catalytic converter

3 Articles

See-Through Catalytic Converter

February 1, 2020 by 16 Comments

There’s always something to be learned from taking things apart. Sometimes the parts can be used for other things, sometimes they can be repaired or improved upon, but sometimes it’s all in good fun. Especially in this case where extremely high temperatures and combustible gasses are involved. This is from the latest video from [Warped Perception] that lets us see inside of a catalytic converter as its operating.

Catalytic converters are installed on most vehicles (and other internal combustion engines) in order to process unburned hydrocarbons from exhaust gasses with a catalyst. These can get extremely hot, and this high temperature complicated the build somewhat. There were two prototypes constructed for this build and the first was a cross-section of a catalytic converter with a glass window sealed on in order to allow the viewing of the catalyst during the operation of a small engine. It was easy to see the dirty exhaust gasses entering and cleaner gasses leaving, but the window eventually blew off. The second was a complete glass tube which worked much better until the fitting on the back finally failed.

A catalytic converter isn’t something we’d normally get to see the inside of, and this video was worth watching just to see one in operation in real life. You could also learn a thing or two about high-temperature fittings as well if you’re so inclined. It might be a nice pairing with another build we’ve seen which gave us a window into a different type of combustion chamber than ones normally found on combustion engines.

Thanks to [Ryoku] for the tip!

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Mining Platinum From The Road

June 6, 2016 by 93 Comments

For several decades now all petrol-driven motor vehicles have had to feature a catalytic converter in their exhaust systems to meet the requirements of emissions legislation. These feature a high surface area coated with platinum, palladium, and rhodium, which catalyses the high-temperature breakdown of the exhaust gasses.

When a vehicle reaches the end of its life its catalytic converter is recycled and those metals are recovered, but this recovery does not account for all the metal. [Cody Reeder] noticed that the weight of platinum in a catalytic converter taken from a scrap vehicle is significantly less than that of a new one. Some of that metal has escaped, so where has it gone?

The answer to that question is that it has become detached from the converter and blown out through the rear of the exhaust pipe. Therefore in the area around a busy highway with many thousands of cars passing there must be a reasonable concentration of platinum. The video below the break details [Cody]’s quest to verify that theory, and it opens with him and a friend sweeping dust from beside a freeway in the early hours. The resulting bags contain a lot of gravel and bits of tire, plus a few cigarette butts and a large amount of very fine dust. He sieves away the debris, and heats a sample of dust in a furnace with a flux mixture containing lead oxide. He hopes that as this oxide degrades to metallic lead it will dissolve any platinum and settle in the bottom of his crucible, and indeed when he pours out the resulting slag there is a bead of lead. Taking away the lead reveals a speck of impure platinum, which he further purifies and assays to determine the percentage of platinum and to detect the other catalyst metals.

He finally arrives at a figure of 6.7 g per ton of his fine-sifted roadside dirt “ore”, a figure which as he points out would be considered quite valuable were it to be encountered in a mine. His process might be a little difficult for individuals with sweeping brushes to hit pay dirt and a modern gold rush to descend on their local Interstate, but it’s not impossible that a highways agency equipped with sweeper trucks could have the metal extracted at a more profitable level.

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The Platinum Catalyst Use In A Vintage Lighter

November 1, 2014 by 13 Comments

[Ben Krasnow] has an inimitable knack for choosing the most interesting concepts for his experiments. We’re sure it’s a combination of base knowledge and epic-curiosity. This time around he’s showing off a vintage cigarette lighter whose quirk is not needing to be “struck” to produce a flame. It’s a catalytic lighter that uses platinum to ignite methanol vapors.

The concept shown in the video below is platinum’s catalyst properties with some types of flammable gasses. The image above shows the cap of the lighter which includes a protective cage around a hunk of fine platinum powder known as platinum black. It is suspended by platinum wire and as the hydrogen passes by the reaction causes the platinum black and wire to glow red-hot.

This simple, quick experiment fills in our own knowledge gaps. We were already familiar with the role that catalytic converters play in automobiles; consuming any unburned hydrocarbons before they exit a vehicle’s exhaust system. We also know the these devices are targets for thieves seeking the platinum (and other metals like palladium and rhodium) found inside. Now we know exactly how catalytic converters work and the integral role that platinum plays in the process. All thanks to [Ben’s] demonstration of how this lighter works.

Now, if you wear a platinum wedding band and your hand passes a jet of hydrogen are you likely to get burned?

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