What is the difference between energy-from-waste (EFW) and cogeneration, and why is the latter more efficient (let's compare electricity to electricity)? Aren't both essentially incineration?
See below from pages 9 and 12 (respectively) from "The Environmental Impact of Paper Waste Recycling: A Comparative Study" (emphasis added):
In fact, due to the energy requirements of paper production, combustion of unusable fibre can be used even more effectively when integrated into milling. Because a significant portion of the energy required for paper production is thermal, combustion of waste paper can be used directly to fuel the process. Wood fibre cogeneration plants, which generate both electricity and useable thermal energy, obtain efficiencies of 25-30% for electrical generation (mean of 27.5%), and up [to] 75% overall when heat is recovered (FAO 1990). So if the average thermal content of paper is assumed to be 17.3 GJ/T (Morris 1996), a maximum of 2.60 GJ/T could be recovered as electricity through EFW, but 4.76 GJ/T could be recovered through cogeneration, plus an additional 8.23 GJ/T in thermal energy (see Appendices 2, 3). This represents an improvement of 2.16 GJ/T in electrical production, and 10.4 GJ/T overall.