GWE Biogas – HAZOP Assessment

GWE Biogas operate a 60,000 tonne per annum anaerobic digestion plant near Driffield, East Yorkshire, that generates c.6MW of power and heat from a range of food waste inputs.  The company was an early adopter of the technology and operated for a number of years in line with the environmental permit granted in 2010.  Following an industry wide review of biowaste permits in 2018, the Environment Agency requested that GWE undertake a Hazard Analysis and Operability (HAZOP) assessment in line with current permitting requirements.

WRM supported GWE Biogas by taking on the lead role in designing and undertaking a HAZOP assessment in line with the  IChemE best practice guidance.  Our project team brought together colleagues with experience in anaerobic digestion plant design, health and safety, compliance management, and business risk, to work alongside GWE Biogas colleagues within the project team.

To successfully deliver the HAZOP assessment  WRM provided a package of support that included:

Collation and review of process information – Being an operational plant, the project benefitted from a range of existing operational and H&S documentation which supported the design and scope of the study.

Definition of ‘nodes’ and ‘guide words’ –  to reflect the design of the anaerobic digestion system and the individual process phases that are operated by GWE Biogas.

Risk Assessment of the process phases – using primary and secondary guide words to systematically identify and consider risks.  On identifying risks, our project lead worked with the HAZOP team to evaluate the cause and consequence of any deviation from the design and/or operational parameters, with a significance and likelihood score being applied to each risk.

Study recommendations – The risk HAZOP study concluded with the identification of a number of proposed safeguards to be implemented alongside existing health and safety management systems.  Such safeguards included requests for further information, design changes and/or changes to operational procedures and processes. Support was provided to manage out the implementation of the safeguards through the issuing of action sheets.

Outcome – The HAZOP was submitted to the Environment Agency’s satisfaction, thereby off the request from the regulator.  Furthermore, the completion of the study provided a useful review of health and safety arrangements from a technical  perspective.