Pyrolysis Treatment of Different Waste

• Sludge:

Pyrolysis of sludge is an efficient process, which saves the environment, generates electricity and gives yield to a solid biofuel if required. Typical capacities for the delivered facilities: 100-300 tpd. If sludge has to be dried, an indirect heated rotary dryer can be utilised.

Different types of sludge is treated by the pyrolysis: sewage sludge, oil sludge, animal farm sludge, paper pulp sludge, etc.

• Biomass:

Wood waste, agricultural waste like straw, and other types of biomass represent renewable source of green energy. Biomass is pyrolised, and then pyrolysis gas is used for direct electricity production. Biochar recovered from non-contaminated biomass can be either further gasified in accordance with general MPSC scheme or to be used as soil improvement agent.

• Tires:

Every year million scrap tires are generated. Approximately 20% of these tires are reused: the old tread is ground off the tire and replaced with a new tread. About half of all used tires were dumped in landfill sites throughout the countries. Other tires are incinerated. Burning 1 ton of waste tires produces about 450 kg toxic gases. The damage to the environment is obvious.

Performing pyrolysis of scrap tires saves the environment and gives yield to valuable materials. Products of scrap tires pyrolysis will be recovered oil, carbon black, and steel wire. Since tires rubber contains sulphur, the recovered oil will also contain sulphur. Direct electricity generation without oil condensation eliminates this problem. Minimum capacity of the pyrolysis facility is about 20 tpd.

• ASR (Automotive Shredded Residuals):

Automotive Shredded Residue (ASR) results from the reclamation process of recyclable ferrous and non-ferrous metals. The primary source of recyclable materials comes from automobiles, trucks, buses and common household appliances such as washers, dryers and refrigerators. According to estimates from the automotive industry only in the United States about 2 billion pounds of ASR are generated annually. ASR generally consists of a mixture of plastics, rubber, glass, wood products, cloth, paper, foam, dirt, and electrical wiring. The industrial ASR pyrolysis systems implement general MPSC scheme, producing pyrolysis followed by generation of electricity. Comparing with general case of MSW pyrolysis the ASR pyrolysis system is characterised by higher efficiency power generation.

• Electronic waste:

E-waste is not biodegradable and represents a global problem of modern time. Electronic appliances bodies are made of different plastics and could be used as a raw material for the pyrolysis.

Disposal of Printed Circuit Boards (PCB) is a separate issue. Electronic boards represent a mixture of organic resins, fibreglass, and ceramics. Boards also contain valuable noble metals. During pyrolysis the volatile portion of the board materials will be thermally decomposed, solids (including noble metals and fiberglass) will be recycled. Direct electricity generation in accordance with the general MPSC scheme is the efficient way to treat this e-waste.

• Soil remediation:

Pyrolysis technology is efficiently used for the thermal cleaning of soil. The multiple built soil remediation plants (average capacity 150-170 tpd) successfully treat soils, which have been heavily contaminated with organic pollutants such as dioxin, PCB, oil and mercury. The cleaned soil is then reutilized.