Opinion ID: 392800
Heading Depth: 4
Heading Rank: 3

Heading: Regeneration Initiation and Control

Text: 74 The EPA has pointed to two viable means of incinerating accumulated particulates: throttling, which increases the heat of the engine exhaust itself by reducing air intake, and ignition from a separate heating element. Regulatory Analysis at 50, J.A. 529. In either case, use of a noble metal catalyst facilitates burning at lower temperatures, lessening the additional increment of heating required. Id. For systems relying on an independent heat element, dividing the trap into two chambers permits a further reduction in the amount of power required. Id. Throttling has been demonstrated as an effective method for incinerating particulates, and the EPA saw most promise in a system relying on throttling and a catalyst, plus insulation of the exhaust system to reduce heat loss. Id. at 51, J.A. 530. GM achieved good results with throttling alone, at least at speeds over thirty-five mph. GM Response at 110-13, J.A. 262-65. 75 GM complains of the excessive electric demand created by a heating element; as the EPA observed, that demand is considerably reduced by using a dual path trap, insulating the exhaust system, and introducing a noble metal catalyst. Regulatory Analysis at 50, J.A. 529. GM next seeks to characterize air intake throttling as unsafe and unreliable, despite the success of GM's own tests. GM emphasizes the failures in an EPA test conducted in 1979: the EPA investigators created temperatures in excess of 1100o F., and eventually discovered that they had blown a hole through their trap. J.A. 729-35. This anecdote does not demonstrate that proper control of the throttling process is unfeasible, particularly if a catalyst is used to lower the necessary temperature. 76 For both throttling and ignition approaches, some automatic method of initiating incineration is required. A simple mechanical device tied to the odometer is conceivable, but more subtle control can be achieved with microelectronics. 77 GM insists that the agency has no basis for believing that a control mechanism for initiating and regulating the incineration process can be developed. This argument is without merit. GM's own prototype throttling vehicle utilize(d) a microprocessor controller to set the position of the throttle in the air intake as a function of engine speed and rack angle. GM Response at 110, J.A. 262. GM states no theoretical objection to automated control of the incineration process and does not deny that the necessary computer technology exists. GM merely points to the EPA's admission that (i)t is impossible at this time to delineate the exact design of the control unit, Regulatory Analysis at 51, J.A. 530, and insists that the relevant parameters cannot be delineated unless and until a final design is selected. GM Reply Brief at 17 (emphasis in original). Nothing in the record suggests that adaptation of preexisting computer technology to the specific design of a GM trap-oxidizer will be anything other than routine, see Denial of Petition for Reconsideration, 45 Fed.Reg. 48,133, 48,137 (1980), and the EPA is not obliged to establish that no unknown parameters will later prove relevant to proper control. 30 78