Production of Biochar from Biomass

Biochar is a kind of charcoal that’s produced from biomass using pyrolysis technology. As climate change continues to be a growing concern, biochar has been sought for its environmental applications. It is both cost effective and environmentally sound in terms of being a soil additive and renewable fuel. When used as a soil amendment, biochar has been shown to improve water holding capacity and absorb more nutrients. Biochar also sequesters carbon dioxide when applied to soil, and can also be used as a replacement for activated carbon that is prepared from coal. The objectives of this research was to produce biochar from biomass and study biochar’s properties. A thermogravimetric analysis (TGA) was used to measure the weight loss behavior of the wood sample (biomass) as the temperature increased. The biomass was heated to 500 °C in a nitrogen atmosphere and then cooled in nitrogen to prevent combustion of biochar. The overall yield of biochar was 15%. Elemental analysis of biomass shows the composition of the sample to be mostly carbon and oxygen with fewer amounts of hydrogen and nitrogen. Surface area of the prepared biochar was 305 m2/g, which is approximately 100 times the surface area of raw biomass. Biochar’s higher porosity will allow for greater absorption of nutrients when applied to soil

Analyzing the Rare Earth Elements (REEs) and Trace Metals in Tailings

In the process of producing bitumen from oil sand, a by-product called tailings is produced. Tailings are a mixture of clay, fine particles, water, solvent and residual bitumen. The industry’s current approach is to leave them in tailings ponds; however, that may cause environmental impacts to the ecosystems around them due in part to the toxic trace metals found in them. Research has shown that there are also valuable rare Earth elements (REEs) present in tailings. REEs found in tailings include Cerium, Neodymium, Lanthanum etc. Iron, Titanium, and Zirconium are not considered REEs but are still valuable enough to be extracted. The objective of this research was to determine the concentration of REEs and trace metals in bitumen froth treatment tailings (FTT). Our research team used acid digestion and inductively coupled plasma mass spectroscopy (ICP-MS) to measure the concentration of REEs and trace metals in several samples of FTT ash. We learned that Cerium was the most prevalent REE in tailings samples (>1000ppm), followed by Neodymium and Lanthanum. Zirconium was the most prevalent trace metal found in this tailings sample (>1000ppm), followed closely by Vanadium. Knowing the exact concentration of harmful trace metals in tailings will allow us to determine the extent of tailings ponds environmental effect and toxicity. Collecting and selling expensive metals found in tailings could be the start of a new precious metals economy in Alberta, which would provide new investment opportunities and jobs. This would also encourage corporations to invest in finding new ways to extract these precious metals, resulting in more purified tailings and less tailings overall going into tailings ponds

A Review of Hydrothermal Liquefaction of Biomass for Biofuels Production with a Special Focus on the Effect of Process Parameters, Co-Solvents, and Extraction Solvents

Hydrothermal liquefaction is one of the common thermochemical conversion methods adapted to convert high-water content biomass feedstocks to biofuels and many other valuable industrial chemicals. The hydrothermal process is broadly classified into carbonization, liquefaction, and gasification with hydrothermal liquefaction conducted in the intermediate temperature range of 250–374 °C and pressure of 4–25 MPa. Due to the ease of adaptability, there has been considerable research into the process on using various types of biomass feedstocks. Over the years, various solvents and co-solvents have been used as mediums of conversion, to promote easy decomposition of the lignocellulosic components in biomass. The product separation process, to obtain the final products, typically involves multiple extraction and evaporation steps, which greatly depend on the type of extractive solvents and process parameters. In general, the main aim of the hydrothermal process is to produce a primary product, such as bio-oil, biochar, gases, or industrial chemicals, such as adhesives, benzene, toluene, and xylene. All of the secondary products become part of the side streams. The optimum process parameters are obtained to improve the yield and quality of the primary products. A great deal of the process depends on understanding the underlined reaction chemistry during the process. Therefore, this article reviews the major works conducted in the field of hydrothermal liquefaction in order to understand the mechanism of lignocellulosic conversion, describing the concept of a batch and a continuous process with the most recent state-of-art technologies in the field. Further, the article provides detailed insight into the effects of various process parameters, co-solvents, and extraction solvents, and their effects on the products’ yield and quality. It also provides information about possible applications of products obtained through liquefaction. Lastly, it addresses gaps in research and provides suggestions for future studies

Steam Regeneration of Polyethylenimine-Impregnated Silica Sorbent for Postcombustion CO₂ Capture: A Multicyclic Study

Steam regeneration of polyethylenimine (PEI)-impregnated commercial grade silica was investigated in a packed bed reactor. Adsorption was performed at 75 °C under 10% CO₂/N₂, and desorption was carried out under steam at 110 °C for 20 consecutive cycles. CO₂ adsorption capacity was found to decrease by 9 mol % over the period of 20 cycles. No evident signs of sorbent degradation due to PEI leaching or changes in surface morphology and amine functionalities were observed upon characterization of the sorbent after the cyclic study. Most of the loss in adsorption capacity was associated with thermal degradation of the sorbent during drying under N₂ after steam stripping at 110 °C. The desorption kinetics during steam stripping was found to be much faster than during N₂ stripping. Over 80% of the total CO₂ was released within the first 3 min of steam injection into the reactor. A separate packed bed study was conducted to investigate the influence of moisture content (5.3–14.7 vol %) in flue gas on the CO₂ adsorption capacity of PEI-impregnated silica. The presence of moisture had a positive impact on CO₂ uptake of the sorbent; a 4–9 mol % increase in CO₂ uptake was observed in comparison to the adsorption under dry conditions. However, the presence of moisture increased the heat of regeneration of the sorbent significantly. It was calculated that the energy demand increased approximately 2-fold on introduction of 14.7% moisture compared to that of dry flue gas