TERU Focus Report - California Bioresources - Part 2

Analysis of the EPA's 6th Annual Symposium on Regional Organic Residuals
September 19, 2011 -- Michael Theroux

Day 2: "The Need for Biomass Management from a Water Quality Perspective"

Day 2 began with keynote speaker Pamela Creedon, Executive Officer of the Central Valley Regional Water Quality Control Board (CVRWQCB), the largest of the nine state regional water boards.

Salt and nitrate pollutant concentrations are currently predominant concerns for the Central Valley, compromising drinking water for residents. Recent Clean Water Act provisions now require formal Nutrient Management Plans; the CVRWQCB is pushing particularly hard for salt minimization. The agency led development of the recently completed Program Environmental Impact Report addressing dairy digesters, recognizing that co-digestion of food waste with manure was the key to viable biogas generation and volatile solids reduction. A Basin Plan Amendment is underway to effect salt and nitrate reductions within entire Central Valley. The CVRWQCB is building up a "Salt Inventory", using geographic information systems (GIS) data management to graphically order and prioritize Central Valley nutrient contaminant "hot spots". Regarding manure management: you can't treat salt, you must remove it. Income from the conversion of manure wastes to energy, fuels, etc may be able to off-set the cost of removal of the salts from the region; some of those salts, like selenium, are in short supply for animal feed in the native soils of other regions. Constituents of all wastes that are now land-disposed must stop being considered "waste" and instead must be seen as Resource for energy, fuels chemicals and soils amendments.

Utilities' Perspective

The constituents in biogas reflect both the feedstock source and the method of waste conversion. For Utilities to integrate bio-sourced fuel gas into the existing pipeline and power generation infrastructure, those gasses must meet stringent specifications. Standard manure-fed digester biogas must be dried of water and the methane must be selectively concentrated to increase the heat value. If from wastewater treatment plants (WWTP), aqueous silica compounds (silanes, siloxanes) must be removed, as these precipitate residue harming both pipelines and engines. Biomethane upgrading to transport-ready compressed natural gas (CNG) can rank among the cleanest for the Low Carbon Fuel Standard and the current price of biomethane is competitive, at $9 to $12 per million British thermal units (BTU).

The capital equipment and operational cost of biogas upgrading "to pipeline spec" is exorbitant for any one small biogas producer; aggregating raw biogas to regional upgrading hubs appears to be the most cost effective solution. Scale is critical; aggregating biogas generated from the manure of 15,000 to 35,000 cows from co-digestion of 300 to 500 tons per day of mixed green waste and food waste, or the biogas generation from WWTP digesters converting around 100 million gallons, appears necessary to reach economically viable quantities warranting investment in regional upgrading facilities.

The Investment Tax Credit (ITC) provides up to a 30% cost incentive credit for distributed generation (on-site power), yet this is not available for utility-scale renewable biogas to electricity generation. Unevenly allocated support worsens the problem environmentally by favoring usually dirtier on-site generation over cleaner central-plant generation. Regional raw biogas collection pipeline and biogas-conditioning and upgrading (BCU) service hub infrastructure needs to be cost-shared across the public, not simply on the Utility rate-payer.

Biogas cleanup and upgrading projects are just now getting underway; among the more advanced are San Diego County's Point Loma WWTP biogas to pipeline project and the Southern California Gas Company's partnership with the City of Escondido to develop the WWTP BCU demonstration plant. The latter project now has over 150 run-time hours, showing methane concentration to a very acceptable 98.3% after creating 71 million cubic feet of renewable natural gas and capturing 4,000 metric tons of carbon dioxide. The Escondido BCU capital cost is coming out less than $3 million per skid; the expense comes in operations and maintenance, with compressors proving the most problematic.

New Technologies

Greg Kester, California Association of Sanitation Districts, moderated a spot-check on the technologies available for emissions conversion and control, digestion enhancement, and ultra-clean power generation. What approaches are successful, cost effective, advancing in commercial development? What permitting challenges are most difficult to meet? How can public and private sectors work together to get projects financed, permitted and operational?

The Fresno / Clovis WWTP to Energy project provided the "baseline"; emissions compliance over the years has been met by aggressive "adaptive management", shifting plans and systems to meet changing demands. Gas conditioning became necessary, with moisture reduction using compression/refrigeration, SulfaTreat, CO2 removal to increase BTU level, and ammonia injection in advance of selective catalytic reduction (SCR). The new complement should be fully on-line this November.

FlexEnergy, a California-based 100-person firm with over a decade of research, is commercializing 250 kilowatt modular systems capable of ultra-clean conversion of very low heat rate (100 to 150 btu/cuft content) biogas to electricity. The approach uses thermal oxidation to drive a turbine; biogas is cleaned up within the process and further contaminant removal is not necessary. Temperature control is the key, operating below nitrogen oxides (NOX formation temperatures yet above what is necessary for volatile organic compound (VOC) destruction. The firm has one system operating at Lamb Canyon Landfill in LA and another installation underway for the Army in Georgia. An order is being negotiated for a third system by Humboldt County for conversion of their landfill gas to energy.

Industrial-scale capture of emissions using an Automated Photosynthetic Algae Reactor (APAR) was presented by Advanced Algae company president, Dale Hinkens. The commercially viable industrial scale photo-bioreactor platform is gravity fed with 4,600 ft of travel from lift of 20 ft vertical. Depending on the system's purpose, the company uses various algal strains optimized for up to 40% oil production or up to 56% protein production. A system is currently being installed at John Fiscolini's dairy in Modesto, supported by both CEC and SJVAPCD funds. Banks of APARs are being designed for a Port of Los Angeles project in a closed-loop design where industrial emissions become nutrients for the algae. The pro forma indicates an 8 year pay-back, making emissions control a new profit center.

JSH International relies on University research for detailed testing and third party validation of the natural microbial nutrient amendment blends the company produces. Of the three brands optimized to various markets, the company's presentation focused on Prodex material for boosting wastewater digester microbial populations and increasing biogas generation. Using a patented stabilization and extraction process, JSH coverts select peat as a raw material to produce a "super energy drink" for existing microbial populations. The results indicate more resilient microbial populations that more aggressively degrade organics and produce greater volumes of biogas from the same amount of feedstock. VOCs are more thoroughly degraded and the residual slurry is significantly depolymerized allowing better dewatering. Small amounts of the amendment bring large results: an 885,000 digester required only 4 gallons of their product to experience a 77% increase in biogas.

Feed-in Tariff Issues and Barriers to Interconnection

Moderator Allen Dusault of San Francisco based Sustainable Conservation explained that digesters (and other forms of biogas producers) operate at facilities that must remain connected to the regional electric grid to ensure that the facility can be continually running. Interconnection requires important safety and reliability issues, but the process has always been and continues to be both complex and expensive. Older pricing models and interconnection assessment mechanisms can't keep up with the new flood of small-scale DG applications that has come into the Utilities and the PUC within the last two years.

The Clean Coalition is working to fully implement a Feed-in Tariff (FIT) suitable for renewable energy price support, focusing on mid-scale, <20 megawatt electric (MWe), wholesale distributed generation for facilities that need to remain connected to the grid. FIT mechanisms are in place in many areas globally; SB 32 and SB 2 are now moving forward to modify California's FIT program, fixing problems in the earlier AB 1969 version, raising the cap to 3 MWe with new pricing models and a technology-neutral position. A workshop is scheduled for Monday, September 26, 2011 at the PUC on SB 32, which is being "fast-tracked" for certification by the end of the year. FIT per AB1969 was based on the current natural gas price; many contend the price competition should be solely among Renewables, not based on the avoided cost of a natural gas combined cycle generator. SB 32 allows inclusion for the first time of "externalities" in pricing; now the "Value of Product" must be considered, including Baseload potential. At least California is ASKING the question of consideration of externalities in the way electricity is priced; the issue needs to be taken to the Federal Energy Regulatory Commission (FERC) to set national standards that include environmental conditions.

As an alternative to the FIT, the PUC authorized Renewable Auction Mechanisms in 2010 with the first action to take place about a month from now. There is also a fast track mechanism for projects under 2 MWe or 5 MWe, depending on the Utility, and orders to release distribution-level grid maps will help prospective project developers decide on siting options and insertion potential. A new PUC Order Instituting Rulemaking (OIR) has been initiated, should the current discussions not reach consensus. SB 489 would allow multi-technologic DG net-metered interconnection - solar plus biomass, for example – something that rather absurdly is prohibited right now.

Other regulatory actions are in the works; a separate process to streamline interconnection and contracting is in progress for CHP projects under 500 KWe, and a Net Metering bill SB 489 has reached the Governor's desk, offering methodology for determining the amount a Utility should pay for energy above the on-site load, sold back from small generators such as from roof-top solar. Local Government General Offset bill AB 2466 (2008) allows local governments to exchange energy.

Bonus! Bonus! Compost (speaker) for Lunch …

Dr. Peter Green, Associate Research Engineer in the Civil and Environmental Engineering Department at University of California, Davis, presented results of his team's year-long, state and federally sponsored research into VOCs from Compost. For some time, the potential release of VOCs from active composting has posed a barrier simply by being an unknown but highly likely emissions source. Dr. Green's paper, published this week by the Water Environment Research Foundation (WERF) characterizes and quantifies the VOCs, and compares their release in context of other sources on and off site. The paper: "Characterization of Volatile Organic Compounds (VOCs) Emitted from Biosolids Composting" presents results to date of ongoing research into the many different forms of VOC generation in agriculture from pesticides and composting. Bottom line: reactivity of VOCs from composting is surprisingly low, compared to other urban anthropogenic sources in the surrounding community. Being further north in California helps some: UV radiation is attenuated in northern latitudes. To assess and control, we need to consider the Maximum Incremental Reactivity (MIR) of specific VOCs; mitigating on an even basis is misleading because some VOCs are many times more reactive than others. VOCs from engines are far more reactive and abundant than microbial fermentation sourced VOCs by a ratio of 3:1. Compost VOCs are characterized by predominantly low reactivity compounds. The highest quantities of high MIR non-engine agricultural VOCs actually were found to be emitted from a commonly used fermented silage animal feed, prompting a regulatory shift from compost VOC focus to rules for managing fermented animal feed. But the main Conclusion: it's the diesel engines, not the compost.

Cal-Denier Dairy Digester Tour

Located at 10715 Arno Road in Galt south of Sacramento, the Cal-Denier Dairy is home to a covered lagoon manure digester that has been collecting feedstock from around a thousand cows and generating over 30,000 cubic feet per day of biogas since 2008. The dairy's digester is the first in Sacramento County to have been interconnected to Sacramento Municipal Utility District (SMUD), whose Dairy Digester Incentive Program provided about 13% of the development cost to match a 25% USDA Rural Development Grant. The entire system capital cost was about $700,000.

Cal-Denier's dairy flushes about 120 pounds of manure and urine per cow per day into an ambient temperature covered lagoon where anaerobic bacteria digest the volatile solids and generate bio-methane. Biogas fuels I Power Energy Systems internal combustion engines for a generation capacity of 65 kilowatts; RCM Digesters designed the lagoon system. The primary lagoon is about 400 ft by 160 ft and is 24 ft deep, lined with high density polyethylene (HDPE) plastic. A secondary lagoon stores stabilized effluent prior to use for irrigating and fertilizing crops.

California Polytechnic State University (Cal Poly) graduate and owner Richard Denier and his partner Fred Denier have been in the business more than 30 years, and manage the relatively small dairy digester with few employees.

Take-Home Conclusions

·   Dairy Digesters are gaining traction in California, but face daunting challenges of stiff permitting, high costs and difficult Utility power contract negotiations;

·   Wastewater treatment plants have a leg-up, with established sites and deep knowledge base, but are perpetually under-funded and over-worked;

·   Co-digestion of biosolids and manures with high-nutrient food waste is best for efficient biogas production;

·   Governor Brown "Gets It." He's put some Bioresource-friendly leaders in place, has given walking orders to all agencies to kick-start the Bioenergy Action Plan (again) and is working to shift gears toward better distributed bioresources utilization.

Update:Symposium Presentations Now Online

The EPA has now posted the Symposium Agenda and the available slide presentations from both days. First day’s morning panel presentations addressed “Pricing - The Bottom Line?” co-moderated by San Joaquin Air Pollution Control District’s Dave Warner and Allen Dusault from Sustainable Conservation: Paul Martin, Western United Dairymen: Permitting Digesters and Co-digesters in California (PDF, Ted Ko, Associate Executive Director, Clean Coalition: CLEAN efforts in California - Clean Local Energy Accessible Now (CLEAN) (PDF), Jaclyn Marks, California Public Utilities Commission: California’s Renewables Portfolio Standard: Overview of RPS Distributed Generation Programs (PDF), and Jody S. London, Jody London Consulting: Opportunities for Biogas Digesters (PDF). One of the more enlightening presentations came at lunch on the first day: Peter G. Green, Univ. Calif. Davis presented Impacts of Volatile Organic Compounds from Compost on Ozone Formation (PDF). Kathleen Ave of Sacramento Municipal Utility District and Kerry Drake of EPA Region 9 moderated the first day’s afternoon session, “Stationary and Mobile Sources” from which we have Kevin Hardy, Encina Joint Powers Authority: The Encina Wastewater Authority's Biosolids Management Program (PDF), Paul Rydzynski, URS Corp: Transportation Study (PDF), and Frank Caponi, Sanitation Districts of LA County: Managing Biosolids MSW Through Long-Haul Transportation to Distant Facilities (PDF). Karl Longley of the California Water Institute led the second day’s “Utilities’ Viewpoints” morning session from which we find no presentation offerings. The afternoon’s “New Technologies” session, led by Greg Kester of the California Association of Sanitation Districts, fared better: Dale Hinkens, Advanced Algae: New Technologies (PDF), Kevin Mulvihill & Tom Kavookjian, JSHI: Energy Innovation (PDF), and Steve Hogg, City of Fresno: Emission Control Technology (PDF). 11/03/2011