http://chem-eng-net.com/2009/09/is-biodegradable-waste-bags-%e2%80%98more-damaging%e2%80%99-than-pe/ Totally Everything about Chemical Engineering Sat, 01 Oct 2011 02:06:55 +0000 hourly 1 http://wordpress.org/?v=3.3 http://chem-eng-net.com/2009/09/is-biodegradable-waste-bags-%e2%80%98more-damaging%e2%80%99-than-pe/comment-page-1/#comment-4972 Alex Singbeil Tue, 15 Dec 2009 15:23:25 +0000 http://chem-eng-net.com/?p=85#comment-4972 The main complaint I have with this story is that it does not emphasise that the study only looked at “waste” bags, these are bags that I assume contain non-organics/non-recyclables because the study assumes that the end of life for these bags is incineration. No scenarios are presented where bags are disposed in other ways. It makes sense, if you assume incineration, that the impact will be dominated by the mass of raw materials. This study proves nothing regarding the use of biodegradable bags in composting or anaerobic digestion programs. If the study had to look at PE bags vs. bio bags with composting as the end of life assumption, the extra costs of dealing with shredded plastic in the compost would probably produce different results. It’s about using the right bag for the job. The main complaint I have with this story is that it does not emphasise that the study only looked at “waste” bags, these are bags that I assume contain non-organics/non-recyclables because the study assumes that the end of life for these bags is incineration. No scenarios are presented where bags are disposed in other ways. It makes sense, if you assume incineration, that the impact will be dominated by the mass of raw materials. This study proves nothing regarding the use of biodegradable bags in composting or anaerobic digestion programs. If the study had to look at PE bags vs. bio bags with composting as the end of life assumption, the extra costs of dealing with shredded plastic in the compost would probably produce different results. It’s about using the right bag for the job.

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