Submitted by gills_admin on Wed, 09/01/2010 - 10:43
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Gills Onions Debuts New Eco-Friendly Packaging and Sustainability Efforts at PMA.
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October 2, 2009 - Anaheim, CA – Gills Onions’ exhibit at the PMA’s annual Fresh Summit International Convention & Exposition, October 2 – 5, will feature redesigned, eco-friendly PLA retail packaging to further their sustainability efforts.
“We created a smaller 7 Oz. size to give consumers more convenience and better value, to give retailers more turns and more profits, and to provide a more sustainable, responsible solution for fresh-cut produce marketing and sales,” said Nelia Alamo, Gills Onions Director of Sales and Marketing.
“While our customers and retail partners have been increasing their demands for green and sustainable products, Gills Onions has always been an environmentally-conscious pioneer in the fresh produce processing industry,” Alamo continued. “PLA packaging is just one of our sustainability efforts to reduce GHG emissions, conserve water, reduce energy consumption, protect valuable farmland, and reduce waste. Plus, the clear cups made of PLA material shows our products well and the design allows retailers to display and stack them very efficiently.”
Gills Onions’ packaging is made from eco-friendly, recyclable PLA material derived from plants to reduce fossil fuel use and Green House Gas (GHG) emissions. The packaging biodegrades when composted and can be used as a valuable soil amendment. The fresh-cut product line in PLA packaging includes: Diced Yellow Onions, Diced Red Onions, Sliced Red Onions, Diced Celery & Onions, USDA Certified Organic Diced Yellow Onions , and seasonally available Sweet Sliced Yellow Onions, and a Holiday Size (19 Oz.) Diced Celery & Onions.
Gills Onions most recent sustainability effort was the July launch of the AERS (Advanced Energy Recovery System) at their Oxnard facility – allowing them to convert 100% of their 150 tons of daily onion waste into ultra-clean, renewable energy and high-value cattle feed. This effort alone has reduced their GHG emissions by up to 30,000 tons per year – roughly equivalent to the annual GHG emissions of 5,000 cars. Gills Onions has produced a Sustainability Highlights Brochure that is available as a download on their website at www.gillsonions.com/sustainability.
“We’ve embarked on a number of sustainability initiatives in the last few years, and have learned many things. Most importantly, that saving resources actually saves money. This has allowed us to invest in sustainable packaging redesigns and capital expenditures that make us even more sustainable and efficient…allowing us to uphold our product quality and safety standards while delivering tremendous convenience and value to our customers,” Alamo concluded, “One of the ways we translate all these benefits to consumers is through the “Grower Direct” positioning displayed on the top label of all our new packaging. The bottom of the label also carries a mention of our Sustainability efforts and tells the consumer that the container is compostable and recyclable.”
Gills Onions is a 25-year old, family owned and operated grower and food processor with the most state of the art, progressive fresh onion processing plant in the world. In concert with Rio Farms and other entities, there are over 15,000 acres of farmland and 100,000 square feet of processing and warehouse facilities under their responsibility. Gills Onions is committed to continuous process improvement to positively impact the Air, Land, Water, Energy, and Communities they rely upon for their livelihood.
Submitted by gills_admin on Wed, 09/01/2010 - 10:50
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April 29, 2010 - Sacramento, CA, (BUSINESS WIRE) -- On Tuesday evening, the American Council of Engineering Companies awarded Omaha, Neb.-based HDR Engineering, Inc. its coveted Grand Conceptor Award for the Gills Onions Advanced Energy Recovery System Project in Oxnard, Calif. This is the second year in a row that an engineering design project in California has received the council's top award at the Engineering Excellence Awards, also known as the Academy Awards of the engineering industry. Last year's award was bestowed on Cambridge, Mass.-based CDM for its Groundwater Replenishment System designed for the Orange County Water and Sanitation Districts.
The Gills Onions project was one of eight projects considered for ACEC's top award. Other contestants included the new $1.3 billion Dallas Cowboys Stadium in Arlington, Texas and the Sea-to-Sky Highway project in British Columbia, Canada. The award was presented at ACEC's Engineering Excellence Award (EEA) gala in Washington, D.C.
HDR was selected by Gills Onions, the largest fresh-cut onion processor in the nation, as the lead engineering firm on this breakthrough $9.5 million facility that converts onion waste to power. In the facility, juice is extracted from onion peels and treated in a high-rate anaerobic reactor to produce methane-rich biogas. The biogas is then treated and used to power two fuel cells that provide electricity for the processing plant. As a result of this project, the owner has achieved increased energy independence, elimination of a waste stream, reduced operational cost, and a smaller carbon footprint. The combination of the energy produced, cost savings generated, and grant funding achieved by the project will result in a full payback in less than six years.
The EEA Gala applauds the accomplishments of private engineering firms in an elegant celebration attended by industry leaders, members of Congress, federal agency officials and the media. This year's EEA competition featured 163 projects from throughout the world all vying for honors of excellence -- culminating in the Grand Conceptor Award for best overall engineering achievement.
About ACEC California: ACEC California is a statewide association representing more than 1,000 private consulting engineering and land-surveying firms that average 20 employees each. ACEC California is dedicated to enhancing the consulting engineering and land surveying professions, protecting the general public and promoting the use of the private sector in the growth and development of our state. Our members provide services for all phases of planning, designing and constructing projects. For more information, visit www.acec-ca.org.
Submitted by gills_admin on Wed, 09/01/2010 - 10:55
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Last year my father sent me an article from the Los Angeles Times about a company that was using its waste to partially power the company...
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July 17, 2009 - Last year my father sent me an article from the Los Angeles Times about a company that was using its waste to partially power the company. I did not follow up on it at the time, but he called the other day (almost exactly one year after the original article) and said, “There’s this company you ought to look into.” Little did he realize he had already informed me, albeit indirectly, of their exploits.
Gills Onions in Oxnard, California was recently featured on Huell Howser’s California’s Green. In episode #134 (the 34th of the first season), Howser visits Gills Onion “which is not only the largest onion processing plant in California but its also the greenest. Each day they convert over 150 tons of onion peel and juice waste to power fuel cells on site that provide enough power to run the lights and refrigeration.” HDR Engineering, Inc, the company that built and designed the energy recovery system, won the “American Council of Engineering Companies . . . Grand Conceptor Award”, for the project.
According to the Los Angeles Times article, co-owner Steve Gill these efforts have reduced the electric bill by $700,000 annually. “He’s also saving $400,000 a year on disposal costs. And he has secured more than $3 million in government and power company incentives to do it.” Gill is quoted as saying, "It was first a business decision to solve a waste problem." The article reports that “the $9.5-million system will pay for itself in less than six years while eliminating up to 30,000 tons of carbon dioxide-equivalent emissions a year.” By fermenting onion juice, the methane can be burned in two on-site fuel cells.
Although the payback period may be a bit long for some, this type of system demonstrates the twofold impact on companies. By generating their own power and reducing their waste, they save money on both fronts, not to mention decrease their environmental impact. The energy source is both renewable and sustainable.
Submitted by gills_admin on Thu, 09/30/2010 - 13:48
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March 2010 - They say you are what you eat. So perhaps it could be said of food companies: “You are whatyou process.” That certainly applies to Gill’s Onions LLC. Just as an onion has layers, this 26-year-old family company in Oxnard, Calif., has layers of plant initiatives.
Besides several noteworthy food safety achievements, Gill’s was a founding member of the Climate Registry, a Los Angeles coalition committed to green house gas (GHG) emissions measurement, management and reduction. Moreover, the company also has earned state, national and even worldwide recognition for breakthrough technology billed as an Advanced Energy Recovery System (AERS). For the record, Gill’s is quite possibly the world’s largest onion processor – handling about 1 million pounds of onions daily and producing various types of refrigerated onion products for retail, foodservice and industrial channels. To use the best part of an onion, Gill’s eliminates the top, tail and a few outside layers. That generates an estimated 300,000 pounds of waste each day. A vertically integrated company, Gill’s used to collect, haul and spread that waste on nearby fields. It was around 1999, however, that company co-owner Steve Gill realized something had to change. “We were just running out of ground here to [stockpile waste material],” he says. “As business grew, so did the waste and it was becoming too expensive and unmanageable.
It was costing about $400,000 a year to just [maintain the practice]. I thought it would be better to put that money into a project like [AERS] … to stop the waste and solve the problem right here.” That led Gill’s Onions to figuratively break new ground – and consider every technology and procedure to process and re-use onion waste. Having collaborated with university, state utility and private industry researchers, the company last year completed a $9.5 million multi-step installation. In operation since last July, AERS includes technologies to (1) grind and dewater onion peels (reducing solid waste by 75 percent), (2) feed the onion juice to an anaerobic digester to produce bio-methane gas, (3) use specialized fuel cells to convert biogas into clean, usable electric energy and (4) process and press the remaining 25 percent of solid onion waste into high value cattle feedfor non-milking cows. Thus, Gill’s Onions now utilizes 100 percent of its daily product waste. Moreover, utility data verify that AERS is powering two 300-kilowatt fuel cells, which provide the company with its entire base-load electricity requirements (or enough to power 460 homes). Interestingly, Gill’s officials note that the company already has received $2.7 million in outside assistance funding, energy rebates and research funding. With that, Gill’s expects the AERS project to pay for itself – while officials make even more improvements – within six years.
Meanwhile, because AERS serves as an in-house electric power source, officials note that the company can “greatly reduce” its power-related GHG emissions. Sustainability Director Nikki Rodoni says Gill’s is working on a group project with graduate students from the University of California at Santa Barbara (UCSB)’s Donald Bren School of Environmental Science and Management. The group recently helped Gill’s complete the company’s first review of energy use, GHG inventory and reporting. Officials at The Climate Registry, Los Angeles, verified the emissions inventory and accepted 2008 data as Gill’s base year. “Although tedious, the process of accounting for all sources of energy use and emissions, offers numerous benefits,” says Rodoni. “First, we believe that if it isn’t counted, it can’t be improved and now we have a baseline accounting of the costs, energy usage and emissions across our entire organization. “Secondly, with the implementation of AERS, we expect to improve on all fronts – involving energy costs, demand and GHG levels – and now we will have an official, verifiable way to measure and market these improvements,” she continues. “Lastly, in the event of state or federally mandated greenhouse gas reporting, we believe we will be a step ahead by starting early, learning the verification process and working to improve the sustainability of our company.” Student researchers from UCSB’s Bren School also are cutting their teeth on Gill’s “zero waste” initiative.
“They have gone through our entire organization – analyzing our energy, water, onion and material consumption and identifying ways that Gills Onions can conserve, recycle, recover, reuse and replace – thereby eliminating as much as possible,” says Rodoni. “All of these initiatives will save money, reduce our environmental impact and improve our sustainability.”
To check out the online version of the mgazine click here.
Submitted by gills_admin on Thu, 09/30/2010 - 14:02
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March 2010 - Gill’s Onions generates 300,000 lbs/day of residuals from the processing of fresh-cut onions. With an annual disposal bill of $500,000, it opted to install an AD system to treat the waste on-site and utilize the biogas.
Diane Greer
BioCycle West Coast Conference 2010 Related Session:
Biogas Conditioning, Biomethane Markets
Wednesday, April 14, 2010
Presentation:
Onion Processor Upgrades Biogas To Power Fuel Cells
Bill Deaton, Deaton & Associates, LLC
ONION waste, once a liability, is now an asset at Gill’s Onions in Oxnard, California, where a $9.5 million project is converting onion waste into renewable energy and cattle feed. In 1983, Gill’s started slicing and dicing onions for La Victoria Salsa. Over the years the company grew to become the country’s largest producer of fresh-cut onions, processing almost one million pounds of onions and creating 300,000 pounds of waste each day.
Residuals from the process — the tops, tails and peels of the onions — were composted and spread on agricultural fields. “Land applying the waste worked until we got to a certain size and then it just overwhelmed the farming operations,” says Steve Gill, co-owner of the business. Spreading the material on fields resulted in odor, runoff and pest problems. Costs associated with handling and disposing of the waste increased to $500,000 a year. “I had to find a solution to the problem,” Gill adds.
The first alternative tried was making products out of the waste. “It did not work for cattle feed because cows did not like eating raw onions,” recalls Bill Deaton, president of Deaton & Associates, LLC, and consultant on the project. Attempts to reduce the volume by grinding it up morphed into a study with the University of California, Davis, to see if Gill’s could make biogas out of it, he explains.
Testing initially focused on digesting the solid waste streams. “Later they approached me and asked whether they could squeeze the juice from the solids and digest the juice,” says Ruihong Zhang, professor at University of California, Davis. Bench-top tests digesting the solids and the juice found both waste streams to be highly digestible with good biogas yields.
Gill’s opted to digest the juice. With space at the processing facility at a premium, a high-rate anaerobic treatment system to process the juice required significantly less footprint and shorter retention times than a conventional solids digester.
Experiments to extract the juice from the onion waste were successful with yields between 70 to 75 percent by weight, says Juan Josse with HDR, the process engineer and project manager who led the design of the facility. The remaining cake, which is 18 to 20 percent solids, was found to be good feed for cattle. “The farmers were willing to pay for it,” he adds. “If we digested the entire peel and then dewatered the digestate we could not sell it as cattle feed. You have bacteria as part of the feed and this is not welcome as animal feed. Also most of the energy value is already extracted.”
Gill’s also discovered that it could extract polyphenol, an antioxidant for the nutraceuticals market, from the onion cake. The cake could still be sold as cattle feed after the extraction process.
Onion Grower Invests In Digester And Fuel Cells :: BioCycle, Advanci...
The juice extraction process uses two stages of size reduction and pressing to increase the yield. In the first stage, lime is added to the onion waste, which is ground in a maserator and then sent to a screw press to extract the juice. The lime increases juice yields by enhancing the traction between the waste and the outer screen in the screw press, preventing the onions from sliding horizontally against the screen, Josse explains. The highly alkaline lime also elevates the pH, which helps rupture the cell walls in the onion, releasing more juice.
The screw press produces onion juice with some suspended solids and onion cake. “We realized at this point that we had a juice yield of 50 percent, not the 75 percent we wanted,” Josse says. A second stage is used to extract additional juice. The onion cake from the first press is sent to a second grinder for further size reduction. The finely cut cake is then fed to a smaller screw press that extracts the rest of the juice.
Conveyors move the remaining cake to a truck for transport to California farms for cattle feed. Juice collected from the two sets of presses is sent to a vibrator to separate out the small onion pieces suspended in the solution. The pieces are sent back to the second stage of the screw press for juice extraction. The process produces 30,000 gallons of juice and 20 tons of onion cake per day. The juice is high in soluble organics with about 60,000-ppm COD (chemical oxygen demand), Deaton says.
ANAEROBIC SLUDGE BED REACTOR
Onion juice is put into a 70,000-gallon acidification tank with mixers. After about two days in the tank, the juice is fed into the bottom of an anaerobic sludge bed (UASB) reactor supplied by Biothane in Camden, New Jersey. An influent distribution system pulses the juice into the tank. The pulsing action serves to disperse the juice in the reactor and prevents tunneling of the influent through the thick sludge bed.
Bacteria in the granular sludge bed start biodegrading the soluble organics in the juice and producing gas. The gas attaches to the granular sludge, causing some granules to float up through the bed and hydraulically forcing it through a series of baffle plates on a settler at the top of the tank where it is degasified. The degasified sludge granules sink back into the reactor while clear effluent flows over a weir near the top of the tank. Biogas collected below the reactor surface exits for treatment. The up-flow velocity produced by the feed and effluent recirculation eliminates the need for mechanical mixing. Retention time for a UASB reactor typically averages 16 to 18 hours depending on the feedstock.
“We chose the Biothane reactor for the short residence time and robust performance,” Deaton says. “They were also willing to work with us on our specification for not only COD removal but for biogas production.”
The square 110,000-gallon UASB reactor is painted black to absorb heat from the sun, helping to keep the tank warm. Waste heat captured from an 800-hp engine driving an air compressor used elsewhere in the facility maintains the reactor at mesophilic temperatures between 92° to 95°F.
A brewery in St. Louis, Missouri provided 50,000 gallons of granular sludge that was 8 to 9-percent solids to seed the reactor. The microbe population adjusted quickly to its new diet of onion juice. Initially the granules grew too large but have since adapted to the new feedstock, Josse explains. “They are on fire, eating everything we give to them.”
Biogas, produced at a rate of 100 to 110-cfm, contains about 70 percent methane. Effluent from the reactor is fed into an existing activated sludge plant at Gill’s where it is aerated and further treated before being discharged into the City sewer.
FUEL CELLS
The biogas powers two 300-kW fuel cells generating 0.6 MW of electricity to satisfy 75 percent of Gill’s base load power requirements. The fuel cells, supplied by Fuel Cell Energy in Danbury, Connecticut, operate on biogas and natural gas.
Fuel cells were selected over other technologies for their efficiency, exempt status for air quality permitting and available incentives. “Fuel cells are 47 percent efficient versus internal combustion (IC) engines that are 35 percent efficient,” Gill says. Utilizing waste heat from the fuel cells, which will occur in the next phase of the project, will push the
Onion Grower Invests In Digester And Fuel Cells :: BioCycle, Advanci...
overall efficiency of the system to 90 percent.
“The fuel cell had the advantage that we did not have to obtain an air permit,” Deaton says. “It was exempt from air pollution control testing.” Strict air quality regulations already limit the number and operation of stationary IC engines in Ventura County, where Gill’s Onions is located.
The project received $2.7 million in self-generation incentive funds from Sempra Energy, the local utility, and a 30 percent federal investment tax credit for installing the renewable energy process. Sempra’s incentive program provides businesses with financial incentives to install electricity generation technologies and pays higher incentives for technologies that run on renewable fuels. The utility current pays $4,500 per kW of installed capacity for fuel cells running on renewable power.
BIOGAS CLEANUP
One challenge the project faced was cleaning the biogas to meet fuel cell specifications. Fuel cells are extremely sensitive to sulfur, with levels limited to 100 parts per billion (0.1 ppm) or less, explains Ted Barnes, principal engineer at the Gas Technology Institute (GTI) in Des Plaines, Illinois. This is significantly cleaner than biomethane quality standards for pipeline injection.
Onions are high in sulfur. It’s the sulfates in the onions that make you cry and also why they smell and taste so good, Barnes explains. These sulfur compounds end up in the juice and during anaerobic digestion are volatized into biogas creating high concentrations — more than 5,000 ppm of hydrogen sulfide (H2S) and organic sulfur compounds.
When the project was under development, commercial manufacturers of biogas cleanup technologies could not guarantee their systems to meet sulfur removal specifications. “We had to develop new technology to remove the sulfur,” Deaton says. Gill’s project team hooked up with the GTI to research development of a gas purification system. Funding for the research was provided through a $500,000 grant from the California Energy Commission.
Research focused on testing and developing media to capture both the inorganic and organic sulfur compounds. “We found several media that worked,” Deaton says. “We had to design our system so that those medias were in the proportion of the gas impurities. We also went to a lot of effort to understand what pressure, temperature and humidity conditions worked best for the separation and optimize all the variables.”
The first step in the process devised to clean up the biogas uses a two-stage iron sponge to get H2S levels down below 1 ppm, Barnes says. A compression and drying system employs a glycol chiller to remove moisture from the gas. Recovered heat from the compressor reheats the gas. The final step passes the gas through two vessels in series, each with different media, to remove the organic sulfurs that made it through the iron sponge. The two media in combination proved very effective at removing the organic sulfur compounds. Final polishing of the gas uses filters to remove particulates carried over from the prior cleanup stage.
When the iron sponge media becomes saturated with sulfur, it can be regenerated two to three times. “You put oxygen and air through it in the presence of water,” explains Barnes. “The sulfur comes out in elemental sulfur form.” The second polishing media can only be regenerated off-site. When this media is spent it needs to be replaced. Unlike pipeline injection, CO2 does not need to be removed from the biogas. The molten carbonated fuel cells used on the project tolerate CO2.
To date, the gas management system is working well, Gill says. Sampling is currently used to monitor gas quality. Installation of sensors is underway to automate the process.
VARIABLE GAS FLOW
Gas generation in a UASB reactor fluctuates, with the gas flows going up and down in 6 to 7 minute cycles, says Josse. Bacteria in the granular bed produce tiny biogas bubbles as they consume the organic compounds. The bubbles combine to form larger bubbles that are finally able to break through the sludge bed. The physics of forming the larger bubbles has a “certain periodicity to it.”
The team needed to devise a process to overcome the variable gas flow from the digester, a situation that had resulted in inefficiencies in other fuel cell applications, Josse adds. The fuel cells, which operate on both natural gas and biogas, are setup to give preference to biogas. If the devices are not getting enough biogas, they need to compensate with natural gas. Variations in the flow of the biogas are too abrupt for the fuel cells to respond appropriately. As a result, the cells ends up using more natural gas and flaring biogas, which increases operating costs and wastes energy, he says.
To solve the problem, a gas holder with a double membrane and an ultrasonic sensor was devised to absorb the fluctuations. If the level of the gas starts to drop, the sensor sends an advanced signal to the fuel cells to slightly close the valve supplying biogas and slightly open the natural gas valve. “It works wonderfully,” Josse says. “We do not run the flare. Basically everything gets used and there is very little natural gas supplementation.”
Onion Grower Invests In Digester And Fuel Cells :: BioCycle, Advanci...
PROJECT ECONOMICS
Using biogas in the fuel cells is saving $50,000 to $60,000 per month in electricity purchases, Gill says. Another $500,000 is saved annually by eliminating the hauling and spreading of onion waste in the fields. The project is also earning money by selling the onion cake as cattle feed. Taking into account the savings, sales of by-products, self-generation credits and investment tax credits, the $9.5 million project expects payback in five years.
Everyone associated with the renewable energy project emphasizes the level of cooperation and teamwork. “We were successful in pulling together all the right resources, getting the funding and managing the overall project during an awkward time in our country,” Deaton says. “It is really a boon for Gill’s Onions. They are taking a problem and making it into a profit center.”
Diane Greer is a Contributing Editor to BioCycle. Bill Deaton will be speaking at the 25th Annual BioCycle West Coast Conference on the Gill’s Onion project.
Submitted by gills_admin on Thu, 10/21/2010 - 08:28
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October 7, 2010 - Gills Onions, one of the largest fresh onion producer/ processors in the world, was disposing of 1.5 million pounds of onion waste every week by spreading it as compost across 15,000 acres it farms in Oxnard, Calif. It was an arduous, time-consuming process that cost the company approximately $400,000 annually.
Gills had also long-faced two even potentially costlier concerns: high electricity costs (12 to 13 cents per kilowatt hour plus a 15 percent rate hike for 2010) and electricity blackouts. After experiencing a series of blackouts that had jeopardized the extensive refrigeration required to process and protect its fresh-cut onions, the 27-year-old family owned company began to aggressively pursue a long-held desire to convert its onion waste into energy.
Determining how to efficiently convert onion waste into methane gas through anaerobic digestion presented a challenge, according to Bill Deaton, president of Deaton & Associates LLC, the Kayenta, Utah, chemical engineering and energy consulting firm retained by Gills to study the concept and develop a plan.
“It works well at breweries where beer waste is used to run boilers and on dairy farms where manure is converted into fuel. But until Gills decided to try it, no one had used microorganisms to generate digester gas from onion waste before,” Deaton says.
After testing by Ruihong Zhang at the University of California, Davis confirmed that the sugar content in onion waste was ideal food for methane-producing microbes, Deaton assembled a team of engineers and contractors to develop an efficient waste-to-energy system they named the Advanced Energy Recovery System.
In late winter 2009, following a multiyear research and design process, a new energy recovery system went fully on line at Gills, converting the company’s onion waste to methane gas that feeds two 300-kilowatt fuel cells. Today this system is offsetting 100 percent of the company’s baseload power costs and its expensive waste hauling and disposal operation is no longer necessary.
Biogas Production
During its fresh cut operations, Gills removes the top, tail and skin, which is roughly 35 to 40 percent of the onion. This waste, generated at a rate of approximately 300,000 pounds daily, now goes through grinding and pressing equipment where 30,000 gallons of onion juice (approximately 75 percent of the total waste) is separated from the solids. The juice is diluted and fed to the energy recovery system’s fully automated anaerobic digestion process. Microorganisms in the digester convert the juice’s sugar content into methane and carbon dioxide. The remaining leftover solids are sold as high-value cattle feed.
In the first step, the onion juice flows to the anaerobic reactor’s equalization tank that ensures the influent is pumped to the anaerobic digester at a constant, continuous flow. The equalized water is pumped to a rapid mix tank, where the influent is mixed with a dilution stream and conditioned for efficient anaerobic digestion by adjusting temperature, pH and nutrients (including phosphoric acid and nitrogen). A heating recirculation loop maintains the necessary temperature. From the rapid mix tank, the stream is pumped through a static mixer, which injects ferric chloride and micronutrients into the stream prior to entering the digester.
“The temperature of the feed flow is between 35 and 40 degrees Celsius (95 to 104 degrees Fahrenheit),” Deaton says. “To obtain this mesophilic condition, we brought waste heat from other processes in the plant to heat the digester feed.”
The system’s upflow anaerobic sludge blanket (UASB) reactor has a working capacity of 550 cubic meters and a hydraulic retention time of just 29 hours. During this period, anaerobic bacteria within the digester convert the biodegradable onion waste material into methane, carbon dioxide and new biomass.
Feed flow from the rapid mix tank splits and enters the bottom of the digester through two feed headers. A proprietary feed distribution-piping system is used in the distribution of the digester feed across the bottom of the digester. The distribution system is specifically designed to create good initial flow distribution of the conditioned onion juice through the sludge bed.
The feed flows upwards through the digester. At the top of the reactor, effluent flows over weirs that spill equally into a continuous trough system and combine into a settler drop box. Once collected in the drop box, it exits the digester and flows to a standpipe. An anaerobic effluent composite sampler located in the recycle piping upstream of the rapid mix tank automatically collects samples of the effluent to determine digester performance.
Biogas exits the digesters through a gas nozzle at the top of each digester vessel. Excess biomass is periodically removed from the digester and pumped to a tanker truck. Vent gases from the equalization tank, rapid mix tank, digester and standpipe are collected via a vent air blower and purified in a biofilter.
One initial challenge the team faced was foaming generated in the sludge bed due to the high protein content of the onion waste. “But by making several modifications and changing some of the gas piping, we eliminated the foaming issue,” Deaton says.
Digester Selection
The team selected Biothane to build the specialized reactor to produce the methane. Biothane, a Veolia Water Solutions & Technologies company, is a leading biotechnology company that focuses on highly efficient, cost-effective biological methods to treat wastewater while creating energy and reducing pollution.
“We liked the idea of the UASB reactor having a sludge bed system rather than a fixed bed,” Deaton says. “Initially we had considered using a fixed-bed reactor because of the high surface area for the bacteria to form. But after further consideration, we decided we didn’t want to deal with the blockage, cleaning, or any of the other issues that can arise with fixed-bed reactors when treating a waste material containing pulp, like diluted onion juice,” says Deaton. Biothane’s UASB reactor forms a blanket of granular sludge that suspends in the tank.
“By suspending the bacteria, you can mix the feed with it and get good contact, and you don’t have to deal with the problems of the fixed media in the bed. Ultimately, the simplicity of the UASB played a big part in our decision to select it,” Deaton says. “Plus, there was a lot of engineering we did outside of the reactor—we transferred waste heat from other processes in the plant with the onion juice, then diluted the onion juice and added micronutrients when necessary.”
Before the methane could be safely fed into the system’s fuel cells, the team had to first overcome a serious obstacle. The methane produced by the feed flow has high sulfur content—part of what makes onions smell and makes people’s eyes water. “You can’t send high-sulfur gas to these fuel cells because they have very stringent gas quality specifications for displacing natural gas as a fuel source,” Deaton says. A grant to fund research by the Gas Technology Institute helped solve the issue. Consequently, the reactor was modified to allow for the collection and conditioning of the biogas.
“With this modification, the biogas flows from the digester into a conditioning process that purifies, dehumidifies and compresses the gas, making it acceptable for use in these high-efficiency fuel cells,” Deaton says. “As a result, the system produces about a 70 percent methane gas, which is very high quality for biogas.”
Fuel Cells=Clean Energy
Because Gills wanted an energy recovery system that produces clean heat and electricity, it ruled out engines, combustors or boilers, choosing fuel cells instead. Although relatively new to commercial industry, fuel cells are increasingly being adopted because they generate a highly clean form of energy, run quietly, and produce power and heat at high efficiency.
The new energy recovery system at Gills uses two 300-kilowatt fuel cells manufactured by Fuel Cell Energy. The methane produced by the anaerobic digester feeds the fuel cells, which re-form the methane to hydrogen and carbon. The hydrogen and carbon recombines with air in the fuel cells to generate electricity in a classic oxidation/reduction reaction. The end-products are electricity, water and carbon dioxide. The two fuel cells generate enough combined electricity to power the equivalent of 460 homes.
“A standard power plant runs at about 30 percent efficiency,” Deaton says. “These fuel cells are currently running at 47 percent efficiency. And, because this is an industrial site, Gills can take advantage of all the heat being generated, too—using it to heat water, evaporate water, and refrigerate or chill plant water. So, the system is actually running at about 80 percent efficiency and negligible emissions.” The emissions avoided by using fuel cells, plus the emissions avoided by not trucking away and land applying the onion waste, yields an approximate 15,000 ton-per-year reduction in the company’s carbon emissions.
Since the fuel cells are designed to supply base-load power and do not ramp up and down quickly, Gills Onions is able to offset 100 percent of its base-load power costs. Therefore, the company is able to bring the power up and hold it steady 24/7.
“In a large fresh-cut produce plant like Gills, there are high, around-the-clock refrigeration demands. You don’t ever want to lose the cold chain in maintaining fresh onions. This constant demand is now satisfied with the AERS process on-site,” Deaton says.
Quick Payback, Flexibility Gained
The entire project cost $9.5 million. Deaton says the savings of $400,000 a year from eliminating waste hauling, $700,000 a year in deferred electricity costs, plus $2.7 million in incentives for the project from Southern California Gas Co. (as part of the state’s Self-Generation Incentive Program) and tax credits should enable Gills to receive a five-year payback.
“Meanwhile, we’re working on another process to take the remaining 25 percent of the waste left after the grinding and pressing process and reduce that by half. This should add another 20 to 50 percent to energy production. When you’re offsetting Edison Power at about 12 to 13 cents per kilowatt hour, the payback comes fairly quickly,” he says.
As the system’s project manager, Deaton says he is pleased with what has been accomplished, but he also says the work is not yet finished. Future plans include further reducing the carbon footprint through energy storage, water re-use, and extracting quercetin from the onion waste for use as an anti-oxidant supplement for humans.
To read the article at BioMass Magazine click here.
Submitted by gills_admin on Mon, 01/03/2011 - 11:35
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When Steve and David Gill founded their onion processing company back in 1983, the brothers only had one customer and a handful of employees working as peelers. Today, Gills Onions is the world’s largest, providing over 80 million pounds of processed onions to restaurants, retailers and manufacturers of salsa, soups and spaghetti sauce out of a fully mechanized plant in Oxnard, California.
Recently, the company has made headlines for a groundbreaking, environmentally advanced solution it came up with to deal with all the waste coming out of the facility. Traditionally, Gills had trucked most of its peels and other onion waste from the plant out to local fields for composting back into the soil. But that solution was costly and environmentally problematic given the fuel and carbon emissions required.
“As the plant grew, the waste problem grew,” Steve Gill said. “I had no idea what to do with it.” Steve Gill conferred personally with engineers at the University of California-Davis and devised a plan to convert the onion waste
into power using biomass technology. Gills Onions built a first-of-its-kind system through which bacteria in special tanks break down onion waste into methane, which is then converted into electricity via fuel cells.
The system generates enough power to supply 100 percent of the baseload electricity consumed by the plant every year. The $9.5 million plant, financed by CoBank and Farm Credit West, has received an array of public accolades from the government, media and environmentally conscious customers like McDonalds. It even beat out the new Dallas Cowboys football stadium for a first-place award from the American Council of Engineering Companies.
Steve Gill says Farm Credit is his lender of choice due to its longstanding commitment to and deep understanding of agriculture. “Farm Credit allows us to make decisions based on our own experience, and they stand by you in and out of market cycles,” Gill said. “I value the relationship, and having bankers I can count on.
Submitted by gills_admin on Tue, 01/25/2011 - 15:09
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A California company wins awards, saves money and cuts greenhouse gas emissions by turning agricultural waste into energy.
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By Steve Fox - Think about innovative California companies and what probably comes to mind are Google in search engines, Oracle in business software, Intel in silicon chips, and Hewlett-Packard in printers and computers. Certainly not Gills Onions.
Think again. This family-owned processor of onions in the coastal town of Oxnard, about 95 kilometers north of Los Angeles, is making electricity from onion juice—and saving itself more than $1 million a year in the process. By installing what the lead engineer on the groundbreaking project calls “a big stomach” at its plant, Gills is turning agricultural waste into energy and winning praise from engineers and environmentalists alike.
As one of the largest processors of raw onions in the United States, Gills slices up some 362,800 kilograms of the pungent vegetable every day for a wide variety of customers, including supermarket chains, restaurants and fast-food companies such as McDonald’s. About 40 percent of the onion is lost in the process, leaving Steve and David Gill, the brothers who own the company, with a challenge that might bring some to tears.
“I had to solve the problem of our onion waste,” Steve Gill says in a SPAN interview.
“It was very expensive to haul away and we were spreading so much of it on the fields that it was beginning to affect the crops we were growing. I had to find another way.”
The solution didn’t happen overnight, but the Gills, who started their company in 1983 with 16 people and now employ 400, learned patience on a family farm in California’s fertile Central Valley where they grew tomatoes and peppers. “It took me 12 years to figure it out,”
Gill says. “The technology wasn’t available to handle waste like this when I started looking into it, and I had to do all the research and development myself. But I was persistent. Then the permitting process took quite a while, and financing was difficult, too. The technology is ahead of what everybody is used to, so that slows everything down a lot.”
What became the company’s Advanced Energy Recovery System ultimately cost $10.8 million, with Gills Onions receiving assistance in the form of $1.8 million in investment tax credits from the federal government and $2.7 million from Sempra Energy as part of the utility’s renewable energy Self Generation Incentive Program.
Gills now gets about 80 per cent of its power from onion juice and expects to recover its investment in six years while removing more than 90,700 kilograms of onion peelings from the plant’s waste stream every day. The company also eliminated a significant amount of greenhouse gas emissions associated with the thousands of truck trips formerly needed to haul the waste away.
To put the innovative project together, Gills brought in Bill Deaton of Utah based Deaton & Associates. An independent consultant with a background in chemical engineering and 25 years of food industry experience, Deaton took Gills into the finer points of waste-toenergy conversion and assembled a team to turn concept into reality.
“It was a great project to manage because we had a lot of sharp people who were all eager to do things, and that was critical because we had to create our own resources as we went along,” Deaton says. “Nobody had really done a project like this before, and nobody was working with onions.”
Deaton’s team included engineers from HDR, Inc., an Omaha, Nebraska-based architecture, engineering and consulting firm that has done projects in all 50 American states and 60 countries. Among HDR’s many unique projects are a solar power system for Alcatraz Island, the infamous former prison in the middle of San Francisco Bay that is now a U.S. national park; and design and construction support on the Hoover Dam Bypass, which took car traffic off the mammoth dam and onto what is now one of the longest concrete arch bridges in North America.
The HDR contingent was led by Juan Josse, who is now vice president of engineering at UTS BioEnergy in Irvine, California.
“We had to develop the technology to extract the onion juice and we had to develop a way to digest the onion juice, which no one had done before,” Josse tells SPAN. “Then one of the biggest challenges was how to put together all the different technologies involved. We couldn’t get anyone to commit to do the whole thing and give us a package, so we decided to put together the best equipment we could find and we did that successfully.”
The energy recovery system essentially involves piping the 113,500 liters of onion juice Gills winds up with each day into what’s known as a high-rate upflow anaerobic sludge blanket reactor or, as Deaton puts it, “a big stomach.” Spurred by bacteria purchased from a beer brewery, the onion juice ferments inside the 548,800-liter digester and produces methane gas, which is treated and compressed, then used to power two fuel cells Gills purchased and had installed at the company’s 5.6-hectare plant. The fuel cells produce enough electricity to power about 450 homes—or most of the company’s energy needs. Onion waste that can’t be converted into juice is sliced into fine pieces that are compressed into onion “cake” used for animal feed.
While the fuel cell technology was relatively straightforward, getting the digester to consume high-sulfur onion juice was somewhat trickier.
“The digester seems like it has a mind of its own and we had to deal with that,” Gill says. “But once we let it do what it wanted to do, it started producing a highquality gas.”
The showcase project won a number of awards, including the Grand Conceptor Award of the American Council of Engineering Companies, the governor’s Environmental and Economic Leadership Award (California’s highest environmental honor), the Cool Planets Projects Award and McDonald’s 2010 Best of Sustainability Supply Chain. In winning the engineering companies award, the innovations at Gills came in ahead of much larger projects that included the $1.3 billion Dallas Cowboys Stadium in Arlington, Texas and the Sea-to-Sky Highway project in British Columbia, Canada.
“They’re setting the standard,” California Environmental Protection Agency Secretary Linda Adams said at an event Gills hosted in July to mark the first year of successful operations of the recovery system. “It’s really a tremendous thing to see private industry taking this kind of leadership.” Deaton and Josse believe more companies will follow the example that Gills set.
“These projects are getting to be very popular and there are going to be a whole lot more of them,” Deaton says. “You go to countries like Sweden and Germany and you’ll find that they have converted lots of things into compressed biogas. The important thing is that it’s renewable. You’re taking something that was grown above the ground, converting most of it into energy and putting the rest back into the ground and renewing the cycle.”
“What we did can be applied widely in any food processing industry, not just in the plant but out in the fields,” Josse says.
“A lot of the waste from harvesting that’s now plowed into the ground could become energy, electricity. It could be done anywhere. It’s just a matter of using the right engineering and the right technology.”
Renewability and sustainability are now standard operating procedure at Gills, with the company looking at turning the plant into a zero-waste facility by, among other things, recycling employees’ lunch leftovers.
“Our goal is to recycle as much of our waste as we can,” Gill says. “It’s a dollars and cents thing, but it’s also accountability to the environment.”
Steve Fox is a freelance writer, former newspaper publisher and reporter based in Ventura, California.
Creating Sustainability. I’m Greg Martin as Line On Agriculture presents the Harvest Clean Energy Report.
Businesses all across the U.S. are finding out that with just a bit of outside of the box thinking they can turn a negative into a positive when it comes to sustainability. Nikki Rodoni is the Director of Sustainability for Gills Onion in Oxnard, California who found that sustainability meant a lot of different things.
RODONI: Gills Onions is one of the nations largest fresh cut facility for onions. Sustainability for us, the understanding or trying to understand it came about three years ago and it was my job to go find out at every level of operation what sustainability meant to us. And the more people I asked, the more definitions I got. For us it translates into economic benefit
She says that necessity led to invention.
RODONI: We started small to now having one of the leading sustainability programs in the produce industry. What really catapulted us into that arena was our waste energy project. About 10 years ago Steve Gill was looking at ways t o get rid of his waste other than what we were doing. We were generating up to 300-thousand pounds of onion waste on a daily basis.
That waste was being dumped on their fields which was both expensive and potentially hazardous. They discovered they could produce methane off that waste.
RODONI: Now what we have is we take our 300-thousand pounds of onion waste that we generate and through anaerobic digestion and fuel cell technology we’re generating our base load of electricity. So we’re utilizing 100% of our onion waste and now instead of looking at it as a liability, it’s this huge asset for us. We’re no longer hauling this waste out to the field so that’s eliminated $450-thousand dollars a year, plus we’re saving up to $700-thousand dollars on our electricity costs.
Onion juice makes up 75% of the waste and it is used by the digester. The other 25% has also become an income stream for Gills.
RODONI: The solids, which is about 20 tons are then taken to dairy farms to feed non-milking cattle. There’s a high nutrient content inside the onion fibers. In addition we’ve done some extensive research and study on the human benefits. It’s high in quercetin which is an antioxidant and we’ve figured out a way to extract and dry that nutrient content. What’s left over from that are some fibers and we’ve been working for the last 3 years on how to incorporate those fibers into packaging materials.
For additional information on clean energy, visit harvestcleanenergy.org. That’s today’s Line On Agriculture. I’m Greg Martin on the Ag Information Network.
Submitted by gills_admin on Tue, 04/12/2011 - 11:44
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In today’s world, sustainability, waste management and energy consumption are major challenges food companies must face...
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Issue 6 Spring 2011
In today’s world, sustainability, waste management and energy consumption are major challenges food companies must face. Gills Onions has been in the press a lot lately for the unique, innovative work they’ve done in this field.
Gills Onions, owned by Steve and David Gill, is one of the world’s largest producers of fresh-cut onions, producing nearly one million pounds of onions each day. When a company processes that many pounds of onions a day, a lot waste is generated from the topping, tailing and peeling process – 200,000 to 300,000 pounds a day, in fact. Traditional disposal can be both time-consuming and expensive. Gills originally tried hauling this onion waste, then disking it into company-owned farmland, but this created unfortunate side effects: unwanted pests, release of greenhouse gases, and potential ground water contamination.
To solve this challenge, Gills teamed up with the University of California at Davis to devise a novel approach to using onion waste for conversion into electricity. In this process, onion waste is separated into solid and liquid components. About 75% of the waste matter is liquid, which is diluted with water and sent to a large anaerobic digester. Visually akin to a silo, this digester contains microorganisms that thrive on the sugars found in onions. As these microorganisms digest the sugars, they produce methane and carbon dioxide gases as by-products. This methane gas is collected, cleaned and conditioned to power fuel cells, which in turn provide energy for the processing plant. A whopping 600 kilowatts is created during this process annually, accounting for 100% of the plant’s base load of electricity. Overall, this accounts for 60% of the plant’s total energy requirement, and, alternately, would provide enough power to supply 460 residential homes for an entire year!
Similar systems have been built for other food and beverage industries, but Gills has pioneered this process for onion waste. The Gills took a calculated risk, and it paid off. In fact, the project was so successful that it won several prestigious awards, most notably the 2010 Most Outstanding Engineering Achievement presented by the American Council of Engineering Companies. Gills bested other successful sustainability-friendly projects such as the Dallas Cowboys new football stadium, waste water treatment plants, bridges, highways and even entire high rise building projects.
So what’s the next step for Gills in the constantly changing world of sustainability?
For starters, Gills is installing a Vanadium Redox Battery (VRB) to create energy storage at their Oxnard facility. This will improve their energy efficiency, provide the facility with backup power in emergency situations and will allow Gills to make fewer (and cleaner) purchases from energy companies during peak demand times.
Another area they are working on is alternative uses for their solid onion waste. Traditionally, this waste has been sold as cattle food, but new concepts are emerging involving the extraction of the chemical quercetin. Found naturally in many plants, quercetin has many applications in the pharmaceutical and food industries, among them as a mental alertness aid. Gills has piqued the interest of the Department of Defense who may wish to use the extracted quercetin in their long-lasting meals-ready-to-eat (MREs), sports drinks and other food products.
Gills is currently exploring utilizing onion fibers in fully biodegradable packaging material including paper plates and cups. Pilot studies have been very promising and the next step is commercialization.
Gills has found many payoffs for their sustainability initiatives, beyond the obvious environmental impacts and financial gains. By putting forth the efforts needed to complete these programs, the company has been able to understand their business far better, and they have been able to stay well ahead of government regulations.
