Pyrolysis Process 5: Pyrolytic Oil Gas to Fuel Conversion Condensers Introduction Video

The conversion of pyrolytic oil gas into liquid fuel is a critical phase in the waste-to-energy lifecycle. Once the raw materials have undergone thermal decomposition in the pyrolysis reactor, the resulting oil-gas mixture must be effectively cooled and condensed. In this fifth installment of our process series, we examine the technical specifications and operational differences between the two primary condensation systems utilized in DOING pyrolysis plant: the shell-and-tube condenser and the tank condenser.

Below is the video detailing the condensation process and the differences between these two systems:

Shell-and-Tube Condenser

The shell-and-tube condenser targets a different operational priority: maximum condensing performance at scale. Its staged condensing arrangement — where vapor contacts progressively cooler tube surfaces along the flow path — achieves a more complete phase transition, which consistently results in a clearer, higher-quality end product and a higher overall oil yield.

Cooling surface area is scalable to match the pyrolysis plant' s gas output and available footprint. DOING' s system can be configured to fit the specific output capacity of any large standardized production line, which makes it the preferred choice for high-throughput continuous or semi-continuous operations where process consistency is paramount.

The trade-offs are real. The shell-and-tube design is a multi-piece assembly — on-site installation is more involved and demands a higher level of craft from the installation crew. Inside the tube bundle, carbon black carried by the vapor stream can gradually accumulate on the narrow tube walls, which reduces heat transfer efficiency over time and requires periodic manual cleaning. For clients without an on-site maintenance capability, this is a meaningful consideration.

A dedicated circulating cooling water basin is also required on site. The water quality in this basin is typically better controlled than what a standard cooling tower loop provides, which is one reason the shell-and-tube system achieves its higher condensing ceiling. This dedicated basin does add to the infrastructure scope and upfront project cost.

DOING pyrolysis plant shell-and-tube condenser

Water Tank Condenser

The water tank condenser is widely deployed condenser type across DOING' s customer base, largely due to its versatility and practical design. The unit is built around an integrated rectangular tank housing a custom coil assembly — DOING' s standard configuration uses 33 precision-engineered variable-diameter coils arranged in a front-thick, rear-thin layout. The larger-diameter front section absorbs the full burst of incoming vapor without resistance, while the progressively narrower rear section slows the flow and provides extended contact time for fine, controlled cooling. The entire coil assembly sits at a incline, which keeps the vapor flowing continuously without pooling or congestion, and supports more stable condensation throughout.

The operational advantages are straightforward: the integrated tank structure means no complex on-site assembly, no separate circulating cooling water basin to build, and no reliance on auxiliary infrastructure beyond a standard cooling tower. Maintenance is equally uncomplicated — both end caps open to provide full access to the coil interior, allowing quick rodding-out of any deposits without disassembling the unit. This translates to lower daily operating costs and minimal downtime.

For plastic to oil and aluminum-plastic pyrolysis applications, where wax buildup in the coil can be a recurring issue, DOING offers a hardened coil package: oversized and thickened coils paired with a dedicated dewaxing tank and a damping tank. These additions prevent wax from solidifying inside the pipework and are among the most practical add-ons for this feedstock category.

The one consistent trade-off is physical size. The coil assembly requires a larger footprint than the shell-and-tube alternative, which adds constraints on transport logistics and plant layout.

DOING pyrolysis plant water tank condenser

Selecting the Right Condensation System

The choice between these two systems is determined by project-specific requirements:

Shell-and-Tube Condensers: Recommended for high-capacity facilities where cooling efficiency and maximum oil yield are the primary objectives.

Tank Condensers: Ideal for operations prioritizing ease of installation, simplified maintenance, and a more compact equipment footprint.

Selecting the appropriate condenser is essential to ensuring the long-term reliability and output quality of your pyrolysis plant. If you require technical guidance on selecting the optimal cooling system for your specific plant configuration, please contact our engineering team directly to discuss your project requirements.