This text accommodates paid for content material produced in collaboration with HRS Warmth Exchangers.
An award-winning biogas plant which pioneered meals waste assortment and remedy in New Zealand has benefitted from utilizing a devoted pasteurisation system provided by HRS Warmth Exchangers. In July, Ecogas, which operates New Zealand’s first and solely commercial-scale anaerobic digestion (AD) facility gained the AD Hero of the Yr award on the prestigious 2025 AD and Biogas Trade Awards in Birmingham.
Ecogas constructed New Zealand’s first full scale power plant powered by meals waste at Reporoa, in the midst of the North Island. The plant processes round 75,000 tonnes of natural waste annually from council kerbside collections, business and industrial meals producers – eliminating greater than 11,000 tonnes of CO2 a yr and serving to in direction of New Zealand’s goal of being web carbon zero by 2050.
Commenting on the award, CEO of Ecogas and Pioneer Power Group, Peter McClean, stated the success has solely been doable by way of robust partnerships and a shared imaginative and prescient to divert natural waste from landfill and create lasting worth for New Zealand. “We championed this know-how in a extremely aggressive market with restricted coverage mandates or monetary incentives. We’re extremely grateful to our companions, councils, and business prospects who’ve supported us on this journey,” he defined.
The plant, which was formally opened in October 2022, produces biogas and digestate biofertiliser, with the biogas upgraded into biomethane for injection into New Zealand’s gasoline grid, and the carbon dioxide is provided to a close-by tomato greenhouse the place it helps crop development.
The co-mingled meals waste used as feedstock at Reporoa has the potential to comprise organisms which have the potential to impression human, animal, or plant well being. The HRS Digestate Pasteurisation System (DPS) pasteurises the digestate produced on the plant prior to make use of to render such pathogens inert, together with different undesirable components reminiscent of weed seeds. Which means the dear and sustainable biofertiliser may be safely utilized by farmers and growers.
Conventional pasteurisation methods warmth the digestate in a tank utilizing a heating jacket – a bit like ready for a large kettle to boil – after which dump the warmth after it has served its authentic goal. The HRS system, nonetheless, employs power restoration and is often two to 3 instances extra environment friendly. By transferring power from the warmer (pasteurised) sludge to the colder (unpasteurised) sludge, power consumption is diminished, and the necessity for extra warmth sources is eliminated.
The HRS DPS utilises ‘waste warmth’ from the location primarily based Mixed Warmth and Energy Crops (CHP) to warmth digestate to >70 °C and maintain it for one hour at this temperature, earlier than cooling. That is finished with the HRS DTI Collection warmth exchangers, that are designed in such a strategy to get better as much as 70% of the warmth power required for the method. The tube which carries the digestate by way of the system’s warmth exchanger incorporates a distinctive corrugated design; not like the sleek or dimpled tubes utilized in various exchangers. This boosts warmth switch by creating additional turbulence and helps cut back fouling, leading to much less downtime and upkeep, and rising the system’s lifespan.
The absolutely automated system offers an auditable kill-step for environment friendly and efficient discount of pathogens reminiscent of Salmonella, Staphylococcus, E. coli and so on. As soon as handled on this approach, the digestate produced is protected biofertiliser product, turning what would in any other case be a waste stream right into a value-added natural substitute to mineral fertilisers. Not solely does the DPS heat-treat the digestate, but it surely additionally helps to take away odours whereas sustaining the standard of the ensuing biofertiliser.
The DPS was delivered to website and put in in February 2022. The warmth exchanger part of the HRS DPS is cut up into two body modules, that are stacked and inter-connected for diminished footprint on website.
Alzbeta Bouskova, Common Supervisor at Ecogas defined why the corporate selected to make use of the HRS DPS system. “Ecogas adopted UK-based PAS110 digestate requirements as our main design and operation precept to make sure that the biofertiliser produced from the Reporoa facility is of the best high quality, security and worth for the potential customers. Pasteurisation is a key step within the PAS110 commonplace for source-separate meals waste for destroying pathogens and viruses doubtlessly current in such a waste.
“The Reporoa plant is the primary of its variety in New Zealand, and with that comes the method of introducing our new biofertiliser product, Fertify™, to the farming and horticulture sector. We all know that model belief is tough to earn however simple to lose with the neighborhood and we’ve got no room for errors. We selected HRS primarily based on their popularity and powerful observe file in digestate pasteurisation. This was additional supported by the extremely engaged native HRS crew, who labored arduous to fulfill their timelines and high quality of the tools and set up.”
Ella Taghavi, Gross sales Engineering Supervisor at HRS Warmth Exchangers, added, “It’s implausible to have prolonged our world footprint for HRS Digestate Pasteurisation Options to New Zealand, significantly as Ecogas Reporoa is such a big undertaking within the improvement of NZ’s Bioenergy Sector. We firmly consider that if renewable power from Biogas and Anaerobic Digestion is to achieve its full potential globally, then it must be as environment friendly as doable, and that features extracting essentially the most profit from digestate by way of its use as a renewable natural fertiliser.
“We foresee a step-change within the worth of this ample and nutrient-rich by-product, which, with the ever-increasing price of chemical fertilisers, could very nicely find yourself being a key business driver for AD Initiatives in future. The HRS DPS ensures that digestate may be put to good use with the total confidence of the shopper and the patron, returning vitamins to the land from the place they originated.”
