Late last spring, the BRDI team began acquiring testing apparatus and field equipment needed for torrefaction, drying, and briquetting of biomass at a test site located on Green Diamond property at Big Lagoon. The area, a demolished mill site, consisted of dilapidated cement, old iron railings, and overgrown shrubs. Drawings had already been prepared for electrical lines, equipment placement, and emergency evacuation locations for the test site, so site set up proceeded quickly.
From right to left: the torrefier trailer, the biomass drying unit, and the homemade chip screener used to sift feedstocks to acceptable chip sizes.
The torrifier was a pilot unit custom-built by Norris Thermal Technologies (NTT) and hauled on a trailer over 2000 miles from Indiana. This was the largest piece of equipment on site and was the main focus for our summer testing of feedstocks at various temperatures and dwell times. NTT also provided a drying unit, which was purchased by BRDI for future biochar field-testing. This is the same type of drying unit used in many industries, including food and agriculture. BRDI’s application of the dryer was unique in that it used waste heat from the torrifier to dry the feedstocks to varying degrees of moisture content. The team found that moisture content in the woodchips, hard to control due to the combination of summer rains, early fog, and blazing mid day heat, had a significant impact on torrefaction. Moisture content in samples also affected the briquetting of the woodchips. Dry feedstocks of small particle sizes were observed to form dense briquettes of uniform size. Briquettes made of larger wet chips tended to crumble easily, and if the moisture content was high, the bricks expanded and deformed. In addition, because water is incompressible, too much moisture could damage the process mold and hydraulic pistons used to densify the woodchips into briquettes.
The summer testing team from left to right: Yaad Rana, Andy Eggink, David Carter, Greg Pfotenhauer, Kyle Palmer, Anna Partridge, and Marc Marshall.
Overall, testing was successful and the BRDI team has a plethora of samples to analyze in the lab. An exciting year is expected, as analysis is performed in preparation for continued testing using full-scale equipment next summer.
SERC is the home of the new North State Regional Office of the Northern California Center for Alternative Transportation Fuels and Advanced Vehicles (NorthCAT). The formation of NorthCAT was made possible by a grant from the California Energy Commission. The UC Berkeley Institute of Transportation Studies is the project lead and, along with SERC, has joined with numerous other project partners to offer education, training, demonstration, and project deployment services to the Northern California region, which stretches from the San Francisco Bay Area north to the Oregon Border. One of SERC’s key roles is to serve the rural North State region.
SERC has just completed an office space expansion to house the NorthCAT office. A space designed as a hydrogen generation and storage room but used for general storage has been converted into a five-person workspace. All that remains is to add a sign on the door reading “NorthCAT North State Regional Office.” This new space will help us provide alternative fuel vehicle services to the region, and in conjunction with our larger facility, including our hydrogen fueling station, will allow us to host trainings, workshops, and demonstrations. We also have plans to add an electric vehicle charging station in our driveway, with interpretive signage to be funded by the CEC grant.
In other NorthCAT news, SERC has participated in the development of a NorthCAT Center Development Plan and SERC staff will attend a NorthCAT strategic planning meeting at UC Berkeley in August. Plans are also in the works to hold NorthCAT stakeholder outreach meetings in the North State region later this year to solicit input and spread the word about the new Center. Finally, a NorthCAT web page is under development and should go live by the end of this month.
As the number of plug-in electric vehicles (PEVs) in Humboldt County grows, publically available charging stations are crucial to continued PEV adoption success. According to the International Council on Clean Transportation, one out of every five new light-duty vehicles in the Eureka area is a PEV – the third highest percentage of all metropolitan areas in the United States.
One of the many benefits PEV drivers enjoy is that the majority of charging occurs overnight at home; however, there is still a need for PEV charging in public locations. Currently, there are eight active Level 2 PEV chargers available to the public in Humboldt County. SERC has partnered with the Redwood Coast Energy Authority (RCEA) to design and oversee the installation of an additional ten dual Level 2 charging stations in Humboldt County, each of which will be capable of charging two PEVs simultaneously. The work is funded by the California Energy Commission’s Alternative and Renewable Fuel and Vehicle Technology (ARFVT) Program and is part of a regional effort to install PEV charging stations in the North Coast (Humboldt, Trinity, and Del Norte counties) and Upstate (Shasta, Siskiyou, Tehama, Colusa, and Glenn counties) regions.
Ten dual charging stations, such as the one pictured above, are slated for installation on the North Coast. Photo credit www.evsellc.com.
The ten dual charging stations are slated for deployment this summer in nine locations: Greenway building in Arcata, North Coast Unified Air Quality Management District building in Eureka, St. Joseph Hospital in Eureka, McKinleyville Safeway shopping center, Trinidad library, China Flat Museum in Willow Creek, Rio Dell City Hall, Fortuna City Hall, and 4th St. parking lot in Ferndale. The charging stations are sited in convenient locations for PEV drivers to charge their vehicles while completing daily tasks such as attending work, shopping, or visiting museums and libraries.
Since over half of Humboldt County’s energy-related greenhouse gas emissions come from transportation, successful PEV adoption is a positive step toward a low-carbon, sustainable transportation future for the north state region. SERC plans to continue working with RCEA and our Upstate partners to support the goal of adding more PEV charging station infrastructure throughout the North State region.
The 175 kW biomass-fired fuel cell power system being installed at the Blue Lake Rancheria is nearly complete. The Proton Power gasifier has been installed and gone through initial start-up procedures, including heating up the gasifier to temperature and running the flare. The gas compression system (rotary claw compressor, syngas ballast tank, and reciprocating compressor) has been tested and the control strategy has been confirmed. The Xebec pressure swing adsorption (PSA) hydrogen purifier is installed and ready for testing, and the Ballard PEM fuel cell is in place and has undergone pre-commissioning. Most of the peripheral systems (biomass feed, control, fire alarm and life safety, cooling, and ventilation) are complete or very near completion. Our next steps will be to obtain a fuel with a moisture content no greater than 40% (wet basis); begin making syngas; test and confirm syngas quality; and then fully commission the PSA and fuel cell system, as well as the fully integrated system. We submitted a draft final report to the CEC in March, but work on the system will continue over the next few months until we achieve full system operation and performance testing. Following these activities a revised final report will be submitted.
The Proton Power biomass gasifier installed at the Blue Lake Rancheria.
SERC continues work on the BRDI Waste to Wisdom project, a three-year, multidisciplinary project to study pathways to convert forest residuals – or slash piles – into valuable energy and agricultural products at processing sites near timber harvest locations. Many of the potential processing sites do not have access to electricity, so SERC has been analyzing various methods to power this industrial equipment in remote locations. With help from the Environmental Resources Engineering capstone design course, SERC completed a technical and economic feasibility analysis comparing various remote power generation technologies, including waste heat recovery, biomass gasification, solar photovoltaic, and others. The results from this paper study indicate that a biomass gasifier is likely to outperform the other technologies in terms of mobility, cost, reliability, and environmental impact. After presenting these finding to the U.S. Department of Energy, the funding agency for this project, we procured a mobile, 20 kW biomass gasifier (similar to the one in the photo above) from All Power Labs in Berkeley, CA. Once it arrives, we will begin a series of tests to evaluate whether its performance will meet the requirements to operate in the demanding conditions of a forest-landing site.
With the gasifier being fabricated and a torrefier and a briquetter being prepared for shipment, it’s shaping up to be an exciting and eventful spring and summer of biomass fieldwork. SERC will lead the effort to test the torrefier, briquetter, and gasifier generator set at a forest-landing site in Big Lagoon, CA. We will measure the performance characteristics of each machine with a variety of biomass feedstocks recovered from timber harvest operations here in northern California. In addition to testing these machines individually, their synergy in an integrated system will be evaluated by connecting them together. For example, we will conduct experiments to densify torrefied biomass and to evaluate whether the gasifier generator set can reliably provide electricity to the other machines. Having these three commercial-scale technologies at a single site provides a unique testing and demonstration experience.
To prepare for this fieldwork, we have been busy developing the testing matrices, procuring feedstocks, detailing our instrumentation plans, preparing our data analysis tools, and coordinating associated logistical issues. The entire BRDI team is looking forward to a productive season of data collection and analysis that will help address the key issues posing a barrier to recovery and utilization of forest residual waste.
Last year, in partnership with the Redwood Coast Energy Authority (RCEA) and other key regional partners, SERC embarked on a two-year Alternative Fuels Readiness Planning (AFRP) project funded by the California Energy Commission (CEC). This project seeks to assess the potential for development of alternative transportation fuels such as electricity, hydrogen, and some biofuels in the North Coast region of California.
The goal of the SERC-led analytical work is to explore pathways for the North Coast region to achieve the 10% reduction in average fuel carbon intensity by 2020 mandated under California’s Low Carbon Fuel Standard (LCFS). To this end, we have recently finished developing a simulation model, drawing on price data for fuels, vehicles, and distribution infrastructure, as well as analysis of regional transportation trends and fuel life cycle greenhouse gas (GHG) emissions. The model allows us to simulate the economic efficiency of GHG reduction via each fuel pathway individually as well as for a suite of technologies deployed to meet the LCFS target. It offers a nuanced understanding of the systems in question, enabling us to evaluate the impact of changing fuel and vehicle prices, electric grid carbon intensities, and other factors on the cost of GHG abatement through alternative fuel deployment.
Outputs of this analysis are being used by RCEA as it engages with both public and private sector transportation energy stakeholders across the region. This collaboration will lead to the development of a strategic plan for deploying a more sustainable transportation system in the North Coast of California.
Marginal Abatement Cost (MAC) for each of the fuel pathways considered. Presented here is aggregate marginal cost above a conventional fuel/vehicle baseline. These costs include fuel cost as well as any incremental vehicle or distribution infrastructure cost required for a given fuel type.
As reported previously, SERC is leading the biomass conversion technology demonstration portion of the Waste to Wisdom project. Waste to Wisdom is examining the entire biomass supply chain, from collection, transportation, and pre-treatment of the material in the woods, to the conversion of the material into energy and other marketable products. Our role is to oversee the testing and evaluation of three biomass conversion technologies: a biochar unit, a briquetter, and a torrefier.
We are pleased to announce that the Norris Thermal Technologies (NTT) of Tippecanoe, Indiana is joining the project as the torrefaction research and development partner. SERC conducted a competitive selection process involving 10 firms currently operating in the biomass torrefaction space. NTT’s proposal stood out due to the readiness of their team’s technology and their ability to field mobile torrefaction systems at two different scales within the project’s budget and schedule constraints.
NTT will provide a pilot-scale torrefaction unit (see photo at right) for field-testing during the summer of 2015. This unit, which was recently operated alongside two other biomass conversion units in a demonstration sponsored by the Washington Department of Natural Resources, is trailer mounted and will be modified and then delivered to a forest operations site of our choosing near Arcata, CA.
After completion of pilot testing, NTT’s team will build a larger torrefaction reactor of the same design and retrofit it into a shipping container. NTT will then ship this containerized unit to Arcata for testing at a forest operations site and provide an operator for testing. Testing of the larger unit is currently scheduled for the summer of 2016. We are looking forward to continuing our biomass conversion research efforts with such a strong industry partner and we are confident that the torrefaction research objectives of the Waste to Wisdom project will be met through collaboration with NTT.
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.
Contractors installs one of the two heat pump units at Blue Lake Elementary school.
In our last update we mentioned that SERC is working with the Redwood Coast Energy Authority to install and test heat pump systems at Blue Lake Elementary School. We hope to determine how well such systems work in our local climate and whether or not they can save money as well as reduce greenhouse gas emissions compared to conventional systems.
Completed installation of the outdoor unit on top of the covered walkway in front of the classroom.
In July, the project moved out of the planning phase and into hands-on implementation when HVAC contractor Crystal Air of Weaverville installed two Daikin mini-split units at the school. These systems consist of an outdoor compressor unit connected via insulated refrigerant lines to an indoor, wall mounted head (or air handler) which distributes the conditioned air throughout the classroom.
Data loggers with a USB cable for downloading the data to a laptop.
SERC installed a battery of monitoring sensors and data loggers on each of the heat pumps, as well as on the existing natural gas furnaces in two other classrooms. The information collected by the test equipment is being used to determine the amount of heat energy delivered to each of the classrooms as well as the total energy consumed by each of the systems in the process. In the case of the heat pumps, this consists entirely of electricity, while the gas furnaces (as the name implies) rely mostly on natural gas, but also require a moderate amount of electricity for the fan and other electrical components.
Following a shakedown period in which various problems were discovered and rectified, the system is now reliably collecting data around the clock. Preliminary results show that the heat pump systems are consuming less electricity than the conventional furnaces. However, the weather has been so mild up until recently that none of the systems have been used extensively. In addition, the colder it is outside, the more difficult it is for heat pumps to absorb enough energy from the outdoors to heat a room. The true test will come when outdoor temperatures are much lower and heat demand is correspondingly higher.
Biochar unit with instrumentation installed for testing.
In late July, Marc Marshall, Mark Severy, and I traveled to Pueblo, Colorado to conduct testing on a biochar production machine manufactured by Biochar Solutions Incorporated (BSI). The purpose of our three-week trip was to collect experimental data for use in evaluating stand-alone operation (i.e. without an external source of energy to power the process) of the biochar unit as part of the BRDI project.
Infrared image of biochar unit flare during operation.
Biomass conversion technologies (BCTs), such as the BSI biochar machine, can create higher market-value products in near-woods environments, justifying the transport of these products to market. This in turn could allow fuels reduction and forestry residual management projects to be implemented in greater numbers thereby reducing greenhouse gas emissions and the risk of catastrophic wildfires. One of the goals of the BRDI project is to explore whether stand-alone operation of BCTs improves the economic and environmental benefits of removing slash and other woody residues from the forest.
We spent the first week in Pueblo installing instrumentation on the machine and setting up the data acquisition system. During the second and third weeks, we conducted experiments producing biochar with various biomass feedstocks.The variations in feedstock included tree species, particle size, anatomical distribution, percent contamination, and moisture content. Additional experiments led to design changes in the feedstock drying system and the air injection system for the flare.
The machine generates significant heat while operating (see photo at right). Some of this thermal energy is used for drying feedstock and some is used to preheat fresh air that is injected into the flare for complete combustion. Beyond the heat used for those purposes, there is a significant amount of high quality thermal energy that could potentially be used to generate electricity to power the machine at a forest landing site. Over the coming months, we will analyze the data and evaluate technologies that could be paired with the biochar machine to generate process electricity for stand-alone operations in near-woods environments.