This text incorporates paid for content material produced in collaboration with HRS Warmth Exchangers.
An award-winning biogas plant which pioneered meals waste assortment and therapy in New Zealand has benefitted from utilizing a devoted pasteurisation system equipped 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 course of the North Island. The plant processes round 75,000 tonnes of natural waste every year from council kerbside collections, industrial and industrial meals producers – eliminating greater than 11,000 tonnes of CO2 a 12 months and serving to in the direction of New Zealand’s goal of being web carbon zero by 2050.
Commenting on the award, CEO of Ecogas and Pioneer Vitality Group, Peter McClean, mentioned the success has solely been potential 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 expertise in a extremely aggressive market with restricted coverage mandates or monetary incentives. We’re extremely grateful to our companions, councils, and industrial clients 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 equipped to a close-by tomato greenhouse the place it helps crop progress.
The co-mingled meals waste used as feedstock at Reporoa has the potential to comprise organisms which have the potential to influence 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 comparable to weed seeds. Which means the precious and sustainable biofertiliser could be safely utilized by farmers and growers.
Conventional pasteurisation techniques warmth the digestate in a tank utilizing a heating jacket – a bit like ready for an enormous kettle to boil – after which dump the warmth after it has served its authentic goal. The HRS system, nevertheless, employs power restoration and is often two to 3 occasions extra environment friendly. By transferring power from the warmer (pasteurised) sludge to the colder (unpasteurised) sludge, power consumption is diminished, and the necessity for added 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 executed with the HRS DTI Collection warmth exchangers, that are designed in such a option to get well 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; in contrast to the graceful or dimpled tubes utilized in various exchangers. This boosts warmth switch by creating additional turbulence and helps scale back fouling, leading to much less downtime and upkeep, and growing the system’s lifespan.
The totally automated system offers an auditable kill-step for environment friendly and efficient discount of pathogens comparable to Salmonella, Staphylococcus, E. coli and many others. As soon as handled on this manner, the digestate produced is secure 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, however it 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 break up into two body modules, that are stacked and inter-connected for diminished footprint on website.
Alzbeta Bouskova, Normal 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 normal for source-separate meals waste for destroying pathogens and viruses doubtlessly current in any such waste.
“The Reporoa plant is the primary of its type 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 difficult to earn however simple to lose with the neighborhood and we’ve no room for errors. We selected HRS primarily based on their popularity and powerful observe document in digestate pasteurisation. This was additional supported by the extremely engaged native HRS workforce, 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 unbelievable to have prolonged our international footprint for HRS Digestate Pasteurisation Options to New Zealand, notably as Ecogas Reporoa is such a big undertaking within the growth of NZ’s Bioenergy Sector. We firmly imagine that if renewable power from Biogas and Anaerobic Digestion is to succeed in its full potential globally, then it must be as environment friendly as potential, and that features extracting probably the most profit from digestate when it comes to its use as a renewable natural fertiliser.
“We foresee a step-change within the worth of this considerable and nutrient-rich by-product, which, with the ever-increasing price of chemical fertilisers, might very effectively find yourself being a key industrial driver for AD Tasks in future. The HRS DPS ensures that digestate could be put to good use with the complete confidence of the shopper and the buyer, returning vitamins to the land from the place they originated.”
