Closing The Biodiesel Loop Through Recycling and Renewable Energy


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Closing The Biodiesel Loop Through Recycling and Renewable Energy

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Closing The Biodiesel Loop Through Recycling and Renewable Energy

  1. 1. Closing the biodiesel loop through recycling and renewable energy. By Richard FreudenbergerThe Collaborative staff photosBiodiesel ProjectP roponents of biofuels have always     maintained that sourcing energy     from domestic renewables suchas plant biomass and bio-based wastesreduces our dependence on imported Appstate Appropriate Technology For Jeremy Ferrell, a graduate stu- dent in the A-T Department at Appala- chian State University, biodiesel is far photovoltaics to run the pumps, light- ing, and system controls. How the System Workspetroleum, diversifies our energy base, more than an academic topic of discus-and offers cleaner end-use emissions. sion. After completing his undergradu- The process begins with 80 gallonsOne particular biofuel—liquid bio- ate studies in1999, he went to work of waste vegetable oil collected eachdiesel derived from soybeans, waste for the U.S. Park Service, then served week from the ASU cafeteria. It’s acooking oil, or animal fats—has re- a three-year stint in the Peace Corps, mixture of soy, peanut, and canola (aceived prominent national attention and working with subsistence farmers in low-acid rapeseed oil) and comes to theenough investment that the number of Paraguay on agroforestry, apiary, and facility in five-gallon carboys.commercial production facilities has tilapia projects. Subsequent permacul- The containers are stowed in cov-grown from 65 in mid-2006 to 145 in ture studies in Brazil exposed him to ered storage outside a 280-square-footJune of this year. farm-scale biofuels potential and laid greenhouse, where the initial processing But critics aren’t so convinced. Their the groundwork for his ensuing interest begins. The first step is to empty theconcern is that biodiesel fuel is not in renewable fuels back home. waste oil into the collection barrel, asustainable on a large scale. First, they Ferrell and an interdisciplinary team 55-gallon drum fitted with a 400-micronquestion whether the energy invested of ASU students began the biodiesel drumhead filter, recessed to capturein growing, harvesting, and processing project with the goal of “closing the solids and thwart spillage. From there,soybean feedstocks will surpass or even loop”—designing the entire production the strained oil is pumped into twoapproach the energy available from the facility to be self-contained and wholly 120-gallon storage and settling tanksfinished product. Further, they hold sustainable so that every by-product linked in series. Here, excess water canthat the by-products of manufacture— either found a use within the system or be drawn off and the oil sent through aglycerin and wash water from the fuel- had marketable value outside of it. To 30-micron filter before being movedcleaning process—have limited value carry this through to completion, they on through an insulated chase to a 120-and are essentially contributing to the had to develop a solar thermal hot water gallon processor tank in the adjacentwaste stream themselves. system for heat processing and rely on processing shed. BackHome Magazine Sept/Oct 2007 17
  2. 2. Collaborative Biodiesel Project The processor tank is one of severalpurchased at a salvage yard. (Stainlesssteel dairy equipment often finds itsway to auctions and scrap yards andhas proved ideal for biodiesel produc-tion.) This tank is equipped with aninternal heat exchanger to heat the oiland was modified by adding a lid to sealthe reactor chamber. This prevents theescape of methoxide fumes and alsoallows for methanol recovery through fuel to the wash tanks, two vertically A grid-tied PV system provides power forvacuum distillation as part of the recy- stacked stainless steel containers, each pumps and lighting. Four solar thermalcling process. 210 gallons capacity. There, a three- panels on the processing shed at right To achieve the necessary reaction stage water-washing procedure car- heat the oil.temperature of 130°F, a series of four ried out over a period of several dayssolar thermal collectors mounted on removes remaining impurities (free through the use of biological organismsthe processing shed—144 square feet methanol, glycerin soaps, fatty acids, such as wetland plants, algae, plankton,of total surface—supply a superinsu- etc.) that can lead to corrosion, sediment and aquatic wildlife. Currently, a smalllated 30-gallon water tank in the lab buildup, and injector blockage in a die- wetland pond built just behind thebelow. A 60-watt pump circulates the sel engine. The washed biodiesel is then polycarbonate glazing at the front ofwater through the thermal system. circulated through a perforated annular the greenhouse contains water hyacinthIndividual valves control where in the ring in the wash tank to evaporate out and azolla, more commonly known asprocess heat needs to be distributed by the last traces of moisture from the fuel, duckweed fern. Future plans includefeeding exchanger coils built into the then the finished product is pumped one the addition of cattails, mollusks, andtanks. A backup hydronic oil-burner, last time through a 5-micron filter and possibly some water-loving trees suchoperating on either biodiesel or clean into a 55-gallon storage drum, where as figs and willows.vegetable oil, can be called into use it’s hand-pumped into Ferrell’s 1985 Water from the lab sink and thewhen needed. Toyota diesel pickup or transported to fuel-washing process is piped into two A smaller 35-gallon HDPE conical the project’s Fuel Sampling Partners 350-gallon containers at the rear of themix tank next to the processor allows to be used in various off-road applica- structure. A single solar thermal panelfor safe and consistent blending of the tions such as farm equipment and home on top of the greenhouse preheats themethyl alcohol and potassium hydrox- heating. water prior to introduction. The firstide catalyst. Methanol from a 55-gallon stage is the treatment of 120 gallonsdrum is pumped into the methoxide Reuse and Recycle with anaerobic bacteria to break downtank through a stainless steel funnel that any solid material. Following that,holds the potassium hydroxide (KOH) None of this is unique for biodiesel an open aerobic tank of 150 gallonsflakes. They dissolve in the filling processing plants of this size. What capacity further clarifies the waterprocess, and the resulting methoxide makes the Appstate Collaborative and removes objectionable odors. Themix is transferred to the oil-filled pro- Biodiesel Project distinctive is that the final step is the wetland pond, wherecessor tank through a mixing tube to team has consciously sought practical the water is purified by the plants andstart the biodiesel reaction. The mixing end-use applications for the by-products eventually is returned to wash subse-itself is carried out over one and a half that habitually have been difficult to quent batches of biodiesel. A 25-watthours using a stainless steel centrifugal dispose of, mainly wastewater from the pump on a scheduled timer circulatespump, which is the most workable washing cycle and glycerin from the the water at a rate of 100 gallons, orchoice for a closed container system. transesterification reaction. about 10 percent, every hour. The liquid is then pumped into a Wastewater is an issue especially in Glycerin from the reaction process120-gallon settling tank, where it’s larger operations because the system has always been a question, even forkept for at least 48 hours to allow the produces too much volume over time home producers. Approximately 20glycerin to separate from the biodiesel to simply discard. To alleviate that, the percent of the yield is a crude glycerinfuel. Glycerin can be drawn off at both ASU students have built an “ecological composed of free fatty acids, glycerol,the processor and settling stages. Eighty machine” within the greenhouse to treat excess methanol, and residual catalyst.gallons of raw biodiesel will yield about the spent water for reuse. The living That’s 20 gallons of material for every16 gallons of glycerin by-product. machine is a micro-ecosystem designed 100 gallons of biodiesel made. Glycerin A third pump moves the biodiesel to treat a specific volume of influent soap has typically been a marketable18
  3. 3. end product, and the Appstate group has fuel-quality monitoring with near in- crop has left many in the agriculturalbeen successful in finding applications frared spectroscopy, waste composting community searching for viable marketnot only for industrial cleaners but also for CO2 and methane production, and composting operations and as fire- expanded educational and outreach In the meanwhile, the project isstarter briquettes, using wood chips as programs. moving forward and taking advantagea substrate. Members of the program have also of the successes and interdisciplinary Part of the project’s “loop” includes cast their eyes toward the area’s farmers approach that has served it well thus far.the use of renewable energy to run the and its extension service in hopes that Both the algae and composting researchvarious pumps. Ten 170-watt Sharp the growth of biofuels may be an op- may well prove viable additions to themodules and a Sunny Boy inverter are portunity for local growers to find new ongoing biodiesel loop.the key components in the grid-tied sys- markets for feedstock material and oil-tem, which provides lighting and power seed by-products such as high-protein For more information visit the controls as well. Conveniently, seed meal. The ongoing loss of tobacco diesel.appstate.eduthe pump motors are not required tooperate simultaneously, so there’s nolarge surge demand in the system, andwith one-inch line and no appreciableelevation, no single pump is particularly Western North Carolinalarge. Renewable Energy InitiativeWhere From Here? 2007 Workshop Schedule In 2006, the Appstate team exhib- 4/21-22 Small Scale Wind Energy with Southwest Windpowerited the project in Washington, D.C.,as part of the Environmental Protec- & WNCREI staff at Beech Mountain R&D sitetion Agency’s EP3 Student Design 5/26-27 Microhydro with Don Harris and WNCREI staffCompetition for Sustainability. Asone of the winners of the competition, at Appalachian State Universitythe team was awarded further funding 6/2 Domestic Solar Water Heating Design & Constructionfor continuing Phase 2 of the project, with Fred Stewart at Appalachian State Universitywhich includes continued research intobiodiesel feed stocks such as algae and 6/22-23 Sustainable Community-Scale Biodiesel Productionalternate oilseed crops, reaction and Workshop at Appalachian State UniversityA micro-ecosystem within the 8/29 PV and the National Electrical Code with John Wilesgreenhouse treats system waste- at Appalachian State Universitywater using wetland plants. 9/15 Active Solar Hydronic Space Heating with Fred Stewart at Appalachian State University 9/22-23 Small Scale Wind Energy Installation Workshop with Robert Preus of Abundant Renewable Energy at Beech Mountain R&D site 10/20–21 Small Scale Wind Energy with Southwest Windpower & WNCREI staff at Beech Mountain R&D site 828-262-2933 • 828-262-7333 Bachelors and Masters degree programs available BackHome Magazine Sept/Oct 2007 19