History of the catalytic converter

Two way converters are designed to oxidise carbon monoxide into carbon dioxide. This process involves adding an O2 molecule to each carbon monoxide molecule to create carbon dioxide:. At the same time, two-way converters also oxidize hydrocarbons into H2O and CO2. These hydrocarbons are present in the exhaust as either partially-burned or unburned fuel, so excessive hydrocarbons are typically the result of various problems that need to be repaired i.

Three-way converters reduce nitrates of oxygen into nitrogen and oxygen. In the early s, two-way converters were replaced by three-way converters in vehicles that use gasoline engines. In addition to oxidation reactions, these three-way converters also perform a reduction process that works on nitrates of oxygen.

So, while these converters perform the same two functions that two-way converters do, they also reduce NOx to the component oxygen and nitrogen molecules:. Catalytic converters are one of the primary components targeted by opportunistic thieves for a number of reasons. First of all, catalytic converters are external components that are relatively easy to remove. This is particularly true for vehicles that have a lot of ground clearance, where a thief can simply slide under the vehicle, unbolt the converter, and slide back out.

Secondly, catalytic converters contain a number of precious metals that make them relatively valuable. Furthermore, if the thief cuts the pipes in front of and behind the converter, the repairs will be that much more expensive. Tags: definitions emission controls exhaust. JD Laukkonen turned wrenches in the north end of Seattle for a decade, so he's no stranger to the inner workings of modern automobiles. Most automobile spark ignition engines in North America have been fitted with catalytic converters since the mids, and the technology used in non-automotive applications is generally based on automotive technology.

Regulations for diesel engines are similarly varied, with some jurisdictions focusing on NOx nitric oxide and nitrogen dioxide emissions and others focusing on particulate soot emissions. The regulatory diversity is challenging for manufacturers of the engine as it may not be economical to design an engine to meet two sets of regulations.

Regulations of fuel quality vary across jurisdictions. Any sulfur in the fuel can be oxidized to SO2 sulfur dioxide or even SO3 sulfur trioxide in the combustion chamber. If sulfur passes over a catalyst, it may be further oxidized in the catalyst, i.

SO2 may be further oxidized to SO3. Sulfur oxides are precursors to sulfuric acid, a major component of acid rain. While it is possible to add substances like vanadium to the catalyst wash coat to combat sulfur oxide formation, such addition will reduce the effectiveness of the catalyst. The most effective solution is to further refine fuel at the refinery to produce ultra-low sulfur diesel. Regulations in Japan, Europe, and North America tightly restrict the amount of sulfur permitted in motor fuels.

However, the expense of producing such clean fuel make it impractical for use in many developing countries. As a result, cities in these countries with high levels of vehicular traffic suffer from acid rain, which damages stone and woodwork of buildings and damages local ecosystems. Some early converter designs greatly restricted the flow of exhaust, which negatively affected vehicle performance, driveability, and fuel economy. The aftermarket supplies high-flow converters for vehicles with upgraded engines, or whose owners prefer an exhaust system with larger-than-stock capacity.

Most of the pollution put out by a car occurs during the first five minutes before the catalytic converter has warmed up sufficiently. Catalytic converters have proven to be reliable and effective in reducing noxious tailpipe emissions. However, they may have some adverse environmental impacts in use:. This increases the amount of fossil fuel consumed and the carbon dioxide emissions of the vehicle. However, NOx control on lean burn engines is problematic.

Although catalytic converters are effective at removing hydrocarbons and other harmful emissions, they do not solve the fundamental problem created by burning a fossil fuel. In addition to water, the main combustion product in exhaust gas leaving the engine — through a catalytic converter or not — is carbon dioxide CO2. Environmental Protection Agency EPA has stated catalytic converters are a significant and growing cause of global warming, due to their release of nitrous oxide N2O , a greenhouse gas over times more potent than carbon dioxide.

Due to the external location and the use of valuable precious metals including platinum, palladium, and rhodium, converters are a target for thieves.

The problem is especially common among late-model Toyota trucks and SUVs, due to their high ground clearance and easily-removed bolt-on catalytic converters. Welded-in converters are also at risk of theft from SUVs and trucks, as they can be easily removed.

Various jurisdictions now legislate on-board diagnostics to monitor the function and condition of the emissions control system, including the catalytic converter. On-board diagnostic systems take several forms. Temperature sensors are used for two purposes. Four federal judges who might receive the case were strongly opposed to criminal sanctions in antitrust cases. In addition, it had been long-standing Justice Department policy to reserve the criminal route for price-fixing and other traditional cases in which there was no question of blatantly illegal conduct.

However, this auto pollution case was not traditional. This, however, was a very novel approach at the time, especially in the conservative world of antitrust litigation. But finally, in January , as noted at the top of this story, a civil suit was filed against the automakers. The auto industry, meanwhile, was in very competent legal hands. Lloyd Cutler, then a well-known and respected 51 year-old attorney at the Washington, D.

Cutler, in fact, had been in and out of meetings at the Justice Department for weeks during on the smog conspiracy case, negotiating on behalf of his clients. By late summer , there came rumor of a deal on the smog conspiracy case.

Sure enough, on September 11th, — nine months after the case was filed — the Justice Department announced that the case would be settled by consent decree. In the legal trade, consent decrees are viewed as a way to save face, save cost, and not drag all the parties through a public display of charge and countercharge. For the automakers, that was good news. There would also be no findings or admissions of illegal activity. September New York Times story on proposed consent decree.

Others supporting the DOJ lawsuit, however, were furious. They viewed the consent decree as a clear victory for the auto industry, a way to avoid a public airing of the case, essentially escaping more than fifteen years of illegal activity. McLaren, asserting that criminal wrongdoing was uncovered by the grand jury, that the consent decree was weak by comparison, contained insufficient enforcement procedures, and that key provisions of the decree would expire after ten years.

Nader and others asked Justice to rescind the decree and bring the matter to trial. A key issue became the evidence compiled by the grand jury investigation. Under the consent decree, that evidence would be sealed forever. However, if the case were brought to trial, and the defendants found guilty of conspiracy, under the antitrust laws, any injured parties could then bring their own suits to recover three times the damages suffered.

Triple damages are designed to serve as a deterrent to future violations, and in this case, future conspiracies against the public good. Earlier on Capitol Hill, as rumors swirled about a settlement, a group of nineteen congressmen, led by Reps. George Brown D-CA and Bob Eckhart D-TX , sent a letter to Attorney General Mitchell expressing their concern that a full trial was needed to show the public that corporate law breaking was no different than any other violation of law. The Justice Department, nevertheless, proceeded with its agreement.

In fact, when asked by a Los Angeles Times reporter if there was more to the case than the consent decree suggested, Mr. The big manufacturers all conspired. This case is the most important legal battle in the history of the air pollution fight.

If we lose it, we will go back twenty years. He was unable to question key grand jury witnesses. A brief but intense campaign to prevent the approval of the decree followed. Thousands of individuals, scores of congressmen, and numerous municipalities petitioned Federal District Court Judge Jesse W. Curtis not to approve the decree. Other related developments at the time included the following:. At the time, other municipalities were also being asked to join Los Angeles in the intervention. With other parties joining the case, it was thought that the court might be reluctant to agree to the settlement before holding an open trial.

George Brown D-CA started a statewide petition drive requesting the Justice Department to withdraw the settlement, and he also introduced a four-part resolution in the House, part of which requested the full transcript of the grand jury investigation, including subpoenaed documents.

Lloyd Cutler rose on behalf of his clients. Yet, the public only had a fleeting glimpse of what this case was all about, and more importantly, what the auto industry had done — or not done — to deserve this level of federal action. Some twenty-eight states and another ten cities and counties brought private actions against the automakers after the federal case was settled.

Later consolidated into one case in California, the suits sought a variety of remedies, asking, for example, that auto companies be ordered to take steps to eliminate smog, make contributions toward the establishment of mass transit systems, and provide free emissions testing of automobiles.

In June , the U. Court of Appeals in San Francisco ruled that the plaintiffs could not sue for damages in the case but they could seek equitable protection under the antitrust law.

However, in October , Federal Judge Manuel Real dismissed thirty-four of the thirty-eight cases saying that the antitrust laws did not give him the power to force the automakers to find a solution to the pollution problem.

The automakers argued that antitrust laws were reserved for the regulation of business conduct and the adjudication of business damage. The cases brought, they argued, were not about business damage in the strictest sense of antitrust tradition, as in price-fixing. Judge Real agreed. In , U. It revealed, among other things, that a criminal proceeding was recommended rather than the civil case that DOJ finally did bring.

House of Representatives, where he was immune from prosecution for revealing court-sealed documents. Burton urged Attorney General John Mitchell to reopen the case, conduct both a Justice Department investigation and convene a new grand jury to consider a conspiracy indictment—none of which ultimately occurred.

Yet Burton was especially interested in an investigation to determine whether the alleged conspiracy was continuing. Some of the technological delay the DOJ memo reveled follows below. The first part of the automobile to receive pollution control attention — courtesy of pressure from California officials — was the crankcase, the engine compartment directly below the combustion chamber in which firing pistons located in sleeve-like cylinders above, connect to and turn a crankshaft that brings drive power to the vehicle.

The gases, however, did not go into the exhaust system, but rather, were vented out of the crankcase and into the atmosphere. In fact, for decades prior, these crankcase pollutants were simply released from the bottom of the engine through a vent pipe opening to the road below.

There were no controls— or at least none in use for most vehicles. Engine graphic at left shows crankcase pollutants being recirculated for recombustion. Yet for decades prior, crankcase pollutants were simply released from the bottom of the engine through a vent pipe to the road below and into the atmosphere. There were no controls — or at least none in use for most vehicles.

PCV valve was known about since the s — and the principle of vacuuming off the gases from the crankcase back to the carburetor or intake manifold for recombustion — long before that. Howe Hopkins, an industry old-timer, former federal emissions official, and long-standing member of the American Society of Automotive Engineers SAE , offered this account in Back in about , I went down to the Studebaker plant to meet W.

James, the company engineer who demonstrated for me a simple tube attachment from the crankcase to the intake manifold to recirculate and recombust the crankcase gases. They were offering a conversion kit for this which was essentially only a length of copper tubing. Although certainly by the early s there was sufficient understanding of crankcase blowby, some in the industry would portray crankcase ventilation as a new development. Auto industry officials, then eyeing possible statewide regulation in California with strong pressure from local officials in Los Angeles, soon began to see that installing the relatively simple PCV device on California cars might be a way to forestall even tougher regulation by the state.

His research would end up having wide-reaching applications. Leaded gas destroys catalytic converters by coating it in lead, resulting in its inability to filter the toxic emissions.

This all changed in the s when the Clean Air Act of was enacted. The Clean Air Act of required all cars after the year to be equipped with a catalytic converter. Later amendments to this act in the s banned leaded gasoline sales by , amplifying the need for catalytic converters by automobile manufacturers.

The first iteration of the catalytic converter contained steel beads attached to a mesh at both ends of the converter. These beads, coated in a catalyst, would create the transformation when the toxic gases came into contact with them.