Just B superyachts sets sail for sustainability with food waste digester

May 20, 2022

GLOBAL — JUST B is an active 59 meter long luxury expedition superyacht. She was built to her owner’s unique requirements in 1974 and refitted in 1999 with a steel hull and an aluminum superstructure, with teak wood decks. Her top speed is 13.5 knots and she boasts a maximum range of 6000.0 nm when navigating at cruising speed.

Image from damenyachting.com

Just B was designed to comfortably accommodate up to fourteen guests in seven suites with fourteen full time crew members. Just B is on the ocean only for a few weeks per year and docked in various harbors the rest of the time. On deck is a full kitchen and a spacious living area. 

In early 2021, Just B purchased and commissioned the installation of the world’s smallest commercial grade biodigester: the LFC-25 biodigester. Since its installation in March 2021, the biodigester onboard Just B has digested over 2000 kilograms of food waste.

Sustainability and superyachts

Sustainable superyachts are a bit of a misnomer as yachts have historically been one of the largest sources of carbon emissions. However, a wave of sustainability has been sweeping across yachts along with growing awareness of ecological impact, green shipbuilding and operating practices, and savings from energy efficiency. In the past five years, many yachts have committed to sustainability programs and initiatives that range from green energy to food waste.

Food waste is not a new issue that maritime vessels have to face. Food pulpers have typically been the main solution for food waste on older maritime vessels. However, pulpers are not an economic or environmentally sustainable solution as they require high maintenance, have strict regulations on what time of food waste can go into the pulpers, and do not solve the problems that come with food waste such as storage, capacity, odors, and disposal.

One of the biggest challenges that maritime vessels face is how to prevent plastic from accidentally entering the waste stream and subsequently, the ocean. Food pulpers cannot discriminate between types of waste and require oversight from an Environmental Manager for usage. Biodigesters have built-in safeguards that prevent anything that isn’t food waste from entering the waste stream. Biodigesters can only digest food waste and utilize a filtered mesh screen to catch items that are indigestible. For this reason, many ships have started using biodigester as their onsite food waste solution.

Swimming ahead of food waste

The International Convention for the Prevention of Pollution from Ships (MARPOL) is the main international convention covering prevention of pollution of the marine environment by ships from operational or accidental causes. MARPOL was adopted in 1973 and is enforced by the International Maritime Organization (IMO, a specialized agency of the United Nations). MARPOL Annex IV and V hold all Flag ships accountable for the disposal of their sewage and garbage.1

MARPOL Annex IV contains a set of regulations regarding the discharge of sewage into the sea from ships, including regulations regarding the ships’ equipment and systems for the control of sewage discharge, the provision of port reception facilities for sewage, and requirements for survey and certification.2

MARPOL Annex V prohibits the discharge of all garbage into the sea, except as provided otherwise in regulations 4, 5, and 6 of the Annex, which are related to food waste, cargo residues, cleaning agents and additives and animal carcasses.2

With a minimum of fourteen people onboard on Just B at any given time, a long term food waste solution was required. Each person typically generates an average of 1 kg of food waste per day. The superyacht did not have the capacity to hold waste onboard long term, nor did it make sense for the crew to continually offload waste on a daily basis. 

In 2021, Just B inquired about the LFC-25 biodigester, a modern food waste solution geared towards yachts and facilities with limited space. The LFC-25 biodigester is an onsite food waste digester that is the size of a residential dishwasher. It uses a natural process called aerobic digestion that allows the microorganisms living in the machine to eat food waste and turn it into water. The machine has the capacity to digest 10–75 kg (25–165 lbs) of food waste every 24 hours. With limited impact on utility consumption and space, the biodigester made sense for the superyacht’s unique needs. To date, the biodigester on Just B has digested over 2300 kg (5000 lb) of food waste.

The biodigesters were strategically placed in areas where food waste was typically produced, such as the ship’s galleys. Mesh filters at the bottom of the machine prevented debris and any plastic from accidentally leaving the machine.

About Just B

JUST B is an active 59 meter long luxury expedition superyacht. She was built to her owner’s unique requirements in 1974 and refitted in 1999 with a steel hull and an aluminum superstructure, with teak wood decks. Her top speed is 13.5 knots and she boasts a maximum range of 6000.0 nm when navigating at cruising speed.

Industry: Marine
Location: Marshall Islands

Works Cited

  1. International Maritime Organization. (n.d.). International Convention for the Prevention of Pollution From Ships (MARPOL). International Maritime Organization. Retrieved April 11, 2022, from https://www.imo.org/en/About/Conventions/Pages/International-Convention-for-the-Prevention-of-Pollution-from-Ships-(MARPOL).aspx 
  2. International Maritime Organization. (n.d.). Prevention of pollution by sewage from ships. International Maritime Organization. Retrieved April 11, 2022, from https://www.imo.org/en/OurWork/Environment/Pages/Sewage-Default.aspx