Power to the paper mills
Pulp and paper mills refine their waste in a new system called 'black liquor gasification'.
Mon, May 11, 2009 at 02:27 PM
With newspaper and magazine circulations shriveling before our eyes, paper mills might not seem like they'd be a hot target in the battle against climate change — especially given that lots of mills have shut down in the past 12 months due to financial troubles tied to factors such as the drop in print advertising and a rise in fuel costs. But a couple of mills have begun taking steps towards integrating their waste streams with efficient biofuel refineries, which can potentially produce cleaner transportation fuel in addition to heat and electricity for the plants.
Pulp and paper mills produce thousands of tons of a liquid biomass byproduct every day. Called black liquor, this oily substance is typically burned to produce heat in a fairly inefficient way. A number of techniques attempt to improve on how the mills’ waste streams, which have historically been quite polluting, can be recycled or reused. The one that is arguably the best of the lot, developed by a Swedish company called Chemrec, just secured $20 million to commercialize its form of biorefining, known as black liquor gasification.
Talk about a branding problem: the name makes it sound like the plight of a Wild West prospector suffering from indigestion. Undeterred, proponents of black liquor gasification believe that the technology could serve a dual purpose. First, it could make pulp and paper mills entirely energy self-sufficient and improve their emissions profiles. Secondly, the mills could diversify their product range and begin selling the fuel. All around, the techniques promise a much smaller environmental impact for black liquor-based fuels when compared with older forms of biofuel, namely ethanol. According to some estimates, these biofuels use less than 2 gallons of water for gallon of fuel — OK, still not great — compared with a stunning 18 gallons of water per gallon of ethanol. (Sheesh, and Obama let his corn-growing constituents talk him into supporting that stuff?)
Chemrec has been operating a couple of successful pilot bio-refineries in its home country and now intends to bring the technology to the United States. Reflecting the massive improvements on the first round of questionable fuel alternative, the offerings coming out of Chemrec and similar companies are being termed “second-generation” biofuels.” Volvo invested in the company last year and announced its interest in accelerating the development of the biofuel industry for motor vehicles.
The idea of paper mills and fuel refineries skipping through the fields together is just so pleasing to this blogger. The approach is so inherently local, as most environmentally conscious design is. It buys into a mindset where every industry, company and household thinks individually about how to reduce greenhouse gas emissions. With Poznan tackling the big picture for climate change this week, examples such as this serve to remind that there are more possibilities for constructive change out there than anyone can begin to enumerate.
Story by Sandra Upson. This article originally appeared in Plenty in December 2008.