Inherently Functionalized Carbon from Lipid and Protein-Rich Biomass to Reduce Ultraviolet-Induced Damages in Bituminous Materials

Abstract

This paper examines the merits of using an inherently functionalized carbon, referred to as biochar as a free radical scavenger. The biochar was made from thermochemical liquefaction of a blend of algae (rich in protein and nucleic acids) and manure (rich in lipid). Here, we studied biochar’s efficacy as a free-radical scavenger and ultraviolet blocker to qualify it as an anti-aging additive in construction, including roofing shingles made from the bituminous composite. The study’s results show that the addition of biochar to bitumen significantly reduced the aging of bitumen. All tested biochars made from various relative proportions of algae and swine manure were found to be effective at reducing the extent of aging; however, the biochar made from algae alone was the most effective. The algal biochar was found to be an effective antiaging additive delaying aging up to 36%, as evidenced by lower rheology and the chemistry-based aging index compared to those of control bitumen after being exposed to the same aging protocol. Algal biochar was found to be more effective than other studied biochar scenarios owing to its inherently functionalized nature. The latter result could be attributed to the high surface area and rich phenol functional groups in algal biochar, turning it into an effective free-radical scavenger. The study outcome highlights the applicability of this inherently functionalized carbon referred to as biochar in construction to enhance sustainability while promoting the circular economy and the biomass value chain.

Inherently Functionalized Carbon from Algae to Adsorb Precursors of Secondary Organic Aerosols in Noncombustion Sources

“…It has been documented that IFC made from algal biomass significantly delays the aging of bituminous composites. 22 Here, it is hypothesized that the observed delay in aging is partly due to a delayed loss of volatile oxygenated compounds of bitumen in the form of emissions. Among those volatiles are benzofuran, dibenzo-thiophene, and benzoic acid.…”

“…This can explain part of the delayed progress of aging observed in our recent study. 22 The following section explains the molecular modeling used to quantify the binding energy between the typical volatile compounds emitted from bitumen and the functionalized carbon.…”

“…17−21 The recent studies on an IFC derived from the thermochemical liquefaction of a blend of algae (rich in protein and nucleic acids) and swine manure (rich in lipids) indicated the merits of the newly made carbonaceous material as a free-radical scavenger that significantly reduces the aging of bitumen exposed to ultraviolet irradiation. 22 On the basis of the study results, the IFC made from algae alone performs even better than hybrid IFC made from algae and swine manure. The efficacy of algae IFC as a free-radical scavenger and ultraviolet blocker was attributed to the rather high surface area and rich phenol functional groups (C 6 H 5 -OH) in algal IFC.…”

“…Considering the urgent need for the development of alternative and renewable resources, algae are among the promising biomasses for energy production and other environmental applications. − In addition to algae’s capability in energy production, algae have a good record as a promising appropriate sorbent for CO 2 fixation. − The recent studies on an IFC derived from the thermochemical liquefaction of a blend of algae (rich in protein and nucleic acids) and swine manure (rich in lipids) indicated the merits of the newly made carbonaceous material as a free-radical scavenger that significantly reduces the aging of bitumen exposed to ultraviolet irradiation . On the basis of the study results, the IFC made from algae alone performs even better than hybrid IFC made from algae and swine manure.…”

Effects of Elemental Sulfur on the Aging Trajectory and Adhesion Characteristics of Rubber-Modified Bitumen

“…However, if liquefied rubber blends so thoroughly as to become indistinguishable from the bitumen matrix, sulfur oxidation would then occur throughout the material and could therefore make the mixture more susceptible to age-related hardening. Additionally, crumb rubber could act as a physical barrier to slow diffusion or as an oxygen sink in a manner similar to how carbon black or biochar may act as antiaging agents. Depending on the specific process, liquefaction of rubber could also remove antiaging additives like carbon black that would otherwise be retained in crumb rubber. , Similar considerations may also apply to elemental sulfur, where sulfur dissolved into the bitumen is less prone to sedimentation but more prone to oxidation.…”