Non-thermal plasma technology for the abatement of NOx and SOx from the exhaust of marine diesel engine

Non-thermal plasma based technology is proposed to the abatement of NOx and SOx of the exhaust gas from marine diesel engine. Proposed technology uses electron gun and microwave energy to generate the plasma. Fundamentals of non-thermal plasma and chemistry are presented with a set of simulation results of the reduction of NOx and SO2 for a typical two stoke marine diesel exhaust engine which is supported by an experimental results obtained with microwave plasma. A new scheme is also proposed in this paper to generate required plasma for the treatment of NOx and SOx form high exhaust flow rate

Reduction of NOx and PM in Marine Diesel Engine Exhaust Gas using Microwave Plasma

Abatement of NOx and particulate matters (PM) of marine diesel exhaust gas using microwave (MW) non-thermal plasma is presented in this paper. NOx mainly consist of NO and less concentration of NO2 in a typical two stoke marine diesel engine and microwave plasma generation can completely remove NO. MW was generated using two 2kW microwave sources and a saw tooth passive electrode. Passive electrode was used to generate high electric field region within microwave environment where high energetic electrons (1-3eV) are produced for the generation of non-thermal plasma (NTP). 2kW gen-set diesel exhaust gas was used to test our pilot-scale MW plasma reactor. The experimental results show that almost 100% removal of NO is possible for the exhaust gas flow rate of 60l/s. It was also shown that MW can significantly remove soot particles (PM, 10nm to 365nm) entrained in the exhaust gas of 200kW marine diesel engine with 40% engine load and gas flow rate of 130l/s. MW without generating plasma showed reduction up to 50% reduction of PM and with the plasma up to 90% reduction. The major challenge in these experiments was that igniting the desired plasma and sustaining it with passive electrodes for longer period (10s of minutes) as it required fine tuning of electrode position, which was influenced by many factors such as gas flow rate, geometry of reactor and MW power

Non-thermal plasma system for marine diesel engine emissions control

Air pollutants generated by ships in both gaseous and particulate forms, have a long term effect on the quality of the environment and cause a significant exposure risk to people living in proximities of harbors or in neighboring coastal areas. It was recently estimated, that ships produce at least 15% of the world’s NOx (more than all of the world’s cars, buses and trucks combined), between 2.5 - 4% of greenhouse gases, 5% black carbon (BC), and between 3-7% of global SO2 output. Estimation of contribution of maritime shipping to global emissions of VOC and CO is not yet available. In order to reduce the environmental footprint of ships, the International Maritime Organization (IMO) recently issued the legislation of Marpol Annex VI guidelines which implies especially the introduction of, inter alia, stricter sulphur limits for marine fuel in ECAs under the revised MARPOL Annex VI, to 3.50% (from the current 4.50%), effective from 1 January 2012; then progressively to 0.50 %, effective from 1 January 2020, subject to a feasibility review to be completed no later than 2018. The limits applicable in Emission Control Zones (ECAs) for SOx and particulate matter were reduced to 1.00%, beginning on 1 July 2010 (from the original 1.50%); being further reduced to 0.10 %, effective from 1 January 2015. The Tier III controls apply only to the specified ships built from 2016 while operating in Emission Control Areas (ECA) established to limit NOx emissions, outside such areas the Tier II controls apply. The United States and Canada adopted national regulations enforcing IMO Tier III equivalent limits within the North American ECA effective 2016. The US Environmental Protection Agency (EPA) rule for Category III ships, however, references the international IMO standards. If the IMO emission standards are indeed delayed, the Tier III standards would be applicable from 2016 only for US flagged vessels. One of the proposed solutions towards marine diesel emission control is the non-thermal plasma process. We designed and built a non-thermal plasma reactor (NTPR) using a combination of Microwave (MW) and Electron Beam (EB) for treatment of marine diesel exhaust gas. A numerical model has been developed to better understand the marine exhaust gas/plasma kinetics. The reactor modelling and design can sustain 10kW of combined MW and EB power with a gas flow rate of 200l/s. The removal of NOx and SOx was continuously monitored using a portable dual Testo gas analyzer system while all other parameters (MW power, EB power, gas temperature/flow rate, etc.) were remotely recorded & stored through a Labview DAQ system. The reactor performance in NOx and SOx removal will be tested on a 200 kW two stroke marine engine. This study is a part of the DEECON (Innovative After-Treatment System for Marine Diesel Engine Emission Control) FP7 European project.The work was supported by the European Commission under DEECON FP7 European Project "Innovative After-Treatment System for Marine Diesel Engine Emission Control", contract No. 284745

Chromium coated silicon nitride electron beam exit window

A Si3N4 membrane with a thin Cr coating is proposed and demonstrated as an electron beam exit window. On average, 85% electron power transmission efficiency was achieved with a 1 μm thick Si3N4 membrane coated with 1 μm thick Cr and the membrane sustained a beam current of up to 3 mA at 60 keV electron energy for the continuous operation of 3 min. However, for an uncoated membrane of same thickness, the average electron power transmission efficiency was 71% and the maximum beam current sustained was 800 μA. It was also shown that a one micron thick Si3N4 square membrane window of 10 mm × 10 mm could withstand a differential pressure of 1.3 bars.The work carried out at Brunel University was co-funded by the EC Seventh Framework Programme theme FP7-SST-2011-RTD-1 for the DEECON project (grant number 284745)

Microwave plasma system design and modelling for marine diesel exhaust gas abatement of NOx and SOx

A set of procedures for the design of microwave based non-thermal plasma reactor for the abatement of NOx and SOx from marine exhaust gas is presented in this paper. The design is supported by finite element based analysis developed in COMSOL multi-physics environment. The proposed design suggests that use of rightly chosen slots arrangements for the insertion of microwave energy into the multi-mode cavity can increase the supplied microwave energy to the gas

Electrostatic properties of wheat bran and its constitutive layers: Influence of particle size, composition, and moisture content

J. Food Eng. ISI Document Delivery No.: 432LE Times Cited: 15 Cited Reference Count: 44 Hemery, Youna Rouau, Xavier Dragan, Ciprian Bilici, Mihai Beleca, Radu Dascalescu, Lucian European Commission in the Communities Framework Program [FOOD-CT-2005-514008]; Poitou-Charentes Regional Council; European Union The authors thank G. Maraval for the preparation of the samples, T.-M. Lasserre for help with the biochemical analyses, and S. Das for helpful discussion. They also gratefully acknowledge the valuable experimental help given by R. Darracq, G. Paillet, W. Pillet, T. Rey-Vigneau, and N. Vincent. This work was supported in part by the Poitou-Charentes Regional Council and by the European Union, within the framework of ERASMUS program for Student and faculty mobility. This work was also financially Supported by the European Commission in the Communities Framework Program, Project HEALTHGRAIN (FOOD-CT-2005-514008). This publication reflects the author's views and the Community is not liable for any use that may be made of the information contained in this publication. Elsevier sci ltd OxfordInternational audienceBran is the by-product of white flour and is composed of distinct adhesive tissues with aleurone and pericarp being the most significant. The present work pointed out the good potential of using electrostatic separation as a bran-fractionation method to produce nutritionally interesting food ingredients. The tribo- and corona-charging behavior of ground bran, an aleurone-rich fraction, and a pericarp-rich fraction were characterized, and the influence exerted by the composition, particle size. and moisture content was determined. The tribo-charging experiments showed that the opening of the aleurone cells after grinding modified the particles surface composition, and thus the samples charging behavior. The cell walls of aleurone and pericarp fractions displayed different tribo-charging characteristics, suggesting that by designing an appropriate tribo-charging device, these two bran layers might be separated. The behavior of the samples after corona-charging was found to be highly influenced by their Moisture content. Dried samples were all found to behave like insulators, whereas when the materials were not dried. the pericarp-rich fraction behaved like a conductor while the fine aleurone-rich fraction behaved like an insulator, probably due to the presence of lipids at the particles surface. These characteristics could also be exploited for the development of another electrostatic separation process