Burning fossil fuels is a major contributor to global warming and climate change, threatening biodiversity and presenting challenges for scientists and policymakers. To address these issues and promote sustainable development, bioenergy is based on efficiently utilizing biomass resources such as biomass feedstock for energy. Moreover, intensified global changes adversely affect our environment, signifying the importance of biomass and energy conservation research as a re-emerging topic of scientific interest. This study aims to comprehensively review the existing research trends, knowledge gaps, and future research in this field. A scientometric analysis was conducted using CiteSpace based on 1177 articles retrieved from the Web of Science Core Collection from 2000 to 2021. The leading countries, authors, and institutions are the USA, the Chinese Academy of Science, and Prof. Dr. Mehdi Bidabadi, respectively. The “Biomass and Bioenergy” is a prominent journal. European and North American countries collectively contribute around 73% of the publications. While there has been an increasing trend in publications over time, effective cooperation among institutions and authors, especially in developing countries, remains weak. The current research hotspots include “metabolic pathway”, “Clostridium ljungdahlii”, “short-term harvesting”, “anaerobic digestion”, “environmental impacts”, and so on. Future research will focus on cutting-edge techniques, the potential of biomass feedstocks for bioenergy, and the role of biomass feedstocks in mitigating climate change. This review provides comprehensive and valuable information for researchers, institutions, and policymakers to develop an effective, environmentally friendly, and sustainable strategy to cope with global environmental issues.