Biogas and Methane Feed Plants

Power to the plug ... say those who champion electromobility!

Sustainable, environment-friendly energy sources – those are the modules for the future of humanity – in the personal, industrial and mobility sectors. Since the surrounding conditions always vary, our ability to turn customer wishes into reality is of particular interest. Our in-depth experience in the natural gas sector makes it easy for us to satisfy both the stringent requirements of legal and technical regulations (DVGW G260, GasNZV) as well as the customer’s instrumentation, control, regulation and safety expectations. Especially worth mentioning is the ability to obtain from a single source both the biogas conditioning system and the biomethane feed system. That eliminates annoying interface matching problems for our customers. 

To render biogas usable as an energy source for the future, it is necessary not only to produce the fuel by way of fermentation and subsequently to condition it. The next essential step in the utilization chain is feeding that biomethane into the local gas supply grid. This task initially sounds far simpler than it actually is. A particular challenge to biogas feed is the high quality standards imposed on the biomethane being supplied, as specified in legal and technical regulations (DVGW G260, GasNZV). This is why highly accurate, continuous measurement and logging of both the characteristics and the quantity are assigned the highest priority. Continuous measurements of the gas make it possible to quickly and accurately modify the qualities of the biomethane being injected in the event of deviations from the prescribed quality. Biogas quality and quantity are measured by a variety of instrumentation, in some cases calibrated. These include the process gas chromatograph, biogas analyzers, calorimeter and calibrated rotary lobe and turbine-type flowmeters. Our systems feature highly diverse measurement and analysis systems built by expert manufacturers and perfect combination of the differing systems in accordance with the principle: “As rough as possible, as fine as necessary”.

To match magnitudes relevant in terms of gas technology – such as the calorific value, relative density and thus the Wobbe index – as well as the share of other defined substances, it is possible to add LPG, air or nitrogen, as required, to the biomethane arriving from the biogas conditioning plant. Often a combination of these additives will be required. The plant’s measurement and evaluation technology is, for this purpose, coupled by means of the software with the corresponding process and regulation metering equipment (regulating valves, evaporators, metering pumps). Biomethane infeed systems made by Schwelm Anlagentechnik GmbH are normally equipped with an odorant injection system for feed into low  or high-pressure grids. This may be omitted for feed into non-odorized, high-pressure gas grids. 

The advantages of combining the biomethane infeed system with a Schwelm gas conditioning plant in conjunction with low  and medium-pressure grids is that this eliminates the need for a compressor stage. The output pressure of the biogas conditioning plant at about 6 bar is higher than the pressure required for feeding gas into the grid. 

In other cases compressors of any of a variety of designs and concepts will be used. Each is matched to the application range, the operator’s requirements, and local conditions. 

A biogas infeed system can be installed in a sheet steel container, a concrete enclosure, in a split configuration if required or in an existing building. And just like the conditioning technology itself, the basis for all our products is the satisfaction of industrial demands.

For everyone who wants to take a closer look at the details