Models of syngas concentrations five minutes after a leak with the original (top) and final (bottom) ventilation designs. The pink areas are the zones where the concentration is immediately dangerous due to CO toxicity.
Last summer, the RePower team began evaluating the proposed ventilation system for the Blue Lake Rancheria (BLR) biomass energy facility. Each phase of the BLR gasification process involves a dangerous gas. First, biomass is processed into a syngas rich in hydrogen and carbon monoxide. This syngas is then processed into pure hydrogen and a waste gas rich in carbon monoxide. In normal operation, the syngas and hydrogen are fully contained, and the waste gas is safely burned in a flare. However, an accidental leak in the system could pose an immediate toxic or explosive danger. The ventilation system must give personnel enough time to safely exit, and must clear hazardous gases from the building after the gasifier system shuts down.
To test different system designs, the RePower team used a software package from the National Institute of Standards and Technology to model contaminant flow in 3-D. We simulated various leak scenarios and examined how the placement of exhaust fans and intake vents affected the removal of toxic and flammable gases. We were able to improve on the original system design and create a more responsive, and robust system. The final design uses a combination of ceiling fans, wall fans, and floor vents to provide optimum ventilation. Following installation, the ventilation system will undergo a smoke test to validate the model results. Completion of this work will ensure a safe operating environment for the biomass facility.
The design and procurement phases of the BLR Biomass to Energy Project are in full swing and the project team is involved in a flurry of activity. A group of engineers from SERC, as well as staff from Serraga Energy, LLC at the Blue Lake Rancheria (BLR) project site, are meeting weekly to discuss design decisions and move the effort forward. Frequent interactions are also taking place with our technology partners: Proton Power (gasifier), Xebec Adsorption (PSA gas cleanup unit), and Ballard Power Systems (fuel cell). Below is a list of key activities currently underway:
- site layout is largely completed
- fire marshal review – first phase is complete
- site work has begun and will ramp up significantly over the next few weeks
- gasifier is being fabricated – witness testing will occur in late July with delivery in August
- PSA design and fabrication are underway – delivery is expected in late August
- syngas compressor requirements have been specified and quotes have been obtained – orders will be placed in the next couple of weeks
- fuel cell is on site – installation is slated for July or August
- central control and monitoring system – design is underway
- ventilation system – design analysis is underway
- fuel storage and processing – design is underway
- electrical service (auxiliary power supply and fuel cell generator/utility interconnection) – electrical engineer and contractor team are working on design, procurement, and the utility interconnect application with Pacific Gas & Electric
Neil Harris (far right) with electrical and construction experts implementing site design at Blue Lake Rancheria. Photo credit Serraga Energy, LLC.
The next phases of the project will include component installation (summer and early fall 2014), system integration and commissioning (fall 2014), and system operation, data collection, analysis and reporting (late fall and winter 2014/15). Stay tuned for additional updates in upcoming newsletters.
Dana Boudreau of RCEA displays air flow measuring equipment that will be used in the heat pump study.
Numerous SERC staff are busy working on the RePower Humboldt with Community Scale Renewable Energy project. Most of our recent efforts have been focused on the design of the biomass gasification to fuel cell project at the Blue Lake Rancheria. We also met recently with Redwood Coast Energy Authority staff at the Blue Lake Elementary School to scope out the installation and testing of a mini-split heat pump system. The RePower Humboldt Strategic Plan indicated that use of heat pumps could be a cost effective way to utilize local renewable energy resources to meet heating demands while reducing greenhouse gas emissions. However, heat pump performance can vary significantly in different climates, so the strategic plan recommended conducting a heat pump pilot study to examine performance characteristics in the Humboldt climate. Blue Lake Elementary will receive one or two heat pump systems to be installed in individual classrooms. These systems will be equipped with monitoring instruments. At the same time, we will measure the energy consumption and performance of the small natural gas furnaces that currently provide heat to these classrooms. This will allow us to evaluate the energy efficiency, cost-effectiveness, and greenhouse gas impacts associated with the heat pump systems compared to conventional heating systems. This information can then be used to inform decisions about the potential future installation of heat pump systems throughout the county.
Biomass energy is an important resource in Humboldt County and other heavily forested regions. Woody biomass residues include waste materials generated during timber harvest operations. Often referred to as slash piles, these materials are typically piled and burned in the forest. Small trees, limbs and brush cleared in fire hazard reduction efforts are another source of biomass that are often piled and burned. Under the right set of circumstances, these materials can be processed, transported and used as a renewable fuel source, providing environmental and economic benefits.
The Woody Biomass Utilization Group at the University of California, Berkeley has been working for many years to further the use of biomass energy. To accomplish this, they have hosted regional workshops throughout the state since 2006. This past fall they held a series of regional workshops with a focus on “community scale wood bioenergy.” SERC co-hosted one of these workshops at the Humboldt Bay Aquatic Center in Eureka.
The biomass workshop featured presentations and site tours, including the Community Scale Biomass Power System at Blue Lake Rancheria.
November 7th was a beautiful day on the Eureka waterfront, and we had an enthusiastic turnout of more than 60 attendees, as well as a full slate of dynamic speakers. One key topic at the workshop was an update on California Senate Bill 1122. This bill, enacted in September of 2012, directs investor-owned utilities in California to purchase 50 MW of biomass power from community-scale, distributed energy systems of less than or equal to 3 MW. The woody biomass fuel must be sourced from by-products of sustainable forest management, such as materials generated during fire threat reduction activities. This bill will create new opportunities for the development of distributed biomass energy systems.
Other topics covered during the workshop included siting and permitting, project financing, feedstock and technology, and regionally specific topics such as local case studies and projects. Presentations on local projects in which SERC is significantly involved included the RePower Humboldt planning project, which identified biomass energy as an important local renewable energy resource; the Blue Lake Rancheria biomass gasification project, where SERC is leading the design and installation of a local distributed biomass energy system; and the HSU Biomass Research and Development Initiative project, which is soon to get underway.