The following is the introduction of the manufacturer's website. In principle, there is not much water:
China's household biogas utilization technology has been at the leading level in the world. From the domestic point of view, the traditional biogas plant is mainly built with concrete. Although its structure and construction technology have been continuously improved for many years, there are still some problems such as long construction period, complicated construction technology, inconvenient daily management and high maintenance cost.
Rural household biogas digesters have great market potential at home and abroad, and are suitable for rural areas in Southeast Asia, South America and African countries. China organized technicians to provide technical assistance to rural biogas digesters in more than 10 developing countries, which was highly valued and welcomed by the recipient countries. In 2005, 30 demonstration projects of rural household biogas digesters aided by China were completed, which was highly praised by the Cambodian government.
The mobile solar biogas generator is the latest patented product (patent application number: 200720 16952 1.5) developed by the solar biogas engineering research group of Beijing Qingda Huamei Environmental Protection and Energy Saving Technology Research Institute (www.199.cn), which consists of a solar collector and a biogas generator.
A, solar heat collection device
It is mainly composed of solar collectors and heat pipes. Solar collector is a kind of heat collecting device, which can be assembled into heat collecting systems with different lighting areas according to needs. Its main function is to collect heat and exchange heat with its supporting equipment. The solar collector is the main heat-absorbing component, which converts the absorbed solar energy into heat energy through a large amount of illumination, and transports it to the biogas digester through the heat pipe to raise the temperature in the biogas digester, thus achieving the best effect that can be used all year round.
Second, the biogas generator
The biogas generator is refined from organic fiber cloth and inorganic composite materials, and has an air outlet, an air inlet and an air outlet. The wall thickness is 2-6cm, the tensile strength is 93.5pg, and the bending strength is 100 mpg. It has strong mechanical strength and elongation, which greatly exceeds the strength of traditional underground biogas digesters. The models are 4m3, 6m3, 8m3, 65438+ 100m3, 12m3 and other specifications, which can meet the needs of different regions and families. Using dry fermentation technology, gas production is fast and large, which completely changes many problems of traditional underground biogas digesters, such as high construction cost, large area, long construction period and no gas production in winter. And it can continue to produce gas with a single charge.
Third, the preparation of biogas fermentation raw materials and the principle of gas production
1. Distribution of raw materials
There are many raw materials available for biogas fermentation in rural areas. The most commonly used are human and animal (pig, cow, sheep, horse, chicken, duck) feces and various crop straws (rice straw, wheat straw, corn straw, rape, soybean, peanut straw), various green grasses, rotten vegetable leaves, water hyacinth, waste residue, wastewater (distiller's grains, tofu-making wastewater) and so on.
2. Types and characteristics of biogas fermentation raw materials
According to the chemical properties and sources of biogas fermentation raw materials, it can be divided into the following categories:
A, nitrogen-rich raw materials; Nitrogen-rich raw materials mainly refer to human and animal manure, which contains more low-molecular-weight compounds and higher nitrogen content, and the ratio of carbon to nitrogen is generally less than 25: 1. It does not need pretreatment, and its fermentation cycle is short, and it decomposes and produces gas quickly. It is the main raw material of rural biogas at present.
B other raw materials: organic wastes, including all kinds of waste residue and wastewater, such as distiller's grains, tofu wastewater, domestic sewage and organic garbage, all kinds of straws, grasses, weeds and aquatic plants. With soft tissue, it is easy to be decomposed and utilized by microorganisms.
C. Gas production characteristics of common biogas raw materials and influence of temperature: Gas production characteristics of raw materials are important technical parameters of biogas fermentation. There are many kinds of raw materials for biogas fermentation. Because of their different chemical compositions, each raw material has different gas production characteristics, including gas production rate and gas production speed. The gas production of different raw materials at different temperatures is shown in the following table:
Raw material name
Medium temperature 15-25℃
Normal temperature 6- 15℃
pig manure
0.45-0.76
0.25-0.30
cow dung
0.30-0.68
0.20-0.25
human excrement
0.43-0.7 1
0.25-0.30
Green weeds
0.44-0.73
0.20-0.25
3. Gas production principle
The first stage, hydrolysis stage: insoluble organic matter and polymer are converted into soluble organic matter by enzymatic method;
The second stage, acidification stage: the organic matter in the first stage is fermented into organic acid;
The third stage, methanation stage: organic acids are fermented to produce methane.
4. Gas production rate of biogas raw materials
Gas production rate refers to the rate at which raw materials produce biogas under suitable fermentation conditions, which is expressed as the percentage of biogas production to the total output in a certain period of time. The gas production rate is related to the internal factors such as the composition and properties of raw materials, and is also influenced by external factors such as fermentation conditions and inoculum biogas generator. It is of great significance to correctly grasp the gas production rate of raw materials for reasonable batching and daily management.
Gas production rate of common fermentation raw materials (percentage of total gas production)
Raw material name
fermentation time
10
20-30
40-50
60-70
80-90
human excrement
40.7
8 1.5
94. 1
98.2
98.7- 100
pig manure
46.0
78. 1
93.9
97.5
99. 1- 100
cow dung
34.4
74.6
86.2
92.7
97.3- 100
All kinds of weeds
-
30.3-47.7
78.3-88.7
93.2-96.7
98.9- 100
wheat straw
18.8
30.8-53.7
78.3-88.7
93.2-96.7
98.9- 100
All kinds of organic wastes
10.08
29.4-45.7
77.5-85.3
94.7-97.9
98.8- 100
Five, the conditions of biogas fermentation and the effect of inoculum on gas production of similar raw materials.
Biogas fermentation is a biochemical process, which does not have the corresponding conditions and can not get biogas or get little.
A. Strict anaerobic conditions: Biogas fermentation microorganisms include acidogenic bacteria and methanogenic bacteria. The acidogenic bacteria (methanogens) in the acid-producing stage are mostly anaerobic, and some are aerobic and facultative anaerobic, while the methanogens in the gas-producing stage are obligate anaerobic and do not need oxygen, but oxygen is toxic to methanogens. Therefore, good anaerobic conditions must be created. These two types of biogas bacteria constitute a complex ecosystem. When biogas fermentation starts or new materials are loaded into the generator, some oxygen will be brought in, but in a sealed generator, the activities of aerobic bacteria and facultative anaerobic bacteria will quickly consume this oxygen, thus creating good anaerobic conditions.
Inoculum B: In the process of anaerobic decomposition of organic waste to produce methane, it is completed by a variety of biogas microorganisms. Therefore, it is extremely important to add enough required microorganisms as inoculum (commonly known as strains) in biogas fermentation. The influence of biogas inoculum on gas production of similar raw materials is shown in the following table:
raw material
Inoculation amount%
Biogas production (ml)
Methane content%
50 grams of human excrement
10
1435
48.3
50 grams of human excrement
20
3085
55.2
50 grams of human excrement
50
10093
69.3
50 grams of human excrement
150
16030
87.2
Ten advantages of mobile solar biogas generator
1. Advanced technology: dry fermentation technology, fast gas production and large gas production;
2. Scientific design: spherical design, consisting of two hemispheres, with good thermal insulation effect, small floor space and convenient charging and discharging;
3. Good sealing performance: good air tightness, no water leakage, no air leakage, corrosion resistance, aging resistance and convenient maintenance;
4. Good mechanical properties: earthquake resistance, pressure resistance and ground icing may damage underground concrete biogas digesters, while glass fiber reinforced plastic products have certain elasticity and tensile resistance and will not be frozen and cracked by frozen soil, so they are suitable for use in cold areas in the north;
5. High gas production rate: the thermal conductivity of FRP material is 1.42 kJ(m/h), and that of concrete is 5.44KJ(m/h), which ensures a high gas production rate, and the gas production rate and gas storage capacity are increased by about 30%;
6. Automatic desulfurization: the automatic desulfurization device and the gas-water separator can automatically remove sulfur dioxide and water vapor during the reaction, thus maximizing the purity of methane and increasing the calorific value (pure methane is about 8,000 kcal/m3, 8,600-9,500 kcal/m3);
7. Anti-crusting technology: Due to design reasons, traditional underground biogas digesters must rely on manual stirring to prevent liquid materials from crusting, and the biogas generator is scientifically and reasonably designed, which completely solves this problem;
8. High safety factor: automatic voltage stabilization, equipped with safety valve, barometer, automatic pressure reducing valve and automatic exhaust valve, which is safe and reliable;
9. High strength, light weight, simple installation: it can be stacked, easy to carry, installed on the ground, ready to use, not limited by geographical conditions, and convenient to move;
10. Low cost and long service life: the manufacturing cost of each set is between 350-400 yuan, and the service life can reach about 20 years.
Product technical maturity and ownership attributes
In 2005, the demonstration project of "biogas generator" was established in Hainan Province and Hebei Province, which achieved good results and was well received by the local government and farmers.
As of June 5438+February, 2006, biogas generators have been widely used in Beijing, Hebei, Shanxi, Sichuan, Yunnan, Hainan, Jiangxi and other places, and achieved good results, which were well received by local government departments and farmers.