Answers to common questions about biogas, biogas plants, and construction
Not at all. Unlike propane or butane, biogas cannot be liquefied at normal temperatures. Biogas is primarily methane gas and carbon dioxide. As temperature decreases, carbon dioxide liquefies earlier than methane. Methane evaporates at a temperature - 161.5 ° C. Biogas is normally purified to methane and stored in cylinders, not liquefied but compressed under a pressure of 200-300 atmospheres. Methane can be liquefied as well but an additional costly cryogenic technique is required.
It is possible, but such storage containers are expensive. Typically, low pressure gas tanks are designed for 1-4 hours of storage. There are spherical gas tanks of medium pressure for 2-5 days.
For long-term storage, biogas must be purified to methane and compressed at a high pressure of 200-300 atmospheres. In this case, storage should be underground which is similar to how natural gas is stored.
The price depends on size, type of input raw materials and equipment. The smaller the biogas plant, the more expensive it is per kW of installed capacity. 10 MW silage biogas plants cost €1,400 euros per kW. 1-2 MW manure biogas plants cost €2,000-€3,000 euros per kW. 300 kW plants cost €5,000 Euros per kW.
There are simple and cheap cattle manure plants. But there are also complex and expensive ones which are able to process contaminated raw materials requiring special preparation.
The cheapest 100-150 kW installation costs €600,000 euros.
In each case, plants are developed individually for the customer’s specific requirements. After receiving answers to the main questions, the proposal is prepared within 2-5 days.
We do lend after the evaluation of the borrower' finacial condition.
Financial instruments are not economical for us for small and medium-sized projects. For large projects however, bank guarantees and performance bonds are available.
The total project price is the same. Higher equipment price or a lower construction cost or vice versa. Reactor lifetimes are also the same. A steel reactor is faster to install, and banks perceive steel as having lower risk. Sometimes, a concrete plant is farther than 80 km from a construction site, and the transportation of concrete is not possible.
There is a paper stage and materialization stage. The paper stage consists of initial data collection, design, approvals and permissions lasting 6-8 months. Materialization comprises equipment supply and installation, construction, commissioning lasting for another 6-9 months.
The timing is affected by seasonal factors. Snow and rain add delay, and it is difficult or expensive to build in some countries. On average, a project takes 1–1.5 years. We have completed small projects in which the equipment was ready, allowing us to build an entire biogas plant in 4 months with certification following.
The payback period for biogas plants is from 2-3 years to 6-7 years. In general, the larger the project, the shorter the payback period. Projects using waste, which cannot be sold, pay off better than maize silage projects. However, there is special technology for maize silage. And on a large scale, silage plants can reach payback in 3-4 years.
The payback periods of biogas plants also depend on the concept. This are gas-to-grid or power-to-grid projects. These are strongly impacted by energy prices and green tariffs in the country of operation. The payback period also greatly depends on the reliability of the technical solutions and the professional experience of the engineering company. One can buy equipment, albeit high-quality, but with the wrong technology or a poorly thought-out concept, the payback period will be extended.
Zorg Biogas has a proven 16-year track record. The company is well-established and experienced, and such companies, in this field, can be counted on one hand. The company employs specialists with extensive experience in biogas. Zorg Biogas has recruited the best German technologist with the global reputation. The сoncepts for biogas plants are highly reliable. Moreover, the company offers a unique product that no one can match.
Typically, companies use just one technology. Most use the Continuous Stirred Tank Reactor (CSTR). Zorg Biogas is distinguished by the fact that it uses all the proven technologies. We use high-load reactor technologies for silage, vertical reactors with a central mixer for sugar beet pulp, CSTR for manure and chicken litter, for solid waste - the dry method.
Unlike some of our competitors who claim support for various technologies, biogas technologies listed in Zorg’s prospectus have been implemented in operational biogas plants. This sets Zorg apart from the rest.
The classical CSTR technology implies a load of organic dry matter (ODM) of 2-4 kg per m3 of reactor per day. We use HLR technology and achieve ODM load of 7-16 kg per m3 of reactor per day. There are even plants with the load ODM of 18 kg.
CSTR has 3-10% dry matter in the reactor. The HLR has 16-18%.
Reactors based on HLR technology are 3 times smaller in volume and 2 times cheaper in comparison with CSTR.
The dry method allows to process highly contaminated municipal solid waste without a deep sorting. When using CSTR, fine sorting is required. The dry method is several times cheaper and no less effective.
There is the Fischer-Tropsch technology for converting natural gas into liquid hydrocarbons such as gasoline and kerosene. However, such plants cost hundreds of millions of euros. Fuel does not have to be liquid to be used as an automobile fuel. Biogas purified to methane can be filled in gas tanks and used to power vehicles. Such purification, biogas-to-methane plants, are relatively inexpensive.
The best substrates are free, clean and high-calorific. But there are exceptions. For example, maize silage is not cheap, but with the special technology of high load reactors, large scale biogas plants are very cheap. And even with costly substrates, payback periods are acceptable.
Many will say that is possible or even recommended. We believe in the case where raw materials are so different that it is better not to mix. For example, liquid manure and silage have significantly different fermentation periods, so it would be better to ferment them in different reactors. If mixed, the silage will not be fully fermented. We recommend only raw materials with similar hydraulic retention times should be mixed.
They can be used only after special thermochemical preparation. Milling, pelletizing or steam explosion are required. Biogas output from the milled straw is 300 m3 per tonne. When using a steam explosion, the biogas output reaches 450 m3 per tonne.
No. There are not enough trace elements in the silage, and the reaction, at best, will go halfway. Worst case, it will not go at all. The silage is fermented always with the addition of trace elements. If manure is mixed with silage, trace elements are still required. Trace elements in the manure are sufficient only for the manure itself. Silage still requires chemical additives. Not using micronutrients for a silage / manure mixture is a common mistake.
No. In its pure form, it produces ammonium. Dung must be mixed either with carbon-containing organic matter, water, sewage water or reagents.