The effect of fuel on the physical and chemical characteristics of particle emissions from marine engine

Laivojen dieselmoottorit muodostavat merkittävän hiukkaspäästöjen lähteen. Syntyvien pienhiukkasten on osoitettu huonontavan ilmanlaatua rannikkoalueilla ja mustaa hiiltä sisältävät hiukkaset voivat aiheuttaa paikallista lämpenemistä arktisella alueella. MARPOL-sopimus rajoittaa laivojen kaasumaisia päästöjä ja myös mustan hiilen päästöjen rajoittamista harkitaan. Rajoitukset vaativat laivanomistajia käyttämään vähärikkisempiä polttoaineita tai savukaasun puhdistusmenetelmiä. Tässä diplomityössä tutkittiin polttoaineen vaikutusta laivamoottorin päästöhiukkasten lukumäärään ja ominaisuuksiin. Mittaukset tehtiin laivakäyttöön suunnitellulla 1,6 MW dieselmoottorilla laboratorio-olosuhteissa. Tutkitut polttoaineet olivat raskas ja keskiraskas polttoöljy, meridiesel sekä vähärikkinen meridieselin ja kasviöljyn seos. Työssä määritettiin syntyvien hiukkasten koko ja lukumäärä sekä hiukkasmoodikohtaiset päästökertoimet kullekin polttoaineelle. Lisäksi tutkittiin hiukkasten haihtuvuutta, hygroskooppisuutta sekä kemiallista koostumusta. Työssä kuvatun mittauskampanjan pääasiallisena tarkoituksena oli mustan hiilen mittausmenetelmien arviointi osana SEA-EFFECTS BC -projektia ja tulokset mitattujen hiukkasten lukumäärästä ja ominaisuuksista voivat auttaa selittämään eroja mittausmenetelmien välillä. Lisäksi ne antavat viitteitä laivamoottorien päästöhiukkasten lukumäärästä ja käyttäytymisestä ilmakehässä. Laivamoottorista syntyvien hiukkaspitoisuuksien havaittiin olevan korkeimmillaan ultrapienille, alle 100 nm hiukkasille. Tutkitusta polttoaineesta riippuen lukumääräkokojakaumissa nähtiin 2–3 hiukkasmoodia ja haihtuvuustarkastelu osoitti, että minkään moodin hiukkaset eivät ole kokonaan haihtuvia 265 °C lämpötilassa. Määritetyt kokonaishiukkaspäästökertoimet vaihtelivat välillä 1,16–4,32 × 1015 #/kWh. Hygroskooppisuusmittausten perusteella sekä kuorma että käytetty polttoaine vaikuttavat tutkittujen hiukkasten taipumukseen kasvaa kosteissa olosuhteissa.Marine diesel engines constitute a significant source of particulate emissions. The fine particles from ships have been shown to impair air quality in coastal regions and particles containing black carbon could enhance local warming in the Arctic. MARPOL convention sets limits for the gaseous emissions from ships, and limit for black carbon is anticipated. Regulations demand ship owners to switch to alternative fuels with lower sulphur content or to introduce abatement technologies. The aim of this thesis was to study the effect of fuel on the number and characteristics of particles emitted from ship engine. Measurements were carried out with 1.6 MW marine diesel engine operated in laboratory conditions. The fuels tested were heavy and intermediate fuel oil, marine diesel oil and a blend of marine diesel oil and vegetable oil. Particle size and number were measured and modal particle emission factors calculated for each of the tested fuels. Volatility, hygroscopicity and chemical composition of the particles were also studied. The main aim of the campaign part of the project SEA-EFFECTS BC, was to evaluate measurement methods for black carbon. The number and particle characteristics presented here could partly explain differences in BC measurement methods as well as estimate the real world emissions from ships. Highest number concentrations were measured for ultrafine particles under 100 nm in size. The number size distributions observed were bi- or trimodal depending on the fuel in question. The particles seem to include considerable amount of volatile condensates but none of the observed particle modes did fully evaporate in 265 °C. The total number emission factors determined in this study range from 1.16 to 4.32 × 1015 #/kWh. The hygroscopicity measurements indicate that both fuel and the engine load influence the aptitude of the particles to grow in humid conditions

Methane slip emissions from LNG vessels - review

The International Maritime Organization (IMO) regulations on emissions of nitrogen oxides (NOx) and sulphur oxides (SOx) have lead to increased utilization of liquefied natural gas (LNG) as a fuel for shipping. Due to very low sulphur content in LNG, the contribution to SOx emissions is negligible. NOx emissions depend on the engine combustion cycle and with LNG engines utilizing otto-cycle (or diesel cycle engines with post combustion treatment) also the strict IMO Tier III NOx limit can be achieved. In addition, it is shown that LNG utilization leads to significantly lower particle emissions compared to liquid marine fuels. Thus, LNG utilization has direct effects and indeed benefits on air quality and human health. Moreover, CO2 emission can be reduced with LNG use compared to diesel fuels, since LNG is mainly composed of methane with a higher H/C ratio compared to diesel. The hydrocarbon emissions, on the other hand, are higher with LNG compared to diesel fuels and mostly include the main component of LNG, methane. This ‘methane slip’ should be minimized because methane is astrong greenhouse gas and reduces the benefit of lower CO2 emissions. While the formation of methane slip is known to result from LNG combustion, there has been a lack of knowledge of the methane slip emission’s magnitude from the LNG engines. In this review paper, methane slip values are collected from the current literature and ship owner data is utilized to complement the data with engines from recent years. This will contribute to understanding the methane slip from the current LNG fleet. High-pressure 2-stroke slow speed (diesel cycle) engines already show very little methane slip today, while higher methane slip values are reported for low-pressure dual fuel engines. Out of 614 vessels with an identified LNG engine, the low-pressure dual fuel concept (either 4-S or 2-S) is also the most popular LNG engine technology found in 78.1% of the ships, while high-pressure dual fuel technology is found in 14.8% of the ships and lean burn spark ignited engines in 1.7%. This is reflected in the amount of methane slip data found in the scientific literature which focuses on low pressure dual-fuel-engines. The engine load has a significant effect on the methane slip formation. In general, the lower loads tend to increase the methane slip formation compared to higher engine loads

Methane slip emissions from LNG vessels - review

The International Maritime Organization (IMO) regulations on emissions of nitrogen oxides (NOx) and sulphur oxides (SOx) have lead to increased utilization of liquefied natural gas (LNG) as a fuel for shipping. Due to very low sulphur content in LNG, the contribution to SOx emissions is negligible. NOx emissions depend on the engine combustion cycle and with LNG engines utilizing otto-cycle (or diesel cycle engines with post combustion treatment) also the strict IMO Tier III NOx limit can be achieved. In addition, it is shown that LNG utilization leads to significantly lower particle emissions compared to liquid marine fuels. Thus, LNG utilization has direct effects and indeed benefits on air quality and human health. Moreover, CO2 emission can be reduced with LNG use compared to diesel fuels, since LNG is mainly composed of methane with a higher H/C ratio compared to diesel. The hydrocarbon emissions, on the other hand, are higher with LNG compared to diesel fuels and mostly include the main component of LNG, methane. This ‘methane slip’ should be minimized because methane is astrong greenhouse gas and reduces the benefit of lower CO2 emissions. While the formation of methane slip is known to result from LNG combustion, there has been a lack of knowledge of the methane slip emission’s magnitude from the LNG engines. In this review paper, methane slip values are collected from the current literature and ship owner data is utilized to complement the data with engines from recent years. This will contribute to understanding the methane slip from the current LNG fleet. High-pressure 2-stroke slow speed (diesel cycle) engines already show very little methane slip today, while higher methane slip values are reported for low-pressure dual fuel engines. Out of 614 vessels with an identified LNG engine, the low-pressure dual fuel concept (either 4-S or 2-S) is also the most popular LNG engine technology found in 78.1% of the ships, while high-pressure dual fuel technology is found in 14.8% of the ships and lean burn spark ignited engines in 1.7%. This is reflected in the amount of methane slip data found in the scientific literature which focuses on low pressure dual-fuel-engines. The engine load has a significant effect on the methane slip formation. In general, the lower loads tend to increase the methane slip formation compared to higher engine loads

STUDI TEKNO-EKONOMI MESIN PENGIRIS BAWANG MERAH (Allium cepa var ascalonicum (L) Back) BUATAN UPTD BMP-TPH BUKITTINGGI

STUDI TEKNO-EKONOMI MESIN PENGIRIS BAWANG MERAH(Allium cepa ascalonicum (L) Back) BUATAN UPTD BMP-TPH BUKITTINGGI Fitri Amelia, Santosa, Andasuryani ABSTRAK Tanaman bawang merah termasuk tanaman holtikultura dimanfaatkan sebagai bahan makanan, penambah cita rasa dan nilai estetika pada menu makanan. Pengirisan merupakan satu cara pengolahan dan penangganan bawang merah yang sering dilakukan. Penelitian bertujuan melakukan studi tekno-ekonomi mesin pengiris bawang merah buatan Unit Pelayanan Teknis Daerah Balai Mekanisasi Pertanian Tanaman Pangan Hortikultura Bukittinggi, yang dilaksanakan pada bulan Juni sampai Agustus 2018. Bawang merah yang digunakan adalah varietas bima. Metode yang dilakukan pada pengamatan ini dengan cara mengganti ukuran puli, sehingga RPM akan berubah. RPM yang digunakan pada pengamatan ini sebesar 1114, 1300 dan 1560. Masing-masing RPM dilakukan sebanyak lima kali ulangan. Berdasarkan hasil pengujian mesin bahwa RPM yang lebih cocok digunakan adalah 1560 karena kapasitas kerja lebih tinggi yaitu sebesar 96,93 kg/jam, energi spesifik lebih rendah yaitu sebesar 0,0038687 kW.jam/kg dan biaya pokok yang lebih rendah yaitu Rp 1164,38,-/kg. Kata kunci – Bawang Merah, Pengirisan, RPM, Studi Tekn