The Crestone Eagle, June 2008:

The giant of China
Energy & the development of biogas fuels

story & photos by Nicholas Chambers

Napoleon Bonaparte said over two hundred years ago: “Let China sleep, for when she wakes the world will shake.” Now at the toe of the 21st century, she’s well and awake and she’s hungry. She has a fifth of the world’s population within her borders on the same land area of America, while consuming a quarter of the world’s steel and half of its concrete. Starting just a few years ago she began importing food for her people, tipping the global coffers for her sustenance. She is gargantuan in magnitude, thriving in economy, and exploding with entrepreneurial zest and technology. If China and India start consuming at the level of America, we would need several more Earths to sustain our appetites.

As China grapples with techniques to meet the needs of her people, biogas digesters are still in the forefront of the most basic of organic food/nutrient cycles. As part of a feasibility study for small farm biogas digesters, I had the opportunity to travel to Southern China to learn about a new hydraulic-pressure, domestic-scale biogas plant and the people that gave rise to it.

Shenzhen: The New China
Shenzhen was merely a fishing village of seven hundred thousand in the year 1976, the year Mao Zedong died and the Cultural Revolution officially came to an end. Shortly thereafter, the de-facto Prime Minister Deng Xiaoping toured the newly created Special Economic Zones (SEZs) of Shenzhen and Zhuhai and left a lasting legacy. He wanted to make Shenzhen the model of the new China. “To get rich is glorious,” he said. Chinese people needed to go into business “even more boldly” and “more quickly” to create a socialist market economy with Chinese characteristics, he said. The result has been an economic growth unparalleled in human history and the rise of Shenzhen to now possessing a population of 12 million.If it were a country on its own it would have the world’s 11th largest trading economy. If it says “Made in China,” there’s a good chance it came from Shenzhen.

“Five thousand new cars on the road every week,” says my contact Dr. Jianan Wang of Puxin Science and Technology as we navigate unbridled traffic among endless shipping containers and belching sulphur diesels. Hearing this reminds me of the astounding fact that China is also bringing a new coal-fired power plant on line every week. The resulting smog was inconceivable, yet right in front of my face across the entire horizon. There was no sun, only a dim orangeish glow across the sky until it sets as an ominous orb below the skyline of the cityscape. I did not see any blue in the skies of Shenzhen.

Bike power was still in heavy use, even along the busiest of streets, and they would load the three-wheeled rickshaws totally full so that the cyclist almost looked like a turtle with a huge load on his back. Every morning they would be loading up with trash, recycling, food scraps, and used cooking oils. The food scraps and oils went to feeding pigs as part of the ubiquitous food propagation efforts that seemed to be crammed in any arable space on the sides of roads and highways.

The food, to say the least, was spectacular. Every meal was accompanied with copious amounts of green tea, before, during, and after the meal. Some men even used it like mouthwash. There was always a pickled something on the table and at the nice restaurants an entire bulb of garlic was the first thing that hit the table for everyone to have a raw clove. These seemed to be the secrets of their good digestion, fit bodies, and overall immaculate health, despite 130 days per year of classified hazardous air quality.

Puxin biogas
Dr. Wang was out in the field during the Cultural Revolution installing the traditional Chinese fixed-dome biogas digesters. He noted their inherent drawbacks, such as needing an expensive and skilled mason, the difficulty of detecting and fixing leaks, and their difficulty in removing solid fermentation material like straw. After earning his physics degree in Canada, he came back to China to launch Puxin Science and Technology, Ltd. of Shenzhen (Puxin means “spread of new technology” in Chinese). His goal was to develop a new hydraulic pressure, domestic scale biogas plant that could be easily built, the components mass produced, and be easily replicated around the world in both developed and developing nations. His result, which is still being improved upon and expanded, has won several awards for renewable energy sustainability and he has filed several patents in numerous countries.

The key aspects: the digesters are cast with concrete using steel molds; they are built within only a few days, and can be in a range of sizes of 3, 6, 8, and 10 cubic meters; for larger installations, the 10 cubic meter can be put in series or parallel and the water coming out of the final digester is pumped through a sand filter and can be used to flush toilets and/or used for irrigation. He is currently working on a 100 cubic meter mold set for even larger applications.

The other salient features of the Puxin digester include the range of feedstocks that can be used, from kitchen scraps, to manure, to straw, and its long life of thirty years. The fixed fiberglass gasholder is an amalgamation of the Indian floating drum-style digester and the Chinese fixed dome. As gas is generated it displaces water on top of the gasholder and thus provides just the right amount of pressure for delivering the gas up to 2 kilometers to the point of use.

Lastly, there are no moving parts or pumps and there is no steel to corrode. There is no rocket science, imported ingredient, or huge capitol outlay, just plain one-hundred-percent sustainable microhusbandry. Quite simply, the Puxin biogas digesters are standing on the shoulders of thousands of years of human harnessed biogas generation. Some Indian folks who were visiting Puxin to take back a mold set further confirmed this. Being no stranger to the problematic digesters of their own country, they hailed the Puxin system as the solution.

Growing pains
China is under a tremendous amount of global scrutiny right now: lead-based paints in toys, suppression in Tibet, and hosting the Olympics for the first time.There is even a sort of blame about producing so much poor quality merchandise or contributing to so much environmental strain. Even a brief encounter with this vastly rich and ancient culture lends this perspective to these notions: American companies manufacture American-bound goods in China. If there are quality/toxicity issues, it more than likely is due to the penny pinching and decision-making company than the people just trying to do their job. The Chinese are not without skill.

Secondly, conquest and imperialism is practiced by governments and not necessarily the people, and is a disease for which America has shown little immunity. Lastly, hosting the Olympics for the first time seemed profoundly significant for every sector of Chinese society. It is their opportunity to have the world on their turf while displaying the sacrifice, skill, and extreme dedication of their nation’s athletes. Plus, being under the global eye is a catalyst to clean up Beijing and continue addressing their environmental problems in earnest. They are well aware of them. Perhaps their predicament is what happens when a four thousand year old human civilization chooses contemporary economic development over continuing to live in their past? What human culture has chosen otherwise?

This most recent economic development is also matched with the development of a “green culture.” Hi-tech, green industrial parks (similar to our SEED Park initiative) are gaining tremendous interest and they even already had one in Beijing. They have tremendous capacity for engineering and manufacturing. While I was there several solar technology providers producing solar refrigeration units contacted me. They want to do business with the United States to get their technology out there, because they know we will pay for it and have numerous government subsidizing programs.

I had a chance to go to a green building (not straw bale and adobe, but efficient skyscrapers) workshop conducted by an architect and developer from Portland, OR. After espousing the excellent work they have done, and their continuing goals of making their buildings treat more waste than they produce, and create more power than they use, a Chinese gentleman asked, “This is all great which you have said, but America still is five percent of the world’s population, yet consumes twenty five percent of the world’s resources. Buildings are not the real solution by themselves. When will the mindsets of your people change to accept less?” To this the presenters applauded the insight and question, but didn’t have much of a response. Indeed, it is a deeply involved question. Unbridled expansion and consumerism are practically the cornerstones of the infantile 232 year-old America. Perhaps change will come with adolescence.

If you are interested in participating in a pilot biogas digester installation, contact