On-Road Use of Fischer-Tropsch Diesel Blends

Abstract

Alternative compression ignition engine fuels are of interest both to reduce emissions and to reduce U.S. petroleum fuel demand. A Malaysian Fischer-Tropsch gas-to-liquid fuel was compared with California #2 diesel by characterizing emissions from over the road Class 8 tractors with Caterpillar 3176 engines, using a chassis dynamometer and full scale dilution tunnel. The 5-Mile route was employed as the test schedule, with a test weight of 42,000 lb. Levels of oxides of nitrogen (NO x ) were reduced by an average of 12% and particulate matter (PM) by 25% for the Fischer-Tropsch fuel over the California diesel fuel. Another distillate fuel produced catalytically from Fischer-Tropsch products originally derived from natural gas by Mossgas was also compared with 49-state #2 diesel by characterizing emissions from Detroit Diesel 6V-92 powered transit buses, three of them equipped with catalytic converters and rebuilt engines, and three without. The CBD cycle was employed as the test schedule, with a test weight of 33,050 lb. For those buses with catalytic converters and rebuilt engines, NO x was reduced by 8% and PM was reduced by 31% on average, while for those buses without, NO x was reduced by 5% and PM was reduced by 20% on average. It is concluded that advanced compression ignition fuels from non-petroleum sources can offer environmental advantages in typical line haul and city transit applications.

Present Day Engins Pollutant Emissions: Proposed Model for Refinery Bases Impact

“…-Correlations on NOx emissions are quite different than those calculated for the VTEC engine: the most important contributor is ETBE, with up to 30% on the EUDC cycle. This result is consistent with the Auto/Oil program results [2], who noticed an increase of NOx emissions (+5.5%) when using a gasoline with 17% ETBE. This result can be explained by the fact that with the VTEC engine, low equivalence ratio induced combustion difficulties for ETBE and consequently high CO emissions.…”

“…Nitrogen Oxides An important result is that the Fischer-Tropsch fuel contributes weakly to NOx emissions, while it also contributes to reduced smoke and particulate emission levels [2]. Constant relative factor from 12 to 14% is found in the models.…”

“…LCO and hydro-converted vacuum distillation residue bases contain a high percentage of heavy aromatic species known to be involved in the classic schemes describing particulate formation. On the opposite, synthetic Fischer-Tropsch fuel, containing exclusively saturated molecules, has a weak contribution to emissions [2][3][4].…”

“…This mutation of the engine technology and the more acute impact of fuel properties on exhaust emissions will lead to new diesel and gasoline fuel formulations. Some work has been carried out in order to study the impact of fuel composition on pollutant emissions (Auto/Oil Air Quality Improvement Research Program [1][2][3], EPEFE [4,5], but even if a lot of theoretical data are available, the fuel formulation becomes more and more complex year by year. In this context, it is crucial to have an excellent knowledge of the relative impact of the different refinery bases available for the blending of future fuels on modern engines operation and emissions.…”

Transportable Heavy Duty Emissions Testing Laboratory and Research Program

“…In two separate studies [28][29] in 1998-1999, the Translab was used to test transit buses and trucks fueled with Malaysian Fischer-Tropsch gas-to-liquid fuel, Mossgas synthetic diesel, California diesel, and a 50/50 blend of Mossgas synthetic and regular diesel. These studies had the objectives of testing the viability and emissions performance of synthetic fuel on six transit buses and class 8 tractor trucks.…”