BRDI Waste to Wisdom: Summer 2015 Testing

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.

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.

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.

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.

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.


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.


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.”

SERC Speaks Up on State Energy RD&D Funding

California is just now launching the first round of funding opportunities under its new Electric Program Investment Charge (EPIC) program, which will support research, development and demonstration (RD&D) for promising new energy technologies. Meanwhile, the State has already begun planning for the next round of EPIC funding, to become available starting in 2015. The California Energy Commission (CEC) recently released a draft 2015-17 Triennial Investment Plan and solicited public comments on funding priorities for this second round. SERC provided input on two important fields, forest biomass energy and offshore power, including wind and wave technologies.

Our letter on offshore energy points out how these untapped resources offer great potential for California’s renewable energy portfolio. However, we note that California is at risk of falling behind on developing offshore wind and wave technologies. We also make the case that California’s north coast is especially ripe for RD&D and eventual commercial development of coastal energy.

Many rural northern California communities generate substantial volumes of biomass residue in their forestry sectors, and these resources offer significant biomass energy development opportunities. The EPIC program has a substantial focus on biomass energy funding initiatives. SERC voiced general support for these initiatives, with an emphasis on field deployable densification technologies, such as torrefaction, and efficient energy conversion technologies, such as gasification. These technologies are critical to the economic viability of biomass energy development.

Visit the CEC’s EPIC page to view comments from SERC on biomass and offshore energy.

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.


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 3We have completed the transition from summer to fall here in far northern California, and – while it has been clear and sunny for the past few days – we recently had the first heavy rainstorm of the season. As the seasons change, we remain busy at SERC with a diverse portfolio of clean energy projects. The selection of articles in this newsletter reflects this diversity.

In the lead article, Richard Engel reports on a project that is in line with our broader work aimed at enabling energy access in off-grid areas ranging from South Asia to East Africa. We are also happy to report on recent progress in our biomass energy collaboration with Renewable Fuel Technologies (RFT). We look forward to deepening our work with RFT and others in the field as we expand our efforts in this arena.

Several other articles reflect our long tradition of work related to clean transportation. We were pleased to be in a position to fuel the hydrogen fuel cell vehicle that SERC alum Anand Gopal and his wife Liz Pimentel drove up from the Bay Area. We hope this event will be the first of many such occurrences made possible by our hydrogen vehicle fueling station.

We are also pleased to extend our plug-in electric vehicle (PEV) charging infrastructure planning work from California to India. The work in New Delhi, which involves collaboration with Anand Gopal and colleagues from Lawrence Berkeley National Laboratory, will require analysis in a new and complex setting involving very different driving patterns and electricity infrastructure. We at SERC always like to get involved in new and challenging work, and we hope to contribute meaningfully to the wider effort to enable cleaner transportation systems in New Delhi and beyond.

I will close by welcoming several new members to the SERC team. This August, Nick Bryant of Washington state and Amit Khare of New Delhi, India started work at SERC. They are also pursuing master’s degrees in the Energy Technology and Policy (ETaP) program here at HSU. We also have three additions to our docent team, including Yaad Rana, Onomewerike “Robo” Okumo, and Jake Coniglione. All are undergraduate students in the Environmental Resources Engineering program. It is great to have these students on board.

SERC Completes Instrumentation of RFT Torrefier

torrefier photo

The newly-installed air-measurement devices.

In September, Greg Chapman and I made our second trip to Renewable Fuel Technologies (RFT) to continue work on measuring the energy and mass balances of RFT’s pilot-scale torrefier. The one-ton-per-day torrefier produces a charcoal-like product called bio-coal from wood waste by heating biomass to 300°C in the absence of air. The bio-coal can then be co-fired in a power plant with standard fuels such as coal or wood chips to generate renewable electricity. SERC’s measurements of the device will aid in designing the torrefier for mobile, stand-alone operation and optimizing the technology for commercial use in converting timber waste into very low carbon renewable energy. This work is funded by the California Energy Commission.


The newly-installed torrgas sample condenser.

During this visit, we installed new instrumentation on the pilot-scale torrefier to measure power, air and gas flows.  Greg also designed, built, and installed a condenser to sample the condensable portion of the gas by-product of the torrefaction process, called torrgas, which is used to generate heat as a key part of RFT’s efficient design.  An initial test run of the system using the new instrumentation was successful, and planning is now underway to procure and transport several tons of wood chips to RFT, which will be used in a series of torrefaction experiments under varying conditions to collect detailed data on the operating characteristics of the system.

A Message from the Director

AJ headshot 3Activities on the Humboldt State campus have slowed down for the summer, but we are still very busy here at SERC. The articles in this newsletter highlight some of our current activity. As Colin Sheppard’s article indicates, we have been engaged in analysis related to planning for plug-in electric vehicle (PEV) infrastructure development in Humboldt County. We are also working on a similar analysis for three other northern California counties and are exploring other project possibilities.  All of this work fits into SERC’s longstanding tradition of enabling expanded use of clean transportation technology in the U.S. and beyond.

In this issue we also describe two new biomass energy efforts at SERC. One of these projects, involving torrefaction technology, is motivated by a desire to reduce the cost of transporting biomass fuel from the forest to end-use sites. The second effort explores conversion of biomass-derived sugars into hydrogen, which can then be injected into engines to improve efficiency and reduce emissions. These projects represent important progress in SERC’s bio-energy research, and, in both cases, we are grateful for funding support from the California Energy Commission (CEC).  We will start additional bio-energy work soon on a $1.75M CEC-funded project involving collaboration with the Blue Lake Rancheria, Redwood Coast Energy Authority, and Ballard Power Systems.

We also remain busy on the international front. Our work with the World Bank Group’s Lighting Africa and Lighting Asia programs continues to involve laboratory, field, and policy activities. In the lab this summer, we are grateful to have participation by student assistants Melissa Lancaster and John Hunter. Recent activities have taken team members to Kenya, Tanzania, India, and Bangladesh. Additionally, last month I attended meetings hosted by the Global Off-Grid Lighting Association (GOGLA) in Munich, Germany on the sidelines of Intersolar-Europe. As reported in our last newsletter, we are also working on a feasibility analysis and design for solar powered mini-grids in India. Two members of our team, Richard Engel and Brendon Mendonça, traveled to India last month as part of this effort.

Last but not least, we recently received good news related to the cost of education for some of our graduate students. Over the years, a number of graduate students from the Energy Technology and Policy (ETaP) and Environmental Resources Engineering (ERE) options of the Environmental Systems (ES) Graduate Program have worked at SERC. The ES Graduate Program was recently accepted by the Western Regional Graduate Program (WRGP), which means that students from eligible states will be able to attend HSU at a cost equivalent to the rate for California residents. This makes the ETaP and ERE graduate program options much more affordable for students from these states. This is great for SERC, as it will help us recruit talented students from western states such as Oregon, Washington, Colorado, Alaska, Hawaii, and others. More information is available on the ETaP and ERE graduate program websites. Goodbye until next time.

SERC Receives Funding for Bio-Energy Research

A $95,000 California Energy Commission (CEC) grant enables SERC, in partnership with Renewable Fuel Technologies (RFT) of San Mateo, to continue experiments aimed at converting slash from logging and fuel reduction efforts into energy dense bio-coal. RFT has developed a pilot-scale, one ton per day torrefier which produces bio-coal from timber waste by heating biomass to 300°C in the absence of air. Bio-coal can be co-fired in a power plant with standard fuels such as coal or wood chips to generate renewable electricity.

This new project involves measuring the energy and mass balances in RFT’s pilot-scale unit. These measurements will aid in designing the torrefier for mobile, stand-alone operation and optimizing the technology for commercial use. Mobility is considered crucial if torrefier technology is to become commercially viable. A good deal of forest debris lies in remote, difficult to reach locations, generating high logistics overhead. By making biomass three times as energy dense, the mobile torrefier would provide a far more economical approach as well as a major incentive to commercial conversion of timber waste into very low carbon renewable energy.

The CEC also awarded SERC Faculty Research Associate Dr. David Vernon $94,993 to examine the use of sugars from biomass to offset fossil fuel use, increase efficiency and reduce emissions in combustion processes. This work uses plant-derived sugars in chemical reactions that consume waste heat to produce a hydrogen-rich gas that can be mixed with traditional fuels to promote more complete combustion. This process has the potential to replace up to 50% of the fossil fuel and to increase efficiency by as much as 25%. It could also reduce emissions of NOx by over 95% while maintaining or reducing emission levels of other pollutants. If successful, the technology developed from this work could be retrofit onto existing gas turbines and engines in power plants and gas pipeline compressor stations without requiring costly modifications to the existing systems.

Graduate Student Assistants Mark Severy and Billy Karis (left) and Faculty Research Associate David Vernon test aqueous phase reformation reactions.

Graduate Student Assistants Mark Severy and Billy Karis (left) and Faculty Research Associate David Vernon test aqueous phase reformation reactions.

Specifically, this project explores the use of aqueous phase reformation reactions that directly process sugars and operate at lower temperatures than the gas phase reformation reactions that are being investigated for waste heat recovery elsewhere. Sugars can be produced from virtually any cellulosic biomass, including waste resources such as forestry slash, lumber mill waste, crop residues, portions of municipal solid waste, yard waste, etc. By operating at lower temperatures, aqueous phase reformation has the potential to recover significantly more waste heat compared to gas phase reformation reactions.

Torrefaction Continues at SERC

Wood chips before and after torrefaction.

Unprocessed wood chips (front) and the same feedstock after torrefaction. Photo credit Kellie Brown, HSU Photographer.

SERC is continuing its work with Renewable Fuel Technologies (RFT) on torrefaction. Torrefaction is the process of heating biomass to 250 – 300 degrees Celcius in the absence of oxygen.

The resulting product, referred to by RFT as “BioCoal,” has a higher energy density and is easier to pelletize than raw biomass. It is also hydrophobic, meaning it does not absorb water. These properties make BioCoal easier and less costly to store and transport compared to raw biomass. BioCoal can be used as a feedstock for liquid biofuels or co-fired in a coal power plant, thus replacing fossil fuels with a renewable energy source.

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