Factsheet: ÖVGW directives (gas quality) G31 & B220

ÖVGW directives (gas quality) G31 & B220

Key Information
Full name of Instrument & Measure (English): 
ÖVGW Directives
Full name of Instrument & Measure (native language): 
ÖVGW-Richtlinien G31 & B220
Description: 
The quality requirements for biogas, if it is injected to natural gas grids, are specified in the General Distribution System Conditions and are provided for in Chapter 6 of the Technical Code of Other Market Rules. A list of ÖVGW Directive, which must be fully respected if biogas should access the grid, follows below: ÖVGW Directive G31 “Natural gas in Austria - gas composition”, 2001.05 This directive should ensure safe transport within the Austrian gas network. ÖVGW Directive G33 “Regenerative Gase - Biogas” , 2006.06 In this directive the additional, specific requirements for biomethane, e.g. gas quality measurement are listed. In 2011 it was replaced by the following directive G B220. ÖVGW Directive G B220 “Regenerative Gase - Biogas”, 2011.11 This directive replaces the ÖVGW Directive G33. It allowes to inject also upgraded sewage gas into public gas grids for the first time and the max and the Si content of biomethane has been lowered. ÖVGW Directive G79 G79 sets the requirements on odorisation. If fed into a grid containing odorized gas, biomethane has to be odorized as well. The grid operator determines the kind of odorant and the minimum requirements for safe operation. For documentation of the amount of biomethane fed into the grid, a measurement of the gas quantities must be provided for. The selection of measurement methods and installations is up to the grid operator.An excess of the allowable pressure in the gas distribution network must be prevented by appropriate measures. Appropriate installations (see ÖVGW Directives G73/1, G73/2, G73/3, G73/4) have to be implemented. Lower methane contents than 96 % are permitted if the gas quality specification rules according to ÖVGW Directive G31 and a upper calorific value of at least 10.7 is adhered to, therefor augmentation with LPG or propane is possible in order to adjust biomethane to become on-spec. Also blending of "off-spec" biogas with natural gas in the grid is only possible with augmentation with LPG and propane. The gas quality monitoring of parameters such as methane and H2S content and water dew point is regulated through ÖVGW Directive G B220 and has to be measured continously. Quality parameters of production conditions in digester have to be determined continously. Frequency of measuring according G 31 and B 220 has to be agreed on in reconciliation with the grid operator.
Goal/Aim: 
regulation of biogas and sewage gas injection into the gas grid

Sector/Topic targeted:

Responsible Authority: 
Austrian Standards Institute

Status:

Trade Relevance: 
Technical rules on gas and the access to the grid
Year Instrument & Measure Started: 
2001