Artificial boards are not disposable products; they can be recycled and put to great use!

Unlike solid wood furniture, panel furniture lacks collectible and heirloom value, has a lifespan of only a few years, and is quickly replaced. It is well known that China is a major producer of engineered wood products, but at the same time, the country also generates a large amount of waste engineered wood every year. Waste disposal requires enormous human and material resources and also burdens environmental resources.

Reusing waste engineered wood products can effectively reduce environmental pollution, conserve timber resources, and create economic value.

Currently, the reuse of waste wood-based panels mainly focuses on two aspects: one is material reuse, which refers to processing wood materials and using them as raw materials to produce other products; the other is energy reuse, which refers to processing waste wood-based panels into energy materials such as fuel.

Recycling of waste engineered wood products

The recycling of waste engineered wood products mainly involves using the wood materials in the engineered wood products, which are then processed through physical and chemical means and used as raw materials in the production of new materials.

The production of recycled particleboard, wood composites, activated carbon, and liquefied products are the main products of waste wood-based panels recycling.

01. Recycled Particleboard

Recycled particleboard is made by screening and separating waste particleboard to produce shavings, which are then washed and dried. The waste shavings and fresh shavings are mixed in a certain proportion, and appropriate processing conditions are selected to produce particleboard that meets national standards. Studies have shown that adding 40% fresh shavings to waste shavings results in particleboard that meets national standards.

This method can save timber resources and reduce environmental pressure, but it generates a lot of dust pollution during the mechanical crushing, grinding and screening of waste boards. It needs to be combined with dust removal equipment to reduce environmental pollution.

02. Wood-based composite boards

By processing waste engineered wood panels and combining them with one or more other materials, wood-based composite materials with new properties can be prepared.

Waste fiberboard or particleboard powder can be mixed with thermoplastic resin to produce composite boards; composite boards made by mixing waste fiberboard with cement or gypsum in a certain proportion meet national standards.

As research progresses, more composite boards made from waste engineered wood panels will surely enter the market.

03. Activated Carbon

Activated carbon is a porous material with a strong adsorption capacity, widely used in separation, purification, catalyst and reagent recovery. In daily life, people often place several bags of activated carbon in newly renovated rooms to adsorb free formaldehyde gas in the air.

Using waste engineered wood products to prepare activated carbon can make full use of the wood materials in the engineered wood products. Moreover, the adhesives in engineered wood products contain a large amount of nitrogen, and nitrogen-rich activated carbon has a much higher adsorption capacity than ordinary activated carbon. Therefore, activated carbon prepared from waste engineered wood products has better quality.

04. Liquefied products

Waste engineered wood products can be liquefied using specialized processing methods and used in the preparation of other materials. These products contain significant amounts of cellulose, hemicellulose, and lignin, making them potential chemical raw materials. Liquefied waste engineered wood products can be used to produce adhesives, foaming materials, molding materials, carbon fibers, and other products.

Currently, the technology for liquefying waste engineered wood panels is not yet mature, and its high cost prevents its widespread adoption in the market. Further research is needed to explore this technology further.

▲ Fuel ethanol

▲Biodiesel

Energy recycling of waste wood-based panels

Energy reuse refers to processing waste engineered wood panels into various types of fuels, including pellet fuels, liquid fuels, and gaseous fuels. Common processing methods include pellet fuel preparation and pyrolysis refining.

01. Preparation of pellet fuel

Wood-based materials from waste engineered wood products can generate a large amount of combustion heat, making them an excellent energy conversion material. As fossil fuel resources (coal, oil, natural gas, etc.) are gradually depleted, biomass energy conversion is receiving increasing attention.

Waste engineered wood products can be crushed, processed, and compressed into solid pellet fuel under high pressure. Pellet fuel has advantages such as being environmentally friendly, having excellent combustion performance, high thermal efficiency (more than 5 times that of direct combustion), and being easy to transport and store. It can be used for heat supply, power generation, and domestic fuel, and its production and use are relatively environmentally friendly.

02. Thermal pyrolysis refining

Thermal pyrolysis refining refers to the process of converting biomass raw materials into intermediate products such as liquid bio-oil, solid pyrolysis char, and biogas through thermal pyrolysis reactions, thereby achieving high-value utilization.

▲ Biomass pyrolysis method

Pyrolysis mainly refers to the process of converting substances in waste engineered wood products into easily stored and transportable intermediate products (such as bio-oil, pyrolytic charcoal, biogas, etc.) in an environment with isolated oxygen or limited oxygen supply, under conditions of moderate reaction temperature (450-600℃), high heating rate (1000-100,000℃/s), and extremely short gas residence time (less than 2 s) using thermochemical methods. These intermediate products are then further refined to obtain energy, materials, or chemical products.

Summarize

With the development of technology, the methods of waste disposal will become more scientific and environmentally friendly, making full use of the residual value of materials, improving the utilization rate of forestry resources, and reducing environmental pressure.

Some textual references:

Li Jian, Hou Xianfeng, Du Yueming, Liu Siqin, Yuan Zixiang, Gao Zhenzhong. Research progress on the reuse of waste wood-based panels [J]. Forestry Science and Technology, 2019, 44(3):55-58.