Wood Pellets are the Best Choice for Residential Heating

As temperatures dive and natural-gas costs soar, perhaps you are considering the purchase of a wood-pellet stove. But you wonder, is this an environmentally friendly choice?
Tony Bi reflects upon engineered wood pellets.

As temperatures dive and natural-gas costs soar, perhaps you are considering the purchase of a wood-pellet stove. But you wonder, is this an environmentally friendly choice?

The answer is yes.

According to Chemical and Biological Engineering Professor Xiaotao (Tony) Bi, wood pellets are the best choice for residential heating.

“In an isolated environment, when only the emissions from the burning fuel are analyzed, natural gas appears to be a cleaner option,” says Bi. “But when you factor in the entire life cycle of natural gas—a fossil fuel—with that of engineered wood pellets, which come from a renewable resource, the pellets are a far better environmental choice. They’re clean, and they’re sustainable.”

Environmentally speaking, wood pellets are an ideal fuel for industry and district heating.

Waste-wood materials, such as sawdust, are bound into pellets in a high-temperature pelletization process; no additives or glues are used. No new trees are cut down to create pellets, and pelletization is a beneficial use of trees killed by the mountain pine beetle.

Engineered pellets have a uniform size and moisture content and can be cleanly burned in specially designed automatic pellet furnaces, unlike wood logs or wood residues in traditional wood furnaces. Wood pellets have been endorsed by the U.S. Environmental Protection Agency and are one of the cleanest-burning and most renewable energy sources on Earth.

Bi, an expert in fluid-particle systems and multiphase reactors, is part of UBC’s Biomass and Bioenergy Research Group (BBRG), a multidisciplinary team that collaborates with industry and government to meet the needs of the emerging bioeconomy. Over the past five years, the BBRG has grown from three members to 15. The group collaborates extensively with the Wood Pellet Association of Canada (WPAC) to engineer a better pellet.

Bi conducts life-cycle analyses—evaluations of the environmental and social impacts of a given product or services caused by or required for their existence—to investigate the health and environmental concerns of pellet burning and improve the environmental performance of pellet making, transportation and distribution.

His research team works to quantify net carbon dioxide emissions and investigate the gases that pellets emit during storage and transportation, to help prevent fires and ensure good air quality for workers exposed to pellets. In addition, the group works to improve the energy density and durability of pellets, using various multiphase processes to produce torrefied-wood pellets—pellets dried by heat to expel easily degradable, volatile ingredients—and steam-exploded pellets—pellets treated by steam to break fiber-wall structure and enhance lignin-binding strength.

B.C. is the centre of wood-pellet production in North America and roughly 90% of B.C.’s wood pellets are exported, including more than 500,000 tonnes to Europe. The B.C. wood pellet industry has grown by 20% each year over the last five years. More than 11,500 biomass (biological matter that can be used as fuel) installations in the European Union have generated over 260 million tons of CO2 credits, valued at over C5 billion. The E.U. currently produces 4% of its electricity from biomass sources and intends to double its output by 2010 through the initiatives outlined in the E.U. Biomass Action Plan.

So why are wood pellets so popular in Europe and yet underutilized here in Canada? Bi lists, in order, the various factors that influence decision making with regard to energy: economy, society and the environment.

“Canada needs to offer financial incentives, like Europe,” he says. “Residents there get green-energy credits for using wood pellets to heat their homes and run their factories. So not only is it the environmentally right thing to do, it’s economically viable too.”

Bi teaches Green Engineering and Sustainability, one of the first green-engineering courses in Canada, focusing on multiscale engineering approaches to sustainability. The course involves life-cycle analysis and exposes students to industrial-ecology practices through presentations from local experts and hands-on projects related to community sustainable development.

Students have performed life-cycle analyses of electrical, diesel and biodiesel fuels for UBC campus utility vehicles; plastic versus china dining ware in food service; greenhouse-gas reduction options for the campus boiler house; and solvent recovery and recycling for Plant Operations. Bi hopes to develop the class into a core UBC Engineering course, applicable not only to chemical engineers but to all engineers.

“As a professional engineer and an educator, I feel that we should take the challenge to develop engineering solutions by inventing environmentally friendly technologies and green products so that the ecological ‘footprint’ of the technology and product can be minimized,” says Bi.

“At the same time, I feel obligated to equip future engineers with green- and sustainable-engineering design skills so they can continue the current effort to develop transforming technologies for solving the seemingly unstoppable global-warming problem facing future generations.”

This research has been enabled in part by NSERC, BIOCAP, Agriculture and Agri-Food Canada (AAFC), BC Ministry of Forests and Range, and Wood Pellet Association of Canada.