Alchemy TD - Alchemy Utilities

The Next Generation of AD











Higher Gas Output

Bagged Organic Dry Fertiliser

Small Footprint

Continuous Biogas Production

The Alchemy Thermophilic Digester (TD) is a revolutionary biogas system that uses a next generation dry digestion process, improving the energy efficiency typically associated with traditional Anaerobic Digestion (AD) systems. The system is a modular and scalable solution for efficient conversion of organic wastes into biogas and high quality dry pelletised or granulated fertilisers. Taking the advantages of both Thermophilic reactors and dry digestion processes the Alchemy TD is streaks ahead of anything currently available. The Alchemy TD system is able to run on a wide range of organic feedstocks including 100% chicken litter

The Alchemy TD produces 100 kW of electricity and 100 kW of heat through a CHP engine specifically designed to run on the biogas produced by the plant. Requiring as little as 4.7 tonnes per day (@40% dry matter) of input fuel it is an incredibly efficient process. The patented process design produces more gas that is higher in methane content than a traditional AD process, meaning better outputs and returns than similar sized alternatives.

All this is delivered from a package that fits neatly onto a 25 x 25 m space, a significant reduction in size than what can be expected from an AD plant.



What wastes can we process?

The Alchemy TD can process most organic wastes, including those that are typically avoided by traditional anaerobic digestion systems. Below are just a few highlights of the options available for processing by the Alchemy TD, however, this doesn’t mean we can’t process your organic waste. If your’s isn’t listed then please contact us to discuss the system in more detail. 

Dairy Wastes

Many dairy food processors are facing growing issues with removal of their process wastes. Current methods of removal are causing issues with infrastructure and escalating costs to maintain equipment. 

Alchemy’s solution can not only remove the need for the traditional waste removal methods, but utilise the waste materials in their revolutionary Alchemy TD digester system to produce a clean renewable biogas. Furthermore the remaining digestate can be converted into dry, bagged, organic fertiliser. 

Converting what would be entirely a waste stream into valuable biogas, desirable fertiliser and returning clean water to the producer for re-use it’s not hard to see why this solution is so astounding.       

Chicken Litter

Unlike traditional anaerobic digestion system’s Alchemy have developed a process that can handle aggressive fuels that are typically avoided, such as chicken litter. In conventional systems, the high ammonia content of these types of wastes causes issues with the digestion process and so are avoided or only used in very low quantities mixed with other wastes.

The novel pre-treatment system developed by Alchemy extracts the ammonia at the front end such that the wastes with up-to 100% concentration can be processed and digested effectively. The extracted ammonia can be reintroduced post digestion to boost the nitrogen value of the digestate and fertiliser.       

Cow Manure

Farmers face growing pressures on their current slurry storage with tightening regulations on spreading and storage. With constraints on the amount and times with which they can spread, they need an alternative to simply storing. 

Some farms have turned to anaerobic digestion to process the cattle wastes and alleviate this issue, but for many the sheer scale and investment of a suitably sized system is to great. The Alchemy TD system has been specifically designed to suit the smaller on farm application and is modular so that a range of farm sizes can be accommodated.       

Food Waste

In the UK alone, over 15 million tonnes of food is wasted each year. This food has significant energy potential and is very good for biogas production. Whilst some systems may struggle with the use of 100% waste food as a feedstock, if required our pre-treatment system is able to extract ammonia from the food waste making it perfect for digestion without and negative affects. The nitrogen can then be reintroduced to enhance the quality and benefits of the fertiliser. 

The Alchemy TD can be sized to fit adjacent to food processing/distribution plants to utilise their waste streams. Fitting easily into their daily operation with minimal land impact. Producing a gas that can be used to offset expensive and environmentally detrimental fossil fuels.      

Depending on your location there is also potentially the additional benefit of both heat and power incentives from the government. Please see the table below to find out more:


Incentive Scheme Feed in Tariff (FIT) Feed in Tariff (FIT) Export Rate Renewable Heat Incentive (RHI)
Tariff Type Anaerobic Digestion (<250kW) Anaerobic Digestion (<250kW) Biogas Combustion
Tariff Value 6.19 p/kWh 5.03 p/kWh 4.43 p/kWh

The incentive rates above are an interpretation of the information from the Feed In Tariff, Renewables Obligation and Renewable Heat Incentive Guidance Documents and should only be used as guidance and should not be considered a guarantee.  



Incentive Scheme Feed in Tariff (FIT) Export Rate Support Scheme for Renewable Heat Incentive (SSRH)
Tariff Type Anaerobic Digestion (<500kW) Wholesale price AD Heating Systems
Tariff Value TBC average €60/MWh 2.95 c/kWh

The incentive rates above are an interpretation of the information from the Feed In Tariff, Renewables Obligation and Renewable Heat Incentive Guidance Documents and should only be used as guidance and should not be considered a guarantee.  

Please contact our sales team who will be able to advise more on other tariffs that may be applicable. 




Key Product Features and Benefits

The benefit of this dry digestion process is the use of only a small amount of water. This is achieved by using specially designed double walled digesters. The inner cylinder holds and moves the digesting organic material (40% dry matter) whilst the outer cylinder helps maintain the working temperature of the thermophilic process by providing a water bed in a closed circuit vastly reducing the need for water, the need to heat a substantial amount of water in order to achieve the thermophilic temperatures and the power requirement to turn the inner cylinder. Furthermore, this also means that the digestate isn’t diluted providing a more valuable end product.

Using the dry digestion we are able to reduce the amount of heat energy needed by approximately 33%. By operating at thermophilic temperatures the Alchemy TD has the potential to produce 10% more gas at a higher methane concentration than regular AD systems. Combining the benefits of dry digestion and thermophilic process the Alchemy TD is by far the most advanced digestive system in the market significantly out performing AD plants and others alike.

The biogas that has been produced can be used for either combined heat and power production (CHP) or simply burned to produce around 250 kW of heat. The digestate left at the end of the process can be used as an organic fertiliser or soil conditioner.

Organic digestion is not a new technology, and has been widely applied in the UK for the treatment of sewage sludge for over 100 years. However, until quite recently it has not been used here for treating waste and creating such a high value product. From just 4.7 tonnes a day feedstock the system is capable of producing 100 kw of heat 100kW of electricity and 1.7 tonnes of pelletized fertilizer. (the system is still in development however early test on cow manure and food waste suggest that these figures will be easily achievable)


Benefits over traditional Anaerobic Digestion (AD):




Footprint  25m x 25m Larger footprint needed for digester typically 5,000 sq m, digestate treatment, pasteurization and feed stock storage Designed for application to small-medium sized farms with much lower space impact
Feedstock Input

A range of feedstocks (20%-40% dry mater) Pure Slurry/Pure Food Waste/ Mix of Slurry / Chicken Litter / Food waste 

46 tonnes of pure slurry a day required to achieve similar electrical output.* Feedstocks that normally attract a gate fee utilised therefore fuel costs are zero or negative; no need for energy crops; and aggressive fuels, such as 100% chicken waste, can be utilised
Start-up 1 – 2 weeks 4 – 5 weeks Quicker to realise returns from installation
Higher methane concentration 10-15% less methane gas produced Greater gas output for similar fuel input 
Digestate Output 1.7 tonnes per day of dry organic fertiliser easier to spread and store Wet digestate can be messy to store and handle Production of nitrogen rich organic fertiliser has high market value circa £170K/yr – extraction of nitrogen from feedstock has huge financial and carbon reduction benefits (£400/tonne)
Heat & Electricity Production (via CHP engine) Innovative thermophilic dry digestion process requires significantly less energy Large proportion of valuable energy (heat & power) required to operate digestion process Larger amount of valuable energy available for use or sale and eligibility for government incentives (RHI and FIT)

*Figure from report published by IEA Bioenergy on small scale AD systems

Creating Revenue from Waste

‘Muck to Money!’

Frequently Asked Questions (FAQ)

What Feedstocks can be used in the Alchemy TD?

The Alchemy TD can take a wide range of organic wastes in it’s novel digestion process, including chicken/poultry manure, cattle slurry, pig slurry, farm yard manure, silage, maize, straw, hay and rushes. The quantity of feedstock material required will vary between wastes but the efficient digestion process means that less material is required for quality gas production. Please contact us to discuss specific waste inputs.  

What volume of feedstocks can be used?

Depending on the dry matter percentage (DM) and the type of feedstock, the Alchemy TD system is capable of processing 5 ton to 10 ton of organic material per day.

Can a mix of feedstocks be used and how?

Yes, a mix of feedstocks can be used but a certain mix has to be specific for each site. See examples below:

A farm in Monaghan with poultry and cattle can use a mix of both poultry manure and cattle slurry but the percentage of each feedstock has to be the same for the bacteria to maximize the highest yield of gas.

A farm in Leitrim will have cattle slurry and perhaps bales of rushes available. This could be the type of feedstock to be used in that part of Ireland.

A farm in the midlands and south of Ireland could have access to multiple feedstocks from intensive pig, dairy and beef farms along with straw from the tillage sector.

Along with ‘On Farm’ solutions we can also cater for bio wastes in the diary processing sector and process organic waste from the Brown Bin collection.

What yield of biogas can the Alchemy TD produce?

Depending on the feedstocks used the Alchemy TD system can produce anywhere from 50 to 100m3 of biogas per hour.

Can a Combined Heat and Power (CHP) system be installed alongside the Alchemy TD?

Yes, our system is capable of running a 100 kW Combined Heat and Power (CHP) system. This particularly useful where there is a constant heat load on poultry and pig farm units.

The Alchemy TD can be set up to suit a range of different scenarios and the energy outputs depend on the system configuration. The system can be set up for CHP, gas only production for use in a biogas boiler or upgrade to biomethane and grid injection. There are lots of different combinations available and it can be tailored to suit the site specific requirements.

Does the Alchemy TD biogas qualify for the SSRH (Support Scheme for Renewable Heat)?

The Alchemy TD can qualify for the SSRH (Support Scheme for Renewable Heat) once the Biogas produced is used to displace heat from conventional fossil fuel sources. The Alchemy TD is an ideal size to maximize the tariff from the SSRH for heat from Biogas.

Can the digestate be spread on agricultural land of all types including grassland?

Yes, the Alchemy TD has a pre-treatment system that pasturises the feedstocks at over 80 degrees Celsius for an hour. This makes I suitable for spreading on all land types.

Is there any nutrient loss in the feedstocks after it has been converted into digestate?

No, if cattle, pig or poultry manure etc is used it will still have the same NPK value. The pre-treatment system extracts the nitrogen from the feedstock at the front end. However this can be incorporated back into the digestate so there is no loss of Nitrogen.

What is the DM% and NPK value of the digestate?

The DM of the digestate is typically between 20 and 40%. As the digestate is drier than slurry and digestate from a Wet AD system it can be spread with a muck spreader and makes storage easier. If the digestate is spread on land it can act as soil conditioner along with reducing the need for chemical fertiliser.

The NPK value of the digestate varies depending on the feedstocks. Poultry litter is higher in NPK than cattle slurry. However Alchemy test the digestate to optimise a farmers Nutrient Management Plan to comply with all nitrates regulations.

How much water can the pre-treatment system extract from slurry?

The pre-treatment system can extract approximately 3 ton of water from a 9 ton (2000 gallons) load of cattle slurry

What is the size of an Alchemy TD system?

Complete system fits into approx. 25m x 25m Footprint. (Including: Pre-Treatment, Digester units, Seperator, CHP system, Gas Processing, Pelleting / Granulating Plant)

Our Solution to the Waste problem:

In the UK 15 million tonnes of post farm food waste is created every year.  Half of this waste is produced from households, the other half is generated from the manufacturing, retail and hospitality sector. However there is Evidence that one third of this could be avoided. The production, distribution and disposal of this avoidable waste amounts to a large proportion of the UKs annual greenhouse gas emissions (GHG) 3% in total. This amounts to approximately 20 million tonnes of CO2 associated with avoidable food waste per year.

Along with food waste manure and slurries waste stored within the UK amount to approximately 90 million tonnes per year. Not only does this require large structures that take up a lot of space on the farmyard, such as lagoons and silos, it can contribute to environmental factors such as contamination of surface water through leeching, and possible secretion of a bad odour.

There is potential for this slurry to be spread on the farmland as a natural fertilizer however this again has issues of its own. One concern is the possibility of spreading too much slurry, this in turn could potentially kill off earthworms, which are a major part of the echo system when it comes to breaking down dead matter, secondly if slurry was to be spread before heavy rainfall there is a chance that the increase in minerals such as nitrogen and phosphorous may impact local water sources, due to surface runoff. Furthermore the “nitrate vulnerable zone regulations” stipulate that many organic manures cannot be spread through certain times of the year contributing to an already growing surplus that takes up a lot of space and can be costly to store correctly.

The Alchemy TD system is the perfect solution to this growing problem in the UK and abroad. Being able to take a wide range of organic waste streams to produce energy locally, it could significantly reduce the amount of food waste that goes to landfill and agricultural organic waste stored on site. Furthermore, the generation of electricity local to the point of use means that inefficient power plants are less in demand and transmission losses are brought to an absolute minimum.    


Source: WRAP (Waste & Resources Action Programme) 

Source: Eurostat via The Guardian

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