Chapter 353 - 172: Owen’s Bacteria

Chapter 353: Chapter 172: Owen’s Bacteria

June 29th.

It was also the second day after Jiang Miao’s arrival at the Monan Branch.

Jiang Miao borrowed a laboratory United Mining Company had set up near the town of Home County. This was originally a small breeding lab funded by a cattle and sheep breeding company, but the company ran into operational issues in ’23. United Mining Company took it over in April, repurposing it as an experimental base for bio-mining technology research.

The 240-mu laboratory was located southeast of the county town. While its equipment wasn’t top-of-the-line, it was at least adequate for some basic microbiological research.

Regarding Jiang Miao’s request, Lin Yonghua had originally intended to let him use it for free. However, Jiang Miao refused, asking them to draw up a rental contract. After all, he wasn’t short on cash, and United Mining Company was not a wholly-owned subsidiary of Hailufeng Company. It was better to be meticulous about such matters.

Inside the modest laboratory.

Jiang Miao obtained the various bacteria and fungi stored there. Since the lab was intended for bio-mining research, it naturally had a stock of relevant microbial strains.

The previous evening, during a conversation with Wu Song, an idea had sparked in Jiang Miao’s mind.

Wu Song had mentioned the livestock base. As the scale of cattle and sheep farming expanded, the manure they produced needed to be disposed of quickly.

Generally speaking, there are four common ways to handle cattle and sheep manure from a farm.

One is to pile it up in the open air to dry, then use it as fuel.

Another is to sell it to other businesses or individuals who need it.

A third method is to compost it through fermentation, then use the resulting soil as organic fertilizer for the fields or sell the organic fertilizer.

The fourth is to first use it to produce biogas through fermentation, and then process the resulting slurry and sludge into organic fertilizer for personal use or sale.

Currently, the Monan livestock base uses the third method: fermenting it into organic fertilizer.

As for why they didn’t adopt the fourth, more economically beneficial method, the answer was the climate.

The climate in Eastern Monan is similar to that of the Northeast—it’s too cold.

In biogas fermentation, the optimal temperature for efficient mesophilic digestion is 30–35 degrees Celsius. The number of days in Eastern Monan when the daytime temperature exceeds 30 degrees Celsius is only 30 to 40 per year.

Even if they used underground pit-style digesters, which benefit from geothermal insulation, the surface air temperature would still need to be above 20 degrees Celsius. Eastern Monan only has 90 to 120 days a year with daytime temperatures above that.

If they had to use artificial heating to maintain the fermentation temperature, would producing biogas even make sense?

After all, the whole point of biogas fermentation is to produce energy. Using artificial heating to maintain the digester’s temperature in cold weather would drastically increase production costs, resulting in a very low cost-benefit ratio and no economic viability.

In the early 2000s, China vigorously promoted small-scale household biogas systems in the Yangtze River Basin. However, most of those fermentation pits have now been abandoned. The reason is that once the temperature drops, fermentation efficiency plummets, and gas production sharply declines.

Currently, only in parts of Guangxi Province do villagers still use biogas, simply because Guangxi’s climate is warmer. The number of days per year with temperatures above 20 degrees Celsius is around 200 to 250. This is especially true in the southern coastal areas of Guangxi Province, where there are nearly 250 days with temperatures above 20 degrees Celsius. Such an environment allows biogas fermentation systems to operate efficiently for long periods.

That’s why Wu Song never even considered setting up a biogas fermentation system near the livestock farm in Home County. After all, such a project would be a thankless, labor-intensive effort.

But Wu Song’s words had given Jiang Miao an idea.

Cattle and sheep manure is actually a very complex resource.

It can be used as a raw material for organic fertilizer, a substrate for growing edible fungi, a direct fuel source, or for producing biogas through fermentation.

This is because cattle and sheep cannot fully digest the roughage they consume; that is, they can’t completely break down the grass. A large portion of the cellulose and lignin from the grass remains behind.

In dried cattle and sheep manure, cellulose, hemicellulose, and lignin make up 70–80% of the content. The rest consists of humus, water, and inorganic salts.

This is the fundamental reason why dried manure can be used as fuel—it is rich in carbon sources.

When completely combusted, one ton of dried manure from grass-fed cattle and sheep has a calorific value roughly equivalent to 0.75 tons of thermal coal. For manure from grain-fed livestock, one ton is equivalent to about 0.7 tons of thermal coal.

It was practically biological coal.

As for why no thermal power plants use cattle and sheep manure as fuel, the reasons are manifold.

For example, the supply chain for the raw material is complex, collection is difficult, and production sites are scattered, which is not conducive to stable power plant operation. The calorific value of manure varies by region, complicating heat management during power generation. Furthermore, if the manure isn’t dried beforehand, it increases transportation difficulty and cost, not to mention the very unpleasant odor.

At the same time, thermal coal used for fuel costs only 500 to 800 yuan per ton.

Therefore, no thermal power plants bother using cattle and sheep manure as fuel.

However, some herders in China’s Monan, Western Regions, and Snowfield areas do dry cattle and sheep manure to use as fuel in their daily lives.

It wasn’t that Jiang Miao wanted to build a whole thermal power plant just for the few hundred tons of fresh manure produced daily.

He had thought of another technology that could utilize this manure: microbial fuel cells.

The so-called microbial fuel cell technology is a technique that generates bio-electricity by harnessing the electron transfer produced during the metabolic processes of exoelectrogenic bacteria within microorganisms.