Biogas Production For Surprisingly Little Effort

December 4, 2025 by Jenny List 29 Comments

Probably most people know that when organic matter such as kitchen waste rots, it can produce flammable methane. As a source of free energy it’s attractive, but making a biogas plant sounds difficult, doesn’t it? Along comes [My engines] with a well-thought-out biogas plant that seems within the reach of most of us.

It’s based around a set of plastic barrels and plastic waste pipe, and he shows us the arrangement of feed pipe and residue pipe to ensure a flow through the system. The gas produced has CO2 and H2s as undesirable by-products, both of which can be removed with some surprisingly straightforward chemistry. The home-made gas holder meanwhile comes courtesy of a pair of plastic drums one inside the other.

Perhaps the greatest surprise is that the whole thing can produce a reasonable supply of gas from as little as 2 KG of organic kitchen waste daily. We can see that this is a set-up for someone with the space and also the ability to handle methane safely, but you have to admit from watching the video below, that it’s an attractive idea. Who knows, if the world faces environmental collapse, you might just need it.

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An array of current or next-generation boosters powered by methalox engines.

How Methane Took Over The Booster World

April 27, 2025 by Tyler August 42 Comments

Go back a generation of development, and excepting the shuttle-derived systems, all liquid rockets used RP-1 (aka kerosene) for their first stage. Now it seems everybody and their dog wants to fuel their rockets with methane. What happened? [Eager Space] was eager to explain in recent video, which you’ll find embedded below.

Space X Starship firing its many Raptor engines. The raptor pioneered the new generation of methalox. (Image: Space X)

At first glance, it’s a bit of a wash: the density and specific impulses of kerolox (kerosene-oxygen) and metholox (methane-oxygen) rockets are very similar. So there’s no immediate performance improvement or volumetric disadvantage, like you would see with hydrogen fuel. Instead it is a series of small factors that all add up to a meaningful design benefit when engineering the whole system.

Methane also has the advantage of being a gas when it warms up, and rocket engines tend to be warm. So the injectors don’t have to worry about atomizing a thick liquid, and mixing fuel and oxidizer inside the engine does tend to be easier. [Eager Space] calls RP-1 “a soup”, while methane’s simpler combustion chemistry makes the simulation of these engines quicker and easier as well.

There are other factors as well, like the fact that methane is much closer in temperature to LOX, and does cost quite a bit less than RP-1, but you’ll need to watch the whole video to see how they all stack up.

We write about rocketry fairly often on Hackaday, seeing projects with both liquid-fueled and solid-fueled engines. We’ve even highlighted at least one methalox rocket, way back in 2019. Our thanks to space-loving reader [Stephen Walters] for the tip. Building a rocket of your own? Let us know about it with the tip line.

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Mining And Refining: Fracking

June 5, 2024 by Dan Maloney 53 Comments

Normally on “Mining and Refining,” we concentrate on the actual material that’s mined and refined. We’ve covered everything from copper to tungsten, with side trips to more unusual materials like sulfur and helium. The idea is to shine a spotlight on the geology and chemistry of the material while concentrating on the different technologies needed to exploit often very rare or low-concentration deposits and bring them to market.

This time, though, we’re going to take a look at not a specific resource, but a technique: fracking. Hydraulic fracturing is very much in the news lately for its potential environmental impact, both in terms of its immediate effects on groundwater quality and for its perpetuation of our dependence on fossil fuels. Understanding what fracking is and how it works is key to being able to assess the risks and benefits of its use. There’s also the fact that like many engineering processes carried out on a massive scale, there are a lot of interesting things going on with fracking that are worth exploring in their own right.
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Micro Robot Disregards Gears, Embraces Explosions

September 30, 2023 by Donald Papp 18 Comments

Researchers at Cornell University have developed a tiny, proof of concept robot that moves its four limbs by rapidly igniting a combination of methane and oxygen inside flexible joints.

The device can’t do much more than blow each limb outward with a varying amount of force, but that’s enough to be able to steer and move the little unit. It has enough power to make some very impressive jumps. The ability to navigate even with such limited actuators is reminiscent of hopped-up bristebots.

Electronic control of combustions in the joints allows for up to 100 explosions per second, which is enough force to do useful work. The prototype is only 29 millimeters long and weighs only 1.6 grams, but it can jump up to 56 centimeters and move at almost 17 centimeters per second.

The prototype is tethered, so those numbers don’t include having to carry its own power or fuel supply, but as a proof of concept it’s pretty interesting. Reportedly a downside is that the process is rather noisy, which we suppose isn’t surprising.

Want to see it in action? Watch the video (embedded below) to get an idea of what it’s capable of. More details are available from the research paper, as well.

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The Clathrate Gun Hypothesis: Unearthing Puzzles Of Warming Events Past

August 21, 2023 by Lewin Day 36 Comments

As the Earth continues to warm at a worrying rate, scientists continue to work to understand the processes and mechanisms at play. Amidst the myriad of climate-related theories and discussions, the clathrate gun hypothesis stands out not only for its intriguing name but for the profound implications it might have on our understanding of global warming events.

Delving into this hypothesis is akin to reading a detective novel written by Mother Earth, with clues hidden deep beneath the ocean and Arctic ice. It’s a great example of how scientists attempt to predict the future by unpicking the mysteries of the past.

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Methane-Tracking Satellites Hunt For Nasty Greenhouse Gas Emissions

May 30, 2023 by Lewin Day 41 Comments

Much of the reporting around climate change focuses on carbon dioxide. It’s public enemy number one when it comes to gases that warm the atmosphere, as a primary byproduct of fossil fuel combustion.

It’s not the only greenhouse gas out there, though. Methane itself is a particularly potent pollutant, and one that is being emitted in altogether excessive amounts. Satellites are now on the hunt for methane emissions in an attempt to save the world from this odorless, colorless gas.

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Methane Pyrolysis: Producing Green Hydrogen Without Carbon Emissions

February 13, 2023 by Maya Posch 52 Comments

Generally, when we talk about the production of hydrogen, the discussion is about either electrolysis of water into oxygen and hydrogen, or steam methane reforming (SMR). Although electrolysis is often mentioned – as it can create hydrogen using nothing but water and electricity – SMR is by far the most common source of hydrogen. Much of this is due to the low cost and high efficiency of SMR, but a major disadvantage of SMR is that large amounts of carbon dioxide are released, which offsets some of the benefits of using hydrogen as a fuel in the first place.

Although capturing this CO₂ can be considered as a potential solution here, methane pyrolysis is a newer method that promises to offer the same benefits as SMR while also producing hydrogen and carbon, rather than CO₂. With the many uses for hydrogen in industrial applications and other fields, such as the manufacturing of fertilizer, a direct replacement for SMR that produces green hydrogen would seem almost too good to be true.

What precisely is this methane pyrolysis, and what can be expect from it the coming years?

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