Affiliation: | 1. Department of Hydraulics and Sanitation, School of Engineering of São Carlos, University of São Paulo, Av. Trabalhador São Carlense, 400, 13566-590 São Carlos, SP, Brazil;2. Department of Biology, Federal University of São Carlos, UFSCar, João Leme Dos Santos Highway, Km 110, 18052-780, Sorocaba, SP, Brazil;3. Department of Chemical Engineering, Federal University of São Carlos, Rod Washington Luiz, Km 235, SP 310, 13565-905 São Carlos, SP, Brazil;1. Laboratory for Process Engineering, Environmental, Biotechnology and Energy (LEPABE), Faculty of Engineering of University of Porto, Rua Roberto Frias s/n, 4200-465, Porto, Portugal;2. ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal;3. Chemical and Biomolecular Engineering Department, University of Cantabria, Av. Los Castros 46, 39005, Santander, Spain;1. College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China;2. Institute of New Energy and Energy-Saving & Emission-Reduction Technology, Hunan University, Changsha 410082, China;1. College of Materials Science and Engineering, Sichuan University, Engineering Research Center of Alternative Energy Materials & Devices, Ministry of Education, Chengdu 610065, PR China;2. Collaborative Innovation Center of Sustainable Energy Materials, Guangxi Key Laboratory of Electrochemical Energy Materials, Guangxi University, Nanning, 530004, PR China |
Abstract: | Research focused on reusing lignocellulosic waste has been gaining ground, both for the purpose of obtaining energy from renewable sources, as well as for reducing feedstock costs and preventing environmental pollution. Despite being currently evaluated as a promising feedstock, large-scale application of lignocellulosic waste to obtain bioenergy is still scarce. One of the obstacles in terms of reusing it is its recalcitrant composition, often requiring pretreatment applications to break its fibers, increasing its bioavailability. In addition to the type of substrate, there are many operational parameters that may affect the process efficiency, including the type of reactor, temperature, pH, inoculum source, among others. Considering this, it is interesting to consider using statistical tools instead of “one-factor-at-a-time” methods for simultaneous optimization of these variables to increase the production of value-added compounds, such as Plackett-Burman screening design and Central Composite Rotational Design. In this context, this review aimed at compiling data regarding obtaining value-added compounds, focusing on bio-H2 and bio-CH4, from different lignocellulosic waste, such as sugarcane bagasse, citrus peel waste, coffee and cereal husks, brewer's spent grain, cocoa processing waste, sawdust, among others, considering the main operational parameters involved (temperature, pH, inoculum) and the type of pretreatment applied (physical, chemical and/or biological). The results described here may support future research on reusing residual lignocellulosic waste, in addition to elucidating the importance of different operational parameters to convert this waste into H2 and/or CH4. |