Monitoring of Odorants in Natural Gas

The gas odour level of natural gas needs to be monitored at regular intervals to secure the required level of the organosulphur compounds tetra-hydro-thiophene (THT) and tert-butyl-mercaptane (TBM) or the sulfur-free (Gasodor®-S-Free®) markers which are used worldwide to odorize natural gas. The safety concern is to assure a minimum concentration of the alarming smell while not overdosing the high-priced odour markers.

With experience of more than 10 years in the natural gas  application G.A.S. in 2015 launched a new customized instrument generation. Compared to former products the GC-IMS-ODOR is based on gas chromatography which enables an excellent separation of any natural gas matrix and to measure any odorant with an accuracy of better than +/- 1 mg/m³. Moreover the configuration, workflow and particularly its user-interface are optimized to correspond to the daily routines and operations of utility personnel in the field.

The GC-IMS-ODOR is versatile as its 19" housing allows a portable on-site use with an automatic pressure independent flow adjustment, one-klick operation and a measurement time of 4 minutes. Results are stored on the compact flash card, can be linked to locations and later being downloaded using a USB stick to be printed as report or converted to Excell tables.

The GC-IMS-ODOR can alternatively be operated as on-line monitoring device where it samples and fully automatic re-calibrates itself at user defined intervals. Data can be transfered via Ethernet or 4-20mA output to a control room. Using this operation mode and positioning the instrument at critical 'end-points' of its grid the utility assures a 24/7 control of its odour concentration and can react immediately in case of a problem at the point of odorization, the grid or an empty odorant container. 

Therefore the GC-IMS-ODOR represents a rugged, value for money high-end equipment that can still be operated by the technical personnel of natural gas utility.