Clean Technologies

Arabinoxylans (AX) and their oligosaccharides (AXOS) have potential as functional ingredients. The emergence of biorefineries, leading to more Distillers Dried Grains with Solubles (DDGS) entering the animal feed market, encourages commercial production of AX products. Extracting AX from the two components of DDGS offers the opportunity to increase the biorefinery’s product portfolio and reduce costs. This paper explores AX extraction from solubles and wet grain, using a Gunt pilot-scale bioethanol plant to produce the two streams. After fermentation and distillation, solids were separated from the liquid to give Wet Distillers Grain (WDG), from which alkaline hydrogen peroxide extraction of water-unextractable AX (WUAX) was performed. The water-extractable AX (WEAX) was recovered from the solubles by ultrafiltration and ethanol precipitation. Both extracts were tested for suitability for AXOS production and characterised for their functionality. 10 kg of wheat yielded 3.2 litres of ethanol at 90% purity, 85 g of WUAX (51.6% purity, 110 kDa) and 92 g of WEAX (74.2% purity, 70 kDa). Enzymatic conversion of WEAX into oligosaccharides was 53%, whereas WUAX was unsusceptible to enzyme hydrolysis. Both AX fractions showed interactions with starch that could increase the shelf life of bakery products. AX-based products could be produced from a range of agricultural and biorefinery waste or low value streams, with the global market potentially > £1 billion per annum.

Anthropogenic CO₂ emissions have accelerated climate change, prompting the need for effective capture technologies. Adsorption using clay-based sorbents offers an eco-friendly alternative, although performance often requires enhancement. This study explored mechanochemical modification of two halloysite-rich kaolin clay samples—iron-poor (Hal) and iron-rich (HalFe)—using locust bean gum and quillaja saponin and compared their CO₂ uptake with the calcined counterparts (CHal, CHalFe). All samples were characterized using standard techniques, and their CO₂ uptake was measured volumetrically across 0.1–20 bar and 15–35 °C. Modified sorbents showed enhanced mesoporosity and binding sites, increasing CO₂ uptake by up to 26% at 20 bar (11.85 mg/g) and 125% at 1 bar (2.25 mg/g). Calcination, however, reduced surface area and sorption capacity. Isosteric heat values remained within the physisorption range, as supported by FTIR, XRF, and XPS, which showed no bulk carbonate formation. These sorbents show lower CO₂ uptakes than conventional ones. Yet their low costs, abundance, biocompatibility, and solvent-free synthesis indicate strong potential for large-scale applications, especially for low-pressure implementations such as landfills. Further detailed studies on kinetics, thermodynamics, and sorbent regeneration are needed. Spent sorbents can potentially be repurposed for subsequent use in other applications, e.g., water treatment, construction materials, thereby minimizing waste production and supporting circular economy principles.

The widespread use of petroleum derivatives in industrial settings poses a challenge due to their toxicity and the difficulty of removing them from tanks, pipes, and equipment. Conventional degreasers are generally expensive, toxic, and harmful to workers’ health and the environment. In this study, an environmentally friendly biodetergent formulated from natural ingredients was produced in a pilot plant with 480 L h⁻¹ capacity, in 250 L homogenizers, at 3500 rpm and 80 °C, and its performance evaluated under different operating conditions. Furthermore, the biodetergent efficiency was compared with that of commercial degreasers commonly used in industrial settings. Stability tests indicated 100% stable emulsion with 2.0% fatty alcohol and 1.0% stabilizing gum after one week of storage. In application tests, the biodetergent promoted up to 100% removal of heavy fuel oil (OCB1) and diesel from metal surfaces, both in concentrated and (1:1 v/v) diluted forms. In direct comparisons, the product performed equally or better than commercial degreasers, notably removing >95% of OCB1 in 10 min and maintaining efficiency after multiple reuse cycles. Unlike acidic or solvent-based formulations, the biodetergent did not induce corrosion on pieces or release toxic vapors when applied to heated surfaces. In summary, the developed bioproduct demonstrated industrial scalability and high efficiency, constituting a sustainable alternative for petrochemical cleaning operations in onshore and offshore environments.