The Editor: The article "Bio-conversion technology is viable" (PM, Jan. 24) by Cheryl Croucher reminded me of a series of articles that I read in Discover Magazine more than 10 years ago.
Between 2003 and 2008, Discover published four articles examining a new process for transforming agricultural, industrial, and municipal waste into usable fuel, other useful products, and sterile, easily disposed waste.
Changing World Technologies, beginning in 1999, developed and commercialized a high temperature "thermal depolymerization" process that could deal with plastic bottles, used car tires, slaughterhouse offal, municipal liquid waste, and refinery residues that separated out the water and mineral content and produced a light fuel oil and natural gas.
Links to these Discover articles can be found at the end of the company's Wikipedia entry: https://en.wikipedia.org/wiki/Changing_World_Technologies
The 2008 Discover article detailed the problems Changing World Technologies unfortunately had in scaling up the process to be commercially successful, in terms of market price and desirability of the final products. The use of turkey offal feedstock in the first large scale plant led to it being closed due to complaints about odour, as stated in the Changing World Technologies' website: Changing World Technologies | The Solution for Energy Independence
The company opened a new plant using different feedstock (used fryer oil) in 2011. Both were sold in 2013 to a Calgary-based company, Ridgeline Energy Services. The plant now appears to be operating successfully.
It should be noted that demand for such "renewable fuels" stems largely from government-mandated reductions in new carbon production.
I would be surprised if the University of Alberta spin-off company, Forge Hydrocarbons Corp., which your article reported on, was not aware of the U.S. history with converting "dirty" feedstock into fuel, and I would be interested to know if the process they use is similar to that developed by Changing World Technologies, and more economical. — Roger Schmitz, Saskatoon