We had lunch in the courtyard where Ma Yilong lived.

Of course, the protagonist on the table is potatoes. Zhao Hao plans to boil the big potatoes to test their taste, and use the small potatoes to stew beef.

What, where did the beef come from? This one was drowned, seriously.

The cattle in Kunshan County are suffering. Diseases and accidents kill more than a dozen of them every day...

It’s a pity that the tomatoes and peppers are not ripe yet, otherwise I would have had some scrambled eggs with tomatoes and diced spicy chicken, which would have gone really well with rice.

While cooking, the cooking utensils in Mr. Menghe's kitchen attracted the attention of the two children.

"Master, come and see. Mr. Menghe's stove is amazing. It can boil water without any firewood or fire." Two children ran in and insisted on taking Zhao Hao to the kitchen to take a look.

Zhao Hao had no choice but to follow, and saw that the kettle was already boiling on the red brick stove.

There was indeed no fire under the stove, only a copper tube making a hissing sound, which boiled the water.

No wonder the two kids were making such a fuss. Anyone who saw this scene would shout "invincible"... Oh no, it's incredible.

Zhao Hao asked someone to close the door. The light in the kitchen dimmed, and a ball of blue flame appeared under the stove, dancing happily at the mouth of the copper pipe.

"So there really is fire, no wonder we are not allowed to touch it..." The two children were so shocked that they asked in fear, "Master, is this a sorcery?"

"Nonsense, this is science!" Zhao Hao slapped the two men twice, and was about to say, "If you don't even understand this, are you qualified to be my apprentice?" Then he remembered that they were still second-grade elementary school students, so he sighed helplessly and patiently explained to them what biogas was.

The one used by Ma Yilong is a hydraulic biogas digester developed by Institute 04 of the Xishan Island Research Center according to Mr. Zhao’s “Elementary Chemistry” textbook.

It connects the toilet, pigsty and biogas tank into one. The biogas tank is buried shallowly underground and is a cylindrical concrete structure with a movable cover on the top, so that human and animal feces and kitchen waste can be directly swept into the tank for fermentation.

There is also a small water tank connected to the biogas tank through an outlet pipe. When the gas is produced in the tank, the pressure continues to increase, pushing the material into the water tank, which will increase the liquid level in the water tank. When the gas is used, turn on the biogas switch, the biogas can be discharged under the water pressure, and the liquid level in the water tank will naturally drop.

In this way, by relying on the rise and fall of the liquid in the water tank, the gas pressure in the tank can be automatically adjusted during gas production and use, thereby ensuring the stability of the output firepower.

There is no technical threshold for this thing. It all relies on organic matter to ferment in an anaerobic environment to produce combustible gas to boil water, cook and provide lighting.

Moreover, the biogas slurry can be used as pesticide, fertilizer and feed additive, and the final biogas residue is an excellent fertilizer... The manure taken out from the biogas digester is three to five times more effective than ordinary compost!

Another important point is that because it is a closed space, it is not easy to breed mosquitoes and there is no odor, which is a great killer for maintaining rural hygiene. This plays an important role in eliminating common rural infectious diseases such as schistosomiasis and hookworm disease.

Therefore, Qu Rukui, the director of the 04th Institute, thought that this thing was just like a cow taking a plane - Niu Boyi flew to the sky. He used his spare time to make it last year. After the test showed no safety issues, he installed several sets at Kunshan Agricultural College first, hoping to hear the professional opinions of Ma Yilong and agricultural technicians to see if it is possible to promote it in rural areas. This is the only way from laboratory to factory production.

Ma Yilong and others also thought this invention was great. However, there were also some problems. First, the gas was transported through a copper pipe with a valve, and a simple glass pressure gauge was installed next to the water tank. The cost was too high, and farmers were afraid that they would not buy it.

No matter how many benefits you have, you can't beat the firewood everywhere. So it won't work if you are expensive.

The 04 institute then used treated bamboo to replace the copper tubes. They also eliminated the barometer and installed a retractable bamboo strip in the water tank to judge the air pressure by the water level, thus successfully reducing the cost.

Furthermore, the Agricultural College also discovered that this thing is good, but it smells very bad when burned, and it is uncomfortable to smell it too much.

This is normal, because biogas contains not only colorless and odorless methane, but also a small amount of hydrogen sulfide. The rotten egg smell that Mr. Zhao smelled when he visited sulfur production on Iwo Jima was also caused by this substance.

But it doesn’t matter. Just add a bamboo tube desulfurizer filled with activated carbon and iron oxide between the outlet of the biogas tank and the gas pipe.

Activated carbon comes from dry distilled wood and has a strong adsorption effect, which can make biogas pure. Iron oxide is rust, which can react with hydrogen sulfide to form iron sulfide, leaving the sulfur atoms in the desulfurizer. This is the most common and efficient desulfurization method.

And when the user smells an unpleasant odor, just remove the desulfurizer for ventilation, the iron sulfide will react with oxygen and be reduced to iron oxide and sulfur, and then it can continue to be used.

When the desulfurizer turns completely yellow, you can contact the staff to come and replace the material. This step is free because pure sulfur can be recovered from the desulfurizer...

~~

In short, biogas with a desulfurizer installed is still very comfortable to use. Especially in the hot and humid southern region, a biogas tank can be used by a family of six to boil water, cook and light.

Zhao Hao thinks that the next step is to find a few farms in the county and conduct a small-scale pilot to see how the farmers and workers respond. If there is no problem, it can be promoted in the thousands of farms under the group, and this business alone will be profitable. When thousands of farms are using it, biogas digesters will be popularized in Jiangnan, and it will be much easier to promote it to ordinary people.

After leaving the kitchen, the two children were curious and wanted to see the biogas lamp. Shi Jizhi took them to the study. In fact, the biogas lamp is just another pipe nozzle with a glass lampshade, so the effect cannot be seen during the day.

But according to Shi Jizhi, this lamp at night can illuminate the whole room as bright as day, which made the two children stunned. They thought how happy it would be if they could study in this room... So the academic bully really deserves a beating.

Zhao Hao thought the biogas lamp was just average in brightness, not as bright as the calcium carbide lamp. Shi Jizhi and the others thought it was really bright because they had never seen what it was like to be as bright as daylight...

The main brightness of later biogas lamps actually comes from the lampshade.

The lampshade that emits dazzling white light when heated is made of linen mesh soaked in thorium sulfate solution. Linen is easy to make, but Mr. Zhao only knows that thorium is extracted from monazite. But he has never seen monazite, let alone how to prepare it. So he can only let them blow a glass cover first.

In fact, it is the same without a cover. I have never seen a candlestick with a cover. Therefore, the glass cover can be added to the exclusive version set together with the copper pipes and glass barometer, which is specially selected by the big dog owners. Although the price is much higher, the rich want the feeling that the poor can't afford. If they don't have this feeling, they won't pay for it...

~~

After half an hour, the meal was finally served. The potatoes were smooth and sticky, and the stewed beef was so delicious that the kids next door cried...

When Mr. Zhao took a bite, he almost cried. This was the taste of his hometown that he could never return to.

"This thing can really be used as a staple food." Thanks to Master Zhao, Fu Shi Jizhi ate potatoes for the first time. He was so excited by the new taste that he couldn't help himself.

"Yeah, it's better than corn." Ma Yilong nodded and said, "If we increase the yield, maybe this thing can save the Ming Dynasty in the future."

Zhao Hao smiled and didn't refute. It was good that the old man thought this way at his age.

He peeled the potato slices slowly, and after calming down, he changed the subject and said, "By the way, I wonder if you have heard of this, sir?"

"What's the matter?" Ma Yilong ate his meal in big mouthfuls.

"This month, the group received reports from several counties in Huzhou and Jiaxing saying that a terrible silkworm disease was spreading on farms." Zhao Hao said in a deep voice. This was his real purpose for coming here today.

"There are two types, not one. And it's not this year, it started the year before last." Ma Yilong swallowed a mouthful of rice, picked up a handkerchief to wipe his mouth and said, "It was first discovered by silkworm farmers in Tongxiang County, Jiaxing the year before last. The silkworms they raised were fine the day before, but most of them died the next day. Even those that successfully made cocoons produced less than half of the silk they normally produce. But at that time, the price of silk was low, and no one except the silkworm farmers took it seriously."

"Last year, silkworm farmers in Wukang County, Huzhou, discovered a strange disease. Some silkworms had black spots on their bodies. These silkworms moved slowly and weakly, were picky eaters, and died early. Once one was found, it would spread quickly, and a large number of silkworms would die." Ma Yilong is the most authoritative agricultural expert in Jiangnan, and even in the Ming Dynasty. Apparently, someone had reported the situation to him a long time ago. He has also been paying attention to it.

"But at that time, your Jiangnan Textile Company was eager to collect less silk, so naturally they would not reflect this to you." He sneered at Zhao Hao and said, "At that time, the common people had a poor harvest, and your people were only concerned about collecting silk at a low price, and did not care about the plight of the silkworm farmers at all. This year, sea trade has been opened, and the demand for raw silk has skyrocketed. You finally care about the silkworms' illness. You are really kind!"

"During the initial stage of the group, many things were not done properly and people's concepts had not changed." Mr. Zhao thought to himself, no wonder Ma Yilong always argued with me after meeting me for the first time. It turned out that he had been dissatisfied with Jiangnan Textile for a long time.

He knew that with the unscrupulous business style of Liu Zhengqi and his gang, he would definitely not complain about being scolded. He could only say awkwardly: "I will be more careful in the future."

"Humph, of course, you are much better than those ruthless rich people. But you can't compare with them, right?" Ma Yilong said it out loud, so he stopped while he was ahead and got back to the point: "Usually, silkworm diseases will not be passed on to the next generation. But these two diseases are weird. They came again this year, and the scope has expanded to six counties at once - in addition to Tongxiang and Wukang, there are also four counties adjacent to them that have broken out."

"The spring silkworms in these counties are already in vain. If we don't find a way to control it, not only will the summer silkworms be destroyed, but it will also spread to all the counties in Jiaxing and Huzhou." He said with a serious look: "Next year, there may be a major outbreak in the whole of Jiangnan. By then, you will have no silk to harvest!"