• BWEP funding $98,996.70
• Water savings 25.6 million litres a year

Background

The iconic Ginger Factory at Yandina on the Sunshine Coast has slashed its water use by 25.6 million litres a year with the support of the Business Water Efficiency Program.

Buderim Ginger produces a range of ginger products including crystallised ginger, cordials, jams and sauces. Most retail products are contract packed, with the Yandina plant mainly producing syruped, crystallised and dried ginger.

Confectionery ginger is harvested over a six week period in February to April. A second harvest takes place around May to August and most of this is used to produce dried ginger.

The early harvest washed green ginger is transferred to preservation vats for up to 12 months or more until it is ready to be processed. The ginger is preserved in a brine solution of town water and sodium metabisulphite. Sulphite is an oxygen scavenger that removes all bacteria, bleaches the ginger and softens the rhizome. To ensure the end product is of the highest quality, all sulphite is then removed from the ginger rhizomes.

In the past, this cleansing was done using copious quantities of hot water, all of which was dumped into the sewer drain.

Water saving projects

Over seven years, Buderim Ginger trialled several technologies to recycle and reuse its flushing water. Some systems worked, but were impractical, while others created product quality issues.

Further investigation revealed that ozone would be a suitable oxidant to remove sulphite. Mathematical models were used to simulate its performance and to size a suitable system. On site trials with an ozone unit confirmed it would work.

The sulphite stripping system was designed to reuse flushing water from ginger and return it to a central storage system. The storage system holds approximately 300,000 litres and is continuously ozonated to remove the sulphite. An additional chlorine dioxide dosing unit controls bacteria levels.
Water is circulated through the system from the storage tanks to syruping and returned via six pumps. Each syruping chain has a supply and return line with recycled water available to all 63 processing tanks.

Water saving achievements

The plant’s green ginger area also takes recycled water. This allows make up water to go into the storage tanks, as it is not possible to continuously recycle the water due to starch build up in the system. Although not a water saving as such, it allows for more than one use of the water.

A large recuperating heat exchanger has been designed to allow for the recycling of waste heat. Previously this energy went down the sewer, a little bit like pouring gas down the drain. Now when cooling tanks, waste heat is recovered and returned to the processing area.

The supply water is then heated up to its control point by a large vertical steam heat exchanger. This is delivered to each of six processing chains.

The return water passes through an automatic self cleaning filter that removes solids from the stream. The cleaned return water goes through the recuperating heat exchanger, cooling this water down and returning it to the storage tanks for sulphite treatment.

Buderim Ginger has seen excellent water and wastewater savings, along with a reduction in gas use. Approximately 330,000 litres of gas have been saved so far by using this system. Further savings are anticipated in 2008.

The business continues to seek new ways to save water, including:

• reviewing daily usage to reduce water required for cleaning plant
• investigating waste water reuse to ultimately have zero discharge
• designing a rainwater harvesting system.

A word from the business

‘Buderim Ginger is the global market leader in our field and this project has seen us revolutionise a time honoured process which has been in place for 66 years. This highly complex project utilising a combination of technologies has been designed in-house and is a world first for the ginger industry. Government support of the project through the Business Water Efficiency Program has been very important. Our competitors are based in low operating cost countries such as China and Thailand. Accordingly our operating margins are under severe pressure, making it hard for us to justify large investment in process changes on purely environmental grounds. The BWEP funding has been a critical part of the financial impetus to get this technology in place and we have now set a new global benchmark for water efficiency.’ - Buderim Ginger Chief Executive Gerard O’Brien.