Environmental sustainability of bioethanol production from waste papers: sensitivity to the system boundary

The production of bioethanol from various waste papers (newspaper, office paper, magazine and cardboard) was evaluated from an environmental standpoint. ‘Cradle-to-grave’ (or ‘well-to-wheel’) analyses were performed using a Life Cycle Assessment (LCA) approach with the aims of identifying the key drivers of environmental impact in the bioethanol supply chains and of comparing the environmental footprints of various bioethanol supply chains with those of conventional petrol. Base cases (bioethanol production from various waste papers) and two state-of-the-art cases including pre-treatment of office paper by dilute acid (DA) and of newspaper by an oxidative lime (OL) process were constructed using laboratory data, expert consultations, literature values, and simulation in AspenPlus™ software. Contribution analysis showed enzyme production needed for hydrolysis of the papers to be the main contributor to the environmental profiles for bioethanol in the base cases. The production of process heat and hydrochloric acid respectively were the main contributors to the bioethanol environmental profiles for office paper-to-bioethanol with DA pre-treatment and newspaper-to-bioethanol with OL pre-treatment. Overall, bioethanol produced from newspaper, magazine paper and cardboard was found to have a lower environmental impact than the conventional transport fuel petrol. However, this conclusion is significantly affected by the system boundaries used for the analysis. When an expanded system boundary is applied to consider virgin and recycled paper production as the potential consequential effects within the bioethanol and petrol systems respectively, office paper-derived bioethanol systems emerge as the most environmentally favourable over petrol.

[1]  Sara González-García,et al.  Environmental performance of lignocellulosic bioethanol production from Alfalfa stems , 2010 .

[2]  David R Shonnard,et al.  Comparative Life‐Cycle Assessments for Biomass‐to‐Ethanol Production from Different Regional Feedstocks , 2008, Biotechnology progress.

[3]  Hartmut Spliethoff,et al.  Thermogravimetry as a tool to classify waste components to be used for energy generation , 2004 .

[4]  Adisa Azapagic,et al.  Bioethanol from waste: Life cycle estimation of the greenhouse gas saving potential , 2009 .

[5]  Reinout Heijungs,et al.  Bias in normalization: Causes, consequences, detection and remedies , 2007 .

[6]  J Villegas,et al.  Life cycle assessment of biofuels: energy and greenhouse gas balances. , 2009, Bioresource technology.

[7]  T. Seager,et al.  Comparative Life Cycle Assessment of Lignocellulosic Ethanol Production: Biochemical Versus Thermochemical Conversion , 2010, Environmental management.

[8]  Gjalt Huppes,et al.  Allocation issues in LCA methodology: a case study of corn stover-based fuel ethanol , 2009 .

[9]  Mahdi Sharifzadeh,et al.  Technology performance and economic feasibility of bioethanol production from various waste papers , 2012 .

[10]  Islam Ahmed,et al.  Evolution of syngas from cardboard gasification , 2009 .

[11]  A L Stephenson,et al.  The environmental and economic sustainability of potential bioethanol from willow in the UK. , 2010, Bioresource technology.

[12]  G. Sakellaropoulos,et al.  Pyrolysis kinetics and combustion characteristics of waste recovered fuels , 2009 .

[13]  M. Holtzapple,et al.  Oxidative lime pretreatment of high-lignin biomass , 2001, Applied biochemistry and biotechnology.

[14]  C. Tseng,et al.  Pyrolysis products of uncoated printing and writing paper of MSW , 2002 .

[15]  Benoit Gabrielle,et al.  Life-cycle assessment of straw use in bio-ethanol production: a case study based on biophysical modelling. , 2008 .

[16]  P. N. McFarlane,et al.  Anaerobic digestion of stillage from a pilot scale wood-to-ethanol process. II: Laboratory-scale digestion studies , 1986 .

[17]  M. Holtzapple,et al.  Selectivity and delignification kinetics for oxidative short‐term lime pretreatment of poplar wood, part I: Constant‐pressure , 2011, Biotechnology progress.

[18]  Lian Pin Koh,et al.  The biofuel potential of municipal solid waste , 2009 .

[19]  K. Paustian,et al.  Energy and Environmental Aspects of Using Corn Stover for Fuel Ethanol , 2003 .

[20]  M. Ota,et al.  Pyrolysis Kinetics of Newspaper and Its Gasification , 2009 .

[21]  M. Wayman,et al.  Pretreatment of waste paper for increased ethanol yields , 2005, Biotechnology Letters.

[22]  T. Clark,et al.  Anaerobic digestion of wood ethanol stillage using upflow anaerobic sludge blanket reactor , 1987, Biotechnology and bioengineering.

[23]  J. Hustad,et al.  Pyrolysis characteristics and kinetics of municipal solid wastes , 2001 .

[24]  H. Wenzel,et al.  Paper waste - recycling, incineration or landfilling? A review of existing life cycle assessments. , 2007, Waste management.

[25]  Nicholas E. Korres,et al.  Key issues in life cycle assessment of ethanol production from lignocellulosic biomass: Challenges and perspectives. , 2010, Bioresource technology.

[26]  Henrik Wenzel,et al.  Cradle-to-gate environmental assessment of enzyme products produced industrially in denmark by novozymes A/S , 2007 .

[27]  T. H. Christensen,et al.  Anaerobic digestion and digestate use: accounting of greenhouse gases and global warming contribution , 2009, Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA.

[28]  P. Fluri,et al.  Use of fixed film and CSTR reactor for anaerobic treatment of stillage of wood hydrolysate , 1982, Biotechnology Letters.

[29]  Heather L MacLean,et al.  Life cycle assessment of switchgrass- and corn stover-derived ethanol-fueled automobiles. , 2005, Environmental science & technology.

[30]  Bryan M. Jenkins,et al.  Biomass fueled fluidized bed combustion: Atmospheric emissions, emission control devices and environmental regulations , 1994 .