Smoke from diesel engines

The chief transportation target of the 1970 Clean Air Act was the automobile hence, stringent regulations were directed at automakers. Visible smoke from diesel engines used in heavy-duty vehicles was regulated first. There was a concern that smoky stacks would result in many more complaints as motorists had to pay more for cleaned-up cars. Thus, the first smoke opacity laws were based on the appearance of smoke to the eye. Although the health effect was debated at the time, there was little doubt that smoke obscures visibility. This alone was a sufficient basis for California and U.S. regulations. In 1970,... 

Particulates Very small particles found in the atmosphere, such as certain types of smoke emitted from diesel engines, as well as dust. 

The soot from diesel engines and wood smoke carry mutagenic polycyclic aromatic hydrocarbons and their nitro derivatives.45 Some typical ones are shown in 15.1, the first being a potent mutagen in the Ames Salmonella test. Catalytic afterburners (containing platinum) are now required... 

Japan does not currently regulate exhaust particulate emissions from diesel engines. However, smoke standards have applied to both new and in-use vehicles since 1972 and 1975, respectively. The maximum permissible limits for both are 50 percent opacity however, the new vehicle standard is the more stringent because smoke is measured at full load, while in-use vehicles are required to meet standards under the less severe no-load acceleration test. 

Smoke emission from diesel engines is controlled by operation of the engine within its design limits. (Most smoke emission occurs when the engine is overloaded.) Filters for diesel engine exhaust are under development. 

Fig. 5.11. Relative activity size distribution of the radon decay product aerosols in air containing a high particle concentration of combustion aerosol from diesel engines and cigarette smoke. —, mine air (working + diesel engine) AMDa = 201 nm. - - room air (+ cigarette smoke) AMDa = 270 nm.

The Diesel engine has excessive emission of smoke and odor from aldehydes and oxygenated aromatics, which are not regulated at this moment. It is approximately 50% larger and heavier than a gasoline engine of the same horse power. However, it does have the virtue of better fuel economy and easier maintenance. 

Measures against diesel engine emissions limiting black smoke emissions from heavy duty vehicles Regulation of motor fuels. Limits amount of sulphur in fuel oil... 

It is apparent from the above data that Thermofuel diesel produces significantly less particulates (smoke) at all engine loadings than conventional diesel. This is environmentally significant, as the particulates formed from diesel combustion contain polycyclic aromatic hydrocarbons (PAH) which have carcinogenic potential. The hotter burning characteristic of the Thermofuel relative to conventional diesel is likely to be responsible for the better burn-out of particulates [21]. 

The ammonia concentrations measured in the plumes of seven forest fires in the western United States ranged from 7 to 130 ppb the median value of the 13 measurements was 37 ppb (Hegg et al. 1987, 1988). Fangmeier et al. (1994) reported a slightly higher value for smoke from a forest fire in Canada, 250 ppb. Ammonia has been found in the exhaust of automobile and diesel engines (Pierson and Brachaczek 1983). Ammonia has also been determined to be a component of tobacco and cigarette smoke (Sloan and Morie... 

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