Nexterra technology ready for commercial use

By Anna Austin and Susanne Retka Schill
Web exclusive posted August 22, 2008 at 10:03 a.m. CST

After two years of testing its biomass gasification technology, Nexterra Energy Corp. has announced that synthesis gas produced by its proprietary gasification technology has the ability to displace at least 60 percent of fossil fuels used in lime kilns or furnaces. The results were achieved at the company's product development center in Kamloops, British Columbia.

The testing program was funded by Sustainable Development Technology Canada, a non-profit governmental organization which supports projects that address climate change, air quality, clean water and clean soil.

The company confirmed the results on Aug. 18, and said depending on which biomass feedstock and existing equipment configurations, a 95 percent substitution may be feasible at many pulp mills; 100 percent in certain types of boilers.

Jonathan Rhone, Nexterra president and chief executive officer, said the company's gasification system is ready for demonstration at commercial-scale. "Once proven at this scale, we plan a full commercial rollout for industries such as pulp and paper, wood products, mining and others that want to reduce operating costs while lowering their carbon footprint," he said. "Up to now, these customers were limited to using either natural gas or fuel oil. Syngas offers a cheaper, carbon-neutral and renewable fuel alternative."

In comparison to Nexterra's first generation gasification systems that are close-coupled with heat exchangers to generate hot water, steam or hot air, the new direct fire application enables customers to produce syngas in one location and combust it elsewhere. Tests at the company's production development center in Kamloops, British Columbia, included process simulation of end user equipment, as well as testing of specialized syngas conveying, pressurization and burner equipment.

The gasification technology used by the company involves a fuel in-feed system. The feedstock is first stored in a metering bin designed to provide short-term storage, and delivered at a steady rate through the bottom center of the dome-shaped gasifier. Combustion air, steam and oxygen are allowed to interact with the base of the fuel source, causing partial oxidation, pyrolysis and gasification which occur at 1,500-1,800 degrees Fahrenheit. Syngas and non-combustible ash is produced from the process; the ash is separated and removed through the base of the gasifier with an in-floor ash grate. The clean syngas is then ready to be directed through energy recovery equipment or into boilers, dryers or kilns to be used as energy.

According to the company, when used at a typical commercial pulp mill, the technology may reduce natural gas consumption by more than 800,000 gigajoules (758,570.4 million British thermal units) yearly, which is the equivalent of heating 5,000 residential homes with natural gas. Additionally, the system may reduce greenhouse gas emissions by more than 25,000 tons annually.

Nexterra plans to present a paper on a lime kiln and boiler direct fire program at the Technical Association of the Pulp and Paper Industry's (TAPPI) Engineering, Pulping and Environmental Conferences on Aug. 27 in Portland, Ore.