scholarly journals Analysis of the Influence of CO2 Concentration on a Spark Ignition Engine Fueled with Biogas

2021 ◽  
Vol 11 (14) ◽  
pp. 6379
Author(s):  
Donatas Kriaučiūnas ◽  
Saugirdas Pukalskas ◽  
Alfredas Rimkus ◽  
Dalibor Barta

Biogas is one of the alternative solutions that could reduce the usage of fossil fuels and production of greenhouse gas emissions, as biogas is considered as an alternative fuel with a short carbon cycle. During biogas production, organic matter is decomposed during an anaerobic digestion process. Biogas mainly consists of methane and carbon dioxide, of which the ratio varies depending on the raw material and parameters of the production process. Therefore, engine parameters should be adjusted in relationship with biogas composition. In this research, a spark ignition engine was tested for mixtures of biogas with 0 vol%, 20 vol%, 40 vol% and 50 vol% of CO2. In all experiments, two cases of spark timing (ST) were used; the first one is a constant spark timing (26 crank angle degrees (CAD) before top dead center (BTDC)) and the second one is an advanced spark timing (optimal for biogas mixture). Results show that increasing the CO2 concentration and using constant spark timing increases the mass burned fraction combustion duration by 90%, reduces the in-cylinder pressure and leads to a reduction in the brake thermal efficiency and nitrogen oxides emissions at all measurement points. However, the choice of optimal spark timing increases the brake thermal efficiency as well as hydrocarbon and CO2 emission.

2017 ◽  
Vol 9 (2) ◽  
pp. 168781401668884 ◽  
Author(s):  
Yu Li ◽  
Jinke Gong ◽  
Wenhua Yuan ◽  
Jun Fu ◽  
Bin Zhang ◽  
...  

Ethanol is known as the most widely used alternative fuel for spark-ignition engines. Compared to it, butanol has proved to be a very promising renewable fuel in recent years for desirable properties. The conjoint analysis on combustion, performance, and emissions characteristics of a port fuel injection spark-ignition engine fueled with butanol–gasoline blends was carried out. In comparison with butanol–gasoline blends with various butanol ratio (0–60 vol% referred as G100~B60) and conventional alcohol alternative fuels (methanol, ethanol, and butanol)–gasoline blends, it shows that B30 performs well in engine performance and emissions, including brake thermal efficiency, brake-specific fuel consumption, carbon monoxide, unburned hydrocarbons, and nitrogen oxides. Then, B30 was compared with G100 under various equivalence ratios ( Φ = 0.83–1.25) and engine loads (3 and 5-bar brake mean effective pressure). In summary, B30 presents an advanced combustion phasing, which leads to a 0.3%–2.8% lower brake thermal efficiency than G100 as the engine was running at the spark timing of gasoline’s maximum brake torque (MBT). Therefore, the sparking timing should be postponed when fueled with butanol–gasoline blends. For emissions, the lower carbon monoxide (2.3%–8.7%), unburned hydrocarbons (12.4%–27.5%), and nitrogen oxides (2.8%–19.6%) were shown for B30 compared with G100. Therefore, butanol could be a good alternative fuel to gasoline for its potential to improve combustion efficiency and reduce pollutant emissions.


2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Dongwon Jung ◽  
Byeongseok Lee ◽  
Jinwook Son ◽  
Soohyung Woo ◽  
Youngnam Kim

Abstract This study demonstrates the effects of technologies applied for the development of gasoline direct injection (GDI) engine for improving the brake thermal efficiency (BTE). The test engine has a relatively high stroke to bore ratio of 1.4 with a displacement of 2156 cm3. All experiments have been conducted for stoichiometric operation at 2000 RPM. First, since compression ratio (CR) is directly related to the thermal efficiency, four CR were explored for operation without exhaust gas recirculation (EGR). Then, for the same four CR, EGR was used to suppress the knock occurrence at high loads, and its effect on initial and main combustion duration was compared. Second, the shape of intake port was revised to increase tumble flow for reducing combustion duration, and extending EGR-stability limit further. Then, as an effective method to ensure stable combustion for EGR-diluted stoichiometric operation, the use of twin spark ignition (SI) system is examined by modifying both valve diameters of intake and exhaust, and its effect is compared against that of single spark ignition. In addition, the layout of twin spark ignition was also examined for the location of front-rear and intake-exhaust. To get the maximum BTE at high load, 12 V electronic super charger (eSC) was applied. Under the condition of using 12 V eSC, the effect of intake cam duration was identified by increasing from 260 deg to 280 deg. Finally, 48 V eSC was applied with the longer intake camshaft duration of 280 deg. As a result, the maximum BTE of 44% can be achieved for stoichiometric operation with EGR.


2021 ◽  
pp. 1-28
Author(s):  
Hongqing Feng ◽  
Shuwen Xiao ◽  
Zhirong Nan ◽  
Di Wang ◽  
Chaohe Yang

Abstract Low-carbon alcohols have been universally acknowledged as an alternative to fossil fuel in the world, which is environmentally friendly and clean. In this paper, the detailed exergy and energy analysis were carried out on a turbocharged, spark-ignition (SI) engine fueled with methanol-ethanol-gasoline (GEM) under non-knock conditions. The results indicated that increasing the alcohols proportion in blends could slightly improve the exergy efficiency and thermal efficiency and increase the percentage of total irreversibility in the total exergy. The thermal efficiency and exergy efficiency increased to a maximum value and then decreased, while the proportion of total irreversibility in the total exergy increased significantly with the spark timing retarded from the earliest timing. The exergy efficiency and thermal efficiency increased as the engine load increased. Additionally, the total irreversibility increased but the proportion of total irreversibility in the total exergy presented a trend of decreasing as the engine load increased.


Author(s):  
Shawn M. Grannell ◽  
Dennis N. Assanis ◽  
Stanislav V. Bohac ◽  
Donald E. Gillespie

An overall stoichiometric mixture of air, gaseous ammonia and gasoline was metered into a single cylinder, variable compression ratio, supercharged CFR engine at varying ratios of gasoline to ammonia. The engine was operated such that the combustion was knock-free with minimal roughness for all loads ranging from idle up to a maximum load in the supercharge regime. For a given load, speed, and compression ratio there was a range of ratios of gasoline to ammonia for which knock-free, smooth firing was obtained. This range was investigated at its roughness limit and also at its knock limit. If too much ammonia was used, then the engine fired with an excessive roughness. If too much gasoline was used, then knock-free combustion could not be obtained while the maximum brake torque spark advance was maintained. Stoichiometric operation on gasoline alone was also investigated, for comparison. It was found that a significant fraction of the gasoline used in spark ignition engines could be replaced with ammonia. Operation on mostly gasoline was required near idle. However, mostly ammonia could be used at high load. Operation on ammonia alone was possible at some of the supercharged load points. Generally, the use of ammonia or ammonia with gasoline allowed knock-free operation at higher compression ratios and higher loads than could be obtained with the use of gasoline alone. The use of ammonia/gasoline allowed practical operation at a compression ratio of 12:1 whereas the limit for gasoline alone was 9:1. When running on ammonia/gasoline the engine could be operated at brake mean effective pressures that were more than 50% higher than those achieved with the use of gasoline alone. The maximum brake thermal efficiency achieved with the use of ammonia/gasoline was 32.0% at 10:1 compression ratio and BMEP = 1025 kPa. The maximum brake thermal efficiency possible for gasoline was 24.6% at 9:1 and BMEP = 570 kPa.


2017 ◽  
Vol 20 (K6) ◽  
pp. 79-86
Author(s):  
Quoc Dang Tran

This article shows an investigated research on Compressed Natural Gas (CNG) engine with a port injection when varying ignition timing. The obtained results from simulating study have indicated that both of brake thermal efficiency and torque have a similar trend when varying ignition timing. The effect of ignition timing on the value of brake thermal efficiency is stronger in comparison with torque, however, the increase in engine speed or lambda value have to adjust the ignition timing more early. To reach the maximum break torque at each engine speed, the ignition timing should be adjusted IT = 14 - 32 bTDC, and this is also basic value to design the ignition timing system using CNG engine with port injection.


2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Sachin Kumar Gupta ◽  
Mayank Mittal

Abstract Biogas, which is a renewable alternative fuel, has high antiknocking properties with the potential to substitute fossil fuels in internal combustion engines. In this study, performance characteristics of a spark-ignition (SI) engine operated under methane (baseline case) and biogas are compared at the compression ratio (CR) of 8.5:1. Subsequently, the effect of CR on operational limits, performance, combustion, and emission characteristics of the engine fueled with biogas is evaluated. A variable compression ratio, spark-ignition engine was operated at various CRs of 8.5:1, 10:1, 11:1, 13:1, and 15:1 over a wide range of operating loads at 1500 rpm. Results showed that the operating range of the engine at 8.5:1 CR reduced when biogas was utilized in the engine instead of methane. However, the operating range of the engine for biogas extended with an increase in CR—an increase from 9.6 N-m-16.5 N-m to 2.8 N-m-15.1 N-m was observed when CR was increased from 8.5:1 to 15:1. The brake thermal efficiency improved from 13.7% to 16.3%, and the coefficient of variation (COV) of indicated mean effective pressure (IMEP) reduced from 12.7% to 1.52% when CR was increased from 8.5:1 to 15:1 at 8 N-m load. The emission level of carbon dioxide was decreased with an increase in CR due to an improvement in the thermal efficiency and the combustion process.


Author(s):  
Sachin Kumar Gupta ◽  
Mayank Mittal

Biogas is a promising alternative fuel to reduce the consumption of petroleum-based fuels in internal combustion (IC) engines. In this work, the effect of various biogas compositions on the performance, combustion, and emission characteristics of a spark-ignition (SI) engine is investigated. Additionally, the effect of Wobbe index (WI) of various fuel compositions was also evaluated on the operational limits of the engine. While considering a wide range of biogas compositions (including bio-methane), the percentage of carbon dioxide (CO2) (in a blend of methane and CO2) was increased from 0 to 50% (by volume). A single-cylinder, water-cooled, SI engine was operated at 1500 rpm over a wide range of operating loads with compression ratio of 8.5:1. With the increase in WI of the fuel, both low (limited by coefficient of variation (COV) of indicated mean effective pressure (IMEP)) and high (limited by pre-ignition) operating loads were decreased; however, it was found that the overall operating range was increased. Results also showed that for a given operating load, with the increase of CO2 percentage in the fuel, the brake thermal efficiency was decreased, and the flame initiation and combustion durations were increased. The brake thermal efficiency was decreased from 16.8% to 13.7%, when CO2 was increased from 0% to 40% in methane–CO2 mixture at 8 N·m load. Concerning to emissions, a considerable decrease was noted in nitric oxide, whereas hydrocarbon, carbon monoxide and carbon dioxide emissions were increased, with the increase in CO2 percentage.


2013 ◽  
Vol 1 (2) ◽  
pp. 110-92
Author(s):  
Miqdam Tariq Chaichan

This paper examines the results of performance of a single cylinder spark-   ignition engine fuelled with 20% methanol +80% gasoline (M20), compared to gasoline. The experiments were conducted at stoichiometric air–fuel ratio at wide open throttle and variable speed conditions, over the range of 1000 to 2600 rpm. The tests were conducted at higher useful compression ratio using optimum spark timings and adding recirculated exhaust gas with 20% to suction manifold. The test results show that the higher compression ratio for the tested gasoline was 7:1, 9.5:1 for M20 and 9:1 for M20 with added EGR. M20 at higher useful compression ratio (HUCR) and optimum spark timing (OST) characteristics are significantly different from gasoline. Within the tested speed range, M20 consistently produces higher brake thermal efficiency by about 6%. Also it resulted in approximately 3.06% lower brake specific fuel consumption compared with gasoline. Adding EGR to M20 caused reduction in HUCR and advancing the OST. This addition increased brake specific fuel consumption (BSFC), reduced brake thermal energy, volumetric efficiency and exhaust gas temperatures.


Author(s):  
Dongwon Jung ◽  
Byeongseok Lee ◽  
Jinwook Son ◽  
Soohyung Woo ◽  
Youngnam Kim

Abstract This study demonstrates the effects of technologies applied for the development of a gasoline direct injection (GDI) engine for improving the brake thermal efficiency (BTE) over 44%. The GDI engine for the current study is an in-line four-cylinder engine with a displacement of 2156cm3, which has relatively high stroke to bore ratio of 1.4 (110mm stroke and 79mm bore). All experiments have been conducted using a gasoline having RON 92 for stoichiometric operation at 2000RPM. First, since compression ratio is directly related to the thermal efficiency, four compression ratios (14.3, 15.2, 15.8 and 17.2) were explored for operation without exhaust gas recirculation (EGR). Then, for the same four compression ratios, EGR was used to suppress the knock occurrence at high loads with high compression ratio (CR), and its effect on initial and main combustion duration was compared. Second, the shape of intake port was revised to increase tumble flow of in-cylinder charge for reducing combustion duration at low and high load, and extending EGR-stability limit further eventually. Then, as an effective method to ensure stable, complete and fast combustion for EGR-diluted stoichiometric operation, the use of twin spark ignition system is examined by modifying both valve diameter of intake and exhaust, and its effect is compared against that of single spark ignition. In addition, the layout of twin spark ignition was also examined for the location of Front-Rear and Intake-Exhaust. To get the maximum BTE at high load, 12V electronic super charger (eSC) was applied. Under the condition of using 12V eSC, the effect of intake cam duration was identified by increasing from 260deg to 280deg. Finally, 48V eSC was applied with the longer intake camshaft duration of 280deg. As a result, the maximum BTE of 44% can be achieved for stoichiometric operation with EGR.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Gang Wu ◽  
Deng Wu ◽  
Yuelin Li ◽  
Lei Meng

Ethanol is the most extensively used oxygenate for spark ignition (SI) engines. In comparison with ethanol, n-butanol exhibits a number of desirable properties for use in SI engines, which has proved to be a very promising oxygenated alternative fuel in recent years. However, the dehydration and recovery of bio-n-butanol consume extra money and energy in the acetone-n-butanol-ethanol (ABE) fermentation process. Hence, we focus on the research of ABE as a potential oxygenated alternative fuel in SI engines. The combustion, performance, and emission characteristics of B30, E30, ABE30 (i.e., 30 vol.% n-butanol, ethanol, and ABE blended with 70 vol.% gasoline), and G100 (pure gasoline) were compared in this study. The comparison results between B30, E30, and ABE30 at stoichiometric conditions show that ABE30 presents retarded combustion phasing, higher brake thermal efficiency, lower CO emissions, higher UHC emissions, and similar NOx emissions. In comparison with G100 under various engine loads and equivalence ratios, for the most part, ABE30 exhibits 1.4% higher brake thermal efficiency, 14% lower carbon monoxide, 9.7% lower unburned hydrocarbons, and 23.4% lower nitrogen oxides. It is indicated that ABE could be served as the oxygenate in spark ignition engine due to its capability to improve energy efficiency and reduce pollutant emissions.


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