Current background

There are often overlooked “green treasures” hidden in urban gardens – garden waste, also known as “green garbage” or “garden plant waste”. It mainly comes from two sources, one is the residues naturally produced by plant growth, such as autumn leaves, fallen flowers, and dead branches; The second is the waste generated by manual maintenance and pruning, such as grass clippings and branches. The main components of garden waste are natural organic substances such as cellulose, polysaccharides, and lignin, which can be biodegraded and will not pollute the environment for a long time like plastics and metals. Reasonable treatment can return to nature and can also be used as organic fertilizers in gardens to achieve resource recycling.

Process flow

To achieve the resource utilization of garden waste, “crushing treatment” is a key prerequisite, and efficient crushing can lay the foundation for subsequent recycling. The mainstream processing flow in the current industry adopts a combination of “conveyor belt+double shaft.

shredder”, as follows: first, the material is conveyed and the collected garden waste such as whole dead branches and piles of leaves are placed on the conveyor belt, which automatically sends them to the processing equipment to reduce manual handling costs; Then, the double axis shredder is used to shred and crush the garbage, and the garbage enters the double axis shredder. Two high-speed crushing shafts, combined with special cutting tools, cut and tear hard dead branches, fluffy leaves, grass scraps, and other materials into uniform and fine pieces within a few minutes; Finally, the materials are temporarily stored, and after crushing, the volume of the materials is reduced by 60% -80%, making it easier for subsequent transportation, storage, or direct utilization. The double shaft shredder has strong adaptability and can process hard wood branches and soft herbaceous waste. It has high crushing efficiency and uniform particle size of the finished product, providing high-quality raw materials for resource utilization such as organic fertilizer and fuel rod production.

Two major directions for the recycling and utilization of garden waste

Garden waste is rich in organic matter and is a high-quality raw material for making organic fertilizers. Its treatment achieves resource utilization through “composting fermentation processing”: the crushed garden waste is mixed with livestock manure and microbial agents, and the carbon nitrogen ratio and water content are adjusted before ventilation fermentation. Microbial decomposition is used to produce heat, and pests and diseases are killed at high temperatures of 55 ℃ -70 ℃. After decomposition, organic fertilizer is made by screening and granulation, with an organic matter content of ≥ 45%, which can replace 30% -50% of chemical fertilizers and reduce soil compaction and non-point source pollution.

In addition to producing organic fertilizers, garden waste can also be converted into high-density biomass fuel rods through the “pretreatment compression molding” process, opening up a new path for clean energy: the crushed garden waste is dried to a moisture content of ≤ 15%, and then extruded into rods through a biomass molding machine at high temperature and high pressure, with a calorific value of 3500-4500 kcal/kg, and no black smoke or odor during combustion. The emissions of sulfur dioxide and nitrogen oxides are reduced by more than 60% compared to coal. This fuel rod can be widely used in rural heating, industrial thermal energy, biomass power generation and other fields, replacing traditional fossil fuels.

Recycling advantages

The value of garden waste recycling does not exist in isolation, but rather through environmental actions to reduce ecological risks, economic innovation to unleash resource potential, and social participation to build cultural consensus, forming a synergistic effect of “1+1+1>3”. In the future, with the application of technologies such as the Internet of Things and artificial intelligence (such as intelligent classification devices and composting process monitoring systems), recycling efficiency will be further improved, promoting cities to move towards the goal of “zero waste”. This process is not only a redefinition of garbage, but also a profound reconstruction of the harmonious coexistence between humans and nature.

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