Technical Note; Calculating pH from Sulfuric Acid concentration, STI-TN-20170818-1

This is a STI Technical Note for ?Sulfuric Acid concentration and ph, STI-TN-20170818-1, ?from STI about “Calculating pH from Sulfuric Acid concentration”.


In this note, STI shows

  • How to calculate pH value from a given weight concentration of Sulfuric Acid, and vice versa.
  • A graph showing the relationship between the pH value to a given weight concentration in %.


As a summary, the scrubber effluent with pH=~3.0 is a sulfuric acid solution with ~10-4% of weight concentration.


? ? pH vs. weight concentration of sulfuric acid (%)




This will be used as a guideline in selecting the scrubber material.

Project financing for SOx scrubber projects (11Aug2016)

Project decision about SOx scrubber installation to any shipping companies is not easy at all. Ship owners/operators should consider all aspects of technical, operational, and financial issues.


Among these, technical issues may be the easiest one as SOx scrubber manufacturers provide detailed project proposals including various technical issues. Project review from operational point of view have to do with fleet planning, voyage schedule, fuel price, and related operating costs. Ship owners may find the financial issue as the most difficult one because SOx scrubber projects requires big investment in the beginning. ROI of the SOx scrubber projects with STI is considerably short, but upfront investment is still a big burden to the client.


We learned that Korea Export and Import Bank ( offers “Export Facilitation Loan“, and SOx scrubber projects may?fit into the category. For those Ship owners/operators who are interested in the SOx scrubber project financing, STI can check?the possibilities and eligibilities about the project opportunities.


Any inquiries about the SOx Scrubber system inquiries, please contact STI at


10 August 2016


Join forces; SOx scrubber and Ballast Water Treatment System? (5Aug2016)

Combining SOx scrubber system andBallast water treatment system (BWTS) will benefit both systems.


SOx scrubber system uses seawater and discharges wastewater with decreased pH level. It is because MEPC puts pH criteria in the washwater, Section in MEPC 184(59).


For Ballast water treatment system (BWTS), low pH in the incoming seawater will help the system performance within the electrolysis.


Having some amount of washwater, of course PAH and turbidity should be controlled, stored onboard and mix with the ballast water to lower the pH value would be a way to improve the performance of BWTS.


Being able to have some storage capacity of washwater from SOx scrubber units can give a room to deal with sulfates in solid form, especially when operating in closed loop mode.


This is a preliminary idea to improve system performance and operability of SOx scrubber system and BWTS by combining them.


STI is looking for ways in this way.


Please feel free to contact STI for any questions about this issue.


Aug. 2016



Bunker price vs. ROI estimation for SOx scrubbers (30Jun2016)

Bunker price between high sulfur fuel and low sulfur fuel has been always significant.

  • Price difference was USD150 in Jan 2016, and is USD200 at the end of June 2016.
  • The ratio (=(LS-HS)/HS) was?100% when the price level the lowest in Jan 2016, and is 80% at the end of June 2016.


Whether the bunker price is low or high, price difference between HSF and LSF always exists. Installation of scrubber systems has been always an option for ship owners operating in SECA. The only difference is the Return of Investment (ROI) period that is set by the “Fuel Price Difference” and “Equipment/Installation/Maintenance Cost”.


SOx scrubber system from STI has always been a practical option for shipowners to stick to burning HSF in SECA while complying with the MEPC requirements, which has been due to the competitive equipment cost?and lower installation cost.


STI welcomes any inquiries for ROI estimation for ships operating fully or partially in SECA. STI can generate ROI estimation for specific ships when we are given with some information from shipping companies like,


  • Engine power (kW)
  • Time spent in SECA per year (hour)
  • Voyage time per year (hour)


Please feel free to contact STI for above inquiries as well as inquiries for scrubber systems in general.


30 June 2016. STI

EIB invests to lower emissions from ships (30Jun2016)

EIB investerer i mindre udledning fra skibe

EIB investerer i mindre udledning fra skibe

Mandag 20. juni 2016 kl: 15:22


Bestyrelsen for den europæiske investeringsbank, EIB, har godkendt en samlet investering p? 7,4 milliarder euro, hvoraf de tre milliarder skal investeres i udvikling af renere transport og energi. Der er tale om 17 forskellige projekter, blandt andet udvikling af nye vindmøller i Tyskland.

Nok s? interessant er det dog, at der skal investeres en milliard euro i initiativer, der er med til at reducere den skadelige udledning fra den europæiske skibsfart. Der er b?de tale om investeringer i nye energieffektive teknologier samt finansiering af retrofitting af eksisterende skibe samt finansiering af udviklingen af nye miljøvenlige skibe.

Alle projekter skal dog først godkendt af EIB’s bestyrelse før, at der kan indg?s nogle endelige l?nekontrakter.

Kilde: EIB