FEATURE: BIOENERGY IN INDUSTRY Bioenergy Internat ional No 79, 3-2015 11 Carterheads have been reconditioned and redesigned internally to control the flow of spirit vapour through the distillation process ensuring an energy efficient process, explained Nik. The pure spirit vapour emerges from the top of the column via the lyne arm and into the bottom of the infusion chamber. Inside the infusion chamber perforated copper baskets contain the ten botanicals used. These are layered by species, according to a specific but undisclosed order and quantity. The hot vapour passes through extracting the aromatic oils that provide the unique taste without cooking or denaturing them. The infused vapour comes out the top of the chamber and is then condensed in a water-cooled condenser, turning it into high-strength gin that is collected and stored in a holding vat. – During distillation, hot water is collected in a storage tank ready to be reused, the specially designed condensers recover the heat from gin condensation and this is used to pre-heat the incoming base spirit as well as the two greenhouses and space heating throughout the site which saves both time, energy and water allround, explained Nik. Once the distillation cycle is completed, a new botanical charge is set for the next round, while the spent botanicals are gathered and transported over to the biomass boiler. The entire process is monitored using state-of-the-art PLC systems. Samples are taken from each cycle with various tests performed in the adjacent laboratory to ensure quality is maintained, though the final decision is entirely human sensory based — eye, nose and tongue. – The technology enables precision in process control minimising the guesswork of some of the variables but the ultimate decision is subjective, said Nik. As a single-shot distillation the ABV of the high-strength gin is reduced once with purified water to bottling strength. ABV reduction and bottling takes place at the Warrington plant. International acclaim – The redevelopment of Laverstoke Mill was no easy task and required a substantial upfront investment, but none of it was wasted. Bombay Sapphire will reap the rewards of equally substantial dividends in the form of long-term sustainability, and reduce waste and energy consumption for future generations to come, said Nik Fordham, without detailing what the final figure, for what must have been a multi-million pound project, actually was. It is very hard to disagree, as the multi-faceted project is nothing short of spectacular no matter what aspect you choose to weigh in on. In fact, the Building Research Establishment Environmental Assessment Method (BREEAM), the world’s foremost environmental assessment method and rating system for buildings, dedicated the prestigious 2014 BREEAM Industrial Award to the distillery. BREEAM rated the Laverstoke Mill refurbishment project as “outstanding” — the first ever such project to be awarded such a rating anywhere in the world. Indeed BREEAM gave the renovation project the highest possible marks for the lowest possible environmental impact. – We were of course delighted to achieve an outstanding rating. Fundamentally though we believe building such a sustainable distillery makes financial sense, increasing efficiency and long term operational energy and water use savings, ended Nik Fordham. Text & photos: Alan Sherrard BI79/4846/AS Storage tanks (above left) for the base spirit and the final high-strength gin. The heritage and visitors centre along with its picturesque setting by the River Test is making Laverstoke Mill a popular destination for an outing. Specimans of all the plants that the different botanicals are derived from are grown in the spectacular greenhouses designed by UK’s Thomas Heatherwick.
Bioenergy no 3 May 2015
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