BRDI Waste to Wisdom: Results from Preliminary Biomass Briquetting

The Biomass Research and Development Initiative (BRDI) Waste to Wisdom project is studying various pathways to increase the value of forest residuals and decrease transportation costs to bring this underutilized resource into the renewable energy market. Densifying waste biomass into briquettes during forest operations may achieve both of these goals by converting it into a valuable heating fuel that is easily transported due to its high density and low moisture content.

SERC Project Manager Dave Carter operates the briquetter.

SERC Project Manager Dave Carter operates the briquetter.

Last April, SERC engineers, alongside partners from Pellet Fuels Institute and RUF Briquetting Systems, operated a commercial briquetter with a variety of feedstocks at Bear Mountain Forest Products’ manufacturing plant in Cascade Locks, Oregon. Electricity consumption and biomass throughput data were collected in the field, while a pallet containing feedstock and briquette samples was shipped to SERC for material analysis. Back at SERC’s lab, the samples were sent through a suite of tests to assess the quality of each briquette and determine which feedstock properties influence the end product’s characteristics, such as density, durability, grindability, and moisture absorption.

Briquettes produced from chipped biomass exit the briquetting machine.

Briquettes produced from chipped biomass exit the briquetting machine.

Results show that this briquetting system increases the volumetric energy density of chipped biomass by nearly 250%, producing briquettes with an average packing density of 720 kg/m3. Feedstocks with moisture content exceeding 15% produce lower density briquettes, which expand in height after exiting the briquette press. High moisture content, however, does not significantly impact briquette durability. Instead, the feedstock’s particle size distribution has the greatest effect on briquette durability. Feedstocks comprising mainly large particles, especially chipped biomass, do not bind together as well as fine or ground particles. To improve durability, chipped biomass can be combined with sawdust, which increases briquette durability two-fold and results in briquettes with a binding strength similar to those produced from pure sawdust.

These results help frame and guide our future work with biomass densification. In the next stages of this project, the multidisciplinary BRDI research team will investigate whether the upstream energy investments in drying and particle size reduction are worth the payback when bringing briquettes to the heating market.

RePower Humboldt: Biomass-Fired Fuel Cell Power System

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.

The Proton Power biomass gasifier installed at the Blue Lake Rancheria.

BRDI Waste to Wisdom: Remote Power Generation and Summer Testing

BRDI-2-webSERC 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.

BRDI Waste to Wisdom: Torrefaction Partner Selected

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's pilot torrefaction unit.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.

RePower Humboldt: BLR Biomass Facility Ventilation System Design Complete

Model of syngas concentration 5 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.

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 personnVentilation_Image_2el 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.

BRDI Waste to Wisdom

biochar machine2

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.

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.

Forest Biomass Energy: Looking for the Big Picture

This spring SERC embarked on a major forest biomass energy research project in partnership with Humboldt State University’s forestry department and researchers, entrepreneurs, and natural resource management agencies from a number of western and midwestern states. The “Waste to Wisdom” project will examine the entire supply chain of biomass, including collection, transportation, and pre-treatment of the material in the woods, as well as conversion of the material into energy and other marketable products using a variety of emerging technologies. Experts in economics, life cycle analysis, and environmental impacts will assess and compare the different biomass pathways.

BRDI-group

Mike Alcorn, chief forester for Green Diamond Resource Company, shows the BRDI research team a site where material is collected for use at Humboldt County’s biomass power plants.

The project officially launched with a kick-off meeting at HSU on May 13 and 14. The project’s thirteen principal investigators as well as several other stakeholders gathered to meet one another and discuss how to coordinate the many components of this complex effort. The meeting included a trip to a nearby timber harvest site on Green Diamond Resource Company land where state-of-the-art technology and logistics are being used to gather, chip, and haul slash for use in Humboldt County’s biomass power plants.

BRDI PIs

SERC director Arne Jacobson, U.S. Forest Service economist Ted Bilek, and HSU forestry professor Han-Sup Han will lead BRDI’s three research teams.

SERC’s role in the project is to oversee the testing and evaluation of three different types of biomass conversion technologies (BCTs): a biochar unit, a torrefier, and a briquetter. Biochar is solid, carbon-rich biomass that has been treated at high temperature, above 500°C, and is used principally as a soil amendment. Torrefaction takes place at a lower temperature, near 300°C, producing a solid fuel that can be directly substituted for coal in existing power plants. Briquettes are made near ambient temperature by compressing finely ground biomass and can be used in place of cordwood in biomass-fired heating and power generation systems. An important goal of Waste to Wisdom is to adapt each of these BCTs for mobile, stand-alone use at remote sites where utility service is not available. Decentralized deployment of these BCTs could be an economically viable alternative to the costly collection and transportation of raw biomass from far-flung timber harvest and wildland fuel reduction sites.

The $7.45 million, three-year project is sponsored by the U.S. Department of Energy through the Biomass Research and Development Initiative (BRDI) program, jointly supported by the U.S. Department of Agriculture. Each of the collaborating partners is making a cost share contribution to the project’s total budget. SERC’s share of the federal funding is $900,000, to which the lab is adding $185,000 worth of labor, equipment, and facility use.

SERC director Arne Jacobson will act as principal investigator for the BCT evaluation component of Waste to Wisdom. “We are excited to be involved in this project. We have a great set of partners, and we look forward to a successful effort.”

RePower Humboldt Update

Dana Boudreau of RCEA displays air flow measuring equipment that will be used in the heat pump study.

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.

Stand-Alone Torrefaction Update

As we reported previously, SERC is collaborating with Renewable Fuel Technologies (RFT) to assess performance of RFT’s biomass torrefier. The torrefier converts wood waste from logging or forest thinning, roasting it to make a renewable energy product that can replace coal in power plants. The testing is funded by a grant from the California Energy Commission. The goal of the assessment is to determine whether waste heat from the torrefier can be used to make the device self-powered for off-grid use at timber harvest sites. Such use could make recovery of waste material at these sites more cost-effective.

This past fall, SERC engineers made multiple trips to RFT’s abrication and testing facility in Hayward, CA. We first procured about three tons of tanoak wood chips in Humboldt County and delivered them to RFT. Tanoak is of special interest because it is abundant in northwest California but considered of low value as a timber species.

TorrSolids-adj

An array of torrefied wood chips shows the effects of varying temperature and processing time. The raw biomass is shown in the column on the right.

We next performed a series of test runs with RFT engineers, in which we varied the moisture content of the feedstock, operating temperature, and residence time of the material in the roaster. We collected operating data such as temperatures, material flow rates, and electric power use during each run. In addition, we collected samples of the raw wood chips used for each run as well as the solid, liquid, and gas outputs from the process for later laboratory analysis. All of these data allowed us to perform a rigorous energy and mass balance for the process, key to determining the feasibility of stand-alone operation.

Our tentative conclusion is that such operation may be feasible, though the design may need further modification to reduce heat loss to the surroundings. We are now working to prepare our final report to the Energy Commission.

A Message from the Director

AJ headshot 3Happy New Year! I hope that 2014 is off to a good start for you all. The year promises to be a busy and productive one for the team at SERC. We have an exciting lineup of clean energy projects and activities across a number of subject areas.

In the energy access arena, we are in the final stage of negotiating a three-year, $1.6 million contract with the International Finance Corporation to continue our work as the technical lead for quality assurance for the Lighting Global initiative. Lighting Global is associated with the Lighting Africa and Lighting Asia programs, which support the development of markets for modern off-grid lighting and energy products. Under our contract, we will continue to manage the program’s quality assurance testing and verification program for off-grid lighting products. We will also lead a strategic effort to update and expand the program, conduct laboratory and field research related to the effort, and engage with key industry stakeholders. Our work to date for IFC has helped support rapid expansion of the use of solar charged off-grid lighting and energy systems. For example, over 2.7 million off-grid LED lights that were quality assured through the program have been sold in Sub-Saharan Africa since 2009, and sales have been doubling annually. Sales in South Asian countries such as India are also high. We look forward to our continued participation in the effort to expand access to clean and affordable energy for people without access to grid power in the years to come.

We will be similarly busy in the biomass energy arena. First, we are working closely with the Redwood Coast Energy Authority (RCEA) and the Blue Lake Rancheria on a project involving the development of a cutting edge biomass-fueled power system to be installed at the Rancheria. The system involves a gasifier that converts woody biomass fuel into a hydrogen-rich syngas, which is, in turn, processed for use in a proton exchange membrane fuel cell. This year is a pivotal one for the effort, as we aim to make considerable progress toward the goal of having an operational system in 2015. We will also continue work on the conversion of biomass into useful fuels and other valuable products using technologies such as gasification, torrefaction and densification. We are currently finishing up one project in this area, and anticipate starting a significant new project in the coming months (details forthcoming).

We also have several projects in hand on the clean transportation front, including analyses related to electric vehicle infrastructure planning for Humboldt County, several other counties in the northern Central Valley of California, and the city of New Delhi. We learned in December that a $300K alternative transportation planning project (including electric vehicles and other alternative fuels) that we are conducting in partnership with RCEA and other regional partners was funded by the California Energy Commission. Special thanks go to Jim Zoellick, Colin Sheppard and Kevin Fingerman of SERC and Matthew Marshall, Dana Boudreau, and Jerome Carman of RCEA for leading that proposal development effort. We may have even more work in this area soon, as we learn the outcome of additional submitted proposals.

Last, but certainly not least, we will participate in a feasibility analysis for the development of a wave energy technology test site in California in collaboration with Cal Poly San Luis Obispo and a number of additional partners, including local partners RCEA, the Humboldt Bay Harbor District, and HT Harvey and Associates. The analysis, which is a $750K effort funded by U.S. Department of Energy, involves consideration of sites near Humboldt Bay and San Luis Obispo.

I can say with confidence that 2014 will not be a dull one here at SERC. We are holding on to our hats. Goodbye until next time.