This study provides insight into the decolorization strategy for crude glycerol obtained from biodiesel production using waste cooking oil as raw material. A sequential procedure that includes physico-chemical treatment and adsorption using activated carbon from oil palm biomass was investigated. The results evidenced decolorization and enrichment of glycerol go hand in hand during the treatment, achieving >89% color removal and > 98% increase in glycerol content, turning the glycerol into a clear (colorless) solution. This is attributed to the complete removal of methanol, free fatty acids, and triglycerides, as well as 85% removal of water, and 93% removal of potassium. Properties of the resultant glycerol met the quality standard of BS 2621:1979. The economic aspects of the proposed methods are examined to fully construct a predesign budgetary estimation according to chemical engineering principles. The starting capital is proportionate to the number of physical assets to acquire where both entail a considerable cost at USD 13,200. Having the benefit of sizeable scale production, it reasonably reduces the operating cost per unit product. As productivity sets at 33 m3 per annum, the annual operating costs amount to USD 79,902 in glycerol decolorization. This is translatable to USD 5.38 per liter glycerol, which is ~69% lower compared to using commercial activated carbon.
This study presents a comprehensive techno-economic assessment of woodchip-derived bio-adsorbent production using a self-sustained, pool-type carbonization reactor designed for decentralized and low-energy deployment. The reactor operates at 300-700 °C with a heating rate of 5-7 °C/min, processing 3-5 tonnes of biomass per 7-day batch and yielding up to 1 tonne of biochar (20 wt.%), with an annual production capacity of 48 tonnes. The biochar exhibited strong adsorptive performance in landfill leachate treatment, achieving removal efficiencies of 73.2% for COD, 97.3% for total Kjeldahl nitrogen, and 768.8% for ammoniacal nitrogen, surpassing other biomass-derived chars. Physicochemical characterization showed a substantial increase in BET surface area from 0.91 to 232.1 m2/g and a reduction in average pore size from 324.1 to 15.4 nm, accompanied by a fixed carbon increase from 1.1% to 72.4%, indicating enhanced mesoporosity and aromaticity. An economic assessment based on a 10-year projection yielded a unit production cost of USD 394 per tonne, a net present value (NPV) of USD 36,905, an internal rate of return (IRR) of 94.6%, and a rate of return (ROR) of 92.5%, outperforming most comparable systems that report IRRs between 9 and 55% under higher capital and energy inputs. This study demonstrates that the integration of low-cost infrastructure, self-sustained operation establishes this pyrolysis system as a practical and scalable solution for circular bioeconomy implementation, particularly in resource-constrained and rural settings.