Straw opens the "counter-attack" road
Our reporter Wu Hao
Just after the autumn harvest was finished, Li Gang didn't rest for a moment, and began to harvest corn stalks from the village's 7,000 acres of land.
The waste straw that the villagers didn't want to clean up became the "sweet and pastry" in Li Gang's eyes.
Only by producing straw fuel pellets and feed pellets, Li Gang earns one million yuan a year, becoming a promising young man in the eyes of local villagers.
"There is also a world in the countryside. As long as you work hard, there is a way out." Li Gang is one of the few young people in Anle Village, Hailin Town, Hailin City, Mudanjiang City, Heilongjiang Province.
In late October, when the reporter saw Li Gang, he was busy transporting straw in the field. A straw baler not far away was packing corn stalks into bundles. Waiting for these straw materials".
As a major agricultural province, Heilongjiang produces about 90 million tons of crop straw every year.
Under the ban on straw burning, straw has also started a green and low-carbon "journey of life": straw returning to the field, straw pellets, straw power generation...the humble straw becomes organic matter and nourishes the black soil, and it also forms a cycle. The economic chain realizes "turning waste into treasure".
Turning waste into treasure
In the golden autumn of October, on both sides of the highway from Jiamusi City to Jiansanjiang, the rice waves are rolling and the fertile fields are beautiful.
Located in the hinterland of the Sanjiang Plain, Jiansanjiang has the reputation of "China's Green Rice City". Among 11 million acres of arable land, 10 million acres are planted with rice, and the total annual output of grain is more than 12 billion catties.
After the rice is harvested, how to use the large amount of straw?
"Rice straw is still mainly returned to the field, which is conducive to improving soil structure, increasing soil organic matter, and enhancing soil fertility." Zhou Lilei, director of the Ninth Management District of Qianjin Farm, told reporters.
The reporter learned that in the rice-growing area of Heilongjiang, rice straw returned to the field formed a "three rivers model" to protect the black soil: When rice is harvested, the harvester installs crushing and spraying equipment to crush the rice straw to less than 10 cm and evenly spray it.
Then use the rotary tiller to rotate the ground, and evenly mix the straw in the 20 cm tillage layer.
In the spring of the second year, when the field is soaked and the ground is prepared, a slurry leveler with a cutting and pressing device is used for the mixing operation, and the straw is further cut and pressed and stirred evenly into the 20 cm plow layer to reach the ready-to-insert state.
In addition to paddy fields, the dry land crops in Heilongjiang are mainly corn and soybeans, and the uses of corn stalks and soybean stalks are slightly different.
"Because of its high protein content, soybean straw is basically used as feed for cattle and sheep. Corn stalks are more widely used. Corn stalks can be used for returning straw to the field, straw fertilizer, straw fuel, and biomass power generation." Hailun City, Suihua City Said Liu Xiangbo, director of the Black Land Protection Project Office of the Agriculture and Rural Bureau.
Aiming at the dry land, the "Longjiang model", which uses crushed corn stalks, mixed organic fertilizers to deep turn back into the field, and combines the corn-soybean wheel as the key technology, has become another important model for black land protection.
"At present, the organic matter content of the cultivated land in Heilongjiang Province is 3.6% on average, and the soil organic matter content has been slowly rising by returning straw to the field. After the straw is returned to the field, after a natural year, the straw decomposition rate is 75%, and the remaining 25% It has become a semi-decomposed state and has no effect on agricultural production in the following year.” said Han Xiaozeng, a secondary researcher at the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, and deputy head of the farmland quality construction expert guidance group of the Ministry of Agriculture and Rural Affairs. Deep ploughing and deep turning also help to break the bottom of the plough, which has the effect of deepening the cultivation layer and increasing fertility.
"Straw returning to the field actually belongs to the category of straw fertilizer utilization. It is an important way to protect black soil and occupies a dominant position in the comprehensive utilization of straw in Heilongjiang." Zhang Sitao, head of the straw work class of the Heilongjiang Provincial Department of Agriculture and Rural Affairs, told reporters in 2020. The crop straw output in Heilongjiang is 91.09 million tons, and the collectable amount is 77.828 million tons, of which 56.172 million tons are returned to the field, and the return rate reaches 72.81%.
Broad market
From a national perspective, the state vigorously advocates the "five" utilization of straw, including straw fertilizer, fuel, feed, raw material, and base material.
Behind this "five modernizations" is the support of straw industrialization. The straw will get rid of the fate of being burned and usher in a different "life".
"Straw has become a high value-added product. It is not a fantasy. The straw fertilizer I produce is exported to South Korea at a price of 6000 yuan per ton." In Hailin City, the reporter met Li Yixin, who returned from studying in South Korea. Energetic.
10 years ago, Li Yixin began to cooperate with Bay Aotai, an organic feed production company affiliated to the Korea Institute of Biotechnology, to provide him with raw materials for organic feed.
"Korea has a small land area and it is impossible to grow corn on a large scale, so it needs to import straw from China." Li Yixin told reporters that the added value of original straw is very low after all. After 6 years of cooperation, he began to seek to produce more profitable products.
"Beginning in 2017, I negotiated cooperation with Stebia, an organic fertilizer production company under the Korea Institute of Biotechnology, and finally successfully signed a cooperation agreement at the end of 2019 to produce organic fertilizer pellets for it in China. The main raw material is corn stalks. "Li Yixin said that by switching to the production of organic fertilizer pellets, the annual export value can reach more than 10 million yuan.
Due to the impact of the epidemic in recent years, companies have encountered some troubles in product exports, but the market prospects are very broad.
"We are optimistic about the market prospects of straw fertilizers. We will set up a plant in Jiansanjiang to produce straw carbon-based fertilizers and digest and utilize the abundant local rice straw resources." Wang Jinguo, deputy general manager of Heilongjiang Jiansanjiang Agricultural Reclamation Jiuzhou Fangyuan Biomass New Material Co., Ltd. told reporters. The production of straw charcoal-based fertilizer adopts a circular economy model, which is green and low-carbon throughout.
Wang Jinguo said that the straw must first be made into biomass pellets, and then biomass charcoal is generated through carbonization technology, which is blended with the three major fertilizers of nitrogen, phosphorus and potassium to make a carbon-based compound fertilizer.
During the production process, a light straw vinegar solution is generated, which can be used to make environmentally friendly pesticides and liquid fertilizers, and the generated straw can be recycled and reused, so as to truly "eat dry and squeeze" the straw.
Biomass carbon-based fertilizers also have good stability in terms of carbon sequestration and emission reduction.
"More than 70% of the biomass charcoal in the soil can be stored for more than 100 years without being decomposed to release carbon dioxide. By converting straw into biomass charcoal, the carbon dioxide in the atmosphere captured by crop photosynthesis can be converted into carbon and fixed in the soil. Effectively increase the soil carbon pool and offset the carbon emissions generated by economic development." Wang Jinguo said.
Boosting "Dual Carbon"
Some time ago, rising coal prices and power cuts became a hot topic.
In ensuring national energy security, straw as a renewable resource is also very useful.
“People in rural areas have always regarded straw as a relatively easy-to-obtain fuel, and the lifestyle of using straw to make fires for cooking and heating has been followed for a long time.” Liu Jie, dean of Heilongjiang Black Land Conservation and Utilization Research Institute, said that the use of straw as fuel is not Simply burning straw, but with the help of technical means to achieve clean energy supply.
In Lanxi County, Suihua City, Lanxi Chenneng Biomass Power Generation Co., Ltd. stores a large amount of corn stalks in its yard. This is the first local project to use straws to generate electricity.
In Heilongjiang province, a number of straw power generation projects have been deployed in recent years, which not only solves the large number of straw treatment problems in the local area, but also helps reduce carbon emissions and develop clean energy to ensure energy security.
"The data shows that the calorific value of 2 tons of straw can be used to replace 1 ton of standard coal, and biomass such as straw is the only zero-carbon energy source, and it does not produce sulfide when burned. It is a kind of renewable clean new energy. Energy." Li Xujian, general manager of Lanxi Chenneng Biomass Power Generation Co., Ltd., told reporters that a 30MW biomass power generation unit generates 210 million kilowatt-hours of electricity per year and consumes 300,000 tons of biomass fuel such as straw, rice husk, wood chips, and fungus bags. , Replace standard coal with straw to achieve clean power generation.
In addition to clean power generation, straw is also generally suitable for clean heating.
In Haibei Village, Haibei Town, Hailun City, Suihua City, a 14MW (20 ton) straw direct-fired boiler of Hailun Junjia New Energy Heating Co., Ltd. replaced the old 10-ton coal-fired boiler as a heat source for 1,428 local residents and the whole town. Public facilities provide centralized clean heating, benefiting 83% of the village’s population, and are also included in the Rural Human Settlements Improvement Technical Service and Improvement Project of the Ministry of Agriculture and Rural Affairs.
"A 14MW (20 tons) straw direct-fired boiler consumes 14,800 tons of straw for six months, replaces 8,225 tons of coal, saves about 3 million yuan in fuel costs, reduces 21,000 tons of carbon dioxide, and greatly improves rural areas. Living environment." said Wan Xianjun, chairman of Hailun Limin Energy-saving Boiler Manufacturing Co., Ltd.
In the Harbin New District, the biomass cogeneration and supporting projects invested and constructed by Heilongjiang Hongtong Thermal Power Co., Ltd. can not only generate electricity and heat, but also supply steam to nearby factories and enterprises in the Limin Development Zone. Renewable energy power generation projects in Northeast China For the first time in China, the unity of power generation, heating, and industrial steam supply has been achieved.
"Our two boilers can'eat' 600,000 tons of straw a year, produce 450 million kilowatt-hours of electricity per year, and reduce carbon dioxide emissions by about 360,000 tons per year. It not only solves the problem of straw burning in Harbin New District and Hulan District, but also At the same time, around the industrial chain of straw purchase, processing, storage, transportation, etc., it also provides nearly 1,500 jobs for local rural areas." Gao Bo, deputy general manager of Hongtong Heating Company, told reporters.
At present, Heilongjiang’s comprehensive utilization of straw is at the forefront of the country. This year’s comprehensive utilization rate of straw will exceed 91%, and the rate of returning straw to the field will exceed 66%. This basically forms the basis for the use of fertilizers, feed and fuel use steadily. Comprehensive utilization pattern supplemented by base materialization and raw materialization.
"However, from a national perspective, the degree of industrialization of comprehensive utilization of straw in my country is still relatively low, and there are still bottlenecks in cost control and promotion of innovative technologies for straw utilization. In the future, the investment in scientific and technological innovation for comprehensive utilization of straw should be strengthened and the comprehensive utilization of straw should be continuously expanded. The breadth and depth of stalks will create more value from straw, and promote the modernization of agriculture and the realization of the'dual carbon' goal." Liu Jie said.
Our reporter Wu Hao
Our reporter Wu Hao