June 7, 2017 | General

Anaerobic Digest

BioCycle June 2017

Washington, DC: Positive Legislation For AD Industry

The bipartisan Agriculture Environmental Stewardship Act (S. 988), introduced in May by Senators Sherrod Brown (D-OH) and Pat Roberts (R-KS), will help to deploy new nutrient recovery and biogas systems to recycle organic material into base load renewable energy and healthy soil products. The Act provides a 30 percent investment tax credit (ITC) for qualifying biogas and nutrient recovery systems. “We thank Senators Brown and Roberts for their strong recognition of the need for clean waterways and more productive soils which contribute to healthier communities and a stronger economy,” notes Patrick Serfass, Executive Director of the American Biogas Council. “Biogas and nutrient recovery systems make these goals obtainable and this legislation will help incentivize those technologies.”
No tax incentive exists to incentivize biogas or nutrient recovery systems, adds Serfass.  A production tax credit under Section 45 of the federal tax code, which had been used to incentivize production of renewable electricity, was allowed to expire.   This new investment tax credit would promote the production of pipeline quality natural gas and compressed renewable natural gas vehicle fuel as well as nutrients that are vital to sustainable agriculture production.
A separate bill introduced in the Senate by Ron Wyden, D-OR, the Clean Energy for America Act (S. 1068), could also benefit the anaerobic digestion sector. The Act includes technology-neutral tax credits for domestic production of clean electricity and clean transportation fuel, as well as performance-based tax incentives for energy-efficient homes and office buildings. These credits are open to all resources, including fossil fuels that capture carbon or make efficiency improvements. Currrently, there are 44 different energy tax incentives; more than half, according to Wyden, are “too short-term to effectively stimulate investments, while also providing different subsidies to different technologies with no clear policy direction.”
An assessment of S. 1068 by Power Markets Today explains that “taxpayers could choose between a production tax credit (PTC) and an investment tax credit (ITC), which are scaled based on the carbon emissions of the power generated — measured as grams of CO2 equivalents emitted per-kwh generated. Power plants that emit no more than 35 percent less carbon than the current nationwide average would qualify for a small incentive and plants with zero emissions would be eligible for a 2.3¢/kwh PTC and a 30 percent ITC. The PTC would be available for 10 years after a plant is placed into service. For combined heat and power systems, the emissions rate is calculated using both electrical and useful thermal energy. Plants placed into service before Jan 1, 2019, that add energy storage technology or carbon capture equipment, could claim the maximum 30 percent ITC for those investments.”

Milan, Italy: Testing Digestibility Of Compostable Bioplastics

A study carried out in Germany by IGlux Witzenhausen and Witzenhausen-Institut tested the biodegradability of Novamont’s MATER-BI bioplastic bags in the anaerobic digestion process using equipment made by four different companies: Kompogas, Thoeni, Bekon and WTT. According to Novamont, testing found that its bioplastic carrier bags are 100 percent biodegradable in anaerobic digestion (AD) plants. The percentage by weight of MATER-BI in the input material registered as between 3.5 and 3.8 percent. Over the course of the testing process, the bags were monitored at the pretreatment, AD, post-composting of digestate and maturation stages at each plant.
Novamont said in a statement: “Degradation began during the anaerobic stage and was completed during composting. In total, the process took between five and ten weeks, depending on the plant. No MATER-BI residue was found in any of the samples examined at the end of the test, demonstrating that it had completely degraded in all four plants … within the time normally taken for the process at all four plants.”

Enfield, England: Farm Digester Processes Urban Organics

Cattlegate Farm in Enfield, about 10 miles from London, installed a 1.5 MWe (Megawatts electric) anaerobic digestion plant in 2016 with capacity to process 27,000 tons per year of food waste produced by London’s households, restaurants and food industry. Willen Biogas, formed by Cattlegate Farm to manage its organics recycling and renewable energy operations, selected Xergi to build and operate its new digester. The plant is equipped with a Cesaro depackaging facility that separates plastic and other material from the organic fraction before being processed in the biogas plant. Water is added in order to achieve clean fractions from the depackaging system, which is equipped with a flail to further reduce small inert particles from the organic fraction. Slurried organics are pumped into the Xergi FLEXFEED® modules, which pasteurize the material for one hour at 70°C per the European Union Animal By-Product Regulation and the PAS110 Digestate Standard. The primary digester operates at ~126°F. The depackaging unit has a capacity of 155 tons/day.
The biogas plant has 800,000 gallons of primary digester capacity and 530,000 gallons of secondary digester capacity. Digestate is separated into liquid and solid fractions and is further processed in a digestate concentration system where excess hot water from the combined heat-and-power generator (CHP) system runs through piping to heat the liquid fraction of the digestate effluent, driving off water and concentrating the nutrients in what’s left. The evaporated water (steam) is condensed and cooled back to liquid water, which then is recirculated to the depackager, reducing reliance on fresh water. Digestate is used in Cattlegate Farm’s operations.

Raleigh, North Carolina: Poultry Vs. Swine Manure Nutrient Content Comparison

A new report finds North Carolina poultry farms generate far more nutrients in manure than do hog farms. The report on Basinwide Manure Production, produced by the state Department of Environmental Quality’s (DEQ) Division of Water Resources, concludes poultry growers produced 56.6 million pounds of nitrogen and 79.8 million pounds of phosphorus in 2014, according to an article in North Carolina Health News. That amount is three times the nitrogen and six times the phosphorus produced statewide by swine operations in the same year, the DEQ estimates. The impact of these nutrients on North Carolina’s cannot be determined, the report notes, because the DEQ does not monitor waste disposal at the vast majority of poultry farms across the state. Poultry farms in the state that raise more than 30,000 birds and produce dry litter are “deemed” permitted when it comes to manure disposal, as long as they follow rules that forbid over application of the litter to farmland, among other things, explains the Health News article. “[That] adds significant uncertainty to assessment of the loading contribution of poultry to the state’s nutrient-impaired water bodies,” states the report.
Poultry farmers have become the largest agricultural industry in North Carolina, according to data gathered for the Basinwide Manure Production study, raising the potential pollution from these operations. “Nutrient contributions from swine operations have remained fairly constant over the last several years,” notes the report. “However, the shifts in both location and the type of poultry industry in the state is potentially adding to the current nutrient loading from nonpoint sources. … This adds to the concerns over environmental impacts of manure application on a limited land base.” The basinwide planning program within DEQ’s Division of Water Resources is charged with identifying and providing recommendations for improving water quality based on the cumulative impacts of all activities across a river basin.

Waterloo, Ontario: Dog Waste Digestion Facility

The city of Waterloo in Ontario, Canada, will soon be home to a dog waste biogas facility, according to the Huffington Post. Dog waste from around the city will be collected and anaerobically digested. Special ‘receptacles’ will be set up around the city to accept dog waste. The bins will be bright green, with a dog-shaped opening. “It’s actually a big issue, dog waste,” Waterloo mayor Dave Jaworsky told the Huffington Post. “If you look at our municipal litter bins … it’s 40 to 80 percent dog waste,’’ The city has a population of about 100,000 people. After being stored underground for 10 to 14 days, the dog waste will be vacuumed out and sent to a processing plant outside the city, where it will be anaerobically digested. Digestate will be used for fertilizer.

Bladenboro, North Carolina: Phosphorus Recovery At Hog Farm

Storms Farm’s dedicated phosphorus (P) recovery system has been commissioned and is reported to be capturing 90 percent of the farm’s total P from all the hog waste generated daily. The system employs an organic polymer to capture the P-rich solids. Storms Farm installed a 1.2 million gallon DVO Two-Stage Mixed Plug Flow™ anaerobic digestion system to manage manure collected daily from nearly 30,000 hogs, along with off-site agricultural wastes. “Complete digestion of all the farm’s waste is a critical first step to the P recovery unit’s performance,” explains DVO’s Doug VanOrnum. “Some nitrogen and essential micro-nutrients are also captured. These combined fertilizers are collected in a condensed, stackable solid product that are deposited via conveyor directly into truck bed or trailer for transport and use.”
North Carolina Electric Membership Corporation purchases all of the 600 kW of electricity generated by Storms Hog Power under a long-term contract. The facility uses an engine generator and switchgear supplied by Martin Machinery Inc. and GenTec LLC.

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