Opportunities for the integration of absorption heat pumps in the pulp and paper process.

Implementation of absorption heat pumps (AHPs) in a Kraft pulping process was studied using a new methodology for the optimal integration of those devices in a process. Two generic opportunities were identified for an energy and water optimized mill: (i) integration of a double lift chiller in the bleaching chemical making plant to produce chilled and hot water simultaneously, using MP steam as the driving energy and, (ii) installation of a single stage heat pump to concentrate the black liquor and produce useful hot water by upgrading heat from the bleaching effluent and using MP steam as driving energy. The principles of AHPs operation and their efficient integration into a process are described. The simple payback time (SPB) and net present value (NPV) were used to evaluate the interest of such implementations. Considering 63 $/MWh for the steam price, SPB of 2.7 and 1.7 years have been estimated for the two cases.

[1]  Saidas M. Ranade New insights on optimal integration of heat pumps in industrial sites , 1988 .

[2]  Reinhard Radermacher,et al.  Absorption Chillers and Heat Pumps , 1996 .

[3]  Thore Berntsson,et al.  Learning from experiences with Industrial Heat Pumps , 1997 .

[4]  K. Abrahamsson,et al.  Design and experimental performance evaluation of an absorption heat transformer with self-circulation , 1995 .

[5]  Nicolas Galanis,et al.  Wood chip drying with an absorption heat pump , 2008 .

[6]  Bodo Linnhoff,et al.  A User guide on process integration for the efficient use of energy , 1994 .

[7]  D. W Francis,et al.  Energy cost reduction in the pulp and paper industry - an energy benchmarking perspective , 2004 .

[8]  Louis Fradette,et al.  Retrofit of absorption heat pumps into manufacturing processes: Implementation guidelines , 2010 .

[9]  Andrea Costa,et al.  Economics of trigeneration in a kraft pulp mill for enhanced energy efficiency and reduced GHG emissions , 2007 .

[10]  D. W Francis,et al.  Energy cost reduction in the pulp and paper industry : an overview increased energy efficiency can lead to improved competitive advantage , 2001 .

[11]  Andrea Costa,et al.  Integration of absorption heat pumps in a Kraft pulp process for enhanced energy efficiency , 2009 .

[12]  Thore Berntsson,et al.  Integration of heat pumps in industrial processes , 1993 .

[13]  Thore Berntsson,et al.  Pinch analysis of a model mill: Economic and environmental gains from thermal processintegration in a state-of-the-art magazine paper mill , 2005 .

[14]  Mariya Marinova,et al.  Energy implications of water reduction strategies in kraft process. Part II: Results. , 2010 .

[15]  Gary A. Smook,et al.  Handbook for Pulp and Paper Technologists , 1982 .

[16]  G. Alefeld,et al.  Coefficient of performance of multistage absorption cycles , 1987 .

[17]  Felix Ziegler,et al.  Absorption cycles. A review with regard to energetic efficiency , 1993 .