 따른 차량의 속도를 통하여 차량의 동적 특성은 DME와 디젤을 사용했을 때 거의 비슷한 것을 알 수 있었다. NOx, CO와 THC는 DME를 연료로 사용 시 디젤연료에 비해 더 적게 배출되는 것을 확인하였다. 하지만 PM은 DME연료를 사용 시 거의 발생하지 않았는데, 이는 DME가 함산소연료이고 분자구조상 탄소-탄소 결합이 없기 때문이라고 생각된다. CO₂는 각 연료 사용 시 비슷하게 발생하였으며, 저위발열량 베이스로 계산된 연비는 DME연료 사용 시 디젤연료보다 약 6.7% 더 낮게 나왔다.