Agricultural and forestry waste (straw, wood chips, rice husks, branches, fruit shells, etc.) is a "natural by-product" of agricultural and forestry production, but for a long time, its disorderly treatment methods (incineration, random stacking, and abandonment) have become an easily overlooked "invisible pollution source", which not only wastes resources, but also causes multi-dimensional damage to the ecological environment.
1. "Invisible pollution" of agricultural and forestry waste: an ignored ecological threat
The pollution of agricultural and forestry waste is not an obvious "industrial sewage discharge", but it permeates many links of production and life, forming "invisible damage":
(1) Air pollution: "Breathing pain" caused by incineration
The pollutants generated by straw burning account for 20%-40% of the source of PM2.5 in winter. The burning of a single ton of straw can release 2.3kg of particulate matter (PM2.5, PM10), 6.3kg of carbon monoxide, 0.5kg of nitrogen oxides and a large amount of volatile organic compounds (VOCs), resulting in frequent regional haze. In addition, polycyclic aromatic hydrocarbons (PAHs) produced by open-air burning of branches and wood chips are strong carcinogens and have significant harm to the human respiratory and cardiovascular systems.
(2) Water pollution: "infiltration hazards" caused by stacking
When agricultural and forestry waste is stacked in the open air, it will release leachate containing nitrogen, phosphorus, potassium and humus after being washed by rainwater, and then flow into farmland or water bodies to cause "eutrophication" - for example, if 1 ton of wet straw is stacked for 3 months, the leachate can cause the nitrogen content of 100 square meters of soil to exceed the standard by 5-8 times, or cause algae to grow wildly in small ponds, destroying the balance of aquatic ecology.
(3) Soil pollution: "fertility plunder" caused by abandonment
In traditional concepts, "returning straw to the field" is considered an environmentally friendly way, but untreated straw rots slowly in the field (it takes 6-12 months), during which time it will breed pests and diseases (such as corn borers and root rot bacteria), and compete with crops for soil oxygen and nutrients, leading to "hidden degradation" of cultivated land. A large amount of sawdust and fruit shells abandoned in the fields will also change the soil pH value and reduce the productivity of cultivated land.
(4) Resource waste: "Energy in the wrong place"
If it is abandoned at will, it will not only occupy land (about 5-10㎡ per acre of farmland is required to pile up straw), but also require manpower to clean up, forming a double burden of "pollution + waste".
2. Biomass pellet machine truly realizes "turning waste into treasure"
The core function of the biomass pellet machine is to convert scattered, low-quality agricultural and forestry waste (water content 15%-20%, particle size 2-5mm after crushing) into high-density (1.1-1.3g/cm³) and high calorific value (4000-4500kcal/kg) biomass pellet fuel through high-pressure extrusion. The whole process realizes the dual value of "pollution cutting" and "resource activation"
(1) Pollutant emissions drop sharply
When the original straw is burned, the smoke emission concentration can reach 500-800mg/m³, while the biomass pellets are burned in a special boiler, the smoke concentration can be controlled below 30mg/m³, nitrogen oxide emissions are reduced by 60% (because the pellets are fully burned to avoid the generation of NOx at local high temperatures), and almost no VOCs and polycyclic aromatic hydrocarbons are released.
(2) Replacing fossil fuels to reduce carbon emissions
The carbon cycle of biomass pellet combustion belongs to "short-cycle carbon neutrality" (plant growth absorbs CO₂, and combustion releases an equal amount of CO₂). Compared with coal combustion (2.6 tons of CO₂ per ton of standard coal), burning 1 ton of biomass pellets can reduce CO₂ emissions by about 1.8 tons, indirectly reducing the "hidden carbon pollution" caused by fossil energy.
The biomass pellet machine cuts off these pollution chains from the source through "resource and energy" transformation, becoming the core equipment for solving agricultural and forestry waste pollution.