A British biogas company is fuelling success on farms in the UK through its advanced anaerobic digestion plants, with gas production from organic feedstocks being boosted by fast-acting, cost-effective, silage additives.
According to Guildford-based Future Biogas, using Silasil Energy® and Silasil Energy XD® from FM BioEnergy -the renewable energy division of BOCM PAULS- enhances biogas production. Developed in conjunction with Schaumann BioEnergy, the German market leader in biogas optimisation and process efficiency, the products also help to produce a more stable, compact feedstock and, when necessary, reduce the fermentation period.
“You can produce good maize silage without using additives,” Future Biogas farm adviser Oliver Knowland explains. “But by using these particular products we always get what we need and there is less secondary fermentation. They also help to preserve the energy content of the silage.”
“More importantly the use of these additives has maximised the throughput of maize silage through the digesters. In the clamp the acid produced by the addition of the additive not only helps to conserve energy (less heat) but also gets the feedstock into the optimum state to be used in the primary digester and turned into biogas by the bacteria as quickly as possible. The more energy we can get per hectare, the better but the quicker the feedstock can go through the digester the more gas per hour we can get.”
The Silasil Energy range of biological ensiling agents has been specifically for high-carbohydrate energy plants, including maize wholecrop silage from 25%-40% DM, maize grain products (55%-65% DM), cereal wholecrop silage (28%-40% DM), energy grass (30%-45% DM) and sorghum (>25% DM).
These act through bacterial strains which have been specially selected for biogas production and create a specific fermentation acid pattern. Fast-acting homofermentative bacterial strains start off the fermentation process then heterofermentative lactic acid bacteria strains act to promote acetic acid fermentation. This minimises energy losses in storage and increases biogas yield, both per tonne of fresh matter and per hectare of crop.
By controlling the ensiling process Silasil Energy generates two key advantages. Firstly, the special fermentation acid pattern it produces reduces the risk of aerobic instability, heating up, fungal infection and rotting of the silage, thus providing optimum protection for the energy and nutrients it contains. Secondly, silage treated with Silasil Energy is easier to hydrolyse, biogas formation starts perceptibly earlier and biomass degradation to produce biogas is completed sooner.
Achieving best results
Good silage is as critical for success in farm-based anaerobic digestion plants as it is for top production from good cows, which is why Future Biogas is working closely with FM BioEnergy to ensure that it obtains the best results as rapidly as possible for all its plants.
“We have been working closely with FM BioEnergy for some time,” Mr Knowland explains. “Their technical expertise and range of silage additives allow us to better control the ensiling process, as well as achieving a better balance of the necessary acids, stable feeding and high energy yield. Silasil Energy and Silasil Energy XD have certainly contributed to our success as a company here in the UK.
“With Silasil Energy, ensiling takes 40-plus days in a clamp which is more stable, with less edge losses and a more stable face when feeding out. It also enhances fermentation for biogas production in the digestion tank, with a better balance of acids.
“Silasil Energy XD is good for clamps that will need to be opened quickly. It helps to reduce the fermentation period and the first clamp can be opened after two weeks. We use it when we are in a hurry to get feedstock for the plants.”
Future Biogas’s plants can operate on a range of locally-sourced biomass feedstocks to generate clean, renewable and reliable energy. The company is actively working on introducing a variety of sustainable break cropping feedstocks which include wild flower mixes, HLS grass, sunflower and red clover mixes with ryegrass. On marginal land that is less suitable for food production there are also possibilities to grow perennial crops which offer significant biodiversity benefits whilst delivering excellent biogas yields.
“Our experienced team has a unique, in-depth knowledge of biogas production,” Mr Knowland states. “In addition, our biogas plants provide stable, reliable renewable energy, thereby helping to meet the UK Government’s 20% renewable energy target by 2020, whilst providing a number of farming benefits. This efficient technology provides an ideal solution to meet specific UK needs, whether farmers are using maize or other break crops as feedstocks.
“Farmers who supply our biogas plants have highlighted the fact that growing specific crops for AD fits in well with most rotations, either acting as a break for cereals or an entry for root crops. Farmers have also been able to grow our crops for biogas production after late-lifted root crops such as carrots, parsnips and sugar beet.
“Future Biogas is continually moving forward, with plants across the UK, and we are looking forward to another successful year, with a good rye harvest and the maize crop looking promising. We will continue to work closely with FM BioEnergy, who have been very helpful and proved to be reliable partners, sharing the same philosophy and seeking to be dependable partners for farmers, industry and the wider community.”
In addition to its range of innovative silage additives, FM BioEnergy also offers process additives, laboratory analysis, biological support contracts and gas leakage detection.