November 23 -- SIAD Macchine Impianti - SIAD MI, the SIAD Group's engineering company, has installed and started up at the Port of Ravenna a reliquefaction plant for the evaporated natural gas (boil-off gas – BOG) at the service of the small scale LNG and four cryogenic compression packages (BOG compressors) for the recovery and reliquefaction of evaporated natural gas again.
The installation is located in a latest generation LNG storage facility owned by Depositi Italiani GNL – DIG (Italian LNG depot), a company jointly owned by the PIR group (Petrolifera Italo Rumena), Edison, the latter in charge of the engineering implementation of the project, and Enagás (through its subsidiary Scale Gas).
The storage facility consists of two atmospheric storage tanks for LNG. The LNG is transported by Edison to Ravenna by means of LNG carriers, transferred and stored in the tanks at the depot and made available for bunkering or to be loaded by tankers and distributed on the mainland at the filling stations.
The storage facility has a capacity of 20 000 m3. Having a potential annual handling of more than 1 million m3 of LNG, it will be able to refuel up to 12 000 trucks and up to 48 ferries per year, and will therefore be a strategic point for liquefied natural gas refuelling throughout the northern Adriatic for maritime transport and for the central-north for land transport. This is a fundamental investment to make the transport sector more sustainable. By using methane as a fuel, emissions of sulfur oxides and particulate matter can be reduced to zero, with a 20% reduction in carbon dioxide emissions compared to traditional fuels.
In this context, SIAD MI has been involved in the compression and reliquefaction of the BOG. Liquid methane, in fact, during the various transfer operations (from the LNG tanker and during distribution), partly vaporises and passes from the liquid state to the gaseous state, namely the BOG, which is first compressed and then reliquefied in order to be reintroduced into the storage tanks.
The reliquefaction plant developed by SIAD Macchine Impianti will enable it to treat 1100 kg per hour of methane, for a total of approximately 26 tpd of recondensed gas, thus making it possible to exploit LNG supplies with considerable savings in the long term. Additionally, the green footprint that characterizes the plant is particularly significant: as a result of the use of methane, in fact, during the life cycle of the plant it is estimated that there will be an overall saving of 6 million tons of CO2 compared to the use of other fuels.
SIAD Macchine Impianti also designed and supplied four BOG compressors, which are oil-free and with ATEX certification for installation in potentially explosive atmospheres. Of these four compressors, two will work at the service of the plant for the reliquefaction of the evaporated gas and the other two will be involved in managing the gas boil-off during LNG transfer operations from the LNG carrier to the storage facility.
In order to achieve the ambitious objectives of this plan, Depositi Italiani GNL has chosen the SIAD Group as a reliable partner for a 100% Made in Italy project, starting with the parent company SIAD, with its national distinction in the field of technology and gas management, which supplies the nitrogen. SIAD MI's reputation for the creation of tailor-made projects combines engineering experience with an approach based on the design of solutions specifically constructed for the requirements of its customers. This results in a plant characterised by a high modularity level. Pre-assembled and assembled on modules, it guarantees rapid installation, with a further endorsement of SIAD MI's operational effectiveness.
The plant design and construction work by SIAD MI began in August 2019, and was completed in 11 months, perfectly in line with the design requirements, which were met and maintained, notwithstanding the restrictions due to the 2020 health situation. SIAD MI's work did not end with the delivery, installation, testing, and commissioning of the plant and compressors, but is also continuing with the plant's operation and remote monitoring, using the latest technology systems.
Commencing in August 2021, an LNG carrier has fuelled the plant with LNG, which has enabled the tuning activities to be carried out. The plant entered into operation in October. SIAD Macchine Impianti will continue its commitment at the LNG storage facility, supervising the maintenance and performance evaluation of the BOG compressors and the reliquefaction plant, thus consolidating a lasting partnership with the Depositi Italiani GNL and contributing to the sustainability of sea and land transport in the Adriatic area.