Editor’s Note – August 2025 Update
When we first published this article back in December 2021, it was in the early days of Taiwan’s ambitious journey into livestock-based biogas production. At the time, we spotlighted a rising star in digester mixing: the Landia GasMix system.
Four years later, this is far from being old news. In fact, with the explosive growth of anaerobic digestion plants worldwide—and a sharper focus on performance and uptime—the Landia GasMix digester tank mixer has gone from strength to strength.
This isn't just a product update—it’s a validation. The same externally mounted biogas tank mixer that helped power Taiwan’s first livestock AD plant is now even more relevant today, trusted by digester designers and plant specifiers across continents. Its design remains evergreen, its output proven, and its resilience unmatched.
So whether you’re evaluating options for a new-build biogas facility, retrofitting existing infrastructure, or just want to stay on top of best-in-class digester tank mixing systems, this article is more relevant than ever.
The biogas digester tank mixer, which has been chosen for its high methane output at a new Taiwan AD Plant, is the Landia GasMix.
This best-in-class efficiency is already reported, in the Press Release below, to be providing, not only:
- the hoped-for sustainable biogas energy, but
- other notable spin-offs in reduced polluting manure discharges and
- a better rice crop when the output (digestate) is applied to the fields as a low-cost natural fertiliser.
Read on to find out more about this first-of-its-kind project for Taiwan:
Press Release 2 December 2021:
Superior Mixing Matters at Taiwan’s New Biogas Plant
Taiwan’s newly opened and first-ever biogas plant to use livestock manure as its feedstock is benefiting from a proven digester mixing system made by Landia.
For the project in Hualien County on the east coast of Taiwan, the new Pushige Biomass Energy Center (from a plan implemented by the Yexing Environmental Technology Company), features six of Landia’s externally-mounted GasMix systems, which have a verified track record of enhancing biogas yields.
The 18.5kW units, which were ordered by Fluid Power Co, LTD of Tainan, are helping generate what will amount to approximately 876,000 kilowatt-hours of electricity each year for the Taipower grid (equivalent to the electricity capacity of 250 households) from 300 tons of livestock manure wastewater every day in the breeding area of Sanmin, Yuli Town where eight livestock farms are home to almost 10,000 pigs and close to 700 cows.
Benefitting from the Landia Chopper Pump (which the company invented in 1950), the digester mixing system draws thick liquid from the bottom of the 6,000 cubic meters tank, where solids are chopped to accelerate the digestion process and prevent clogging of pipes and nozzles.
In the first stage of the mixing process, the livestock wastewater is injected into the upper half of the digester, whilst biogas is aspirated from the top of the tank and mixed into the liquid.
This biogas digester tank mixer not only has the benefit of reducing buoyancy at the surface of the liquid but also sees the rising gas bubbles continue to mix after the pumps are switched off.
Manufacturer Landia is no stranger to mixing hard-to-handle liquid manures/wastewaters. In fact, the company was established way back in 1933, making slurry pumps.
‘The very best for producing high levels of methane – and quickly’
Mark Lo, Managing Director of Fluid Power Co, commented:
“The early results already prove conclusively that the Landia digester mixing system is the very best for producing high levels of methane – and quickly. It is also extremely reliable and very easy to maintain”.
As well as producing biogas and creating top-quality organic fertilizer from biogas residue, the $3M Pushige Biomass Energy Center (49% financed by Taiwan’s Environmental Protection Administration) will also help reduce the discharge of the unprocessed manure slurry which is high in potentially polluting:
- COD (Chemical Oxygen Demand),
- BOD (Biological Oxygen Demand) and
- Nitrogen above safe levels.
This helps to avoid pollution from livestock wastewater, which would otherwise be discharged into irrigation channels and the Xiuguluan Creek, amounting to almost 110,000 metric tons each year.
In addition, carbon dioxide emissions will be reduced by approximately 3,000 metric tons.
Rice farmers are already using the nutrient-rich, organic biogas digestate for their farmland.
The feedback received suggests that they are immediately seeing a vast improvement in their crops, compared to the chemical fertilisers used previously.
For further information, contact:
Fergus Clark
Regional Sales Manager – Asia Pacific
email: ftc@landia.dk; tel: +447880816364
PR Ends
❓ Frequently Asked Questions (FAQs)
What makes the Landia GasMix a superior digester tank mixer?
The Landia GasMix is an externally-mounted digester tank mixer that combines hydraulic mixing with gas recirculation, boosting methane output. It draws thick sludge from the tank bottom, chops solids with its integrated chopper pump, and injects both slurry and biogas back into the tank. This dual-action mixing significantly improves substrate homogenisation and gas yield.
How does a biogas tank mixer impact methane production?
Effective biogas tank mixing enhances contact between anaerobic bacteria and organic material, accelerates digestion, and prevents stratification. With systems like GasMix, higher and faster methane yields are achieved, alongside better temperature and pH uniformity within the digester.
Why choose an externally-mounted digester mixer over an internal one?
Externally mounted systems like Landia’s GasMix allow for easy maintenance without taking the digester offline. This reduces downtime, avoids confined space entry, and improves operational efficiency—making them ideal for large-scale or difficult-to-access tank setups.
What are the energy efficiency benefits of the Landia GasMix?
Despite its robust performance, the GasMix runs on just 18.5kW per unit. Plus, once mixing starts, the rising biogas bubbles continue to agitate the slurry even after the pumps are off, delivering additional energy savings over time.
Can a GasMix system handle livestock waste and fibrous materials?
Absolutely. Originally designed for thick, fibrous slurries, the GasMix—equipped with Landia’s signature chopper pump—is purpose-built to prevent clogging and efficiently process fibrous manures, such as pig and cow slurry, making it ideal for agricultural and mixed-feedstock biogas plants.
Is this biogas tank mixer used outside of Taiwan?
Yes. The Landia GasMix has been installed globally, from Europe to Asia to North America, across municipal, agricultural, and industrial biogas plants. Its proven adaptability and performance in a wide range of feedstocks have made it a go-to solution worldwide.
How does the GasMix support circular agriculture?
By boosting digestion efficiency, the GasMix ensures more stable biogas output and produces a nutrient-rich digestate. In Taiwan’s case, this digestate has replaced chemical fertilisers for local rice farmers—closing the loop between livestock waste, renewable energy, and sustainable farming.
[Published 3 December 2021. Updated 27 August 2025.]
