Straw has many uses
Thread Content
Straw is a general term for the stems, leaves (and panicles) of mature crops. It generally refers to the remaining parts of crops such as wheat, rice, corn, tubers, oilseeds, cotton, sugarcane, and other agricultural plants after the harvest of their seeds. More than half of the products of crop photosynthesis are found in straw. Straw is rich in nitrogen, phosphorus, potassium, calcium, magnesium, and organic matter; it is a versatile and renewable biological resource, as well as a type of roughage. It is characterized by a high content of crude fiber (30%-40%) and contains lignin, among other substances. Although lignin cannot be utilized by pigs and chickens, it can be absorbed and utilized by ruminants such as cows and sheep. Straw building materials: Straw is an efficient and sustainable raw material for the light industry, textiles, and construction sector. It can partially replace materials such as bricks and wood, while also helping to protect arable land and forest resources. Straw wall panels offer excellent insulation, decorative qualities, and durability; many developed countries have adopted them as alternatives to wood panels and tiles in the construction industry. Furthermore, straw processed through technical methods can be used to produce rayon and artificial cotton, as well as furfural, maltose, alcohol, and xylitol; it can also be used in the production of fiberboard, etc. Straw can be converted into biooil. The Laboratory for Renewable Clean Energy at the University of Science and Technology of China announced that a new technological achievement developed by professors such as Zhu Xifeng and Guo Qingxiang can fundamentally solve this long-standing problem. They carry out pyrolytic liquefaction and reprocessing of various raw materials such as wood chips, rice husks, corn stalks, and cotton stalks, turning waste into treasure by converting them into biooil. The oil yield from wood chips is over 60%, while that from stalks is over 50%. The calorific value of this biooil is 16–18 megajoules per kilogram. This achievement has been tested on a pilot scale, and industrialization is just around the corner. It is reported that in our country, there are over 700 million tons of agricultural crop residues and fruit peels each year; burning them on site not only wastes resources but also causes severe environmental pollution. With this technology, biomass such as straw can be directly converted into biooil, which can be used as fuel in fuel boilers and industrial furnaces. After refinement, it can be used as a vehicle fuel, and high-value chemical products can also be separated and extracted from it. Based on years of research experience, experts from the University of Science and Technology of China have proposed the best approach for industrializing this technology: first, carry out moderate-scale thermal decomposition of biomass at its source locations, converting it into primary liquid fuel—biooil—that is easy to transport and store. Then, the biooil obtained through thermal decomposition in various locations is collected and further processed. This approach can effectively address the bottlenecks associated with the widespread use of biomass resources, such as their scattered distribution and seasonal limitations. It is reported that the optimal scale for a single unit of pyrolytic liquefaction is to process 2 tons of straw per hour (with a collection radius of about 10 kilometers), producing 1 ton of biooil; the production cost is approximately 790 yuan per ton. After simple quality improvement, the calorific value of biooil increases to about 18–20 MJ/kg. Assuming a selling price of 1,000 yuan per ton, when used to replace diesel and heavy oil to provide the same amount of heat, its price is equivalent to 43.2% of the current price of diesel and 63.1% of the current price of heavy oil, respectively.
Returning straw to the fields enriches them. The mechanical technique for returning all straw to the fields is a completely new practical agricultural method; by using this technique, all of the straw can be returned to the fields, which helps to increase soil organic matter, improve soil structure, and enhance soil fertility, turning straw into the best organic fertilizer for farmland. The main mechanized technologies for returning straw to the field that are promoted include installing a straw crushing and spreading device on combine harvesters, which crushes the threshed straw and spreads it evenly across the field before burying it in the soil ； Use a series of reverse stubble cultivators to crush the wheat straw and turn it back into the soil ； The wheat stubble fields are soaked in water, and then a stubble burial and soil preparation machine is used to turn the stubble over and bury it in the soil, making it easier to plant rice. Straw mixed with soil can be essentially decomposed in about 25 days, adding organic fertilizers such as nitrogen and phosphorus to the farmland and effectively boosting agricultural yields. Straw can serve as a new food source for livestock. To further promote the transformation and increased value of straw, Lianyungang City combines the development of methods for storing straw in silage or through ammonification with the livestock farming industry. Taking advantage of the city’s strong livestock farming sector with a large number of operations on a large scale, crop straw is mechanically crushed and mixed, then sealed up for saccharification or ammonification processes; after some time, it is used as feed for livestock. The treated feed not only eliminates bacteria and microorganisms but also allows for longer storage; as a result, the livestock raised with it grow faster, at lower costs, and yield higher profits. To date, the city has built 500,000 cubic meters of silage and ammoniation tanks for straw, enabling the storage of 200,000 tons of straw per year; more than 20,000 farmers have embarked on a path to prosperity by raising cattle using straw. Dong Yulong, a large-scale farmer in Ganyu County, invested 500,000 yuan to build a large-scale ecological cattle farm with the guidance of the agricultural machinery department. By using Japanese EM original solution microbial breeding technology, he mechanically crushed 500 tons of corn straw while it was still green, then divided it into 12 silos of 80 m3 each. After mixing it with water and EM original solution, the mixture was sealed with plastic film for fermentation; this amount is sufficient to meet the needs of 75 cows for one year, resulting in a 30–50% increase in the overall efficiency of cattle farming. Straw gasification brings a new life to farmers. To improve the utilization rate of straw, Lianyungang City has also actively promoted mechanized straw gasification technology. Gucheng Village in Banzhuang Town, Ganyu County makes use of this technology: straw is mechanically chopped up and burned to produce combustible gases; the smoke and gases are then separated, and the stored gases are delivered through pipes to the households throughout the village for use. This approach is clean and hygienic, and it enables efficient utilization of low-quality energy sources. In Sanlidun Village, Menghe Town, Ganyu County, biogas digesters made from straw have been installed throughout the village; this biogas is used for lighting and cooking. Millions of pounds of various types of straw are consumed each year, bringing economic benefits of over a thousand yuan to the local farmers. Furthermore, it can also be used in biogas production, and biogas will be one of the most valuable fuels in the future! ! !
I would like to ask about the specific process flow for producing biogas from straw – what preparations are needed in the pre-treatment stage? Thank you!
I really hope that **the technology used in this area can develop well!** Over the course of a year like this, who knows how much oil and coal can be saved! How much can pollution emissions be reduced, and how much can that save rural areas in terms of costs! How much wealth can we **accumulate!
Now, straw, just like trash, has a wide range of uses
Straw has many useful applications, but these days, every autumn, some people burn it. It’s important to consider ways to make use of it comprehensively, and cost is also a key factor.
I heard there is a type of stove that first gasifies about 2 kilograms of straw and then burns it, thereby allowing one to prepare a meal.
Fermenting straw using straw fermentation agents is a beneficial project for both the country and its people, and it has now been widely promoted across the nation. Straw can also be used as fuel for power generation, thus enabling it to be utilized as a new source of energy
I only know of one new technology for generating electricity from straw, and I’m not sure if it has been successful
While making great efforts to develop new energy sources, it is also important to proceed in a balanced manner. In recent years, many areas have suffered from famine precisely because of the extensive development of biofuels, which has led to the appropriation of large amounts of arable land for growing such plants.
On the one hand, straw is a bioenergy source that can be used for generating electricity, heating, etc. On the other hand, straw can be used to make floors, which represents waste utilization and recycling, and it also responds to the calls for energy conservation, emission reduction, and a circular economy. But at present, due to the weak foundation, its use on a large scale is still limited; this requires time.