tailieunhanh - Alternative Technologies for Biofuels Production in Kraft Pulp Mills—Potential and Prospects

With combined power and heat generation (cogeneration) the waste heat incurred during engine operation is recovered and utilized to satisfy thermal system process requirements for low- grade steam and/or hot water. In many cases this utilization of waste heat results in overall systems of efficiencies of up to 90+% (thermal + electrical). This efficient form of energy conversion is able to achieve primary energy savings of about 40% using gas engine cogeneration systems, compared with conventional separate power and heat generation. Figure 10 represents a typical Sankey diagram illustrating the Electrical/Thermal energy utilization from a typical Jenbacher gas reciprocating engine. In addition, the Sankey diagram also identifies the various heat sources from. | Energies 2012 5 2288-2309 doi en5072288 OPEN ACCESS energies ISSN 1996-1073 journal energies Review Alternative Technologies for Biofuels Production in Kraft Pulp Mills Potential and Prospects Marcelo Hamaguchi 1 Marcelo Cardoso 2 and Esa Vakkilainen 1 1 Lappeenranta University of Technology LUT Energy Lappeenranta 20 FI-53581 Finland E-Mail 2 Federal University of Minas Gerais UFMG Av. Antônio Carlos 6627 Pampulha Belo Horizonte-MG 31270-901 Brazil E-Mail marcelocardoso@ Author to whom correspondence should be addressed E-Mail Tel. 358-46-643-7042 Fax 358-5-621-6399. Received 22 May 2012 in revised form 21 June 2012 Accepted 2 July 2012 Published 6 July 2012 Abstract The current global conditions provide the pulp mill new opportunities beyond the traditional production of cellulose. Due to stricter environmental regulations volatility of oil price energy policies and also the global competitiveness the challenges for the pulp industry are many. They range from replacing fossil fuels with renewable energy sources to the export of biofuels chemicals and biomaterials through the implementation of biorefineries. In spite of the enhanced maturity of various bio and thermo-chemical conversion processes the economic viability becomes an impediment when considering the effective implementation on an industrial scale. In the case of kraft pulp mills favorable conditions for biofuels production can be created due to the availability of wood residues and generation of black liquor. The objective of this article is to give an overview of the technologies related to the production of alternative biofuels in the kraft pulp mills and discuss their potential and prospects in the present and future scenario. Keywords biofuels black liquor kraft pulp mill wood residues 1. Introduction The need to turn away from the fossil fuel era has opened new opportunities for the use of products from renewable .