72-3 An Evaluation of the Emissions Characteristics of the Esso Well Mixed Thermal Reactor August 1971 John C. Thomson Office of Air Programs ENVIRONMENTAL PROTECTION AGENCY ------- Background Esso Corporation recently announced the development of. an advanced emission control system for reciprocating engines. It was offered to the Environmental Protection Agency for evaluation. Description The vehicle tested was a 1971 Ford LTD with a special Esso thermal reactor and the necessary modifications to the vehicle for the operation of the reactor. The vehicle used a 351 cubic inch V-8 and an automatic transmission. The reactor is attached to the exhaust ports and replaces the exhaust manifold. A combination of fuel rich carburetor, exhaust gas recycle and spark retard are used to control oxides of nitrogen (NOX) while carbon monoxide (CO) and hydrocarbons (HC) are mixed and burned in the reactor with secondary air supplied by an air pump. A special flame holder allows the system to reach operating temperature in less than 10 seconds. A complete description of the system is available in the Society of Automotive Engineers paper number 710608 presented in Montreal in June 1971. Test Program For the evaluation of this system, two test procedures were used. The 1972 and 1975 Federal Emission Test Procedures used for new vehicle certification were used. The 1972 test procedure uses the constant volume sampling system (CVS) to collect an exhaust sample during a 7-5 mile test conducted on a chassis dynamometer. The test is begun after the vehicle has soaked-at-room temperature for at least 12 hours. For 1975 tests basically the same driving cycle and sampling techniques are used but a procedure for weighting the cold portion has been added. This requires the exhaust to be sampled three times during the test and the test is increased to 11.1 miles. A complete description of the test procedures is available in the July 2, 1971, Federal Register. The exhaust gases were measured using a flame ionization detector for HC, while CO and C02 were measured using infrared techniques. A chemiluminescent instrument was used for NOx. ------- - 2 - Results The results from the tests calculated according to the 1972 test procedure are reported in Table 1. For reference the standards for 1972, 1973, and 197^ are also shown In this table. All results from this vehicle are well below the emission standards required for new vehicles through 197^. The results from two of the tests where the 1975 procedure was used are reported in Table II. The standards for 1975 and 1976 are also shown in this table and the vehicle is very close to meeting the 1975 standards. Meeting the 1976 standards with this vehicle will require further NOX reduction, Results from other labs testing this system are shown in Table III. Conclusions This system will meet all standards through 197^ and shows promise for meeting the 1975 standards. In order to achieve the 1976 standards, additional controls for NOx are required, although it may be able to meet standards in a lighter vehicle. The results from testing this vehicle at other labs shows that consistent emission control is achieved and good correlation between laboratories is possible with low emission vehicles. ------- TABLE I 1972 Test Procedure Esso Thermal Reactor 1971 Ford V-8 Automatic Transmission (All results in grams per mile) Test Date June 2, 1971 June 23, 1971 June 24, 1971 1972 Standards 1973-74 Standards HC (FID) 0.2 0.1 0.1 3.4 3-4 CO (IR) 6 5 5 39 39 C02 (IR) 1019 1103 1060 NOX (CI) 0.6 0.6 0.6 3.0 ------- TABLE II 1975 Test Procedure Esso Thermal Reactor 1971 Ford V-8 Automatic Transmission (All results in grams per mile) Test Date June 23, 1971 June 24, 1971 1975 Standards 1976 Standards HC (FID) 0.11 0.10 0.41 0.41 CO (IR) 4.76 3.19 3.4 3.4 NOX (CI) 0.67 0.67 3.1 0.4 ------- TABLE III Esso Data Comparisons 1972 Test Procedure (All results in grams per mile) Test Site EPA #2 Ford GM EPA #-3 EPA #4 HC (FID) 0.2 0.2 0.2 0.1 0.2 CO (IR) 5.9 5.6 5.6 4.5 3.8 C02 (IR) 1019 1080 1050 NOX (CI) 0.65 0.65 0.68 0.62 0.64 ------- |