Related by context. Frequent words. (Click for all words.) 61 aftertreatment 57 NOx 57 selective catalytic reduction 56 diesel particulate filters 56 NOx emissions 55 gas recirculation 55 microturbine 55 nitrogen oxides NOx 54 diesel particulate filter 53 desulfurization 52 particulate emissions 52 nitrogen oxide NOx 52 combustion 51 particulate filters 51 particulate filter 50 microturbines 50 exhaust emission 49 SCR 49 particulate matter PM 49 spark ignition 49 nitrogen oxide emissions 49 BioOil 49 desulphurization 49 SOFC 48 PEM fuel 48 emission 48 Cummins Westport 48 diesel engines 48 GHG emission 48 vacuum furnace 48 combustor 48 VOC emissions 48 particulate matter emissions 48 Nexterra 48 ASTM D# [002] 48 Catalytica Energy Systems 47 BlueTec 47 nitrous oxides 47 syngas 47 Xebec 47 membrane filtration 47 nitrogen oxides 47 cogeneration 47 AdBlue 47 emission reduction 46 hybrid powertrains 46 greenhouse gas emission reductions 46 supercritical 46 CSRV 46 emissions 46 renewable feedstocks 46 electrically driven 46 ABWR 46 Syngas 46 IdaTech 46 Clean Diesel 46 ECD Ovonics 45 EfficientDynamics 45 sorbents 45 Activated Carbon 45 internal combustion engines 45 gasification 45 polyurethanes 45 BACT 45 silane 45 Emission Control 45 exhaust emissions 45 SOFCs 45 flue gas 45 QuestAir 45 IMPCO 45 nitrogen oxide 45 exhaust gases 45 evaporative 45 baghouse 45 FGD 45 centrifugal pumps 44 flue gases 44 RFS2 44 Fischer Tropsch 44 Microgy 44 anaerobic digesters 44 polymeric materials 44 reducing CO2 emissions 44 butyl rubber 44 steam turbine generator 44 proton exchange 44 emission reductions 44 ceramic substrates 44 MACT 44 pollutant emissions 44 Dresser Wayne 44 SO2 emissions 44 thermoelectric 44 CoaLogix 44 Oxides 44 N Viro Fuel 44 VOCs 44 HEVs 44 electrochemical 43 biogas plants