The Pioneers

Abstract

This study surveyed emissions from 2- and 4-stroke new and in-use motorcycles. Emission tests were carried out on a dynamometer following the designated test procedure of the Economic Commission for Europe (ECE). Samples were derived during various driving stages, which included idle, acceleration, 30 km/hr cruise, 50 km/hr cruise, and deceleration. All test motorcycles (10 new and 15 in-use) complied with Taiwan Environmental Protection Administration’s Phase III Motorcycle Emission Standards. The dominant volatile organic carbon (VOC) species were isopentane (53 and 295 mg/km, 2- and 4-stroke, respectively), 2-methylpentane (75 and 83 mg/km), 3-methylpentane (34 and 66 mg/km), and toluene (30 and 100 mg/km). The VOC emission factors for the 2-/4-stroke motorcycles were 311/344 (new) and 1479/433 (inuse) mg/km, respectively. In addition, the dominant carbonyl species for the new and in-use motorcycles were formaldehyde (0.4 and 0.7 mg/km, respectively), acetaldehyde (0.6 and 1.2 mg/km), and acetone (0.5 and 0.7 mg/km). The carbonyl compound emission factors for the 2- and 4-stroke motorcycles were 3.2/3.1 (new) and 5.3/4.6 (in-use) mg/km, respectively. The ozone formation potentials, based on an ECE test cycle, show that the values from the in-use motorcycles were higher than those from the new motorcycles. The dominant VOC species for the ozone formation potential were propylene (65 and 502 mg-O₃ /km, respectively), isopentane (98 and 501 mg-O₃ /km), 2-methylpentane (152 and 167 mg-O₃ /km), 3-methylpentane (79 and 253 mg-O₃ /km), and toluene (127 and 398 mg-O₃ /km). Further, the dominant carbonyl species were formaldehyde (4.1 and 6.2 mg-O₃ /km, new and in-use, respectively) and acetaldehyde (4.8 and 9 mg-O₃ /km).     

Using The Consultant

The information on this page is reprinted with permission from “Guide for Professional Engineers’ Services”, published by the Professional Engineers in Private Practice Division of the National Society of Professional Engineers. The publication was designed “as a guide for selecting and engaging professional engineers in private practice and compensating them for their services”. It is available from the National Society of Professional Engineers, 2029 K Street, N.W., Washington, D.C. 20006.     

The Smogless Automobile

Demands for high performance and reliability of electrostatic precipitators for collection of fly ash from low sulfur fuels has led to rapid escalation of sizes and uncertainties in sizings of cold-side precipitators. This has led to utilization of the so-called “hot-side” precipitator. The underlying concept of hot-side precipitation is the avoidance of the necessity to operate the precipitator under high resistivity conditions. Data on in-situ measurements of resistivity of low sulfur fuel ash, as well as performance parameters of a number of operating installations, will be reviewed. These data will demonstrate the reduced sensitivity of hot-side precipitator sizing to fuel conditions. Other advantages of hot-side precipitators will be discussed.

Operating experience with hot-side precipitators has focused on structural problems which are peculiar to the larger, higher temperature installations. The nature and solution of these problems will be discussed. General comparative economics of hot-side and cold-side precipitators as they relate to fuel properties will be reviewed.     

The Dominant Theory

The following remarks were presented by Mrs. Gorsuch at the Acid Rain Symposium conducted by the Pittsburgh Chamber of Commerce on October 6, 1982.     

The representative day

The work presents a daily trend of pollutant concentrations, referred to as the “representative day”, i.e. the day for which the overal sum of the mean-square differences between its concentration, averaged within each hour, and the concentrations for all other days at the same hour, is a minimum. The approach also allows the identification of the “least representative day” (the daily series that maximises the mean sum of squared residuals), which usually indicates an anomalous situation in pollutant dispersion, characterised by concentration maxima at the ground.     

The APCA Exhibition

On June 5 and 6 of 1980, two parallel plume oxidation studies were carried out in the vicinity of the Tennessee Valley Authority's Colbert Steam Plant. One study was performed in a smog chamber into which stack gases were injected and mixed with ambient air. The other study included direct airborne sampling of the power plant plume. Atmospheric oxidation rates for the conversion of SO₂ to SO₄ ^2- and the removal rates of NO _x (which is presumably the rate of NO₃ ^- formation) were estimated for both studies. The SO₂ to SO₄ ^2- rate coefficients were found to be 0.022 ± 0.009 h^-1 for both chamber experiments and the first airborne sampling day. For the second day, a rate constant of 0.041 ± 0.052 h^-1 was estimated from the aircraft data. The large deviation in this value is explained by the fact that the plume from the power plant combined and reacted with the urban plume from the city of Florence, AL. The formation of a very large "O3 bulge" on this day is also attributed to the mixed plumes. The first order rate coefficients for NO _x removal were estimated to be 0.27 ± 0.14 h^-1 for both chamber experiments and the first airborne sampling day. A NO _x removal rate could not be determined for the second airborne sampling day.     

The prevention principle

Environmentally sound manufacture does not have its source only in developing and improving the techniques for treating solid, liquid and gaseous wastes at the end of the production process. Our experience shows that more effort and capital budgets must be devoted to developing preventive measures. Although the treatment techniques have become very advanced and meet ecological requirements to a very high degree, they are now reaching the limits of their technological and economic feasibility. Environmental protection at the production site has undergone structural change in recent years. The emphasis has shifted to preventive techniques which affect the production process itself, avoiding the emergence of waste at the “end of the pipe” by preventing its formation or recycling it straight away. This integrated approach is in harmony with the demands of sustainable production. The functions of in-process environmental protection measures need to be looked at as a whole from the points of view of both environmental protection and cost-effectiveness. Some integrated methods are described.