• Oscar Bedzo
    Technoeconomic Analysis Lead


A dynamic and purpose driven chemical engineer with expertise in bioprocess development, process design, simulation and techno-economic evaluation through the several years of involvement in the bioeconomy space. He has developed, optimized and designed processes for the production of high value commodities, biofuels and nutraceuticals from an array of biomasses in a biorefinery concept. He also developed industrial scale simulations towards optimisation, value chain development, energy, economic and sustainability assessment of these processes. He is passionate about exploring relevant biorefinery technologies through experimental work and process simulations.

At Celignis, Oscar works in the bioprocess division and is committed to developing and optimizing technologies for efficient and cost effective valorisation of biomass feedstocks to offer clients the opportunity to make the best use of their feedstocks.

He is also the project manager of our involvement in the consortium based research project BIO4AFRICA, sponsored by the Horizon 2020 EU scheme. Celignis’ tasks in the BIO4AFRICA project are centred on the characterization of the biomass feedstocks and products associated with the technologies to be applied to generate sustainable solutions for the agri-food systems in rural Africa. Oscar also plays a pivotal role in our participation in the multi-partner research project EnXylaScope, funded by the Horizon 2020 research and innovation programme as the lead person responsible for conducting the techno-economic assessment of the developed technologies targeted at advancing the scope and industrial potential of xylan-debranching enzymes.

Expertise and Track-Record


Oscar has adept experience in bioprocess development. During his PhD, he developed an efficient and cost effective method of fructooligosaccharides production from sucrose by: (i) developing two immobilization methods for efficient use of the novel enzyme and (ii) optimizing the process parameter to significantly improve productivity. He also optimized the extraction of inulin as well as the enzymatic hydrolysis of Jerusalem artichoke and chicory inulins to produce inolooligosaccharides.

He also has experience in the application of pretreatment technologies such as steam explosion, hydrothermal treatment and solvents extractions targeted at maximum recovery of sugars from lignocellulosic feedstocks such as sugarcane bagasse and sweet sorghum for biofuel and bioproduct applications. He developed and optimized novel methods for the recovery of pectin from different streams of tobacco wastes. He is currently involved in the development of extraction technologies for the recovery of different types of xylans from a variety of lignocellulosic feedstocks.


Oscar has conducted several economic evaluations on several bioprocess technologies and product systems. During his PhD, he conducted comparative techno-economic studies on the biorefinery scenarios for production of prebiotics, biofuels and bioproducts. He has also worked with industrial partners to estimate the capital investment requirement and also assess the economic feasibility of biobased products from seaweed at a pilot scale.

Our techno-economic experts can work with you to evaluate the economic prospects of your technology or feedstock using the bench scale data. We apply accurate and realistic costing models to determine the CAPEX and OPEX of simulated and pilot scale processes which are then used to determine key economic indicators such as IRR, NPV and payback periods.

We provide comprehensive, objective and transparent results to help you obtain a good understanding of your process and its value chain as well as inform your budget and investment resource allocation. Our sensitivity analysis exposes the hotspots in the process flow as well as the main influencing parameters.

Process Design
and Simulation

Oscar has good experience in the development of advanced and detailed conceptual process flow diagrams from the lab scale process, highlighting scale up challenges and the process and engineering requirements for very unit operation in the process flow. With his proficient understanding of biological, chemical and physical systems, he has developed process simulations for several biorefinery scenarios using the appropriate modelling software. These simulations closely mimic the real life manifestation of the industrial process which is beneficial for R and D, mass and energy balance, equipment design and operation of the process or industrial plant. The simulation development significantly cuts down on unnecessary laboratory experiments, pilot scale runs and facilitates design by a convenient comparison of various process alternatives.

Carbohydrate Polymers
and Nutraceuticals

Oscar has a personal research interest in vast the spectrum of carbohydrate polymers and nutraceuticals that exists and their numerous applications. He has worked with a good number of these carbohydrates: including pectins, alginates, celluloses, and xylans. Understanding these carbohydrate polymers constitutes an integral aspect of their extraction mechanism and application as they are the main precursors for many biofuels and bioproducts. Celignis bioprocessing department is heavily involved in cataloguing the extraction technologies, characterizations and applications of these polymers

Project Management

Oscar is excelling at Celignis and is in charge of several projects ensuring that resources are being appropriately allocated and utilized towards meeting project targets, deliverables and milestones in a timely manner. He is building high-value relationships with project partners and clients in the concerted efforts to convert or develop valorisation technologies for biomass feedstocks towards the advancement of the bioeconomy.


PhD: In Chemical Engineering from Stellenbosch University, South Africa (2020) - 'Process improvements and techno-economic analyses for the production of short-chain fructose-containing oligosaccharides from sucrose and Jerusalem artichoke tubers”.

BSc: In Petrochemical Engineering from the Kwame Nkrumah University of Science and Technology, Ghana (2013).


Swart, L. J., Bedzo, O. K. K., van Rensburg, E., Gorgens, J. F. (2022) Pilot-scale xylooligosaccharide production through steam explosion of screw press-dried brewers spent grains, Biomass Conversion and Biorefinery 12: 1295-1309


Brewers spent grains (BSGs) represent the largest quantity of solid waste from brewing, while xylooligosaccharides (XOS) produced from BSG show promising applications in food, beverage and health products. Production of XOS from a Weiss and malt BSG was scaled-up in steam explosion hydrothermal treatment using process conditions from bench-scale liquid hot water optimisations in stirred batch reactors. Three levels of moisture (15, 25 and 32% dry matter) achieved by screw press dewatering were evaluated by varying the treatment temperatures and times. Results show the highest XOS yields (73.1%) were obtained, for both BSGs, at process condition selected (180 C, 10 min) with 25% initial dry matter content. These yields were higher than reported bench-scale optimisations (61%), but obtained using 60% less water; hence, initial dry matter content was an important variable affecting XOS yield. The pilot-scale steam explosion results provide a departing point for a cost-effective commercial production of XOS from BSG.

Allan, K. M., Bedzo, O. K. K., van Rensburg, E., Gorgens, J. F. (2021) The Microbial Devulcanisation of Waste Ground Tyre Rubber Using At ferrooxidans DSMZ 14 , 882 and an Unclassified Sulphur Oxidising Consortium, Waste and Biomass Valorization, Springer, Netherlands


PURPOSE: Sol fraction, a measure of the free polymers removed from a ground tyre rubber (GTR) by organic solvent, and crosslink density, a measure of the number of sulphur crosslinks in the GTR, are necessary to determine whether a microbial activity causes both devulcanization and carbon degradation. The suitability of two sol fraction measurement methods to assessing the devulcanisation performance of At. ferrooxidans and a sulphur-oxidising consortium on industrial GTR was investigated. METHOD: The devulcanisation performance and the relation between two Sol fraction methods (American Standard Testing Method, ASTM D6814 and the altered method) were determined for Acidithiobacillus ferrooxidans (DSMZ 14,882) and a mesophilic, sulphur-oxidising acidophilic consortium (UCT-30), used to treat unleached ground tyre rubber (untreated GTR) for 30 days. RESULTS: Both cultures were able to devulcanise untreated GTR after 30 days of incubation, despite the negative impact of the untreated GTR toxins on growth performance. The sulphur-oxidising consortium displayed the greatest toxin resistance and attached cells were observed at the surface of the untreated GTR particles. At. ferrooxidans (DSMZ 14,882) increased the Sol fraction of the GTR by 1.09+-0.9% (0.46+-0.1% ASTM) without causing any polymer degradation, whereas the sulphur-oxidising consortium increased the sol fraction by 0.56+-0.82% (0.26+-0.1% ASTM), but also caused polymer degradation at the surface of the GTR particles due to the activity of the heterotrophic microorganisms. In the comparison of the Sol fraction methods, ASTM yielded smaller absolute values, but better precision than the altered method. The absolute values for ASTM method fell within the range for the altered method due to the latter's large variance. In addition, the ASTM method produced a change in sol fraction (sol) that was more consistent across the unleached GTR tested than the altered method CONCLUSION: The ASTM sol fraction method provides better precision than the altered sol fraction method, making it more likely to indicate a statistically significant difference, despite the small absolute values measured. The altered method's more aggressive treatment leads to larger observed changes in the sol fraction, making it easier to identify qualitative changes in the GTR properties. However, the higher temperature method also introduces increased variability leading to poor statistical significance of the results. Therefore, the results should not be reported without a quantification of the error.

Swart, L. J., Bedzo, O. K. K., van Rensburg, E., Gorgens, J. F. (2021) Intensification of Xylo-oligosaccharides Production by Hydrothermal Treatment of Brewers Spent Grains: The Use of Extremely Low Acid Catalyst for Reduction of Degradation Products Associated with High Solid Loading, Applied Biochemistry and Biotechnology 193: 1979-2003


Brewers' spent grains (BSG) make up to 85% of a brewery's solid waste, and is either sent to landfill or sold as cheap animal feed supplement. Xylo-oligosaccharides (XOS) obtained from BSG are antioxidants and prebiotics that can be used in food formulations as low-calorie sweeteners and texturisers. The effect of extremely low acid (ELA) catalysis in liquid hot water (LHW) hydrothermal treatment (HTT) was assessed using BSG with dry matter contents of 15% and 25%, achieved by dewatering using a screw press. Batch experiments at low acid loadings of 5, 12.5 and 20 mg/g dry mass and temperatures of 120, 150 and 170 C significantly affected XOS yield at both levels of dry mass considered. Maximum XOS yields of 76.4% (16.6 g/l) and 65.5% (31.7 g/l) were achieved from raw BSG and screw pressed BSG respectively, both at 170 C and using 5 mg acid/g dry mass, after 15 min and 5 min, respectively. These XOS yields were obtained with BSG containing up to 63% less water and temperatures more than 20 C lower than that reported previously. The finding confirms that ELA dosing in LHW HTT allows lowering of the required temperature that can result in a reduction of degradation products, which is especially relevant under high solid conditions. This substantial XOS production intensification through higher solid loadings in HTT not only achieved high product yield, but also provided benefits such as increased product concentrations and decreased process heat requirements.

Swart, L. J., Peterson, A. M., Bedzo, O. K. K., Gorgens, J. F. (2021) Techno-economic analysis of the valorization of brewers spent grains: production of xylitol and xylo-oligosaccharides, Journal of Chemical Technology & Biotechnology 96(6): 1632-1644


Brewers spent grains (BSG) represents around 85% of a brewery's solid waste and common disposal to landfill is increasingly more difficult. Yet BSG is a food-grade by-product with potential economic valorization that can significantly improve resource efficiency and reduction in carbon emissions. This study investigated valorization of BSG through the application of novel high solids hydrothermal processing technology in a small-scale biorefinery, annexed to a brewery. It focused on three scenarios for the production of: (A) the sugar replacement xylitol; (B) prebiotic xylo-oligosaccharide (XOS); and (C) co-production of xylitol and XOS. Economic assessment was conducted by comparing the capital and operating expenditure from process simulations created in Aspen Plus. The process models developed were supplemented with experimental data to improve accuracy.
Internal rate of return (IRR) values obtained were greater than the hurdle rate of 9.7% for all scenarios when considering a conservative market price for xylitol and XOS as US$4500 t-1, yet dedicated production of XOS was economically more favourable with a minimum required selling price (MRSP) of US$2509 t-1 compared to US$4153 t-1 for xylitol. Additionally, the scenario for co-production of xylitol and XOS achieved the lowest MRSP of US$2182 t-1. By-products significantly contributed to 32.7%, 14.2% and 27.5% of the revenue generated in scenarios A, B and C, respectively.
These results provide a good platform from which to develop the cost-effective commercial production of XOS and xylitol from BSG.

Bedzo, O. K. K., van Rensburg, E. and Gorgens, J. F. (2021) Investigating the effect of different inulin-rich substrate preparations from Jerusalem artichoke (Helianthus tuberosus L.) tubers on efficient inulooligosaccharides production, Preparative Biochemistry and Biotechnology 51(5): 440-449


Commercial production of inulooligosaccharides (IOS) relies largely on chicory roots. However, Jerusalem artichoke (JA) tubers provide a suitable alternative due to their high inulin content and low cultivation requirements. In this study, three inulin-rich substrate preparations from JA were investigated to maximize IOS production, namely powder from dried JA tuber slices (Substrate 1), solid residues after extracting protein from the JA powder (Substrate 2) and an inulin-rich fraction extracted from protein extraction residues (Substrate 3). The preferred temperature, pH and inulin substrate concentration were determined after which enzyme dosage and extraction time were optimized to maximize IOS extraction from the three substrates, using pure chicory inulin as benchmark. Under the optimal conditions, Substrate 3 resulted in the highest IOS yield of 82.3% (w/winulin). However, IOS production from the Substrate 1 proved more efficient since it renders the highest overall IOS yield (mass of IOS per mass of the starting biomass). In the case of co-production of protein and IOS from the JA tuber in a biorefinery concept, IOS production from the Substrate 2 is preferred since it reduces the inulin losses incurred during substrate preparation. For all the inulin-rich substrates studied, an enzyme dosage of 14.8 U/ginulin was found to be optimal at reaction time less than 6 h. JA tuber exhibited excellent potential for commercial production of IOS with improved yield and the possible advantage of a reduced biomass cost.

Bedzo, O. K. K., Dreyer, C. B., van Rensburg, E., Gorgens, J. F. (2021) Optimisation of Pretreatment Catalyst , Enzyme Cocktail and Solid Loading for Improved Ethanol Production from Sweet Sorghum Bagasse, BioEnergy Research


weet sorghum bagasse displays many characteristics rendering it a promising substrate for lignocellulosic ethanol production. In this study, the steam pretreatment catalyst, enzymatic hydrolysis and the substrate loading for the fermentation were investigated in order to maximise the production of ethanol from the feedstock. The results deemed water as a sufficient pretreatment catalyst since the SO2 impregnation of the biomass did not produce any significant beneficial effects on the yield of ethanol produced. The preferred pretreatment and enzymatic hydrolysis conditions were incorporated in a fed-batch simultaneous saccharification and fermentation (SSF) process using pressed-only (not washed) WIS at a final solid loading of 13% (w/w) that resulted in the targeted ethanol concentration of 39 g/L with a corresponding yield of 82% of the theoretical maximum. Yeast inhibition coupled with significant glucose accumulation was observed at higher solid loadings of 16% and 20%. Ultimately, the sweet sorghum bagasse could be integrated into existing ethanol production regimes to improve the global bioenergy production.

Bedzo, O. K. K., Mandegari, M. and Gorgens, J. F. (2020) Techno-economic analysis of inulooligosaccharides, protein, and biofuel co-production from Jerusalem artichoke tubers: A biorefinery approach, Biofuels Bioproducts & Biorefining-Biofpr 14(4): 776-793


Jerusalem artichoke (JA) is a crop with excellent potential for application in biorefineries. It can resist drought, pests, and diseases and can thrive well in marginal lands with little fertilizer application. The JA tubers contain considerable quantities of inulin, which is suitable for the production of inulooligosaccharides (IOS), as a high-value prebiotic, dietary fiber. In this study, five JA tuber biorefinery scenarios were simulated in Aspen Plus and further evaluated by techno-economic and sensitivity analyses. Production of IOS, proteins and animal feed was studied in scenarios A and C, applying various biorefinery configurations. Scenario B explored the option of producing only IOS and the sale of residues as animal feed. Scenarios D and E investigated the economic potential of biofuel generation from residues after IOS and protein production by generation of biogas and ethanol respectively, from residues. Based on the chosen economic indicators, scenario B resulted in the lowest minimum selling price (MSP) of 3.91 US$ kg-1 (market price 5.0 US$ kg-1) with correspondingly reduced total capital investment (TCI) and total operating cost (TOC) per mass unit produced of IOS of 18.91 and 2.59 US$ kg-1 respectively, compared with other studied scenarios. Considering the set production scale, it is more profitable when the residues are sold as animal feed instead of being converted into biofuel, due to the capital-intensive nature of the biofuel production processes. The coproduction of protein had a negative impact on the economics of the process as the associated capital and operating expenditure outweighed the associated revenue.

Bedzo, O. K. K., Mandegari, M. and Gorgens, J. F. (2020) Comparison of immobilized and free enzyme systems in industrial production of short-chain fructooligosaccharides from sucrose using a techno-economic approach, Biofuels Bioproducts & Biorefining-Biofpr 14(4): 776-793


Short-chain fructooligosaccharides (scFOS) are nutraceuticals with numerous applications in the food and pharmaceutical industries. The production of scFOS using immobilized biocatalysts offers some functional and technical advantages over free enzyme counterparts. To investigate the economic potential of the immobilized enzyme system relative to the free enzyme system, a techno-economic comparison was conducted on three methods of scFOS production (powder and syrup forms) at a capacity of 2000?t per annum (tpa) by enzymatic synthesis from sucrose: the free enzyme (FE), calcium alginate immobilized enzyme (CAIE), and amberlite IRA 900 immobilized enzyme (AIE) systems. These processes were simulated in Aspen Plus to obtain the mass and energy balances and to estimate the operating and capital costs, followed by economic evaluation and sensitivity analysis. Profitability analysis showed that all three systems are economically viable as their associated minimum selling prices (MSP) were well below the scFOS market price of 5 $ kg-1. However, the FE system was the most profitable with the lowest MSP of 2.61 $ kg-1 because the savings on cost as a result of enzyme immobilization could not offset the additional costs associated with immobilization. Sensitivity analysis demonstrated that total operating cost, fixed capital investment, and internal rate of return (% IRR) have the greatest effects on the MSP. Furthermore, the syrup form of scFOS production leads to 29% less MSP, compared to powder form. In addition, the studied plant capacities of 5000 and 1000?tpa showed 10% and 16% reductions on MSP respectively.

Bedzo, O. K. K., Trollope, K., Gottumukkala, L. D., Coetzee, G., Gorgens, J. F. (2019) Amberlite IRA 900 Versus Calcium Alginate in Immobilization of a Novel , Engineered B-fructofuranosidase for Short-Chain Fructooligosaccharide Synthesis from Sucrose, Biotechnology Progress 35(3): 1-9


The immobilization of B-fructofuranosidase for short-chain fructooligosaccharide (scFOS) synthesis holds the potential for a more efficient use of the biocatalyst. However, the choice of carrier and immobilization technique is a key to achieving that efficiency. In this study, calcium alginate (CA), Amberlite IRA 900 (AI900) and Dowex Marathon MSA (DMM) were tested as supports for immobilizing a novel engineered B-fructofuranosidase from Aspergillus japonicus for scFOS synthesis. Several immobilization parameters were estimated to ascertain the effectiveness of the carriers in immobilizing the enzyme. The performance of the immobilized biocatalysts are compared in terms of the yield of scFOS produced and reusability. The selection of carriers and reagents was motivated by the need to ensure safety of application in the production of food-grade products. The CA and AI900 both recorded impressive immobilization yields of 82 and 62%, respectively, while the DMM recorded 47%. Enzyme immobilizations on CA, AI900 and DMM showed activity recoveries of 23, 27, and 17%, respectively. The CA, AI900 immobilized and the free enzymes recorded their highest scFOS yields of 59, 53, and 61%, respectively. The AI900 immobilized enzyme produced a consistent scFOS yield and composition for 12 batch cycles but for the CA immobilized enzyme, only 6 batch cycles gave a consistent scFOS yield. In its first record of application in scFOS production, the AI900 anion exchange resin exhibited potential as an adequate carrier for industrial application with possible savings on cost of immobilization and reduced technical difficulty.