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Fort Collins, CO, United States

Guo X.,Northeast Forestry University | Du D.,Northeast Forestry University | Qi Z.,Northeast Forestry University | Wang P.,Northeast Forestry University | Song H.,Clean Engines
Wood Research

Wood fiber is a porous biomass material, which has a strong adsorption ability for the PM (particulate matter) emitted by diesel engines. Through the SEM experiments, the fact that the pits of micron wood fiber after heat-treated can adsorb lots of ultrafine particles (aerodynamic diameter is less than 1μm) is shown clearly. In simulation, the particle concentration equations and fibrous filtration theory are applied. The collection media around pits is assumed as a cylinder. The simulation results show that the pits have relatively lower collection efficiency for the particles within the diameter from 0.4 to 0.6 μm. Out of the range of 0.4 to 0.6 μm, the collection efficiency increases rapidly, which implies that the pits have higher collection efficiency to filter the particles with the diameter out of 0.4 to 0.6 μm. Among all the affecting factors on collection efficiency, the reduction of permeate flow rate and the addition of tracheid wall thickness improve the collection efficiency. However, exhaust temperature has negligible influence on the collection efficiency. Source

Song H.,Clean Engines | Jacobs T.J.,Texas A&M University

This study is motivated by so-called "Biodiesel NOx Penalty", which is the often reported increase in nitrogen oxides emissions with biodiesel, relative to petroleum diesel. Biodiesel also reportedly decreases exhaust soot concentrations via a reduction of soot formation during combustion. Soot is a known source of radiation heat transfer during diesel combustion, and can cause a reduction in flame temperature relative to non-sooting conditions. As NO formation is strongly dominated by high combustion temperature, the heat transfer from soot to surroundings can reduce NO formation. The primary objective of this study is to assess if a decrease in soot radiation with biodiesel fuel leads to the increase of NO emission. In the current study, a metallic fuel additive (barium), which is known to effectively reduce soot formation during combustion, is used to control the soot formation of both petroleum diesel and 100% palm olein biodiesel. This study shows that the soot radiation effect might not be a dominant factor on NO formation, thus likely contributes little to biodiesel's increase of NOx emissions. © 2014 Elsevier Ltd. All rights reserved. Source

Clean Engines | Entity website

The ProblemThe battle for climate change will be won or lost in Asias cities. Rachel Kyte | VP for Sustainable Development, World Bank Dirty air sickens and kills, causing uncounted millions of cases of asthma, chronic and acute respiratory disease and millions of premature deaths every year ...

Clean Engines | Entity website

OPPORTUNITYClean Engines will not run out of customers anytime soon. World population is expected to rise this century from 6 billion to between 9 and 11 billion ...

Bugosh G.S.,Clean Engines | Easterling V.G.,Clean Engines | Rusakova I.A.,University of Houston | Harold M.P.,Clean Engines
Applied Catalysis B: Environmental

The steady-state and transient features of methane oxidation on a Pt/Pd/Al2O3 washcoated monolith are reported for a wide range of temperatures and feed gas compositions. Above 400°C the methane conversion dependence on the O2 feed concentration exhibits a multiplicity of states. With increasing temperature the multiplicity, in the form of a clockwise hysteresis in the rich regime, expands over a broader O2 concentration range. At the highest temperature considered (538°C) extinction occurs near the rich-lean transition (O2/CH4=1.9), while ignition occurs at O2/CH4~0.6. A low conversion state exists for all O2 concentrations exceeding the ignition concentration at this temperature. In the rich regime, multiple high conversion states are encountered, all of which produce a mixture of CO, CO2, H2, and H2O. Only the lowest conversion branch of this group is a steady-state. Another high conversion branch is encountered for O2 concentrations spanning a wide lean regime (2 Source

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