Scottish Distillery Whisky Doesn’t Go to Waste
North British Distillery, based in Edinburgh, Scotland, and HydroThane UK, Northumberland, England, have won a major industry award for an anaerobic digestion (AD) project developed in partnership with biogas digester specialist ENER-G, based in Manchester, U.K.
The Edinburgh Scotch whisky grain distillery, which supplies famous brands such as Famous Grouse and Johnnie Walker Black Label, won the AD & Biogas Award for Best integration of AD into a food and drink business.
The $9.36 million green technology project has reduced the distillery’s carbon dioxide emissions by approximately 9,000 metric tons per year, which equates to the annual carbon-saving benefits of removing 3,000 cars from the road.
The project introduced high-rate AD to help the company provide a sustainable solution to a bottleneck in the back-end production process. This comprises a byproducts plant producing Distillers Dark Grain pellets for animal feed.
David Rae, managing director of North British Distillery, says, “Our sustainability business strategy is enabling North British Distillery to make savings in terms of energy costs while at the same time reducing the environmental impact of our production process. By reducing our carbon footprint, we are contributing significantly to the Scotch whisky industry’s global target of sourcing 80 percent of its energy needs from renewable sources by 2050.”
Instead of investing in additional energy-intensive evaporation capacity to process the liquid byproducts from the distilling process, a decision was made to install an AD plant, which produces renewable energy in the form of biogas.
Using HydroThane’s ECSB (External Circulation Sludge Bed) high-AD technology to process one-third of the postdistillation liquor, the company has reduced the load on its existing energy-intensive evaporation plant, increasing productivity while reducing energy demand.
Michael Lyle, managing director of HydroThane UK, says, “HydroThane technology is giving North British Distillery considerable improvements in their energy costs and reduction in environmental emissions. The ECSB technology, a third-generation anaerobic digestion process, ensures that all anaerobic odors are contained within the process, which was an essential factor in the choice of the technology by the distillery due to its central Edinburgh location and environmental licensing conditions.”
As a result of increasing output, the company also is able to flex between selecting either corn or wheat as the optimum raw material, dependent on cost and availability of the feedstock. Previously, wheat hadn’t been a consideration because it reduced capacity.
The AD plant, which was completed in two phases, is capable of treating 59,000 pounds of chemical oxygen demand (COD) per day and producing up to 24,000 megawatt hours of renewable energy in the form of biogas.
A high-efficiency 500-kilowatt (KW) ENER-G combined heat and power system and a 1,000-KW steam boiler convert the biogas into steam and electrical energy for use on site. These two energy streams reduce the distillery’s reliance on the use of fossil-fuel based energy inputs from the national gas and power grids, the companies says.
The third phase, completed in 2012, consisted of the construction of a water treatment plant, designed and installed by MSE Systems, Chesterfield, U.K. The plant uses two large aerobic bioreactors and microfiltration membrane technology to process effluent from the AD plant. This significantly improves the quality of the posttreated water before being discharged to local sewer, enabling up to 40 percent of the total volume to be recycled within the distillery. This represents a considerable savings, considering that the distillery uses an average 5.2 million gallons of water weekly. It also has prevented the increases in trade effluent charges affecting many processing industries.
EnviraCarbon Gives Coal Competition
EnviraCarbon Inc. (ECI), an energy technology provider with locations in Tennessee, Florida and South Carolina, has announced the commercialization of a patented technology that molecularly alters renewable biomass feedstock into EnvirAnized Biofuel™ (EBF).
EBF is a product that looks, transports, stores, pulverizes and burns like coal that does not pollute like coal, according to ECI. The process changes woody biomass into clean carbonized EBF, condensing a process that occurs in nature over the course of 100 million years into a matter of minutes, the company says.
Because EBF allows biomass to take on the physical characteristics of coal, it can be directly used by coal-burning or biomass fired power plants and industrial facilities without any modification or retrofitting to their existing boiler systems, says ECI. The EBF product has the same heat value as bituminous coal from the eastern U.S. (12,000-plus Btu), it exhibits a much greater heat value than wood pellets and, unlike wood pellets, it is hydrophobic, ECI says.
The EBF product contains negligible amounts of sulfur and nondetectable levels of mercury, arsenic and lead and, by most standards, is at or near carbon neutral, adds ECI.
Other EBF characteristics include:
- looks like coal – totally black pellet with no woody material;
- burns like coal – heat range 11,000 to 13,000 Btu, 25.6 to 30.2 gigajoules per ton;
- handles like coal – pellet durability 93-plus percent;
- crushes like coal – Hardgrove Grindability Index 55-plus;
- pulverizes like coal – highly friable; and
- hydrophobic like coal – above 100 degrees hydrophobicity.
ECI says its production plants use only certified sustainable biomass and waste wood as feedstock and require a small footprint to produce large quantities of EBF. With a commercial plant under construction, ECI expects to export EBF in the first quarter of 2014.