Biomass and Energy Production: Thermochemical Methods

Abstract

In this chapter, an overview of bioenergy importance toward energy systems with low (zero or negative) greenhouse gas emissions and general conversion technologies to produce different types of bioenergy products from various biomass feedstock is presented. The bioenergy products from biomass cover all physical phases including solid (biochar), liquid (bio-oil and bio-crude oil), and gases phase (bio syngas) which make them an interesting field in terms of both academic types of research and industrial scale. A discussion on the available technologies for thermochemical, biochemical, and extraction processes is presented, which is followed by some important parameters on each separate process that cause the optimum production rate and desired products. In addition, in the final part, an overview of the technology readiness level for the processes is reported.

Influence upon Biogas Production of the C/N Ratio and the Heavy Metal Incidence in the Manure Composition

“…It can contribute to the activity of microorganisms by influencing the chemical balance of NH3 and H2S [27] (p. 88-95).The optimal range in which they can develop is between 5.5 and 8.5 (almost a neutral pH). This range ensures the optimal functioning of methanogenic bacteria [28] (p. [44][45][46][47][48][49]. For a better functioning of the anaerobic digestion process, it is recommended to adopt a higher pH in the second stage than in the first [29] (p. 1253-1271).…”

“…Knowing the loading rate (OLR) raises the possibility to monitor the stability of the process, the methane yield, and the structure of the microbial community [47] (p. 103099). That is why it is important to know that OLR can positively or negatively influence the process of anaerobic digestion [48].…”

Catch and Cover Crops’ Use in the Energy Sector via Conversion into Biogas—Potential Benefits and Disadvantages

“…Hydrothermal conversion processes such as hydrothermal liquefaction (HTL), hydrothermal carbonization (HTC) and hydrothermal gasification HTG (supercritical water gasification) allow the conversion of wet biomass into biofuels, such as bio-crude oil, hydrochar and a mixture of combustible gases, respectively. These processes are carried out at temperatures of 100-700 • C and high pressures of 5-40 MPa in a liquid media or hot supercritical water [83]. However, technologies based on these processes are not yet widely used at a technical scale.…”