VEHICLE EXHAUST TECHNOLOGY IS ADEQUATE BUT IS PURIFICATION ECONOMICAL?

BILAVGASRENING: TEKNIKEN KLARAR NORMERM--MEN EKONOMIN BROMSAR?

A description is given of the theory of exhaust purification; it is only within a very narrow range of air/fuel ratios that HC, CO and NOX can all be eliminated simultaneously in the catalyser of the exhaust purifier. Exhaust purification systems are normally divided into three groups, (1) catalysers which oxidise CO/HC, (2) two-bed systems which reduce NOX, and (3) a single catalyser unit which controls CO/HC/NOX. System (1) comprises a carburettor with rapid heating choke, catalyser unit, air pump and exhaust recirculation. System (2) requires a rich mixture and comprises a carburettor, a NOX reducing catalyser, a CO/HC oxidising catalyser, and an air pump. System (3) requires automatic adjustment of the oxygen content; this must be regulated very accurately, otherwise H2SO4 content is 35 times as much as in engines without exhaust purification. Leaner mixtures produce lower CO/HC/NOX emissions, but an ordinary engine will not ignite at these mixtures; this is overcome by stratification of the charge. Much higher air/fuel ratios are possible if hydrogen or hydrogen/petrol mixture is used. Hydrogen gas is usually produced by partial oxidation of hydrocarbons, or in a catalytic reactor. Research on vehicle propulsion by hydrogen gas is described. /TRRL/

• Corporate Authors:

  Swedish Society of Engineers

  Box 40058
  S-10342 Stockholm 40,   Sweden 
• Authors:
  • Sjoestroem, K
• Publication Date: 0

Language

• Swedish

Media Info

• Features: Figures; Photos; Tables;
• Pagination: p. 33-39
• Serial:
  • Teknisk Tidskrift
  • Issue Number: 13

Subject/Index Terms

• TRT Terms: Air pollution; Carbon monoxide; Catalysis; Cleaning; Costs; Engines; Equipment; Exhaust gases; Hydrocarbons; Mixtures; Nitric oxide; Nitrogen oxides; Purification; Theory
• Old TRIS Terms: Recirculation
• ITRD Terms: 7127: Catalysis; 1394: Catalytic converter; 3849: Cleaning; 224: Cost; 2442: Emission; 3674: Equipment; 9078: Theory
• Subject Areas: Finance; Highways; Maintenance and Preservation; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00149881
• Record Type: Publication
• Source Agency: Swedish National Road and Traffic Research Institute
• Files: ITRD, TRIS
• Created Date: Apr 13 1977 12:00AM