# Technology-Economy-Policy: Biochar in the Low-Carbon Energy Transition--A Review
## 2 Biomass  
Biomass is a renewable resource that has been utilized by humans since prehistoric times [22]. It encompasses all organic matter of plant or animal origin found in the biosphere, including materials derived from their natural or artificial processing [23; 24; 25; 26; 27]. Mankind has been using biomass since ancient times and the first reports of the intentional human use of biomass date back about a million years. Researchers have discovered that the earliest consciously utilized by-products of biomass combustion were ash and charcoal, which were employed in prehistoric paintings located in caves that are over 40,000 years old [28]. Since early historic times, ashes have also been used in agriculture as a fertilizer to fertilize soils [29; 30]. There is a current growing interest in biomass. It is mainly caused by the threats of climate change due to increased greenhouse gas emissions into the atmosphere and the search for alternative energy sources [23]. In addition, biomass is a readily available resource worldwide [31]. We consider biomass to be wood, its residues and by-products, i.e., wood chips and sawdust, agricultural residues such as quinoa, rice husks, and manure, as well as waste from the paper industry and the biogenic fraction of household waste and wastewater [29; 32].  
Rising living standards and economic development have resulted in a sharp increase in the production of bio-waste (organic, agricultural, and wood waste). [PERSON] et al. (2021) report that the number of crops wasted by European residents in a year is 700 million tons [33; 34]. In 2017, the European Union generated biological waste of various origins equivalent to 144 kilotons of oil [33], of which 70% was incenerated directly or after mechanical crushing (compression), nearly 12% was used for biogas production, and the remaining 6% of bio-waste was landfilled or compost [35]. Commonly used technologies for agricultural waste disposal, i.e., composting or open burning, result in the release of greenhouse gases such as CH\({}_{4}\), N\({}_{2}\)O, and min. pollutants into the atmosphere such as H\({}_{2}\)S, SO\({}_{2}\), and NH\({}_{3}\). Consequently, the potential for the reutilization of agricultural waste diminishes as a result of such incineration [36]. One option for utilizing the biomass from agricultural waste is to produce biochar from it via pyrolysis. Producing biochar from biomass is an efficient and environmentally friendly method of processing it. The main raw materials for biochar production are animal exceta, agricultural and forestry residues, industrial bio-waste, and marine and aquatic organisms, etc. Biomass pyrolysis produces a range of solids, liquids, and gases [37]. Biomass is an indispensable part of sustainable energy development [5]. The use of biomass to generate thermal energy does not contribute to the accumulation of CO\({}_{2}\) in the atmosphere. During conversion, biomass emits approximately the same amount of carbon as is taken up during plant growth, thus helping to reduce greenhouse gas emissions. In addition, numerous studies and technical advances involving crop production and biomass conversion have resulted in higher biomass utilization efficiency at a lower cost compared to earlier years [23]. In the 19 th century, the massive biomass transformation technology was direct combustion, mainly to produce energy in the form of heat. Advances in science and research and development and innovation by many researchers and scientists have led to the emergence of new concepts and technologies for converting biomass into a variety of products such as chemicals, commodities, heat, and most importantly, electricity [22].