PTQ Q2 2022 Issue

ing simultaneously on four lev- els. Sulzer and Linde Engineering inspectors were on-site to supervise the installation works and provide instantaneous inspection of the col- umn internals. The turnaround was completed in 17 days, in advance of the 21 days planned. Post-revamp performance The plant was restarted in October 2019, achieving the new plant capacity and the targeted syngas purities. The solvent flow to the methanol wash column was as per designed; the new HiFi trays and VGPlus trays met both the hydrau- lic and process requirements. The column performance before and after the revamp is summarised in Table 2. Conclusion The revamp of Singapore’s meth- anol wash column with Shell HiFi trays and Sulzer VGPlus trays was a complete success and all the revamp targets were achieved. The column is able to meet the new plant capacity, 30% increase in feed gas while meeting targeted syn- gas purities at the same solvent flow rate. The turnaround, which included the installation of 107 trays, replacement of the mist elim- inator and liquid distributors, was executed by Sulzer Tower Field Services within a record 17 days with zero incident rate. This is the world’s first reference of metha - nol wash column equipped with Shell HiFi trays in operation. Even at reduced tray spacing of 300mm, these trays are able to meet the hydraulic and efficiency demand of the column. This optimal process revamp solution, conceptualised by Linde Engineering, was successfully

Summary of new trays for the revamp

Sections

Trays before revamp

New trays after revamp

A: CO 2 removal

39 two-pass round valve trays

49 Shell HiFi trays of TS 300mm

of TS 400mm

B: CO 2 removal

9 two-pass round valve trays

11 Shell HiFi trays of TS 337.5mm

of TS 450mm

C: H 2 S removal

47 two-pass round valve trays

47 two-pass Sulzer VGPlus trays

of TS 400mm

D: Prewash

9 one-pass round valve trays of TS 350mm

Table 1

Comparison of column performance

Before revamp

After revamp

Gas feed

100% 100%

130% 100%

Solvent flow

Table 2

plan and practise the modifica - tion of the attachments, including the weld-ins of the new expansion rings and support struts onto exist- ing attachments (see Figure 8 ). It also allowed the team to practise installation of the HiFi trays of low tray spacing within a tightly con- fined space (see Figure 9 ). All the 60 HiFi trays were mocked up and inspected in Sulzer’s workshop by Sulzer and Linde Engineering for completeness (see Figure 10 ). They were then pre-packaged, based on the planned installation sequence, to allow a seamless installation process. During the actual turnaround, the tower field service workers were on 24/7 day and night shifts, work-

schedule, special consideration was required from the mechanical design to the planning of the on-site modification and installation works. The trays were designed with Sulzer lip-slot connections within panels and wedge-snaps between the panels and the attachments, reducing the installation time by up to 30%. Training of the tower field service workers, prior to the on-site modi- fication, was critical in saving time during actual turnaround. A train- ing column of ID 1750mm includ- ing the attachments (of existing two-pass trays) was constructed (see Figure 7 ) and placed in Sulzer’s workshop for training. This train- ing column allowed the team to

Figure 7 Training column with column attachments in Sulzer’s workshop

Figure 8 Installing expansion rings and support struts inside the training column

Figure 9 Installing HiFi trays inside the training column

38 PTQQ 2 2022