Lately I've been investigating biomass energy in general, and electricity production from wood in particular, as this is sometimes suggested as an alternative to coal or nuclear power.
Wood has been the leading source of renewable electric power, behind hydro-electric, producing about 18% as much power as hydro in the US through 2006 (http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/table1_3.pdf). Digging a little deeper, I found that the leading technology for electricity production from wood is fueled by "Black Liquor". Black Liquor is a by-product of pulp-making for the paper industry. It is combusted in "Tomlinson Boilers" for process chemical recovery, and sometimes also for energy recovery to provide process heat and electricity from steam turbines. Black Liquor is thus recognized as an important renewable resource for electricity production. With more efficient power conversion technology, it could turn pulp mills into net electricity producers, rather than consumers. A promising technology is gasification with combined cycle gas and steam turbines. Several demonstration plants have been built and operated with varying degrees of success ( http://www.wisbiorefine.org/proc/blackliquorgas.pdf ). An in-depth analysis of the potential contribution to US electric power supply by replacing retired Tomlinson boilers with a black-liquor gasification combined-cycle process optimised for electricity production, a typical mill could export 20MW to 120MW electricity, rather than consume about 40MW. Fully implemented nation-wide, the US might expect up to 8 gigawatts new electric generation capacity from pulp mills within 25 years ( http://www.chemrec.se/admin/UploadFile.aspx?path=/UserUploadFiles/2003%20Princeton%20BLGCC%20Final%20report.pdf or http://tiny.cc/GivJT ). So by fully exploiting this potential at existing pulp mills, that's about 16 big coal plants or 8 big nuclear plants worth of new capacity additions, nation-wide. The US added about 8GW of new capacity in 2006. Projected new capacity additions to 2030 amount to 292GW ( http://www.eia.doe.gov/neic/infosheets/electriccapacity.html ), so at least 97% of that would have to come from sources other than black liquor. I hope carbon capture and storage is feasible and affordable, as we appear to be fossil- fuel dependent for the foreseeable future. -dl --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
