During the summer harvest season, in Lingqiao Township, Huai'an City, Jiangsu Province, where the 'Lingqiao Rice' is produced, it is difficult to see bundles of straw in the field. Instead, a Taiwanese 'stalk granule machine' is used to 'eat' the straw. 1. Squeeze a small piece of straw with a small thickness of chalk.
'This guy can handle more than ten tons of straw a day.' Li Yongqi, manager of Huaian Lianchuang Straw Cooperative, told the reporter that the farmers took the straw from the ground and could process it at their doorstep.
The villager Zhu Haiqing calculated an account. According to the 500 kg of straw per mu, he used to take the straw recycling subsidy of 35 yuan per mu. He worked hard to collect one ton but 70 yuan. Some people were in trouble and burned. Now the straw is sent. Into the machine 'roll', it can sell 350 yuan per ton, which is 5 times the original.
However, in the view of Professor Pan Genxing, director of the Institute of Agricultural Resources and Eco-Environment of Nanjing Agricultural University, these are only raw materials, and the final product of comprehensive conversion of straw is worth nearly 1,000 yuan per ton.
'After the end of summer harvest, it will be planted in two weeks. The time is too tight. Burning straw is not the fault of the peasants.' Pan Genxing introduced, taking the North China and Jianghuai areas as an example, under modern planting conditions, the land can be two years. For even three crops, the amount of straw produced is far beyond the upper limit of natural decomposition. If only the straw is ground and returned to the field, the residual pests and diseases may return to the soil. High temperature incineration can not only kill pests and diseases, but also facilitate the soil absorption, but the cost is pollution. atmosphere.
'This requires us to find a way to deal with the recycling of straw, industrialization, so that farmers and enterprises can obtain sustained and stable income, and everyone can be more motivated to protect the ecological environment.' Pan Genxing said.
The Pan Genxing team began to study thermal cracking technology in 2009. Three tons of rice straw can produce 1 ton of biomass charcoal and 2000 cubic meters of combustible gas. The comprehensive output value is nearly 3,000 yuan. The resource conversion rate of straw decomposition increases from 5% in the natural state. Up to 85%, while reducing greenhouse gas emissions by nearly 80%; the use of biomass-based carbon-based fertilizer can effectively reduce the amount of fertilizers by 10%-15%, very popular with farmers.
Technology can't be placed in the 'deep' of the laboratory, and it should be put on the industrialized 'marriage'. In 2016, through the cooperation of schools and enterprises, Nanjing Agricultural University developed a large-scale straw pyrolysis biomass carbonization supporting production system. The annual processing of straw is 3-5 million tons.
At present, nearly 200 companies across the country use Nannong technology to produce straw charcoal-based fertilizer. Through cooperatives, farmers hand over straw to enterprises and exchange for charcoal-based fertilizers. The income of agricultural products is dividendd by farmers and enterprises, and has become a new model for promoting straw recycling. Recycling straw, farmers have no motivation, cadres are under pressure; now farmers are profitable, and enterprises are also eager to go. 'Pan Genxing said.
It is estimated that by 2020, the annual processing capacity of the national straw recycling industry will reach 5 million tons. The technology of converting straw into combustible gas has also been piloted in Heilongjiang, Shandong and other provinces. If it is widely promoted in the future, it can partially reduce coal burning in the north in the winter. , improve air quality.
Ding Yanfeng, vice president of Nanjing Agricultural University, believes that the essence of the green production concept is to improve resource utilization. Following the fertilizer and variety, the biomass waste recycling industry is expected to lead the third agricultural green revolution.