Pre-Processing of Municipal Solid Waste to Recycle Energy

Why is Municipal Solid Waste(MSW) Processing Necessary?

Although the government advocates the collection of sorted wastes, it accounts for only 16% of the total amount of MSW. Means for municipal solid waste disposal are recycling, landfill, burning and composting. In these disposal methods, landfill accounts for 70%, composting 20%, burning 5%, and the other MSW disposal means such as recycling and waste dumps account for 5%. Landfills occupy large land area, and cause groundwater pollution, soil contamination and air problem. The cost of waste incineration is high; the toxic gas generated from burning is difficult to handle. Poor quality of composting product can not be used widely as a kind of fertilizer resource. Swarms of mosquitoes and flies breed in the wastes composting plant, which damages people’s health in the neighborhood. Therefore,recycling of municipal solid waste as a method of energy conservation and environmental protection gains increasing attention. For example, after pre-processing, MSW can be converted into fuel pellets by wood pellet mill and MSW pellets are a good fuel type. Recycling of municipal solid waste can not only beautify the environment, but also save the new resources exploitation and it can solve MSW problem fundamentally. Furthermore, The cost of processing MSW is low, for example, the cost of processing a ton of MSW is only 200-300RMB, so the economic benefits and social effects are huge.

Processing Technology of MSW for Waste-to-Energy

With the people’s increasing awareness of environmental protection, comprehensive utilization of MSW has been received more and more attention. Thus our company has developed a set of MSW disposal processing equipment including multi-functional Municipal Solid Waste Breaking Machine, Trommel Screen Municipal Solid Waste Separating Machine and Municipal Vertical Solid Waste Fine Grinding Machine. This municipal solid waste processing system can not only reduce labor intensity, but also sort MSW efficiently into organics, combustible materials, uncrushable metal and inorganic refuse. The sorting rate is up to 90%. Compared with the traditional MSW processing technology, our MSW pre-processing system saves the investment greatly, and it is applicable to pre-processing all kinds of municipal solid waste. The most popular utilization of sorted combustible MSW is as a fuel source and it can be used to make high calorific value fuel pellets by using fuel pellet machine. Other recycled materials can be used to make compost, compound fertilizer, generating power, or heating, etc.

Main Processing Procedures of MSW Processing System

1. Picking of large sized waste
If there are furniture, tire, sofa and other big materials in the mixed MSW, they should be picked out manually before conveyed to the MSW pre-processing system. After manual sorting, the materials of the size less than 400mm can be transferred by the conveyor to the Multi-functional Municipal Solid Waste Breaking Machine.

2. Conveying of Municipal Solid Waste
If the waste treatment capacity is less than 15 tons per hour, the material can be conveyed by vertical bucket elevator which occupies less floor space and has low cost. If the capacity is more than 15 tons per hour, the apron conveyor is a good choice. Its feeding speed is fast and the material can be uniformly and evenly transferred.

3. Breaking of MSW bags and primary crushing of big MSW
Multi-functional MSW Breaking Machine combines breaking MSW bags and crushing of big MSW, magnetic separating and dehydrating in one machine. This machine can break waste bags and crush municipal solid waste firstly, then sort materials by the magnetic separation and remove water from the MSW by pressure. After dehydration, the sorted materials are sent to Trommel Screen Air Separating System.

4. Trommel screen air separating system
Waste classification is the core part of MSW pre-processing system. This separating system is multi-functional, combining crushing with sorting. Even wet materials can be separated by this separating system. There are plough type hammers in the feeding inlets of this separating system, these hammers can crush municipal solid material for the second time. You can adjust the hammers number to realize the particle size you want. Then the crushed materials are sorted out by the fan blower based on their different gravity and volume.

5. Manual sorting of metal material
Air separating system can not separate metal materials, so metal should be picked out manually. And at the same time other recyclables can be picked out too.

6. Magnetic separator
It is equipped with underslung belt magnetic separator in the middle of manual belt separator conveyor and the permanent magnetic wheel in the head of manual belt separator conveyor to separate 0.1-25kg magnetic material from the waste automatically.

7. Deodorizing and dedusting
Our MSW processing system adopts the bag filter and it is equipped with the flue pipe in front of the bag filter. The activated charcoal powder is sprayed into the flue pipe to absorb PCDDS/PCDFS residues in gases as well as heavy metal like mercury.

Advantages of Our Municipal Solid Waste Processing System

Our Municipal Solid Waste Processing System is an advanced Municipal Solid Waste Processing Line. The whole processing line adopts centralized control, computer management, visual monitoring system and fully-enclosed structure. When municipal solid waste is conveyed in this enclosed processing system, there is no dust, no smell and gases generated by MSW are purified before emission. The whole MSW processing procedure is clean.

Waste to Energy

If you want to make fuel pellets from these processed municipal solid waste, you can transfer combustible fine inorganic materials to the drying machine directly; after drying, feed them into Municipal Vertical Solid Waste Fine Grinding Machine to be ground again and then these ground powdery material can be made into fuel pellets by the pellet mill directly.