Biogas plant pumps drive the flow through the Anaerobic Digestion Process in all biogas plants. They are literally the heart of the process.
If a biogas plant pump stops working and there is no standby pump, the process will no longer be fed and a biogas production run down will result. Soon, if pumping is not resumed, the plant will cease to produce a useful biogas output and vital revenue from the products the plant produces will be lost.
AD Plant downtime is costly, and also highly damaging to the service that the biogas business is contracted to provide for its customers.
It hardly needs to be stressed here, how important it is that the pumping equipment is of the highest order of reliability.
Many would advise that only a specialist pump supplier to the AD industry with a strong reputation for reliability, can provide the AD plant operator with the high level of service needed for such a vital process component.
List of Pump Types Used in Anaerobic Digestion/ Biogas Plants
1. Submersible Centrifugal Pumps
Free-standing units are used for general flow duties in sumps and chambers, for site surface water drainage, slurry pumping etc.
Inline centrifugal and progressive cavity pumps are used as general water pumps.
2. Chemical Dosing Pumps
Chemical Dosing Pumps are used as their name suggests, everywhere when a precisely timed flow is required for the delivery (dosing) of a liquid into a vessel.
3. Chopper Pumps
Centrifugal pumps are provided with a proprietary rotating knife at the inlet to the impeller chamber to chop off filamentous material, rope etc., which would otherwise block and clog the pump.
4. Impellers and Paddles which Provide Pumping Action/ Stirring for Reactor Tank Mixing
Digester impeller-induced mixing and stirring is provided by what are essentially rating vanes similar to an aircraft or ship's propeller. Large low-velocity and small-bladed high-velocity impellers.
5. Feeding Equipment Pumps
Lobe pumps and progressive cavity pumps are examples of pumps used to feed the organic pulp or slurry into the digester tank. They may be fed via hoppers, macerators, conveyors and augurs.
6. Slurry Pumps
A wide range of pumps are used for manure slurry pumping duties, as the consistency, water content and volume vary, across such a large range depending on each project. Pumps that may be used for slurry tank pump mixing, include submersible impeller pumps, and submersible slurry pumps.
In the article which follows (first published in July 2017), we provide a case study of how specialist pump contractor Verder Liquids/ Verder UK provided the biogas plant pumps for a food waste AD Plant at a brewery in Norfolk.
Biogas Plant Pumps Used by Verder in Anaerobic Digestion Biogas Production at a Brewery in Norfolk UK
Anaerobic digestion provides renewable energy. This is achieved when organic matter is transformed to biogas, in the absence of air. Verderflex HUS Screw-channel pumps have proven to be excellent pumps for anaerobic digestion. Read here about two examples: “Recovery of waste food” and “production of biogas”.
Biogas Pump Case Study: RECOVERY OF WASTE FOOD AND THE PRODUCTION OF BIOGAS
A prestigious brewery based in Norfolk, who produce fine quality real ales have installed an anaerobic digestion (AD) facility. It is used for producing biogas to be inputted into the national gas grid. The anaerobic digestion facility is fed with kerbside-collected food waste, food processing waste, supermarket food waste and brewery waste.
The organic matter is entered into a feed inlet at the start of the process where a rotor chopper breaks down the raw material. Verderflex pumps move the chopped slurry from holding tanks and through a heat exchanger to raise the temperature prior to entering the main AD facility.
As the hot organic material enters the main AD facility it is dosed reliably and accurately by a Verderflex Dura pump with an inorganic pH buffer to accelerate and maximize the breakdown of the material.
The large mass of organic material is ‘churned’ by Verderflex pumps in a plant room connected through a series of pipes to maximize the surface area and further accelerate the AD process and obtain the greatest yield of heat and biogas. The heat is recycled back into the heat exchanger.
Upon completion of the AD process, the digestate and waste water is pumped from the tank by a Verderflex pump for further use as fertilizer. The final product of biogas is then filtered and processed further ready to be inputted into the national gas grid.
Other applications of Verderflex biogas plant pump systems in Anaerobic Digestion are
- Rotor-chopped cold organic material
- Warm organic material
- Warm slurry
- Digestate
- Waste water liquor
- Enzyme dosing and other chemical dosing solutions.
Other Biogas Pumping Solutions Offered by Verder UK
VERDERHUS SCREW CHANNEL PUMPS
Because of their construction HUS screw channel pumps are excellent pumps for use as Biogas Plant Pumps, pumping waste with large solids such as bones. The percentage of solid matter can sometimes increase up to 10-13 %.
Executions available in standard with shaft sealing or cantilever version. Close coupled on base plate or in vertical position. Long coupled in standard or with V-belt drive. Max. flow : up to 1030 m3/h
VERDERPRO PROGRESSING CAVITY PUMPS
For a.o. the pumping of fish waste (fish morts) to produce biogas a Verderpro pump is being used with a real “green”development.
via www.verderliquids.com
[First published in July 2017.]
Our centrifugal pump was no longer doing the job, so we replaced it. The new pump still ain’t delivering. Supplier says the pump is good, but the condition of the substrate surpasses the pump’s physical delivery capacity. How come? It was working for years. Pump guy say we must turn to a positive-displacement or reciprocating type of pump, say a piston pump, gear pump or eccentric spiral pump. Is he right?
It sounds like either the viscosity of your substrate has risen or there is a gradual build-up in your plant pipework.
Have you tried jetting out the pipework?
If you have, and presumably you don’t want to change your feedstock, or in some other way, reduce the viscosity, you will need to consider buying a positive-displacement pump.