Bioenergy

Filling the void: From biomass to heat, power, fuels and chemicals

Issue 4 and Volume 10.

High energy costs have put biomass into focus as a critical resource, and although conventional coal, oil and gas will remain important in meeting our energy needs for a number of years, biomass is presenting itself as a major opportunity. Derek Walters reports on the latest developments.

Several recent technological breakthroughs are increasing the viability of biomass, helping it to meet future electricity and transportation fuel demands, reduce dependence on foreign oil and improve energy security. In addition, biomass is a green source of energy, potentially providing carbon-neutral and low-emission energy, as well as the potential to reduce agricultural wastes.

One of the most promising technologies for widespread use of biomass for heat, power, fuels and chemicals is gasification. Gasification converts carbonaceous materials, such as biomass, into syngas – a combustible mixture of carbon monoxide (CO) and hydrogen (H2). The syngas produced can then be used to produce electricity in an engine or turbine, or synthesized into a wide variety of fuels and chemicals. Waste heat from the process can also be gathered for a variety of purposes, and the EERC is developing a variety of biomass conversion technologies.


Making valuable materials from biodiesel byproducts can seriously improve the economics of biofuels from gasification ALL IMAGES EERC

‘Because of the enormous opportunity it presents, many different applications for biomass gasification are being pursued by the EERC, which, in turn, is drawing significant investment capital to the EERC,’ said Director Gerald Groenewold.

The EERC, which maintains numerous in-house demonstration facilities, understands the entire value chain of gasification, its operational challenges and the opportunities associated with feedstock preparation, gas cleanup and product utilization.

‘We have seen a significant increase recently in commercial projects utilizing biomass with a gasification platform,’ said Darren Schmidt, EERC Research Manager heading the EERC’s biomass gasification efforts. ‘The EERC’s 60 years of experience and expertise developing, demonstrating and commercializing gasification technology is in demand at this time.’

Biomass gasification power system

Biomass gasification power systems can turn low-value waste biomass material into valuable heat and electricity. Such systems are usually designed to match the power requirements of various manufacturing industries, typically generating between 100 kW to 1 MW of power.

Darren Schmidt is currently leading a long-term commercial demonstration project at Grand Forks Truss, a building product manufacturing plant. The gasifier will convert 20-plus years’ worth of sawdust and wood waste from the plant into a combustible gas for heat and electricity, offsetting 100% of the facility’s power use.

The gasifier was developed by the EERC’s Centre for Renewable Energy and Biomass Utilization through several years of projects with the US Department of Energy (DOE), and with commercial industry. The EERC has been working in gasification since the early 1980s when researchers conducted a series of projects involving the use of sunflower hulls, wood residue and sewage sludge for power using both combustion and gasification technologies. This work led to several projects related to biomass – coal co-firing strategies in conventional pulverized coal-fired systems, as well as gasifiers, to reduce carbon dioxide (CO2) emissions and other emissions.

Schmidt’s portable gasification system was constructed at the EERC in 2003 and has undergone extensive performance testing with a variety of fuels. Process and operational data collected over the past 3 years have provided the necessary information to solidify a commercially viable ‘microgasification’-based design.


The EERC’s mobile gasification system

The EERC’s microgasification technology is designed to benefit manufacturers and processing industries that must manage process residues, such as wood wastes, hulls and any distiller grains, and have a simultaneous need for heat and power. The process produces electricity without the disadvantages of a high-pressure steam system. Biomass fuels are converted to a gas, which is used to fuel an engine generator or microturbine. The advantages of the technology are in the robustness, fuel flexibility, attention to environmental concerns, and customization for the end user.

The gasification system has the capacity to handle woody materials of less than 30% moisture with a maximum dimension of six inches. It can process large material such as wood blocks and fine material such as sawdust. Residual solids handling is critical to successful operation of a gasification system. The EERC provides a proprietary system for spent char removal from the gasifier and processing. Condensate and charcoal are converted to potash which is then automatically conveyed to a discharge container. Options are available to eliminate any physical ash handling for the end user. A spark-ignited natural gas engine is used to generate power from syngas. The EERC provides proprietary fuel control technology for burning low-Btu gas in the engine.

‘This power system provides unique energy solutions for industrial clients by producing heat and electrical power from a variety of fuels, including waste materials and other organic feedstocks,’ Schmidt said. ‘Power generation and consumption of the timber scraps ultimately provide cost savings for Grand Forks Truss.’

‘We are very excited and proud to host a project involving renewable energy. We have a vast supply of biomass waste and continue to produce more than we can use in our current heating system,’ said Shaun Johnson, Plant Operations, Grand Forks Truss.

‘We were considering options to better utilize our wood waste when, by chance, the EERC came to us with the answer. It’s exciting to watch a research project, developed locally, being applied and unfold before us. It is an important step forward in the global goal of better use of our natural resources,’ he said.

The gasification unit is expected to be fully operational this summer 2007 and should be fully commercialized within the next five years.

Liquid fuels from crop oils

Simultaneously, EERC is pursuing technologies beyond gasification that use biomass for the production of fuels, including the demonstration of innovative renewable domestic fuels for the US military and civilian markets. The EERC is using numerous pathways, involving Fischer-Tropsch reactions, to produce synthetic fuels from both coal and biomass. Development and demonstration of a stationary Fischer-Tropsch liquefaction system, and a mobile gasification unit for converting syngas from coal, biomass and petcoke into liquid fuels, are currently under way.

EERC Associate Director for Research Tom Erickson commented that one of the greatest challenges is energy security for the US military. ‘This will also expand the EERC’s capabilities in tactical fuels and allow us to demonstrate the effects of recently developed technology to convert fuels made from indigenous resources that can replace imported oil.’

‘Our whole approach with these projects is to develop an affordable new fuel that can be dropped in to replace the current military fuel, primarily JP-8,’ said Ted Aulich, Senior Research Manager. ‘This replacement will allow an easy transition from petroleum-based fuels to 100% domestic renewable fuel.’


Diagram of a typical gasification plant layout

A major challenge for any type of fuel is its use in cold-weather conditions. The EERC fuel is usable in extremely cold temperatures (at or below -45°C), which makes it ideal for use in jets. North Dakota is an exceptional real-world setting for cold-weather testing.

In addition to demonstration of the Fischer-Tropsch fuel, the EERC is also focusing on improving methods for producing the fuel from a variety of vegetable oils and other renewable feedstocks. Several provisional patent applications have already been filed for a new chemical process specifically for producing renewable JP-8. This simplifies the traditional process for converting vegetable oil to fuel with low-freeze-point requirements – a major breakthrough developed exclusively at the EERC.

Groenewold said producing liquid fuels from both coal and biomass that have drop-in capabilities could provide significant opportunities to grow the existing energy economy in North Dakota.

Beyond heat, power and fuels

The opportunities for biomass extend far beyond heat, power, and fuels. Within the past five years alone, the EERC has conducted more than 60 major projects involving value-added by-products from existing biomass industries, grain and lignocellulosic ethanol production, innovative production and use of biodiesel, the production of hydrogen from biomass and wind, as well as demonstrating innovative thermochemical pathways to produce value-added chemicals.

Projects such as these exemplify the EERC’s business model of developing partnerships with private industry, government, and the research community in order to bring biomass technology innovations out of the laboratory and into the commercial marketplace.

Ethanol and other chemicals

For the past several years, the EERC has been developing a fast-pyrolysis-based process for producing ethanol and other fine biochemical streams from lignocellulosic biomass, such as grasses, wood and straw. In fast pyrolysis, a low-pressure, high-flow-rate gas (steam, nitrogen or a pyrolysis gas comprising CO and CO2) is used to effect rapid removal of pyrolysis products from the heated zone, thereby preventing their destruction. Primary products yielded from fast pyrolysis of biomass include anhydrosugars, saccharinic acids and phenolics, which are primarily derived from biomass cellulose, hemicellulose and lignin components, respectively. The EERC’s research has focused on the innovative use of solid acid catalysts to convert the anhydrosugars to glucose and other fermentable sugars. According to EERC Deputy Associate Director for Research Chris Zygarlicke, preliminary results show that fast pyrolysis appears to be one of the most simple biomass pretreatments available today.

Another ongoing effort at the EERC includes the development of a process called the dual fermentation biorefinery (DFB) method for converting biomass to fuels and chemicals. With expansion of ethanol demand and more new plants coming online, the national market for distillers’ dried grains, an ethanol co-product crucial to dry mill ethanol plant profitability, is getting tighter.


Located at the University of North Dakota, EERC has more than 245,000 square feet (22,760 m2) of laboratory, offices and demonstration facilities

‘Increasingly, new and existing plants need an edge – in ethanol production or marketing – to maintain profitability,’ Zygarlicke said. ‘In response to the need for improved ethanol economics and the national security-based need to develop bio-based alternatives to petrochemical products, EERC researchers developed the DFB concept.’

DFB integrates ethanol production via yeast fermentation with the production of lactic and other carboxylic acids via bacterial fermentation followed by subsequent esterification of ethanol and carboxylic acids to produce high-value esters. Esterification is the general name for a chemical reaction in which two chemicals (typically an alcohol and an acid) form an ester as the reaction product.

Success in demonstrating DFB’s commercial viability will enable the option of retrofitting an existing corn-based ethanol plant or configuring a new corn- or lignocellulosic biomass-based ethanol plant to produce a variety of products. Such products include ethanol, carboxylic acids and ethyl esters that have high values as polymer feedstocks, chemical intermediates and biodegradable low-toxicity solvents. Commercialization of the DFB concept would provide ethanol plant product diversification options and enable revenue maximization through selective commodity production in response to changing market demands.

The EERC’s biomass gasification technology is also being evaluated for a variety of other applications, from the production of hydrogen from renewable and fossil fuel sources to the production of methanol. The EERC has surveyed several small-scale biomass gasification power suppliers and has developed a current system approach based on previous commercial successes and failures. The results of a recent methanol feasibility study are confidential, but a small-scale process has been developed in partnership with a commercial client in the US

‘All of these projects demonstrate that the EERC is filling the gap for corporations that are looking to commercialize innovative new technologies and to improve their overall operations and, eventually, their bottom line,’ Zygarlicke said.

Derek Walters is Communications Manager at the Energy & Environmental Research Center (EERC)
e-mail: [email protected]

 


About the EERC

The non-profit EERC provides solutions to today’s most critical energy and environmental issues. Founded in 1951 as the Robertson Lignite Research Laboratory, the EERC now conducts research into clean coal and hydrogen technologies, emission control, oil and gas, climate change, carbon sequestration, water management, biomass, wind energy and alternative fuels. It is a world leader in pollution prevention and environmental cleanup technologies. Today, with nearly 300 employees, the EERC is home to some of the most advanced equipment and instrumentation in the world, and has had over 970 clients in all 50 US states and 49 countries.