the environment. There is also evidence that a particular biomass process can cause greenhouse gas emissions as fossil fuels. Biomass constitutes a wide variety of materials such as lignocellulosic biomass (wood waste, crop residues, rice husk, sawdust and agricultural residues), micro and macroalgal biomass, animal residues, municipal solid waste, sewage sludge, and industrial waste (bagasse). Due to their complex nature, high moisture content, low pH, micro and macronutrients, and C/N ratio imbalance, these residues are slow in degradation on exposure to the environment. To overcome these impacts and for the cheapest energy production, many research works are still in progress to meet the world’s energy crisis via renewable resources. This chapter will give a detailed account of the biomass effect, the energy crisis, biomass impact, and the efficient biomass conversion into energy through developed technology.
Keywords: Biomass, lignocellulosic wastes, biomass utilization, alternate fuel, biomass impact, energy technology
3.1 Introduction
Biomass becomes one of the alternative energy resources to meet the demand for fossil fuels all over the world. The most commonly used biomass for energy conversion includes freshwater and marine water micro and macroalgal biomass, agricultural and forest residues, industrial biomass, municipal waste, food waste, and sewage [1]. The Indian Ministry of New and Renewable Energy (MNRE), considering power generation from biomass efficiency, has promoted many biomass utilization programs through efficient technology. India is one of the leading countries that utilize nearly 30% of biomass as a primary energy resource. About 500 million metric tons of biomass per annum is available in India and the significant biomass contribution from agricultural and forestry residues with 120 to 150 million metric tons [2]. Globally, the distribution of energy output from renewable resources differs from the energy situation in India. Power generation in the world from hydro (62.95%) is higher than other resources, whereas, in the case of India, energy production from solar (68.33%) is higher (Figure 3.1) [3, 4]. India mostly generates energy from biomass like rice stalk, coir pith, sugarcane bagasse, and fruit waste. About 18,000 MW of power was generated from agriculture and forestry residues in India, whereas 7000 MW is from bagasse from sugar mills [2]. India has a high potential to generate electricity from renewable resources (Figure 3.1).
Figure 3.1 (a) Global status of renewable energy distribution from renewable and waste resources in 2020 [3]; (b) Distribution of Renewable energy in India in 2020 [4].
Biomass conversion into energy causes greenhouse emissions as fossil fuels, deforestation, pollution, and water shortage. To prevent this impact, scientists are concerned about developing efficient technology for eco-friendly conversion. Biomass is considered a carbon-neutral renewable source, releases atmospheric CO2 on the combustion that can be further utilized by plants, trees, crops, and aquatic plants (micro and macroalgae) photosynthesis process. Biomass conversion provides occupation to rural individuals. In this chapter, the biomass impact on the environment and its efficient conversion were reviewed and compiled. An overall review of the emerging trends for biomass conversion was designed using BioRender.com and presented in a flowchart (Figure 3.2).
3.2 Non-Renewable Energy Resources: Crisis and Demand
Global energy demand mainly depends on non-renewable resources [10], an abundant natural resource for electrical power, emitting greenhouse gas on combustion [11]. The effects of the continuous use of fossil fuels include environmental pollution, cost expensive, political disturbances, and impact on the tourism industry. The energy crisis’s main challenges are climate changes and the effects of depletion [11]. Reasons behind the energy crisis are vast and varied viz., overconsumption, use of electronic gadgets, congestion of people, less economic development, the slow establishment of energy plants, waste of power, inadequate dispersal systems, significant hazards, and natural disasters, conflict, and fights, and various agents [12, 13]. According to data published by the International Renewable Energy Agency (IRENA), until 2019, CO2 emissions in India were rising with an increase in energy demand [3] (Figure 3.3). In 2020, however, due to the lockdown resulting from Covid-19, CO2 emissions, relative to energy demand, CO2 emissions were substantially reduced [14].
Figure 3.2 Biomass categories, various processes of conversion and biofuel products [5–9].
The energy crisis in the world means energy diminishes as the demand for energy from limited non-renewable natural resources increases. But still, the energy market would rise rapidly in the upcoming years [12]. The world’s energy crisis and demand increase slowly, and all countries in the world faced an oil crisis in 1973 and an energy crisis in 1979 [15]. The non-renewable resource takes nearly hundreds of thousands of years to replenish. The energy crisis facing the world at present is higher than the 1970s energy crisis. The government and scientists of all countries aim to control the energy crisis and to meet energy demand using biomass and other renewable resources. The use of bioenergy emits nearly 4,096 thousand tonnes of CO2-eq/year as greenhouse gas emissions [16]. India’s energy generation from renewable resources rose to 113.20 billion units (BU) in 2020 [17].
Figure 3.3 Energy consumption and CO2 emission in India [3].
Energy insecurity is primarily due to cooking scarcity and a higher energy insecurity rate in larger nations [18]. The change in cost is low for all fossil fuels, but the corresponding price elasticity is high for consumption. Accordingly, the rise in the general price level triggered by the reform of subsidies would reduce actual earnings and have similar healthcare consequences in India [19]. Amrutha et al. [20] reported that Feed-in Tariff (FIT) and Renewable Energy Certificate (REC) schemes efficiently operated in India would provide renewable energy utilities with possibilities to benefit from cheaper rates [20].
3.3 Environmental Impacts and Control by Biomass Conversion
Environmental impacts are of primary importance during biomass conversion [21]. In the current status, biomass could be efficiently converted by physical and chemical processes into solid, liquid, and gaseous fuels. Release of gases and aerosols on biomass combustion into the atmosphere influences the quality of regional climate, visibility, global ozone composition, biogeochemical cycles, and the earth’s radiative expenditure [22]. One of the best ways to prevent environmental pollution is effective biomass conversion into renewable power generation. The energy products like biogas produced from various biomass waste are viz., tannery waste [23]; fish industrial processing waste and fish crude oil waste [24]; cattle slaughterhouse waste [25], biodiesel production from wet sewage sludge with 85% water content [26] and bioethanol conversion from paddy straw and food waste [27]; Spirulina and molasses [28] are the practical solution for control of environmental impact.
3.3.1 Biomass and Its Various Sources for Energy Conversion
