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FIGURE 6 PROCESS FLOW DIAGRAM OF SENT PROCESSING FACILITIES FIGURE 7 CONSTRUCTION COMPLETE

FIGURE 8 DURING FABRICATION OF THE EJECTOR FIGURE 9 AFTER CONSTRUCTION OF EJECTOR AT THE OFFTAKE STATION FIGURE 10 ONLINE CV ANALYSER

2.5 Gas appliance test (LFG+TG) After the design verification, the delivered to an offtake station to be
Before the detailed design and build of processing facility – the largest of its mixed with TG. Further gas appliance
the whole processing facility, a trial test kind in Asia – was finalised (as shown tests were carried out to check and
of the interchangeability of the gas in in the process flow diagram in Figure 6). prove the mixture was interchangeable
appliances was carried out by mixing The facility was constructed under the in Hong Kong’s gas appliances.
small portion of LFG into TG. project control and monitoring of HKCG. The results showed that all the gas
Three sets of gas were tested: An ejector system was installed and appliances operated normally, with a
Pure 100 per cent TG applied to mix the SNG and the TG in a low CO/CO₂ ratio and without light-back
95 per cent TG, five per cent LFG controlled manner. This removed the or flame lift.
92 per cent TG, eight per cent LFG need to introduce extra energy to up the
Domestic and commercial appliances gas pressure of the SNG so it matched Conclusion
were selected for the test and the that of TG at the offtake station. Thanks to an innovative mindset and
results are summarised in Figure 5. Shanghai Fiorentini Gas Equipment implementation process, the LFG
Without treatment, the physical Co Ltd was awarded the tender to from this site has been successfully
properties of LFG deviate somewhat design and supply the ejector transformed into a product that is
from TG and cause a little drop, system, which is the largest of its interchangeable with TG in Hong Kong
but nevertheless an acceptable kind in the world. gas appliances.
performance. The combustion The facility has operated successfully
performance was concluded to be Findings since 2017 and this project now acts as
satisfactory. No light-back, flame lift or Gas composition measurement a model for utilising renewable green
incomplete combustion were found and In 2017, the SENT processing facility energy from LFG. We believe the methods
there was an expected blue flame. was commissioned with online CV used here could be applied in other
analysis and gas chromatography countries, especially those using city gas
Implementation supplied by Tai Po Plant Laboratory or town gas. Ultimately, this will allow
In order to implement the concept, for the purposes of quality control and other urban areas to recover LFG, reduce
HKCG invited tender from potential process validation. Both show that the carbon emissions and contribute to the
suppliers for the detailed design of the SNG is being controlled at 17.27MJ/Sm³ preservation of our environment.
processing facilities. Sichuan Tianyi within acceptable limits.
Science & Technology Co Ltd was Gas appliance test (SNG+TG) Watch Mario’s presentation online.
awarded the tender after an evaluation. LFG was converted into SNG and Go to bit.ly/IGEMtv

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