Achieving an exciting breakthrough in VOC capture thanks to Nord Gas Solutions technology

Volatile organic compounds (VOCs) are organic compounds that, when emitted to the atmosphere, can be dangerous to human health and cause harm to the environment. When loading crude oil tankers, vast quantities of hydrocarbon vapours are emitted, creating significant safety, environmental, and health hazards. Although Nord Gas Solutions’ (NGS) VOC Recovery Systems have been installed on shuttle tankers in the North Sea for the past 25 years, a solution for crude oil carriers loading offshore at SBMs, FPSOs or sea islands has not previously been available.

The project to find the right solution began as far back as 2017. NGS which was then part of the Wärtsilä group, was approached by Vaholmen VOC Recovery, a newly formed Norwegian company interested in developing a means for addressing the problem. Their idea was to have a VOC recovery plant installed onboard an offshore service vessel (OSV) to serve crude oil tankers when loading oil at offshore buoys. For this, they needed Nord Gas Solutions’ technology.

Bringing the concept to fruition

Thus began a close cooperation between the companies that continues to thrive. Various operators were contacted before the initial contract was signed with Texas Gulf Link (TGL), an American midstream company. Over the following six years, NGS, Vaholmen and TGL worked together to finalise the total concept, with the NGS VOC Recovery solutio as an integrated part of the project. This work culminated in TGL obtaining approval from the US government and an operational licence for offshore oil export through two buoys 25 nautical miles off the coast of Texas.

The result is a truly innovative breakthrough solution. While the patent is held by Vaholmen, NGS is the only company in the world with the essential technological competence to efficiently recover the VOC.

“In essence, this represents a first-ever solution for eliminating emissions from oil tanker cargo tanks during loading crude oil,” explains Hans Jakob Buvarp, Sales Manager at NGS. “Together with Vaholmen, we are also making a huge contribution to the shipping industry’s efforts to eliminate greenhouse gas emissions.”

The dynamic-positioned, first-of-its-kind support vessel will pull alongside a VLCC being loaded and capture and condense the VOCs into a liquid that can be sold for industrial use. This process will prevent emissions of up to 310,000 tonnes of CO2 equivalent per ship annually. It will also produce up to 50,000 tonnes of valuable liquid VOC (LVOC) per year. The LVOC can be used as refinery feedstock or fuel, or reinjected into the crude oil at the terminal, supporting an attractive payback on the investment. In addition, local pollution onboard the ship being loaded is removed. This pollution from VOC emissions could otherwise cause headaches, respiratory diseases and other illnesses. The system is essential for TGL to meet its air permit requirements.

The first order with potentially many still to come

Initially, the contract with TGL is for two VOC Recovery ships, each approximately 80 metres long, that will operate off the coast of Texas. NGS will be delivering the VOC Recovery System, which comprises a VOC module and a liquid VOC tank. Also included in the NGS scope are two gas turbines and a gas combustion unit with fuel systems, along with the safety system, control system, switchboards, and auxiliary equipment.

In addition to the significant environmental and health benefits, the produced Liquid VOC (LVOC) will have a considerable commercial value, thus furthering the financial viability of the project.

“We continue to work very closely with the folks at Vaholmen to develop the enormous potential the system has. We anticipate that around 50 VOC Recovery vessels may ultimately be needed, with a couple of ships likely to materialise each year,” concludes Buvarp