Using northwest trees for buildings better for keeping carbon out of atmosphere, study says

A University of Washington study says that using trees from the northwest as a building material is good for carbon mitigation in the atmosphere, especially if the wood waste is also used as a biofuel to replace gasoline and other fossil fuels.

The article, published in the journal Forests, says that if timber from northwestern U.S. forests were harvested sustainably every 45 years and the wood used as a building material, where possible replacing substances like concrete or steel, which require greater amounts of fossil fuels to manufacture, that would both remove existing carbon dioxide from the air while the forest was growing and then keep the gas entering the atmosphere for years  as long as it is part of a building.

It says carbon savings can be increased by using the parts of the trees
not suitable for building materials such as slash, branches and debris
as biofuel, especially ethanol.

It also notes that some forest “residual” may be too
difficult to collect to be used a biofuel or should be left to maintain
the forest ecosystem.

The lead author of the study,  Bruce Lippke, professor emeritus of forest resources at the University of Washington, says, “When it comes  to keeping carbon dioxide out of the atmosphere, it makes more sense to use trees to recycle as much carbon  as we can and offset  the burning of fossil fuels than it does to store carbon in standing forests and continuing burning fossil fuels.”

The University of Washington says this is the first study to look at using biofuels in addition to  using wood from long living trees as a building material, as opposed to woody biofuels studied in isolation. 

The study also looked at forests in the U.S. Northeast and Southeast, and emphasized that different regions will produce different results.

It suggests that using fast growing species, such as willow, especially in the US Southeast, could have advantages.  Willow, while not usually a commercial building wood species, and with a lower carbon conversion efficiency, when used as biofuel can be both economically harvested for biofuel because of its high growth rate and that rapid growth would also be absorbing carbon dioxide from the atmosphere.

Lipke says that properly managed forests mean using wood for both building and bioenergy  is carbon neutral. That’s because the growing trees could absorb enough carbon dioxide to offset emissions from the rotting wood from used building materials after its useful life and from cars using ethanol produced from woody debris.

The biggest problem, the study suggests, is the still relatively low cost of fossil fuels,  and the low cost of  natural gas, which has made large scale conversion of wood biomass to ethanol, so far, uneconomic.

It also notes that the entire forest should be considered in any equations on carbon mitigation because it would include different lifecycles, quality of wood and different collection and manufacturing processes.

Carbon captured in building wood has a half life of 80 years  after harvest.  Then  there is a question of what should happen to that wood after its useful life, thus wood that is burned would add carbon dioxide to the atmosphere, whereas it would be better to either put the wood into landfill so it can rot or that the wood  be processed in some kind of energy recapture process.

Combined use of good wood in building and waste for ethanol, while sustaining the forest, would mean that 4.6 tonnes of carbon are captured per year for each hectare of forest. The study says “this sustainable mitigation from using wood products  and biofuels has the potential to exceed  the growth rate in forest carbon  because of the high leverage  when wood substitutes for fossil intensive  products and their emissions.”

The study also looks at ways the sustainable forest and use of biofuels could increase American energy independence.

Others participating in the study were North Carolina State University, State University of New York at Syracuse, Leonard Johnson and Associates, Moscow, Idaho, Woodlife Environmental Consultants, Corvallis, Or and Mississippi State University.
Sustainable Biofuel Contributions to Carbon Mitigation and Energy Independence

Editor’s note: There should be a follow-up Canadian study that looks at the carbon cost of sending raw logs to China in ships burning high carbon bunker oils, rather than finding new ways of producing lumber here, and as the study suggests, using the lumber, where possible,  to replace steel and concrete.

Forest biofuel may actually increase carbon dioxide emissions, West Coast study suggests

Biofuel Environment

A study of west coast forests  in California, Oregon and Washington concludes that biofuel from forests could increase carbon dioxide emissions by at least 14 per cent.

Oregon  State University calls the study “the largest and most comprehensive yet done on the effect of biofuel” from the US west coast.

A diagram from the Oregon State University shows how using biofuels would increase the carbon emissions by releasing more forest carbon, including the processing and transportation of biofuel.  (Oregon State University)

The study, published Sunday in Nature Climate Change, contradicts previous findings  that suggest biofuel could be either carbon neutral or reduce greenhouse gas emissions.

It is uncertain whether the conclusions of the study could apply to northwestern British Columbia, due to different ecological conditions, including pine beetle devastation and the effects of climate change.

602-6261239015_768f4de19c_m.jpgFor four years, the Oregon State study examined 80 forest types in 19 ecological regions in the three states, ranging from temperate rainforests to semi-arid woodlands. It included both private and public lands and different forest management practices.

Tara Hudiberg, a PhD candidate at Oregon State and lead author, said in an e-mail interview, “We applied thinning scenarios which would remove whole trees and use the merchantable portion for wood products and the rest for bio-energy use (tops, branches, smaller trees of less then five inch DBH  (diameter at breast height ).

“On the [US] West Coast, we found that projected forest biomass removal and use for bio-energy in any form will release more carbon dioxide to the atmosphere than current forest management practices.
“Most people assume that wood bio-energy will be carbon-neutral, because the forest re-grows and there’s also the chance of protecting forests from carbon emissions due to wildfire,” Hudiburg said. “However, our research showed that the emissions from these activities proved to be more than the savings.”

The only exception was if forests in high fire-risk zones become weakened due to insect outbreaks or drought, which impairs their growth and carbon sequestration as well as increasing the potential for large forest fires (a situation prevalent through much of British Columbia due to the devastation caused by the pine beetle.)  The study says in that situation, it is possible  that some thinning for bio-energy production might result in lower emissions in such cases.

“Until now there have been a lot of misconceptions about impacts of forest thinning, fire prevention and bio-fuels production as it relates to carbon emissions from forests,” said Beverly Law, a professor in the OSU Department of Forest Ecosystems and Society and co-author of this study.

(Oregon State University)

“If our ultimate goal is to reduce greenhouse gas emissions, producing bio-energy from forests will be counterproductive,” Law said. “Some of these forest management practices may also have negative impacts on soils, biodiversity and habitat. These issues have not been thought out very fully.”

The study examined thousands of forest plots with detailed data and observations, considering 27 parameters, including the role of forest fire, emissions savings from bio-energy use, wood product substitution, insect infestations, forest thinning, energy and processes needed to produce bio-fuels, and many others.

It looked at four basic scenarios: “business as usual”; forest management primarily for fire prevention purposes; additional levels of harvest to prevent fire but also make such operations more economically feasible; and significant bio-energy production while contributing to fire reduction.

Compared to “business as usual” or current forest management approaches, all of the other approaches increased carbon emissions, the study found. Under the most optimal levels of efficiency, management just for fire prevention increased it two percent; for better economic return, six percent; and for higher bio-energy production, 14 percent.

“We looked at CHP (combined heat and power from combustion) and cellulosic ethanol and we accounted for all sources of Carbon emissions from harvest to use,” Hudiberg said. 

She added,  “We don’t believe that an optimal efficiency of production is actually possible in real-world conditions. With levels of efficiency that are more realistic, we project that the use of these forests for high bio-energy production would increase carbon emissions 17 percent from their current level.”

About 98 percent of the forests in the three western US states  are now estimated to be a carbon sink, meaning that even with existing management approaches the forests sequester more carbon than they release to the atmosphere. Forests capture a large portion of the carbon emitted worldwide, and
some of this carbon is stored in pools such as wood and soil that can
last hundreds to thousands of years, the scientists said.

The study suggests that increases in harvest volume on the US West Coast, for any reason, will instead result in average increases in emissions above current levels.

“Energy policy implemented without full carbon accounting and an understanding of the underlying processes risks increasing rather than decreasing emissions,” they conclude.

When asked about British Columbia, Hudiberg noted: “We are not aware of anything in particular, but we do know that BC forests may (or already are) be more susceptible to climate change impacts and insect outbreaks. So initially, it may be a more suitable region for bio-energy but the same analysis we did here would have to be done [in BC] to know for sure.  She cautions, “The study conclusions are based on the regional conditions and current regional carbon uptake with current management practices For other areas, the current conditions need to be assessed before deciding if bio-energy will increase or decrease carbon emissions.”

Biofuel in northwestern BC

    Biofuels are seen as a growth industry in northwestern British Columbia,  with a number of companies are starting to work on various forms of biofuel investments including large corporations as well as medium  and small business.

  •  In Kitimat, Pytrade has proposed a biomass plant that would use pyrolysis to convert wood waste into liquid bio-fuels and also generate heat that can be used by green houses used to train people in horticulture in conjunction with North West Community College. Pytrade also plans to make money by selling carbon offsets for every tonne of C02 not emitted into the atmosphere they will make money by selling credits. An application by company for a provincial a one million dollar Innovative Clean Energy (ICE) grant has been approved.
  • General Biofuels Canada is planning a 500,000 metric tonne per year wood pellet facility in Terrace.   This project would use hemlock fibre from “non-saw grade fibre” from area forest licence holders.
  • Toronto-based CORE BioFuel Inc. Wants to build a plant, likely in Houston, (and perhaps more plants) to turn forest waste fibre into gasoline.   Each plant would cost $100 million and require 220,000 tons of fibre a year to produce 67 million litres of gas.

 As well as the College of Forestry at  Oregon State University, the study involved institutions in Germany and France. It was supported by the US Dept. Of Energy.

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Kelp has great potential as green biofuel studies suggest

Energy Environment Biofuel

522-tywynsurf.jpgA surfer enters the water on a stormy beach at Tywyn, Wales, July, 2008.  Scientists from nearby Aberystwyth University  have studied kelp as a potential biofuel. The kelp was growing near a rocky outcrop some kilometres south of  Tywyn at Aberystwyth Beach near Ceredigion.  (Robin Rowland/Northwest Coast Energy News)


Kelp has potential as a renewable biofuel resource because it is a fast-growing, large “macro-algae” that could be harvested, processed and turned into ethanol, methane or bio-oil, according to a recent study in Wales.

The study by Jessica Adams  and colleagues at Aberystwyth University in the west of Wales was presented at a biology conference in Glasgow on July 4, 2011 and published in the journal Bioresource Technology.

Coastal Wales has a similar environment to the west coast of North America and  both regions are abundant in kelp.

In her paper, Adams says that most biofuels today come from terrestrial sources such as agricultural products or forests, and both sources can cause environmental problems.  Harvesting kelp  for biofuel would mean that potential food crops,  such as maize, would not be taken out of the food supply chain. She says the ocean  accounts for half of the primary biomass on the planet, but has not been used very much in the search for biofuel.

Her study, assisted by the Energy and Resources Institute at the University of Leeds, concentrated on the potential that kelp has for producing fuel at various times of its life cycle during the year.

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By analyzing the chemical composition of kelp harvested  at low tide at rocky outcrop on Abesrtystwyth Beach, Ceredigion, Wales, Adams and her colleagues determined the best time to harvest the kelp for use as potential biofuel, which in the case of Wales, was in July when the kelp had the highest levels of carbohydrates, including two key sugars, mannitol and laminarn, which are easily converted to biofuel. Those carbohydrates could be fermented or put through anaerobic digestion to produce either ethanol or methane. Another method is pyrolysis,  a method of heating the fuel in the absence of oxygen, which can produce bio-oil.

Another advantage that kelp has over terrestrial plants is that it contains little cellulose and thus is easier to handle when creating biofuel.

The First Nations of British Columbia used the kelp for centuries, as a place to find  fish, crustaceans and shell fish in the kelp beds or to hunt seals that fed on the fish. In some parts of the BC coast, First Nations used kelp branches to harvest herring roe  (before the collapse of the herring stocks)

 For the past century, modern use has concentrated on the minerals the kelp produces,  it was burned to obtain soda ash (sodium carbonate) , used for the production of soap, ice cream and lotions as well as in some processes for making glass. 

Kelp is increasingly popular as a health food, both as an edible seaweed and for health supplements.   In British Columbia, kelp is harvested  for health food at a time of peak mineral content, when the content is  25 per cent to 50 per cent minerals,  including potassium, calcium, magnesium, phosphorus and iodine. Salt extracted from BC kelp is high in potassium and thus attractive for people on low sodium diets.

For biofuel, however,  the time when kelp is highest in minerals, and thus attractive to the current harvesters, is not the time it would be best for biofuel.  Adams says: “Seaweed ash has previously been reported to contain, potassium, sodium and calcium-carbonate  and high concentrations will lead to increased slagging, fouling and other ash related  problems during thermochemical conversion.”

In Wales, Adams’ study showed that the mineral concentration in the kelp peaked in March and was lowest in July, a time when the carbohydrate content is also higher.  She says   “This means that a July harvest would provide the highest heating value and the lowest ash  and alkali index values, making it the best month for harvesting  for thermochemical conversion.”

It appears also that cleaner water will produce kelp that is better suited to biofuel conversion, since the kelp her study used from Cardigan Bay had a lower mineral content than kelp from areas off Cornwall where effluent from the tin mines was carried by rivers into the ocean in that region.

An earlier small pilot project in 2008 at a royal estate on the north coast of Scotland looked into the possibility of setting up a kelp farm that could potentially used for biofuels.  That project showed that using kelp for biofuel meant that agricultural land did not have to be taken out of production for biofuel planting and even that agricultural runoff could be used to fertilize a concentrated kelp farm.

The species of kelp used in the Welsh study had high concentrations of both water and minerals and  that is whyJuly was the optimal time for a possible biofuel  harvest.  Other species, in other areas,  once studied, might be better suited to be used as biofuels. Adams concludes by saying: “Macroalgae or macroalgal residues could pryrolysted to create a bio-oil or used in hydrothermal liquefaction to make bio-crude  in a process which does not require the initial drying of the feedstock.”

Map of the kelp beds on the north coast of Haida Gwaii, taken from the BC provincial government kelp inventory survey.

Correction: An earlier version of the story said the journal was Biosource Technology. This has been corrected to Bioresource Technology.