You promised to build cars, so why did you go into the military industry?

Chapter 76 Large Hydrogen Alkane

Having once again endured the darkness, Lin Yu rushed to the northeast corner of the base before the canteen opened for lunch.

He inspected the building complex in detail, which he had previously overlooked, and discovered that the production line capable of CO02 methanation followed the route of producing hydrogen through water electrolysis and then converting it through a catalyst.

Once the factory is operational, the entire base will no longer emit carbon dioxide. However, if the production lines are running at full capacity, carbon dioxide will need to be captured directly from the air to fill some of the raw material shortage.

The entire production line is a real power consumer.

Electrolysis of water to produce hydrogen is itself an energy drain.

Not to mention that the entire methane production process requires a large amount of electrical energy to create the low-temperature, high-pressure environment suitable for nickel-based catalysts.

However, what United Industries has the least shortage of right now is electricity, especially green electricity.

Not to mention that CO02 methanation is a strongly exothermic reaction, and the integrated heating and power generation modules in the factory make the most of waste heat.

Unfortunately, Lin Yu couldn't find any equipment in the entire factory that could stably preserve H2 for a long time. Otherwise, he would have been prepared to abandon the liquid oxygen and methane project and focus on the liquid oxygen and liquid hydrogen rocket engine.

After all, liquid oxygen and liquid hydrogen have enormous advantages as rocket engines.

With the highest chemical energy efficiency, its theoretical limit for vacuum specific impulse (Isp) is close to 450 seconds, far exceeding the 360 ​​seconds of liquid oxygen methane.

This means that, while consuming the same mass of propellant, hydrogen-oxygen engines can generate greater thrust or operate for a longer period of time, which is a direct manifestation of their "high specific impulse" advantage.

Unfortunately, the current mainstream technology involves compressing hydrogen to 700 atmospheres and storing it in a specially made metal container.

However, tiny hydrogen atoms can penetrate into the interior of metallic materials, leading to reduced plasticity, accelerated crack propagation, and even brittle fracture without warning, a phenomenon commonly known as "hydrogen embrittlement."

Cooling hydrogen to -253°C to liquefy it can significantly reduce its volume, but at a very high cost, as the theoretical energy consumption for liquefying 1 kg of hydrogen is as high as 13.8 kWh, and it also releases a large amount of heat to the outside world.

Although ultra-low temperature liquid hydrogen avoids the "hydrogen embrittlement" phenomenon, it faces other thorny problems, namely the "cold embrittlement" phenomenon caused by the sharp drop in material toughness under ultra-low temperature conditions and the "evaporation loss" caused by the vaporization and escape of liquid hydrogen.

The factory uses cryogenic storage of liquid hydrogen.

Looking at the enormous nickel-based alloy liquid hydrogen storage tank in front of him, Lin Yu put his hands on his hips: "This will make things much easier when we move on to using liquid oxygen and liquid hydrogen engines later on, with its high specific impulse of 455 seconds—"

However, the best storage container for hydrogen is still a carbon chain or carbon atom.

Wait, isn't that a hydrocarbon?

Aren't fuels like petroleum and natural gas all common alkanes?

Turning around and looking at the empty factory, Lin Yu uttered a sentence: "Large-scale hydrogen production requires alkane."

"Wasn't that thing overthrown in the last century?"

The sudden sound from the deserted factory startled Lin Yu. He only breathed a sigh of relief after recognizing Wang Bing and explained the situation.

"Oh, this is a large hydrogen alkane? I thought you meant a large hydrogen alkane."

Wang Bing turned to look at the device beside him that emitted a cold, metallic gleam, and suddenly said, "Following your line of thinking, if people discover in the future that the best way to confine controlled nuclear fusion is through gravitational confinement—"

Lin Yu chimed in, "Then the best controlled nuclear fusion device should be a Dyson sphere."

Wang Bing looked at Lin Yu with a surprised expression: "Huh? Shouldn't it be solar photovoltaic panels?"

The sound of their loud laughter echoed through the factory.

Don't forget the talent recruitment events held by eight top universities in 21 days.

The school you've been assigned to is Northeast Associated University. Your high-speed rail ticket has already been bought, and someone will pick you up when the train arrives.

Remember this: Go all out and recruit talent. As long as they have real skills and abilities, students and professors alike are welcome.

Lin Yu was puzzled: "Why didn't you assign me to Northwest University of Aeronautics and Astronautics?"

I feel like I'd be more popular there.

"They've been assigned to Zhang Chengyuan and Gao Jingming. They live close by, and it's only three days anyway, so they won't be delayed for long."

Yesterday, in a closed-door meeting, Zhao Feng, who was initially ecstatic after being hit by such a huge windfall, finally calmed down and then felt a sense of urgency because SpaceX had achieved rocket recovery.

After the meeting, Lu Xiangwen, Zhao Feng, and Qiu Cunming met with Director Qi Kaifeng to discuss the matter.

Upon hearing from Lu Xiangwen that United Industries wanted to recruit talent, Director Qi Kaifeng immediately called Li Ran, while Zhao Feng, who was eager to do so, returned to the guesthouse first.

Sitting at the small table, Zhao Feng, with his laptop open, showed no signs of fatigue, only excitement.

A budget of 100 billion over 5 years is a lot, but ultimately we need to develop an ecosystem that can provide life support for 30 people.

"If there are 30 biosphere modules connected together, then according to the data currently transmitted back by Tiangong, each module needs to be replenished with at least 1 ton of supplies per year, so 30 modules would require 30 tons of supplies."

Zhao Feng paused, his fingers still on the keyboard. He recalled Director Qi Kaifeng's introduction of the Long March 5 and Long March 0 rockets, both still under design, with lunar transfer orbit (LTO) payload capacities of 70 tons and 32 tons, respectively.

While supplies may seem easy to transport, what about the ecosystem modules themselves?

The rocket body has a diameter of 5 meters, and the fairing's maximum diameter is only 6.2 meters. The height is decent, around 22 meters, but the effective loading space has a diameter of approximately 5.2 to 5.5 meters and a maximum height of no more than 20 meters. The internal effective volume is roughly 440 cubic meters.

"It would be best if there was ice on the moon, otherwise the modular modules might be—"

Before we knew it, dawn had broken.

Clutching his laptop, Zhao Feng, his eyes bloodshot, pounded on Qiu Cunming's door: "Old Qiu! Open the door! How can you sleep at your age?!"

Just after Lin Yu sent over the "Analysis Report on Vertical Recovery Technology of Falcon 9" and the quotation for the R8X-05 control system, Director Qi Kaifeng looked at the report and the 2 billion yuan quotation in his hand and fell silent.

After waiting for a long time without a reply, Lin Yu assumed it was because the price was too high, so he typed an explanation: "This quote is half the total cost of 13 Falcon 9 rockets."

The rocket recovery system is a priceless and unavailable technology that cannot be priced, so we made an internal discount.

Trading 6.5 Falcon 9 rockets for 20 months of trial and error is definitely a worthwhile investment.

We still have to pay half of the taxes, the country actually only spent a little over 10 billion —

After reading Lin Yu's explanation, Director Qi Kaifeng stared at his phone, unsure of what to say.

Are you suggesting he explain that the taxes you pay belong to the government, but the money for buying the technology comes from CNSA?

You, Lin Yu, pay taxes to the country, not to the CNSA!

Why do you look like I've hit the jackpot?

However, Lin Yu was right about one thing: rocket recovery technology is currently priceless and unavailable. There is only one company willing to put it up for sale with a clear price tag.

Director Qi Kaifeng sighed heavily, knowing that only his own people knew his own situation.

The original recovery technology route was to allow the rocket to hover at an altitude of 30-50 meters, and then recover it using a recovery net.

However, the two most important technologies in the hovering technology route are controlled return and hovering, and the recovery net.

As a result, neither of these two technologies has seen a breakthrough.

The 10km high-altitude hovering and controllable return seem impressive, but compared to the rocket body that crosses the Karman line (100km) and then returns, the control difficulty is worlds apart.

Not to mention the recovery net made of four high-strength ropes (barrier cables).

Just like when a carrier-based aircraft lands, the arresting cable doesn't just rigidly pull the aircraft down, but rather uses a complex hydraulic damping system to gradually absorb kinetic energy and spread out the huge impact force.

The recovery net works on the same principle. In order to reduce the impact of free fall after the rocket engine shuts down, the control system flattens it through the combined action of multiple buffer mechanisms, such as the net itself and hydraulic buffer cylinders.

Although there are barrier cable systems that can be used as a reference, their implementation remains fraught with difficulties.

We haven't even found a rope that meets the requirement of a breaking strength of 200 tons yet.

The most important thing is that it's bulky!

If the vertical recovery technology is properly calibrated, as long as there is a flat surface, no matter how many rockets you have, they can recover them all.

What about recycling nets built at a fixed location?

If anything goes wrong and it goes astray, the net will become useless!

A single recycling network facility could cost more than a rocket.

If there is an extreme need to recover multiple rockets at the same time in the future, wouldn't we need to build several in advance?

Is it appropriate to engage in large-scale construction and wasteful spending for an extreme situation?

Whether I can retire peacefully is a question.

But that's 20 billion! That's an enormous single expenditure.

"It's been reported."

Director Qi Kaifeng decided to vent this troublesome matter.