1, for the manufacture of lightweight building materials: The expandable polystyrene foam particles or pre-broken into small pieces of polystyrene foam waste as the main body of additional different fillers, using a different binder system into a variety of lightweight building materials. For example, using wood as the filler wire in order to cement binder, add water, mix, and then molded into various shapes lightweight concrete partitions, or made of artificial wood; lined with wire stent made of lightweight foam board can be used as wall panels, countertops, or decorative plate; to do with the filler can be made of expanded perlite roof insulation boards; to earth as a bonding agent and filler, and polystyrene foam particles uniformly mixed and repression of equal shape, dry After calcination, can be made for the high-rise building with large blocks of light, or to infiltration of the water pipe effluent; to waste nylon yarn as the filling can be made of light bending casting materials, etc.. This recovery method is simple and recyclable large amount of investment, recycling is a good way, the only less than a smaller value is the product of technology.
2, for the manufacture of general-purpose polystyrene: The anti-foaming polystyrene foam waste at high temperature cooling, mechanical crushing, extrusion into the article, and then pelletizing made of general-purpose polystyrene. The main problem is this approach the appearance of recycled materials may be due to obsolete are not washed before the bubble burst and the baking temperature is too high extrusion process for reasons such as partial brown, losing the characteristics of a new polystyrene colorless and transparent. Poor performance of its impact can only be used to do some low-value plastic components, it is difficult with the general plastics such as polyethylene, polypropylene, PVC products is comparable.
3, for then the system can be made of polystyrene: A system of waste PS foam recycling or re-molded EPS foam products, it should be said of waste PS foam is the most rational use of the direction. Because the waste polystyrene foam is a little addition to the surface by the environmental deterioration, the house maintains the original properties of polystyrene foam, which created the conditions for multiple use. Only in this way, re-molding or manufacture of EPS can best play a multifaceted superior characteristics of polystyrene foam. EPS polystyrene foam manufactured from waste or re-molding has the following several ways: first, the dissolution of polymerization. Will waste branded foam dissolved in styrene monomer, by adding dispersant to PS granular beads of styrene solution suspended in the water, heated to polymerization, and then adding foaming agent to continue to beads made of polymer foam material. The advantage of using waste to replace some of the styrene, can reduce the cost, disadvantage is that consumption of styrene monomer, but also by the PS surface cleanliness instability initiator activity it is difficult to obtained uniform products. Second, the ball of re-foaming method. General-purpose polystyrene is cut into cylindrical pellets, suspended in the dispersing agent in aqueous solution, heating to melt the ball of the cylinder, and then cooling pressure increases foam, after cooling by filtration, washing and low-temperature drying system into the beads of this method lies in the quality of raw materials, otherwise the new system difficult to guarantee the quality of EPS. Third, the beads break and then molding. In the liquid medium in the appropriate choice of softeners, surfactants and defoamers, the large pieces of waste PS foam selectively broken into 4-8mm in diameter, spherical beads, add foaming agent and then molded into the foam products . Law process is simple and consumes little additional material, mode of the physical properties of manufactured goods with the original waste, close, and small investment, benefit large enough to warrant promotion.
4, preparation of brominated flame retardants modified. Polystyrene molecules containing benzene ring structure, benzene ring on the hydrogen atom can be replaced by electrophilic reagents. Some people have recovered after cleaning and drying foam polystyrene dissolved in dichloromethane solution, in the aluminum chloride catalyst, and liquid bromine electrophilic substitution reactions obtained brominated polystyrene flame retardant. Bromine capacity will be increased up to 6%, can be used as PVC, ABS, polypropylene, flame-retardant plastic. Compared with other organic flame retardants, brominated polystyrene consumption is low, flame-retardant effect is good, the combustion process does not release (2) cancer-causing dioxin and other toxic substances, especially with antimony trioxide and used, their synergistic better flame-retardant is a flame retardant with good performance. With the preparation of brominated polystyrene of the process, performance, brominated polystyrene flame retardants with products comparable to, and low cost. But because the consumption of flame retardants in itself is not very large, so this method can not meet the large quantity of waste PS of recovery work.
5, thermal decomposition technology: on the one hand, manufacture of styrene monomer may be cracking, that is waste polystyrene foam in the heating conditions, choose a suitable cracking catalyst to produce styrene monomer. Relatively tight supply in the styrene case, the use of polystyrene foam waste depolymerization production of styrene, in order to meet the market needs is a rational use of means. The United States, France, and Japan are also carried out a large number of experiments, but there are no reports of industrialization. Depolymerization of styrene manufacture of styrene The main problem is the conversion rate is relatively low, in better cases, about 70%, however, generally only about 40% conversion rate is low, not only affect production costs, but the residue left behind returned to the pyrolysis equipment cleaning and continuous operation difficult. On the other hand, may be cracking of oil. Isolated from the foam air heating or heating in the decomposition of water vapor available under the mixture of low molecular weight hydrocarbons, and then re-decompose the catalyst can be Debu sulfur gasoline and kerosene fractions and some fraction of gas. 1kg plastic available 11 oil, the rest is mainly carbon residue. Japanese studies in this respect more, China has achieved some success in this regard, is now under way for industrialization.
6, the combustion energy recovery: As the main component of polystyrene foam of carbon and hydrogen, which can be burned and the total calorific value (about 4600kj/kg, larger than standard coal (about 2600kj/kg) and fuel oil (about 4400kj / kg). Therefore, a use of its heat of combustion incineration is also an effective way. In this way, by many well-funded advanced equipment used in developed countries. For example, Japan has just management companies used to do coke, iron scrap plastic instead of the fuel and reductant ; a French air-conditioning company to develop a plastics incineration with waste heat to produce steam of new technology, steam can be supplied for their production, this would save energy. but in my situation, incineration is also lagging behind compared with other methods. plastic combustion heat large, common and easy to burn the stove easy to burn out completely, to be specially designed burner equipment maintenance costs, larger, while burning the gas could easily lead to secondary pollution, but also for processing.