In this dataset, digestate disinfection covers processes and apparatus that reduce pathogen loads in the solid or liquid output of an anaerobic digester, typically before it is applied as fertiliser or soil amendment. Most filings achieve this through thermal hygienization — heating the digestate to a target temperature for a set residence time — often using heat recovered from biogas combustion. The claims are classified mainly under water treatment (C02F) and organic fertiliser (C05F) codes rather than dedicated sterilisation classes, which matters when scoping a prior-art or freedom-to-operate search.

The dataset shows filing activity rising to 6 families in 2018, its highest point in the window covered, before declining toward zero by 2022. This is consistent with early entrants staking out core apparatus and process claims — such as combining a digester with a heat-recovery sanitization vessel — leaving less open claim space for later filers. Publication lag of roughly 18 months means the most recent one or two years will always look thinner than they eventually turn out to be, but the multi-year decline from 2018 is a longer pattern than lag alone explains.

The assignee base is fragmented: 21 families are spread across a long list of filers with only 8 co-assignee pairings, and none show recent filing momentum in the latest year covered. Notable names include DVO Corporation and its licensing entity, Veolia Water Technologies, and individual inventor-assignees such as Andrew R. Walsh working with Celtic Bioenergy. No single assignee holds a commanding share of the corpus, so competitive positioning here depends more on specific claim scope than on overall portfolio size.

GB2509312A describes an anaerobic digester paired with a boiler or CHP plant that combusts the biogas it produces, feeding the resulting hot water and gases into a separate sanitization vessel with valve-controlled heating circuits built into its walls and floor, run under computerised control. A design that reuses biogas combustion heat through a similarly structured, computer-controlled sanitization vessel risks overlapping this claim. Alternatives that avoid the specific heating-circuit and control architecture, such as different heat-transfer mechanisms or vessel geometries, are more likely to sit outside its scope, though a formal claim chart is needed before relying on that distinction.

The clearest gaps sit outside the dominant batch-and-thermal approach: continuous-flow sanitization vessels, real-time pathogen-load sensing with feedback control, and combined phosphate-recovery-plus-pathogen-reduction systems all show little visible claim density in this 21-family corpus. Heat-recovery integration specifically tuned to CHP exhaust streams, rather than generic hot water and gas circuits, is another under-claimed variant. Any of these would need a fresh novelty search given the field's small size, since a handful of new filings could materially change the picture.