Pilmico pig farm anaerobic digestion

Client: Pilmico Animal Nutrition Corporation
Location: Tarlac, Philippines
Service division: Optimisation, Engineering
Sector: Waste, Water

Pilmico Animal Nutrition Corporation own and operate a number of pig farms including a farm in the province of Tarlac in the Philippines which treats its own wastewater and slurry in dedicated anaerobic digester (AD) lagoons and uses the biogas produced by the process to generate electricity for use on-site. Since installation and commissioning, the performance of the AD and generating engines at one of the farms has been less than that anticipated by the design and Pilmico were keen to identify the reasons behind the underperformance and understand what measures, if any, could be taken to improve the situation.

AFECO were appointed to undertake a review of the pig farm operational practises, asset configuration, AD performance and generating engines to assess where possible improvements could be made and highlight any reasons for the underperformance. AF ECO carried out a site visit to the farm and used this visit together with background design information and operational data to fully analyse the plant performance. A process model of the site was composed and used to assess actual performance data and the original design data against the theoretical performance. The modelling highlighted that the original design significantly over-estimated the expected biogas production and that the current biogas production was, in fact, well in line with the theoretical expectations. As a result the generating engines were also over-rated and the down-turn required reduced the engine efficiency. A review of the engine specification also revealed their unsuitability to operate on biogas which potentially lowered the efficiencies even further.

The review highlighted a number of potential improvements that could be implemented to enhance the system performance. These improvements included modifications to the condensate trap to remove the moisture present in the biogas prior to entering the engines, improving their efficiency, and improvements to the existing sand/grit trap prior to the AD lagoon. A conceptual design and CAD drawings for the condensate trap and sand trap modifications were produced to accompany the report.

In summary, the review undertaken by AFECO avoided the need for costly modification works to the pig farm AD plant by demonstrating that the digester performance was in line with expectations and operational staff were carrying out their role effectively. The plant modifications recommended were simple and cost effective with the impact of sustaining the long term performance of the plant.

The services provided by AFECO included:

  • Site investigations
  • Process modelling
  • Process optimisation
  • Feasibility report
  • Conceptual design
  • CAD drawings


Chieveley WwTW technical writing

Client: Damar Group Ltd
Location: Chieveley WwTW, Chieveley, Berkshire, UK
Service division: Engineering
Sector: Water

Chieveley WwTW is a small rural sewage treatment works located within the Newbury area and is owned and operated by Thames Water, the UK’s largest water and sewerage company, serving a population of 14 million across London and the Thames Valley. Upgrade works have been carried out at the site which included a number of process enhancements, incorporating improvement works to the storm tanks and filter recirculation systems.

Damar Group are a construction company, appointed by Thames Water as the principal contractor to carry out the upgrade works to the site. Damar subsequently commissioned AFECO to produce the technical documentation required to enable them to design, install and commission the equipment necessary to allow the storm tanks to fill and empty as required and for the filter recirculation system to operate in conjunction with the storm tank return system. The scope of work for this project included:

  • Site investigations and liaison with site Operational staff to determine the current and desired mode of control required for the storm tank return and filter recirculation system
  • Production of a control philosophy and functional design specification (FDS) on which the plant design could be based

This work was successfully completed by AFECO, enabling Damar to carry out the work required for them to complete the project as required by Thames Water.


Co-Digestion business case

Client: Isle Utilities
Location:  London and Durham, UK
Service Offering: Consultancy – technical & commercial evaluation
Sector: Water; Waste; Energy; Power

Isle Utilities (Isle) is a niche consultancy with a core focus around technology and innovation who work with many water companies, novel technology providers and investors to bring new technologies to market. Isle were commissioned by Northumbrian Water (NWL) to assist in informing their co-digestion strategy and AFECO were subsequently commissioned to assist with the delivery of the project.
The work consisted of the following key areas:

  • An overview of the financial and commercial structures available and the potential sources of funding for any projects the impact of regulatory accounting, marginal costs, revenues and a breakdown of the commercial structures available
  • Production of a financial and technical model including high level capex and opex estimates
  • SWOT analysis covering legislative, regulatory, commercial, organisation and operational issues throughout the project lifecycle

AFECO fed directly into each area of the project but in particular composed the technical model used to evaluate the existing asset capacity, additional asset capacity requirements and the potential inputs and outputs of the process. In addition to the technical model, AFECO prepared the high level capex and opex estimates required to inform the financial model and prepared the SWOT analysis, assessing the risks associated with regulation, feedstock security, operating risks and impacts on the existing business. The project outputs were presented directly to NWL through a series of meetings as well as in a final report.