Tailored Pyrolysis & Carbonization Solutions for Diverse Sewage Sludge Treatment

Sewage sludge can be recycled – but the proper method depends entirely on the type and source of the sludge. If you simply hear "sewage sludge," you need to first clarify: is it the high-moisture municipal sludge from wastewater treatment plants, or the oily waste sludge from oilfields, refineries, and tank cleaning operations? Each requires a different technology to achieve safe, economical, and environmentally friendly recycling.

1. Municipal Sewage Sludge (High Moisture Content) --- Biomass Carbonization Solution

For typical municipal sewage sludge (often 70~85% moisture), direct pyrolysis is not the most efficient choice due to the high energy needed for drying. The recommended solution is a biomass carbonization / charring process that includes three steps: deep dewatering → thermal drying → carbonization.

Sewage sludge carbonization treatment solution

How Sewage Sludge Carbonization Machine works: The sewage sludge is first mechanically dewatered to around 30~40% moisture, then dried to 15% moisture by using the heat generated from the carbonization process itself. Finally, it enters a carbonization reactor where it is heated under oxygen-limited conditions to produce biochar (a stable carbon-rich solid).

Environmental benefits: The biochar effectively immobilizes heavy metals, reducing their leachability in soil. Meanwhile, the process achieves significant volume reduction (up to 90%) and destroys pathogens.

Product applications: The resulting biochar is widely used as a soil amendment (improving water retention and fertility) or as a low-cost adsorbent for wastewater treatment.

Our equipment: Henan Doing Group provides a complete biomass carbonization system designed specifically for high-moisture municipal sewage sludge, integrating a belt dryer, screw feeder, rotary carbonization furnace, and exhaust gas treatment unit. And there are many models to choose from: batch models carbonization machine like 10 ton/day, 15ton/day; continuous models carbonization equipment like 1 ton/hour, 3ton/hour, 5 ton/hour, etc.

DOING biomass to biochar carbonization system

2. Oily Sewage Sludge (Oilfield / Refinery / Oily Waste) --- Pyrolysis Solution

If your "sewage sludge" comes from oil drilling, crude oil processing, or tank cleaning – i.e., waste oily sludge or oily contaminated materials – then pyrolysis machine is the proper and most valuable disposal way.

Wewage oily sludge pyrolysis disposal solution

How Oily Sludge Pyrolysis Machine works: The oily sludge is fed into a sealed, oxygen-free pyrolysis reactor. At high temperatures (300~700°C), the organic oil components vaporize and are then cooled into pyrolysis oil (a liquid fuel). Noncondensable gas is recycled to heat the reactor, saving energy.

Products recovered:

• Pyrolysis oil – can be used directly as an industrial alternative heating fuel, suitable for heating boilers or furnaces of steel factories/brick factories/cement plants/heavy oil power plants, or further refined into non-standard diesel via a waste oil distillation machine.

Oil sludge recovered fuel application

• Solid residue (sludge dirt) – after treatment, this solid meets national landfill standards( HW08 type oily sludge treatment solid residue/dirt, the oil content in landfill is less than 5%.) and can also be used as construction aggregate or road base material.

Advantages over traditional methods: Compared to incineration or landfilling, pyrolysis recovers valuable oil, minimizes carbon emissions, and eliminates the risk of soil and groundwater contamination from oil residue.

Our equipment: Doing Group offers a full line of oily sludge pyrolysis plants with daily capacities from 5 to 50 tons per set, including feeding system, thermal pyrolysis reactor(also called thermal desorption unit), oil gas separator, and exhuast gas cleaning system. Operation modes and Automation degree of oily sewage can be selected: batch type, semi-automatic type and fully automatic type. Customized pyrolysis solutions are available for different oil content and moisture levels.

Three types of oil sludge treatment pyrolysis machines

We help customers first identify their sludge characteristics (moisture content, oil content, heavy metals, etc.) through our free consultation service, then design the optimal treatment plan. Contact Henan Doing Group today, we will help you determine whether carbonization or pyrolysis is the proper sewage treatment way, and provide a customized equipment solution.