Biogas is a renewable and clean energy source that has gained increasing attention for its environmental and economic benefits. The term "biogas" originates from its initial discovery in swamps, where it was first observed as a naturally occurring gas. This combustible gas is produced through the anaerobic digestion of organic materials by specific bacteria under conditions of no oxygen, along with optimal temperature, humidity, and pH levels. Biogas is primarily composed of methane (55% to 70%) and carbon dioxide (30% to 45%), with smaller amounts of other gases such as oxygen, nitrogen, and hydrogen sulfide.
Methane, the main component of biogas, has a calorific value of about 35.9 MJ/m³, while its lower calorific value is approximately 20–25 MJ/m³. When mixed with air, biogas produces a blue flame and reaches temperatures up to 1400°C, making it an efficient heat source. In terms of energy equivalence, 1 m³ of methane is comparable to 5500 kcal of raw coal. A typical rural household biogas digester can produce 450 m³ of gas annually, saving around 1.5 tons of raw coal per year. With 252 million rural households in China, this could replace up to 112.5 million tons of raw coal annually at a 30% penetration rate.
In the UK, a methane automation plant can supply 25% of the country’s gas needs, while the US currently operates 24 such plants. One notable example is a farm in the US that built a large-scale facility measuring 30 meters wide and 213 meters long, capable of processing 1,650 tons of manure daily. This system generates 113,000 m³ of methane per day, enough to meet the energy needs of 10,000 families.
Zhang Baowen, Vice Minister of Agriculture, emphasized the importance of promoting rural biogas digesters based on the “National Rural Biogas Development Plan 2003–2010.†This initiative aims to improve rural living conditions, promote ecological homes, and enhance agricultural productivity while reducing environmental pollution. By 2010, the plan aimed to increase the number of biogas digesters nationwide to over 50 million, with 20% of farmers using biogas. Total investment reached 61 billion yuan, with 44.9 billion yuan from the central government.
Since 2005, the biogas project has been implemented across provinces, serving as a key strategy for poverty alleviation and environmental improvement. For instance, in Henan Province, 30 counties and 306 villages undertook biogas projects, with a total investment of 10.405 million yuan, including 32.788 million yuan in central funds.
China's biogas technology is considered among the best globally. However, traditional concrete digesters still face challenges such as long construction times, high maintenance costs, and inefficiency during colder months. To address these issues, new technologies like the mobile solar biogas generator have emerged. Developed by the Beijing Qingda Huamei Environmental Protection and Energy Technology Research Institute, this innovative system combines a solar heat collector and a biogas generator. It uses dry fermentation technology, which offers faster gas production, higher output, and easier maintenance compared to conventional systems.
The solar heat collector captures and transfers solar energy to the biogas tank, maintaining optimal temperatures throughout the year. The biogas generator itself is made from advanced composite materials, offering superior mechanical strength and durability. Available in sizes ranging from 4m³ to 12m³, it allows for flexible use in different regions and family sizes. Unlike traditional underground digesters, it can produce gas continuously for 150–180 days after installation, with a lifespan of up to 20 years.
Biogas digesters are also gaining popularity internationally, especially in Southeast Asia, South America, and Africa. China has provided technical support to over 10 developing countries, with positive feedback from recipients. For example, in Cambodia, 30 demonstration units were successfully completed in 2005 and received high praise from the local government.
The biogas generation process involves three stages: hydrolysis, acidification, and methanation. Raw materials such as animal manure, crop residues, and organic waste are broken down into soluble compounds, then fermented into organic acids, and finally converted into methane. The gas production rate varies depending on the type of material and temperature. For instance, pig manure produces 0.45–0.76 m³ of gas per kg at medium temperatures (15–25°C), while cow dung produces 0.30–0.68 m³.
Anaerobic conditions are essential for biogas production, as methanogens require strict oxygen-free environments. Inoculation with microorganisms significantly improves gas yield. Adding 150 grams of inoculum to human feces, for example, can increase methane content from 48.3% to 87.2%.
The mobile solar biogas generator offers ten key advantages, including advanced dry fermentation technology, scientific design, excellent sealing, strong mechanical properties, high gas production rates, automatic desulfurization, anti-crust technology, enhanced safety features, easy installation, and low cost with a long service life.
Since its introduction in 2005, the biogas generator has been widely adopted in multiple Chinese provinces, including Beijing, Hebei, Shanxi, Sichuan, Yunnan, Hainan, and Jiangxi, achieving impressive results and receiving strong support from both local governments and farmers. Its success highlights the potential of biogas as a sustainable and efficient energy solution for rural areas worldwide.
Digital 60m short range laser rangefinder is a laser measurement device which is supposed to replace tape measure, ruler, and other traditional length meauring tool. Laser ruler as its name, it is a electronic ruler which user laser to measure distance. Our laser measurer has Multiply fuctions: 1. Height measure & Length measure &Distance measure 2. Area Measure 3. Volume Measure 4. Pythagorean Measure