Hi guys, I'm trying to understand different ways carbon capture is possible. I come from a Mechanical Engineering background, chemistry is a neighbor who I am not very familiar with:)
I'm learning about the Sabatier reaction, how effective is this method? I also worry about the methane product, any method that produces green house gasses is not... Ideal.
Is there a way to make methane inert in the atmosphere or solid
Thank you for any help
This could be interesting tech for SpaceX, for future Mars fuel production.
https://www.cell.com/joule/pdfExtended/S2542-4351(20)30093-3
More specifically, at what scale do propellant plants have to be built & their output each day have to be to refuel a bfs (~1000t of propellant), accounting for propellant boil-off?
The Sabatier reaction, where Hydrogen reacts with CO₂ at high temperature and pressure to form methane and water -- would it be feasible somehow to either demonstrate this process in the laboratory, or even to have students perform this process themselves?
The process must run in a reactor at 300-400°C and "elevated pressure" - I'm guessing 10-30 bars. I would love to be able to demonstrate this process to my students. Ideas/suggestions are very welcome!
I am trying to model the Sabatier reaction using CO2 in Aspen Plus 9 and HYSYS, but the rate expressions that I find in literature are too complex for any of the reaction models. Is there a rate expression for the Sabatier Reaction that can be used easily in Aspen, a way to model the models shown below, or would modelling the reaction with an RGibbs Reactor be acceptable given the complexity of the rate expressions while still being relatively accurate?
Literature Examples
When looking at ideal temperature and pressures for the Sabatier reaction the surface of Venus seems ideal. Would it be possible to seed catalyst on the surface of Venus and attempt to sequester the CO2 in the atmosphere and produce water? Is there a way to sequester the CH4 afterwards?
Relevancy to SpaceX
Recently there has been a lot of news about the ocean that once covered Mars's northern hemisphere^[1] , and more recently about Mars's glacier belts^[2] . While this isn't directly applicable to SpaceX, I thought it might be a good time to make a more detailed post about In Situ Resource Utilization. (ISRU is when local resources such as CO2 and H2O are used for a space mission, instead of ringing supplies from Earth.)
Our Wiki's Mars section mentions ISRU in 2 contexts, both of which have entire articles. The first is that NASA's humans to mars relevant Strategic Knowledge Gaps include some ISRU-related items, such as improving maps of water and mineral availability. Our second article deals with some of the specific requirements of a colony, including the different options by which one might obtain various resources, and the sorts of basic necessities that a colony would use various resources for.
However, I'd like to narrow the focus of this discussion specifically to water, and specifically to applications directly related to SpaceX. MCT is extremely likely to be methane powered, since methane can be manufactured from Mars's CO2 atmosphere via the Sabatier reaction:
CO2 + 4 H2 → CH4 + 2 H2O + energy
However, this requires a small mass of H2 in addition to the CO2 which can readily be pulled from Mars's 95% CO2 atmosphere. The reaction produces some H2O, which can easily be split into H2 and O2 by electrolysis (running electricity through it). Although this significantly cuts down on waste by putting all input hydrogen into methane, a ready source of water would negate the need to import all that hydrogen from Earth.
How much ice is on Mars?
Pretty much all water on Mars is ice, much to the chagrin of all the planetary scientists looking for liquid water which might host life. But there's actually a fair amount of ice, mostly in the polar ice caps. Unfortunately, the ice in the southern ice cap is permanently covered in a layer of dry ice (frozen CO2) about 8 meters deep, and the northern cap gets covered to about 1 meter every winter.^[3]
- The current day total is about 5 million km^3 , or enough to cover all of Mars to a depth of 35 meters if distributed evenly.
Mainly in terms of both energy and apparatus. Is it fairly easy to build a machine which could carry this out on the surface of Mars?
I run /r/htwo and talk about how once hydrogen tanks come down in price, people can run surplus solar panels and store the energy in hydrogen.
I've heard of power plants in a big scale using the Sabatier reaction to store their hydrogen around a carbon and make methane. The problem for me though is I don't know if you can make it in a small scale. I think a hydrogen storage tank would still be required. You don't want to waste energy heating the reaction to around 300^o - 400^o C for small amounts of hydrogen.
Obviously this only works in places you have an abundance of space to lay solar panels out. The reason it works today is that even though it is a lossy transmission of electricity, solar panels are super cheap now and keep getting more efficient and cheap. The "problem" is where to store the overage. Right now people don't buy excess solar panels because even selling back to the grid isn't that profitable. But if you could mass produce methane gas, you could use if for your own house heating. There's probably other market uses for mass producing methane on a farm.
So again my questions are,"Does the Sabatier reaction scale down to small amounts?" And are there premade kits out there to hook up electricity into water and the result output is methane?
Thanks and be kind. This is my first /r/chemistry question.
Currently I am preparing for my science fair in May. Yes, I'm eager. I'm quite set on the idea of formulating an entire manned Mars program, including fuel weight, spacecraft design, and the stoichiometry of rocket propulsion. The project would be centred around using the Sabatier Reaction to generate Methane fuel, oxidizer, and drinking water from the Carbon Dioxide in the Martian atmosphere and brought along liquid hydrogen. The problem is I'd like to, somehow, physically display the Sabatier reaction at the science fair. I'm only 15, so it's quite impossible to construct a working Sabatier Reactor, but, I was wondering if there was another way, any way, to display the reaction. I'm quite new to subject, so I thought this would be the best place to ask. Thanks in advance.
Note: There's possibility that I would have access to my high school's chemistry materials. If not, I am willing to purchase material.
Story Discord (expires in 7 days)
O-O-O
0915, 18 January 2253, ISS Goliath, Trans-Martian Trajectory
Hollis floated with Jina in the main corridor of the Goliath before the tigress asked, “So how much do you know about life support?” Jina opened a large panel marked with a circling set of arrows.
Hollis shrugged and said, “Carbon dioxide and piss go in, oxygen and water come out?”
Jina sighed heavily. “You...are technically correct, I guess? You’re forgetting biomass and food, but that’s close. Our exhaled carbon dioxide is recycled to oxygen. Do you know how that happens?”
Hollis sniffed, mulling the harsh scents in the life support cabinet before she asked, “It’s… something really chemical, isn’t it?”
Jina chuckled and said, “Yes. How’s your chemistry?”
Hollis thought back to her childhood ‘education’ and frowned. Her formal education had ended at 11 years old when the orphanage had been taken over by the Syndicate. She muttered, “Bad. I’m almost entirely self taught.”
“Alright, that’s fine.” A strange warm feeling flickered in Hollis' chest before the tigress continued. “There’s a set of high temperature and pressure vessels in here.” She pressed her hand to one of the obvious pressure vessels and added, “You can feel the heat even through the insulation.” Hollis gingerly reached for one of the vessels and raised her eyebrows. Jina continued, “Carbon dioxide and hydrogen go into a multi-stage heater that feeds into this Sabatier reactor vessel here.” Jina pointed at the smaller of the two vessels. “In there, the hydrogen and carbon dioxide react over a ruthenium catalyst to form methane and water.”
Hollis scratched her head and asked, “Hold on, what does a fusion reaction have to do with that?”
Jina narrowed her eyes in confusion. “It doesn’t. Any chemical reaction on a spacecraft is usually done in a chemical reaction vessel. You’re probably thinking of the fusion reactor crucible. Normally people drop the ‘fusion’ from that.”
Hollis sighed as she drove her palm into her face. “Right, that makes a lot more sense. Go on.”
“Once the water and methane are harvested, water is filtered out of the stream with a condenser and the methane goes to the other reactor vessel, but that’s a topic for later.”
... keep reading on reddit ➡Do your worst!
It really does, I swear!
For context I'm a Refuse Driver (Garbage man) & today I was on food waste. After I'd tipped I was checking the wagon for any defects when I spotted a lone pea balanced on the lifts.
I said "hey look, an escaPEA"
No one near me but it didn't half make me laugh for a good hour or so!
Edit: I can't believe how much this has blown up. Thank you everyone I've had a blast reading through the replies 😂
I'm surprised it hasn't decade.
https://twitter.com/elonmusk/status/1352392678177034242?s=19
They’re on standbi
Buenosdillas
Pilot on me!!
Dad jokes are supposed to be jokes you can tell a kid and they will understand it and find it funny.
This sub is mostly just NSFW puns now.
If it needs a NSFW tag it's not a dad joke. There should just be a NSFW puns subreddit for that.
Edit* I'm not replying any longer and turning off notifications but to all those that say "no one cares", there sure are a lot of you arguing about it. Maybe I'm wrong but you people don't need to be rude about it. If you really don't care, don't comment.
I won't be doing that today!
How does Elon plan to make methane for his fuel used to go to Mars and back……..well using sabatier reaction! His words not mine….
How does sabatier Reaction work? Well that is through electrolysis!
What is electrolysis associated with? Fuel cells !
Who uses fuel cells in space already? NASA for 50 years.
What about blue origin fuel? hydrogen +liquid oxygen.
what does Elon think about “fool” cells?
hahahaha enjoy cause this goes way deeper than this!
You take away their little brooms
This morning, my 4 year old daughter.
Daughter: I'm hungry
Me: nerves building, smile widening
Me: Hi hungry, I'm dad.
She had no idea what was going on but I finally did it.
Thank you all for listening.
There hasn't been a post all year!
[Removed]
When I got home, they were still there.
What did 0 say to 8 ?
" Nice Belt "
So What did 3 say to 8 ?
" Hey, you two stop making out "
