T. P. RYNDERS (1), B. Weaver (2), M. Fischer (2); (1) CDM Smith, Denver, CO, U.S.A.; (2) New Belgium Brewing, Fort Collins, CO, U.S.A.
Saturday, June 7 - 10:00 a.m.-11:45 a.m.
Level 3, Crystal Room
A growing number of microbreweries may be soon facing industrial discharge surcharge fees as they expand to meet higher demands for their beers. Brewers have long resisted the capital expenditure and operation complexity required to operate a biological digester to provide process waste pretreatment. New membrane technology entering the anaerobic marketplace is potentially offering a more palatable solution for many mid to large microbreweries facing process waste pretreatment requirements. CDM Smith and New Belgium Brewing are collaboratively evaluating the effectiveness, reliability, and robustness of anaerobic membrane bioreactor (AnMBR) technologies available in the marketplace. The driver for this study is that the current leading pretreatment technology used in the brewing industry, upflow anaerobic sludge blanket (UASB) style digesters, has high operating costs and limitations with certain process waste flows, such as trub, hops, and yeast. Additionally these digesters can only yield 70–90% chemical oxygen demand (COD) reduction of the process waste flow. This moderate COD reduction typically means aerobic treatment of the UASB discharge is still required, and aerobic treatment is space- and energy-intensive, prone to upsets, and can cause odor issues. This pilot evaluation will test whether the AnMBR-style digester is sensitive to a broad spectrum of brewery waste flows, including various solids that are difficult and expensive to separate from the brewery process waste flows. Both submerged and pressurized membrane systems will be compared and quantified for ease of operation, quality of effluent, and cleaning requirements. The AnMBR technology also may provide increased biogas production, which can lead to much quicker capital investment paybacks and significant overall brewery reduction of fossil fuel energy sources. An additional benefit of considering AnMBR technology for breweries is the possible production of high-quality reuse water (filtrate) from the ultra-filtration (UF) membranes. The effluent quality from membranes can be sufficient to be used to offset process water consumption. Although not intended to offset product water use, non-potable water use can be significant at a brewery. This could result in significantly lowered water to product ratios at breweries. This presentation will provide data gathered in spring 2014 at the New Belgium (Fort Collins, CO) brewery during pilot-scale testing at its existing process water treatment plant. Various vendor technologies are expected to be tested in parallel for direct cross-comparison.
Timothy Rynders is a process engineer at CDM Smith, with 10 years of experience in water treatment process engineering, reverse osmosis and membrane filtration processes, and heat and energy recovery systems. He is an avid home brewer and, more recently, has become fascinated by anything fermented. Timothy received his bachelor’s degree in environmental engineering from the University of Nevada, Reno. He is a registered civil engineer in the states of Nevada and Colorado.