Methanol Emission Research Articles

Numerical comparative study on performance and emissions characteristics fueled with methanol, ethanol and methane in high compression spark ignition engine

Methane, methanol and ethanol are three common high-octane alternative fuels. As fuels for high compression ratio engines, they can improve thermal efficiency while preventing knocking. However, each of these three fuels has its own physicochemical properties and presents different engine performance. This study compares in detail the performance, combustion and emissions of a high-compression-ratio SI engine fueled by methanol, ethanol and methanol. A 4-cylinder high compression ratio SI engine simulation model was built based on 1-D simulation platform. The engine was converted from a CI diesel engine with a CR of 17.5, and the methanol, ethanol of methane injector was installed in the intake port. The results showed that for the methanol, ethanol and methane fuels, under the same engine speeds and equivalence ratios, the BP and BT of methanol were higher than ethanol and methane fuels, methane has the lowest BP and BT; methane has a lower BSFC and BTE than methanol and ethanol, with methanol having the highest BSFC and BTE; the CO and NOx emissions of methanol were lower than ethanol and methane fuels; the HC and CO2 emissions of methane were lower than methanol and ethanol fuels.

Acute methyl jasmonate exposure results in major bursts of stress volatiles, but in surprisingly low impact on specialized volatile emissions in the fragrant grass Cymbopogon flexuosus

Methyl jasmonate (MeJA) is an airborne hormonal elicitor that induces a fast rise of emissions of characteristic stress marker compounds methanol and green leaf volatiles (GLV), and a longer-term release of volatile terpenoids, but there is limited information of how terpene emissions respond to MeJA in terpene-storing species. East-Indian lemongrass (Cymbopogon flexuosus), an aromatic herb with a large terpenoid storage pool in idioblasts, was used to investigate the short- (0–1 h) and long-term (1–16 h) responses of leaf net assimilation rate (A), stomatal conductance (Gs) and volatile emissions to MeJA concentrations ranging from moderate to lethal. Both A and Gs were increasingly inhibited with increasing MeJA concentration in both short and long term. MeJA exposure resulted in a rapid elicitation, within 1 h after exposure, of methanol and GLV emissions. Subsequently, a secondary rise of GLV emissions was observed, peaking at 2 h after MeJA exposure for the highest and at 8 h for the lowest application concentration. The total amount and maximum emission rate of methanol and the first and second GLV emission bursts were positively correlated with MeJA concentration. Unexpectedly, no de novo elicitation of terpene emissions was observed through the experiment. Although high MeJA application concentrations led to visible lesions and desiccation in extensive leaf regions, this did not result in breakage of terpene-storing idioblasts. The study highlights an overall insensitivity of lemongrass to MeJA and indicates that differently from mechanical wounding, MeJA-driven cellular death does not break terpene-storing cells. Further studies are needed to characterize the sensitivity of induced defense responses in species with strongly developed constitutive defenses.

Life cycle assessment of methanol vehicles from energy, environmental and economic perspectives

As a new alternative fuel vehicle for energy reserve strategy, the development of methanol vehicles in China has been at the forefront. Completed pilot projects have demonstrated that methanol vehicles can effectively reduce fuel costs and pollutant emissions during driving. In addition to methanol vehicles, alternative fuel vehicles such as electric vehicles and compressed natural gas vehicles also maintain a sound development momentum in China. It is essential to understand which one has more advantages from sustainable development. This paper uses the Energy, Environment, and Economy (3E) evaluation method to analyze the energy consumption, environmental emission, and economy of methanol, electric, gas, and gasoline vehicles from the whole life cycle perspective. A comprehensive index evaluation model was constructed, and the development potential of the three alternative fuel vehicles was ranked under four different scenarios (energy-oriented, environment-oriented, economic-oriented, and equilibrium scenarios). This research shows that methanol vehicles have higher total energy consumption than gasoline vehicles in the whole life cycle. In terms of greenhouse gas emissions, compared with gasoline vehicles, methanol, and compressed natural gas vehicles decreased by 8.79 tons and 12.45 tons, respectively. At the same time, methanol vehicles have a better economic benefit than gasoline vehicles (37%), which is the same as the completed pilot projects. In addition, results also show that due to the advantages of low renovation cost and fuel price, the user’s cost of methanol vehicles is more down than blade electric vehicles, which makes them have better development potential compared with electric and compressed natural gas vehicles in the economic-oriented and equilibrium scenario. Therefore, methanol vehicles can be used as alternative fuel vehicles for long-term development in China.

Removal of a mixture of formaldehyde and methanol vapors in biotrickling filters under mesophilic and thermophilic conditions: Potential application in ethanol production

ABSTRACT Ethanol is a significant source of energy as a biofuel; however, its production using corn involves the generation of harmful emissions from both fermentation tanks and dryers. Scrubbers control the emissions from fermentation tanks, while the emissions from the dryers are controlled by regenerative thermal oxidizers. Potential alternatives to these energy- and water-intensive technologies are biotrickling filters (BTFs). In this study, two BTFs were operated in parallel to treat formaldehyde and methanol emissions in a volumetric ratio of 4:1, one at 25°C (mesophilic), and the other at 60°C (thermophilic). The mesophilic BTF simulated emissions from fermentation tanks, while the thermophilic BTF simulated emissions from dryers. Both beds were operated at an empty bed residence time of ~30 s and influent formaldehyde concentrations of 20, 50, and 100 parts per million per volume (ppmv). Formaldehyde polymerization was reduced in this study by adding NaOH to pH levels of 7.0–7.4 and heating the solution to a temperature of 60°C. BTFs have successfully removed formaldehyde at typical ethanol plants emissions ~21 ppmv. The BTF technology have the potential in replacing the conventional air treatment methods used at ethanol plants. Implications: Currently, ethanol plants remove and treat hazardous air pollutants (HAPs) using wet scrubbers from the fermenter off-gasses and using thermal oxidizers to combust off-gasses. The utilization of biotrickling filters (BTFs) for HAP removal generally and formaldehyde particularly has wide implication in the field of renewable energy. Utilizing BTFs in the 200+ ethanol plants in USA will save cost and reduce water and energy needs significantly. BTFs can reduce an ethanol plant’s carbon intensity (CI) by 1 to 3 g CO2/MJ. This can result in roughly $50 million per year in additional revenue in Nebraska for instance.

Root Exposure to 5-Aminolevulinic Acid (ALA) Affects Leaf Element Accumulation, Isoprene Emission, Phytohormonal Balance, and Photosynthesis of Salt-Stressed Arundo donax.

Arundo donax has been recognized as a promising crop for biomass production on marginal lands due to its superior productivity and stress tolerance. However, salt stress negatively impacts A. donax growth and photosynthesis. In this study, we tested whether the tolerance of A. donax to salinity stress can be enhanced by the addition of 5-aminolevulinic acid (ALA), a known promoter of plant growth and abiotic stress tolerance. Our results indicated that root exposure to ALA increased the ALA levels in leaves along the A. donax plant profile. ALA enhanced Na+ accumulation in the roots of salt-stressed plants and, at the same time, lowered Na+ concentration in leaves, while a reduced callose amount was found in the root tissue. ALA also improved the photosynthetic performance of salt-stressed apical leaves by stimulating stomatal opening and preventing an increase in the ratio between abscisic acid (ABA) and indol-3-acetic acid (IAA), without affecting leaf methanol emission and plant growth. Supply of ALA to the roots reduced isoprene fluxes from leaves of non-stressed plants, while it sustained isoprene fluxes along the profile of salt-stressed A. donax. Thus, ALA likely interacted with the methylerythritol 4-phosphate (MEP) pathway and modulate the synthesis of either ABA or isoprene under stressful conditions. Overall, our study highlights the effectiveness of ALA supply through soil fertirrigation in preserving the young apical developing leaves from the detrimental effects of salt stress, thus helping of A. donax to cope with salinity and favoring the recovery of the whole plant once the stress is removed.

The Chemical Nature of Orion Protostars: Are ORANGES Different from PEACHES? ORANGES II.

Abstract Understanding the chemical past of our Sun and how life appeared on Earth is no mean feat. The best strategy we can adopt is to study newborn stars located in an environment similar to the one in which our Sun was born and assess their chemical content. In particular, hot corinos are prime targets because recent studies have shown correlations between interstellar complex organic molecules abundances from hot corinos and comets. The ORion ALMA New GEneration Survey aims to assess the number of hot corinos in the closest and best analog to our Sun’s birth environment, the OMC-2/3 filament. In this context, we investigated the chemical nature of 19 solar-mass protostars and found that 26% of our sample sources show warm methanol emission indicative of hot corinos. Compared to the Perseus low-mass star-forming region, where the PErseus ALMA CHEmistry Survey detected hot corinos in ∼60% of the sources, the hot corinos seem to be relatively scarce in the OMC-2/3 filament. While this suggests that the chemical nature of protostars in Orion and Perseus is different, improved statistics is needed in order to consolidate this result. If the two regions are truly different, this would indicate that the environment is likely playing a role in shaping the chemical composition of protostars.

Comprehensive study on unregulated emissions of heavy-duty SI pure methanol engine with EGR

Methanol is a potential alternative fuel for heavy-duty engines to effectively reduce carbon emissions. On the other hand, unregulated emissions from methanol-fueled engines are harmful to the environment. The formaldehyde emission mechanism was investigated in this paper using a premixed laminar combustion experiment and a plug flow reactor (PFR) simulation with a detailed mechanism. Furthermore, the engine test was carried out on a heavy-duty spark ignition (SI) pure methanol engine with EGR to study the effects of the injection strategy, exhaust gas recirculation ratio (EGR), engine load, and speed on unregulated emissions. The high-pressure loop EGR system and port fuel injection system were adopted. Unregulated emissions were measured using a GC-2010 gas chromatography analyzer with a pulsed discharge helium ionization detector (PDHID) and Gs-OxyPLOT. Formaldehyde emission is the post-oxidation production of unburned methanol, according to the experiment and simulation, and it increases first, then decreases as the temperature rises. Unregulated emissions mainly consist of methanol and formaldehyde. The injection timing can be divided into two groups: 120°CA to 300°CA and 360°CA to 780°CA, where 0°CA represents fire TDC. The BTE at αinj of 120°CA to 300°CA is lower than that at other αinj, while methanol and formaldehyde emissions are the opposite. The temperature of unburned methanol post-oxidation is affected by engine speed, load, and EGR ratio, affecting methanol and formaldehyde emissions. The higher exhaust temperature caused by the higher engine speed, load and a lower EGR ratio can reduce methanol emissions. The nonmonotonic trends of formaldehyde emission with the EGR ratio and the different influences of EGR on the formaldehyde emission under different engine loads are the result of the nonmonotonic relationship between formaldehyde emission and temperature. The engine experiment results are consistent with the PFR simulation.

The methanol emission in the J1– J0 A−+ line series as a tracer of specific physical conditions in high-mass star-forming regions

ABSTRACT We present results of the investigations of the properties of the methanol J1 –J0 A−+ line series motivated by the recent serendipitous detection of the maser emission in the 141 – 140 A−+ line at 349 GHz in S255IR-SMA1 soon after the accretion burst. The study includes further observations of several lines of this series in S255IR with the SMA, a mini-survey of methanol lines in the 0.8-mm range towards a sample of bright 6.7-GHz methanol maser sources with the IRAM 30-m telescope, and theoretical modelling. We found that the maser component of the 141 – 140 A−+ line in S255IR decayed by more than order of magnitude in comparison with that in 2016. No clear sign of maser emission is observed in other lines of this series in the SMA observations except the 71 – 70 A−+ line where an additional bright component is detected at the velocity of the maser emission observed earlier in the 141 – 140 A−+ line. Our LVG model constrains the ranges of the physical parameters that match the observed emission intensities. No obvious maser emission in the J1 – J0 A−+ lines was detected in the mini-survey of the 6.7-GHz methanol maser sources, though one component in NGC 7538 may represent a weak maser. In general, the maser effect in the J1 – J0 A−+ lines may serve as a tracer of rather hot environments and in particular luminosity flaring events during high-mass star formation.

Numerical simulation and experimental investigation on pollutant emissions characteristics of PODE/methanol dual-fuel combustion

The current study focuses on the effects of methanol ratio, injection timing and intake temperature on emission performance of a common-rail engine with polyoxymethylene dimethyl ethers (PODE)/methanol dual-fuel combustion mode. Then, the numerical model of dual-fuel combustion is established using CFD software CONVERGE coupled with PODE/methanol chemical kinetic mechanism, and the distribution and evolution characteristics of important radicals, methanol and temperature fields inside cylinder are calculated and analyzed. The results show that the NOx and soot emissions of dual-fuel mode decrease by 12.4% and 26.0% compared with pure PODE at 50% load, but CO and HC emissions increase. With the methanol ratio increasing, the NO and N2O emissions decrease, while the methanol, NO2, HCHO, C2H4, CH4 and C2H6 emissions increase, and the peak HO2 mass of dual-fuel increases by 156.2% compared with pure PODE. With the advance of injection timing and the increase of intake temperature, the generation rate of H and OH radicals in dual-fuel combustion raise, the emissions of NO and NO2 increase, while the emissions of methanol, HCHO, C2H4, CH4 and C2H6 decrease. Therefore, compared with traditional diesel engine, more attention should be paid to the unregulated emissions of NO2, methanol and HCHO for PODE/methanol dual-fuel engine.

Class I Methanol Masers Related to Shocks Induced by Bar Rotation in the Nearby Starburst Galaxy Maffei 2

Abstract We report the detection of class I methanol maser at the 36.2 GHz transition toward the nearby starburst galaxy Maffei 2 with the Karl G. Jansky Very Large Array. Observations of the 36.2 GHz transition at two epochs separated by ∼4 yr show consistencies in both the spatial distribution and flux density of the methanol emission in this transition. Similar to the detections in other nearby starbursts the class I methanol masers sites are offset by a few hundred pc from the center of the galaxy and appear to be associated with the bar edges of Maffei 2. Narrow spectral features with line widths of a few km s−1 are detected, supporting the hypothesis that they are masing. Compared to other nearby galaxies with the detections in the 36.2 GHz methanol maser transition, the maser detected in Maffei 2 has about an order of magnitude higher isotropic luminosity, and thus represents the first confirmed detection of class I methanol megamasers. The spatial distribution of the 36.2 GHz maser spot clusters may trace the rotational gas flow of the galactic bar, providing direct evidence that the class I methanol maser is related to shocks induced by galactic bar rotation. A tentative detection in the 6.7 GHz class II methanol maser (at a 5σ level) is also reported. This is comparable in luminosity to some of the 6.7 GHz maser sources detected in Galactic star-forming regions. The 6.7 GHz methanol emission appears to be associated with star formation activity in a smaller volume, rather than related to the larger-scale galactic activities.

Gas phase Elemental abundances in Molecular cloudS (GEMS) V. Methanol in Taurus

Context. Methanol, one of the simplest complex organic molecules in the interstellar medium, has been shown to be present and extended in cold environments such as starless cores. Studying the physical conditions at which CH3OH starts its efficient formation is important to understand the development of molecular complexity in star-forming regions. Aims. We aim to study methanol emission across several starless cores and investigate the physical conditions at which methanol starts to be efficiently formed, as well as how the physical structure of the cores and their surrounding environment affect its distribution. Methods. Methanol and C18O emission lines at 3 mm have been observed with the IRAM 30 m telescope within the large programme Gas phase Elemental abundances in Molecular CloudS towards 66 positions across 12 starless cores in the Taurus Molecular Cloud. A non-LTE (local thermodynamic equilibrium) radiative transfer code was used to compute the column densities in all positions. We then used state-of-the-art chemical models to reproduce our observations. Results. We have computed N(CH3OH)/N(C18O) column density ratios for all the observed offsets, and the following two different behaviours can be recognised: the cores where the ratio peaks at the dust peak and the cores where the ratio peaks with a slight offset with respect to the dust peak (~10 000 AU). We suggest that the cause of this behaviour is the irradiation on the cores due to protostars nearby which accelerate energetic particles along their outflows. The chemical models, which do not take irradiation variations into account, can reproduce the overall observed column density of methanol fairly well, but they cannot reproduce the two different radial profiles observed. Conclusions. We confirm the substantial effect of the environment on the distribution of methanol in starless cores. We suggest that the clumpy medium generated by protostellar outflows might cause a more efficient penetration of the interstellar radiation field in the molecular cloud and have an impact on the distribution of methanol in starless cores. Additional experimental and theoretical work is needed to reproduce the distribution of methanol across starless cores.

Synthesis and Discovery of Schiff Base Bearing Furopyrimidinone for Selective Recognition of Zn2+ and its Applications in Cell Imaging and Detection of Cu2.

A simplefuro [2,3-d]pyrimidinone-based Schiff base FPS was synthesized via aza-Wittig reaction and structure elucidation was carried out by spectroscopic studies FT-IR, 1H NMR, and 13C NMR and mass spectrometry. FPS showed weak fluorescence emission in methanol and the selectivity of FPS to different metal ions (Mn2+, Ca2+, Fe2+, Fe3+, Mg2+, Al3+, Ba2+, Ag+, Co2+, Na+, K+, Cu2+, Zn2+, Pb2+, Bi3+) were studied by absorption and fluorescence titration. The results show that FPS has selective fluorescence sensing behavior for Zn2+ ions and the limit of detection (LOD) was calculated to be 1.19 × 10–8 mol/L. Moreover, FPS-Zn2+ acts as a metal based highly selective and sensitive new chemosensor for Cu2+ ions and the LOD was calculated to be 2.25 × 10–7 mol/L. In accordance with the results and theoretical calculations, we suspected that the binding mechanisms of FPS to Zn2+ and Cu2+ were assigned to be the cooperative interaction of Zn2+(Cu2+)-N.

Drought effects on volatile organic compound emissions from Scots pine stems.

Tree stems have been identified as sources of volatile organic compounds (VOCs) that play important roles in tree defence and atmospheric chemistry. Yet, we lack understanding on the magnitude and environmental drivers of stem VOC emissions in various forest ecosystems. Due to the increasing importance of extreme drought, we studied drought effects on the VOC emissions from mature Scots pine (Pinus sylvestris L.) stems. We measured monoterpenes, acetone, acetaldehyde and methanol emissions with custom-made stem chambers, online PTR-MS and adsorbent sampling in a drought-prone forest over the hot-dry summer of 2018 and compared the emission rates and dynamics between trees in naturally dry conditions and under long-term irrigation (drought release). The pine stems were significant monoterpene sources. The stem monoterpene emissions potentially originated from resin, based on their similar monoterpene spectra. The emission dynamics of all VOCs followed temperature at a daily scale, but monoterpene and acetaldehyde emission rates decreased nonlinearly with drought over the summer. Despite the dry conditions, large peaks of monoterpene, acetaldehyde and acetone emissions occurred in late summer potentially due to abiotic or biotic stressors. Our results highlight the potential importance of stem emissions in the ecosystem VOC budget, encouraging further studies in diverse environments.

Enhanced elimination of gaseous toluene and methanol emissions in a two-liquid phase trickling bioreactor: Performance evaluation, dynamic modeling, and microbial community shift

Negative interactions of the components usually restrict the application of trickling bioreactors (TBRs) for the simultaneous biodegradation of multi volatile organic compounds (VOCs). Modifications like the addition of non-aqueous phase (NAP) to TBRs can lead to design higher performance biological air cleaner systems for industries with mixed VOCs emissions. In this study, removal of toluene and methanol as hydrophobic and hydrophilic VOCs, respectively, was assessed in an up-flow two-liquid phase TBR (TLP-TBR) in the presence of silicone oil (5% v/v) as the NAP. The toluene and methanol inlet loading rates (ILRT and ILRM) were 18–36 and 0–187.2 g m−3 h−1, respectively, at a constant empty bed residence time of 60 s. The system could withstand against increasing ILRs so that removal efficiency (RE) of toluene >80% was obtained at various ILRs, while RE of methanol was almost stable at >90%. After optimization of a developed dynamic mathematical model, including mass transfer and kinetic mechanisms, the overall mass transfer coefficients of toluene and methanol were obtained as 1.9 × 10−4 and 2.1 × 10−4 m s−1, respectively. About 50% of biofilm depth was active for toluene biodegradation, indicating the prevalence of diffusion-limited regime for toluene removal. The microbial diversity shifted from the original inoculum to dominant toluene-degrading Gordonia and Burkholderia close to the gas inlet with relative abundance of 30% and 20%, respectively. While, methanol-degrading Hyphomicrobium sp. had higher contribution (19%) at top of the column. Therefore, the presence of NAP could facilitate the sustainable application of TBR through a suitable microbial composition shift.

Sensing for hydrazine of a pyrene chalcone derivative with acryloyl terminal group

Hydrazine, as a toxic substance, seriously endangers human health and the environment. Based on the excellent luminescent properties and low biological toxicity of pyrene derivatives, combing with chalcone derivatives easily attacked by nucleophilic group, a pyrene derivative PCA decorated by acryloyl terminal group as fluorescent probe for hydrazine was developed. The compound shows fluorescent peak red shift and intensity enhancement with increasing solvent polarity from hexane (459 nm) to methanol (561 nm). Based on strong fluorescence emission in methanol, methanol-HEPES mixed solution was used as the solvent in the spectral recognition experiments. The probe exhibits fluorescent change from yellow fluorescence (576 nm) to blue fluorescence (393 nm) with 800-fold ratiometric fluorescence enhancement (I393nm/I576nm) after the reaction with hydrazine. The probe can recognize hydrazine in fast response rate with kinetic constant calculated being 2.7 × 10-3 s−1 and 15 min as response time. The probe also can monitor hydrazine in real water samples and various soils.

Volatile organic compound emissions during HOMEChem.

Quantifying speciated concentrations and emissions of volatile organic compounds (VOCs) is critical to understanding the processes that control indoor VOC dynamics, airborne chemistry, and human exposures. Here, we present source strength profiles from the HOMEChem study, quantifying speciated VOC emissions from scripted experiments (with multiple replicates) of cooking, cleaning, and human occupancy and from unperturbed baseline measurements of the building and its contents. Measurements using a proton transfer reaction time-of-flight mass spectrometer were combined with tracer-based determinations of air-change rates to enable mass-balance-based calculations of speciated, time-resolved VOC source strengths. The building and its contents were the dominant emission source into the house, with large emissions of acetic acid, methanol, and formic acid. Cooking emissions were greater than cleaning emissions and were dominated by ethanol. Bleach cleaning generated high emissions of chlorinated compounds, whereas natural product cleaning emitted predominantly terpenoids. Occupancy experiments showed large emissions of siloxanes from personal care products in the morning, with much lower emissions in the afternoon. From these results, VOC emissions were simulated for a hypothetical 24-h period, showing that emissions from the house and its contents make up nearly half of total indoor VOC emissions.

Numerical investigation and experimental validation on the leakage of methanol and formaldehyde in diesel methanol dual fuel engine with different valve overlap

The diesel methanol dual fuel (DMDF) engine is confronting with the problem of high unregulated emissions of methanol and formaldehyde. The previous studies on unregulated emissions of DMDF engine focused on the measuring methanol and formaldehyde concentrations in the exhaust without distinguishing whether emissions come from leakage during valve overlap or incomplete combustion in the cylinder. In this study, a computation fluid dynamics (CFD) model coupled with a detailed chemical kinetic mechanism was developed to investigate the methanol and formaldehyde emissions of DMDF engine. The results showed that the unburned methanol and formaldehyde in the cylinder were the main part of the total methanol and formaldehyde emissions based on the 41 °CA valve overlap of simulation model. Then the effects of different intake valve opening (IVO) and exhaust valve closing (EVC) on methanol emissions were investigated. The results showed that only increasing IVO or EVC had very little effect on the leakage of methanol during scavenging. However, when the IVO and EVC changed simultaneously, the valve lift would significantly increase during the valve overlap of scavenging, which had a great impact on methanol leakage. The simulation results were validated by experiments in a 6170 marine engine. The experimental results were consistent with the simulation results and the increase of effective flow area caused by valve lift during large valve overlap was the most important reason for the increase of methanol emission. Therefore, all engines have almost no leakage in small valve overlap. However, with the increase of valve overlap, the actual results were different due to the different valve lift and mixture concentration of different engines.

An experimental study on methanol as a fuel in large bore high speed engine applications – Port fuel injected spark ignited combustion

Experiments were conducted on a single cylinder large bore high speed diesel engine with ~5 l cylinder displacement converted to a port fuel injected (PFI) spark ignited (SI) methanol combustion system. The effects of the relative air/fuel ratio (rel. AFR), back pressure and engine load on the engine performance as well as NOX, CO, HC, methanol and formaldehyde emissions were studied. The major objective was to evaluate if the substantial benefits of methanol on smaller passenger car engines can be conveyed to larger engines as methanol is sensitive to hot surface ignition and preignitions are favored by the long burn distances and hence longer dwell time at high temperatures.The study results show that the significant benefits of methanol regarding engine performance can be reproduced also for large bore high speed engines. Preignitions were not found to be an issue and engine knock was the limiting factor for the engine load achievable. The results show brake thermal efficiencies above state-of-the-art natural gas engines in the same displacement class (~44%) for a projected full scope PFI SI engine and indicate potential for further optimization. NOX emission compliance with the International Maritime Organizations (IMO) Tier III limits (<2 g/kWh) can be achieved without exhaust gas aftertreatment. However, regarding unburned methanol and especially formaldehyde (~1 g/kWh), the application of an oxidation catalyst is advisable although not required to fulfill IMO Tier III.

Assessing the regional biogenic methanol emission from spring wheat during the growing season: A Canadian case study

As a volatile organic compound existing in the atmosphere, methanol plays a key role in atmospheric chemistry due to its comparatively high abundance and long lifetime. Croplands are a significant source of biogenic methanol, but there is a lack of systematic assessment for the production and emission of methanol from crops in various phases. In this study, methanol emissions from spring wheat during the growing period were estimated using a developed emission model. The temporal and spatial variations of methanol emissions of spring wheat in a Canadian province were investigated. The averaged methanol emission of spring wheat is found to be 37.94 ± 7.5 μg·m−2·h−1, increasing from north to south and exhibiting phenological peak to valley characteristics. Moreover, cold crop districts are projected to be with higher increase in air temperature and consequent methanol emissions during 2020–2099. Furthermore, the seasonality of methanol emissions is found to be positively correlated to concentrations of CO, filterable particulate matter, and PM10 but negatively related to NO2 and O3. The uncertainty and sensitivity analysis results suggest that methanol emissions show a Gamma probabilistic distribution, and growth length, air temperature, solar radiation and leafage are the most important influencing variables. In most cases, methanol emissions increase with air temperature in the range of 3–35 °C while the excessive temperature may result in decreased methanol emissions because of inactivated enzyme activity or increased instant methanol emissions due to heat injury. Notably, induced emission might be the major source of biogenic methanol of mature leaves. The results of this study can be used to develop appropriate strategies for regional emission management of cropping systems.

Effect Methanol, Ethanol, Butanol on the Emissions Characteristics of Gasoline Engine

The increasing volume of motorized vehicles leads to an increase in dependence on fossil fuels and an increase in air pollution. The problem can be reduced by utilizing renewable alcohol fuels such as methanol, ethanol, and butanol. The high number of octane and oxygen content is the main reason. Therefore, this study aims to observe the exhaust emissions of the 160 cc gasoline engine with a mixture of methanol, ethanol, and butanol. The percentage of alcohol used is 0 % to 30 % by volume. The test was carried out in 2000, 3000, and 4000 rpm. The results of the study explained that the use of methanol, ethanol, butanol in the fuel mixture was proven to reduce exhaust emissions. CO and HC emissions decreased as the percentage of alcohol in the fuel increased. The highest reduction in CO and HC emission in methanol blended fuel was 30 %, 94.55 % and 82.71 %, respectively. Meanwhile, CO2 emissions increased by 34.88 % at 2000 rpm engine speed. Based on this test, the addition of methanol to fuel can reduce exhaust emissions better than ethanol and butanol.