Recent Advances in Biomass Pyrolysis Processes for Bioenergy Production: Optimization of Operating Conditions

Abstract

Bioenergy has emerged to be among the primary choices for the short- and medium-term replacement of fossil fuels and the reduction in greenhouse gas (GHG) emissions. The most practical method for transforming biomass into biofuel is thermochemical conversion, which may be broken down into combustion, torrefaction, pyrolysis, hydrothermal liquefaction, and gasification. In this study, producing biofuels using a biomass pyrolysis process was investigated. This study explored the pyrolysis process and operating conditions to optimize the process parameters to maximize the desired product yields and quality. The pyrolysis process produces three main products, which are bio-oil, bio-char, and gas. There are three classifications for the pyrolysis method, with each of them producing a majority of a certain product. First, slow pyrolysis is conducted in the temperature range of 300–950 °C and residence time of 330–550 s. It produces around a 30% oil yield and 35% char yield, and thus, the majority yield of slow pyrolysis is char. Second, fast pyrolysis produces around 50% oil, 20% char, and 30% gas yields with a temperature range of 850–1250 °C and a residence time of 0.5–10 s. The average yield of flash pyrolysis was found to be 75% bio-oil, 12% bio-char, and 15% gas, which is conducted within less than 1 s. It was reported that the pyrolysis of biomass was simulated using ASPEN Plus, where the effects of several parameters, such as the temperature, heating rate, and residence time, on the product yield and composition were investigated. Pyrolysis was performed under different conditions ranging from 400 to 600 °C. The effects of different catalysts on the pyrolysis process were studied. It was found that the addition of a catalyst could increase the yield of bio-oil and improve the quality of the product. The optimal operating condition for the pyrolysis process was determined to be a temperature of 500 °C, which resulted in a higher bio-oil yield. It was found that the biofuel yield was enhanced by selecting appropriate raw materials, such as rice husk, along with the pyrolysis temperature (e.g., 450 °C) and particle size (350–800 µm), and using a low residence time and pressure.

Thermochemical Transformation of Municipal Household Solid Waste Fractions into Bio-Oils and Bio-Adsorbents

“…For thermal pyrolysis, slow pyrolysis is beneficial for oil formation and hinders gas formation. This phenomenon is different from the observed trend of biomass with respect to the warming rate Aboelela et al [61].…”

Assessing the Potential of Teff Husk for Biochar Production through Slow Pyrolysis: Effect of Pyrolysis Temperature on Biochar Yield

“…This thermochemical process decomposes biomass in the absence of oxygen to produce biochar [14,15]. According to research reported elsewhere, the temperature range for slow pyrolysis of biomass is typically between 300 and 800 • C [16][17][18], but recent studies suggest that it can range from 300 to 950 • C [19]. Pyrolysis is a complex process that involves various chemical reactions that occur instantaneously [20].…”

Evaluation of Growth and Energy Parameters of One-Year-Old Raspberry Shoots, Depending on the Variety

“…The adverse effects of fossil-fuel use on the environment and public health have become the foundation for continuous research and development in regards to renewable energy [2]. Bioenergy has been recognized as a key alternative to fossil fuels, offering a potential for replacement in the short to medium term and contributing to the reduction of greenhouse gas emissions [3,4]. The primary challenge in bioenergy production is managing the supply chain while optimally considering economic, environmental, and social factors [5].…”