Polanco Process advantages: performance and technical differentiators

As a continuous thermal hydrolysis technology, the Polanco Process requires a single hydrolysis reactor and differs from technologies that, in order to operate in batches, require 2, 3 or 4 reactors. This smaller number of units results in an inherently more economical process with lower requirements for both investment and space.

By operating in steady state, all process variables remain constant over time and operation is more stable and easier to control, eliminating fluctuations in energy demand and reducing operating costs.

The sludge is heated in injectors specifically designed to condense all the low- and medium-pressure steam recovered from the process and the high-pressure steam generated in the boiler. The steam condenses directly onto the sludge flowing through the process pipes in these in-line injectors which, as external and easily accessible units, minimise maintenance costs.

The operating pressure of the degasifier is a setpoint that can be configured to directly evacuate the non-condensable gases generated in the process. Since no additional mechanical equipment is required to convey these gases, both the investment cost of that equipment and its operating cost are eliminated.

Based on empirical evidence showing that it is the prevailing hydrolysis mechanism, the Polanco Process applies a double flash, or steam explosion, to maximise sludge solubilisation. This has a valuable energy benefit, since the generation of steam at different pressures makes it possible to recover 100% of the process heat, reducing specific energy consumption.

Because the main parameters of the Polanco Process are configurable, the hydrolysis reactor can operate at temperatures lower than the standard values to minimise the formation of recalcitrant compounds linked to Maillard reactions, such as melanoidins, which are produced when sugars and proteins react at temperatures above 150 °C. With optimised conditions, the waste to biogas conversion is maximised and the formation of inhibitory and/or toxic compounds is avoided.

During the standard, annual thermal hydrolysis maintenance shutdown of 1-2 weeks, the sludge is not hygienised and the stability of anaerobic digestion is disrupted. The Polanco Process, however, can continue operating with the Hygienisation Module, guaranteeing pathogen-free sludge and feeding digestion with a partially hydrolysed sludge that minimises the impact on bacterial and archaeal communities.