Towards a circular economy for plastic packaging: Current practice and perspectives in the City of Oslo

publishedVersio

The Effect of Feeding Strategy on Butanol Production by Clostridium beijerinckii NCIMB 8052 Using Glucose and Xylose

We performed fed-batch fermentations of glucose and xylose mixtures producing butanol. Our aim was to develop a feeding strategy for coping with carbon catabolite repression (CCR) and sequential utilization problems as well as understanding the effect of feeding strategy on fermentation kinetics. Experimental results showed that fermenter 1 with only xylose as the initial carbon source could co-utilize sugars for all mixed sugar feeds. On the other hand, fermenter 2 with only glucose as the initial sugar showed sequential utilization. Xylose in fermenter 2 accumulated while glucose was present; it was only utilized after the glucose was completely exhausted. Besides the sugar utilization profile, the feeding strategy had an impact on the fermentation kinetics. Maximum specific growth rates were 0.68 h-1 and 0.94 h-1, for fermenter 1 and 2,respectively. Fermenter 1 produced 4.98 g/l butanol and yield was 0.28 g/g, while fermenter 2 produced 0.5 g/l butanol with a yield value of 0.05 g/g. Total sugar utilization was also higher for fermenter 1, 81 % and 46 % for fermenter 2. The feeding strategy we proposed showed that wild type Clostridium beijerinckii NCIMB 8052 can co-utilize glucose and xylose, and produce butanol. Our observation suggests that we can tackle sequential utilization problem and enhance fermentation process with the proposed feeding strategy without having to manipulate the strain.publishedVersio

Response Surface Methodology for Understanding Glucose and Xylose Utilization by Clostridium beijerinckii NCIMB 8052

We applied response surface methodology to understand the effect and extend of carbon catabolite repression (CCR) on growth of Clostridium beijerinckii NCIMB 8052 using xylose and glucose as representative lignocellulosic sugars. We performed batch growth experiments based on the central composite design with different concentrations of glucose and xylose, and estimated the respective growth rates as the response. Fitting the quadratic model with interaction coefficient to experimental data gave a good quality of fit (R-squared=0.939). We found that glucose is the most significant factor affecting the growth rate. Interaction between glucose and xylose is another highly significant factor. Response surface illustrated that increasing or decreasing both sugar concentrations at the same time results in a decreasing growth rate, and increasing either sugar concentration while decreasing the other sugar increases the growth rate. It is an important finding as it suggests that CCR can be not only from glucose on xylose but also from xylose on glucose. A transcriptional study will be necessary to understand the repression mechanism and to improve the utilization of sugars in mixed form, thus lignocellulosic fermentation processes.publishedVersio

MSW for Energy Recovery - 2020-2035 Scenarios for a Large City

The generation rate, total amount and composition of Municipal Solid Waste (MSW) can be affected by many parameters such as population and economy growth, unfolding of Circular Economy, implementation of new regulations for material recycling and development of sorting and recycling technology. Such changes will also affect measures to treat/utilize the MSW as well as the handling of the residues, primarily ashes. In this work, three scenarios on the future MSW sent to energy recovery for the period 2020-2035 have been developed using detailed MSW composition data from a large Scandinavian city, namely Oslo, Norway. The amount and composition of the MSW sent to energy recovery (incineration) were estimated with consideration of boundary conditions including population growth, improvement of sorting efficiency and increase of recycling rate. This work also evaluated key properties of the MSW sent to energy recovery under different scenarios, including heating value, volatile matter and carbon content and concentration of key ash-forming elements relevant to the operation of an incinerator and ash valorisation. The results revealed that important combustion properties of MSW to incineration might be affected by increased sorting and recycling, towards lower energy and ash content with the conditions set under studied scenarios. Scenario analysis revealed that changes in the fraction of plastic has the largest effect on the carbon content and heating value of the MSW. In addition, changes in the content of ash-forming elements in the MSW were identified, which are the results of the separate collection of an ash-rich subfraction, i.e., food waste

Kinetic Study of Butanol Production from Mixtures of Glucose and Xylose and Investigation of Different Pre-growth Strategies

This study proposes a dynamic model that describes key characteristics of fermentative butanol production from glucose and xylose mixtures. The model has 12 parameters and incorporates noncompetitive inhibitory interaction between sugars as well as inhibitions due to high substrate and butanol concentrations. Different pre-growth strategies to achieve co-utilization of sugars were explored together with their effects on fermentation kinetics. Mixed sugar fermentation by the cultures pre-grown on a mixture of glucose and xylose showed a higher endurance to inhibition, a 2-fold increase in butanol production and a 1.5-fold increase in total sugar consumption compared to cultures pre-grown on xylose only. The average squared correlation coefficients (r2) between experimental observations and model predictions were 0.917 and 0.926 for fermentations done by the cultures pre-grown on xylose only, and pre-grown on a mixture of glucose and xylose, respectively. Sensitivity analysis on the model parameters revealed that the growth parameters were the most critical. The proposed model can serve as a basis for modeling of microbial butanol production from lignocellulosic biomass and be applied to other substrates and microorganisms. © 2019(32 refs)acceptedVersio

Modeling the Growth of Clostridium beijerinckii NCIMB 8052 on Lignocellulosic Sugars

To our knowledge, this is the first growth model of Clostridium beijerinckii NCIMB 8052 on glucose and xylose as representative lignocellulosic sugars, which considers the synergistic effects of sugars on the growth rate. We fitted models with different types of interactions between the substrates to the growth rate data obtained with varying sugar concentrations. Noncompetitive binary substrate growth model gave the best fit with the smallest mean standard errors (MSE), and sum of squares error (SSE), 0.0778 and 0.0071, respectively. Confidence intervals for the parameter estimates showed that the substrate affinity constant for xylose, KsX (g/l) had the largest uncertainty, while the maximum specific growth rate on xylose, µmaxX (h-1) had the smallest. The correlation matrix showed that the model parameters were highly correlated. Carbon cataboliterepression (CCR) effect on the growth rate was of the noncompetitive type. Validation with other sugar concentration values is necessary to evaluate the prediction capability of the proposed model. A transcriptional study will be beneficial to understand global gene regulation mechanisms as guidance for improving the efficiency of lignocellulosic fermentation processes.publishedVersio

Türkiye akademik CAR-T hücre (ISIKOK-19) klinik çalışması ön raporu: Ürün karakterizasyonu ve klinik uygulama sonuçları

Objective: Chimeric antigen receptor T (CAR-T) cell therapies have already made an impact on the treatment of B-cell malignancies. Although CAR-T cell therapies are promising, there are concerns about commercial products regarding their affordability and sustainability. In this preliminary study, the results of the first production and clinical data of an academic CAR-T cell (ISIKOK-19) trial in Turkey are presented. Materials and Methods: A pilot clinical trial (NCT04206943) designed to assess the safety and feasibility of ISIKOK-19 T-cell therapy for patients with relapsed and refractory CD19+ tumors was conducted and participating patients received ISIKOK-19 infusions between October 2019 and July 2021. The production data of the first 8 patients and the clinical outcome of 7 patients who received ISIKOK-19 cell infusions are presented in this study. Results: Nine patients were enrolled in the trial [5 with acute lymphoblastic leukemia (ALL) and 4 with non-Hodgkin lymphoma (NHL)], but only 7 patients could receive treatment. Two of the 3 participating ALL patients and 3 of the 4 NHL patients had complete/ partial response (overall response rate: 72%). Four patients (57%) had CAR-T-related toxicities (cytokine release syndrome, CAR-T-related encephalopathy syndrome, and pancytopenia). Two patients were unresponsive and had progressive disease following CAR-T therapy. Two patients with partial response had progressive disease during follow-up. Conclusion: Production efficacy and fulfillment of the criteria of quality control were satisfactory for academic production. Response rates and toxicity profiles were also acceptable for this heavily pretreated/refractory patient group. ISIKOK-19 cells appear to be a safe, economical, and efficient treatment option for CD19+ tumors. However, the findings of this study need to be supported by the currently ongoing ISIKOK-19 clinical trial.Amaç: Kimerik antijen reseptör T (CAR-T) hücre uygulamaları B-hücreli malignitelerin tedavisinde etkili olmaktadır. CAR-T hücre uygulamalarının sonuçları umut vaadedici olsa da, ticari CAR-T ürünlerinin yükek maliyetleri nedeniyle ulaşılabilirlik açısından ciddi sorunlar yaşanmaktadır. Bu ön raporda, Türkiye’deki ilk akademik CAR-T hücre çalışmasının üretim ve klinik uygulama sonuçları sunulmuştur. Gereç ve Yöntemler: Relaps refrakter CD 19+ hematolojik maligniteli hastalarda ISIKOK-19 T-hücre tedavisinin güvenliği ve etkinliğini değerlendirmek amacıyla yürütülen klinik çalışmaya (NCT04206943) Ekim 2019-Temmuz 2021 tarihleri arasındaki hastalar dahil edilmiştir. Bu raporda ilk 8 hastanın üretim bilgileriyle, ISIKOK-19 hücre infüzyonu yapılan 7 hastanın klinik sonuçları sunulmuştur. Bulgular: Çalışmaya toplam 9 hasta dahil edilmiştir (5 akut lenfoblastik lösemi [ALL] ve 4 non-hodgkin lenfoma [NHL]), ancak sadece 7 hastaya hücre infüzyonu yapılabilmiştir. Hücre infüzyonu alan 3 ALL hastasından 2’sinde ve 4 NHL hastasının 3’ünde tam/kısmi cevap gözlenmiştir (toplam yanıt oranı %72). Dört hastada (%57) CAR-T ilişkili toksisite (sitokin salınım sendromu, immün efektör hücre ilişkili nörotoksisite sendromu ve pansitopeni) tespit edilmiştir. İki hastada ise CAR-T hücre uygulaması sonrası cevapsızlık ve progresif hastalık izlenmiştir. Kısmi cevap veren hastalardan 2’sinde de takip sırasında progresif hastalık tespit edilmiştir. Sonuç: Akademik CAR-T üretimimiz, üretim etkinliği ve kalite kontrol kriterlerinin tam olarak karşılanması açısından tatmin edici sonuçlara sahiptir. Çalışmaya dahil edilen hastaların tedavi yükü hesaba katıldığında tedaviye cevap oranı ve toksisite profili açısından da sonuçlar kabul edilebilir düzeydedir. Bu sonuçlarla, ISIKOK-19 hücrelerinin güvenli, ekonomik ve etkili bir tedavi seçeneği olduğu düşünülebilir. Ancak bu ön sonuçların halen devam eden ISIKOK-19 klinik çalışmasıyla desteklenmesi beklenmektedir

Liquefied synthetic natural gas from woody biomass. Investigation of cryogenic technique for gas upgrading

Biomass-based liquefied natural gas (bio-LNG) is very valuable renewable fuel as it has high energy density and transportability. Bio-LNG requires liquefaction of the synthetic natural gas (bio-SNG). Cryogenic technology is a promising option for integration of the gas upgrading and liquefaction streams with the main biomass gasification and methane synthesis plant. This thesis investigates the feasibility of this technology for future commercial bio-SNG production plants based on indirect gasification technology, similar to that adopted by Göteborg Energi for the GoBiGas project. Two process configurations for production of bio-LNG from woody biomass are investigated: (1) an integrated configuration which uses cryogenic technology for gas upgrading and liquefaction integrated with the gasification and SNG synthesis plant; (2) a base case which uses a traditional gas upgrading (chemical adsorption) and a stand-alone liquefaction unit located downstream of the main Bio-SNG plant. Both cases are simulated with Aspen Plus to obtain mass and energy balances. Pinch analysis is conducted for both cases to investigate utility demands as well as the potential to convert excess process heat to shaft work to improve the energy performance of the processes. The cryogenic unit investigated achieves the targeted product specifications and capacity, and the calculated performance is comparable to published data for commercial cryogenic units in terms of specific power demand and methane loss. The simulation results show that the integrated plant configuration with cryogenic technology has a higher power requirement than the base case. Shaft power outputs are estimated for both the integrated and base cases assuming a steam cycle combined heat and power unit which recovers process excess heat. The estimated work outputs are more than sufficient to cover the process power demands for both cases; thus the excess power can be exported to the grid. The base case achieves a slightly higher overall energy efficiency compared to the integrated case, whereas the cold gas efficiency is higher for the integrated case due to low methane loss. Cryogenic technology is still under development, therefore there is a high potential for performance improvement by application of energy efficiency measures. In addition, high purity liquid CO2 is produced at very low temperature as a by-product which could generate additional revenue.Outgoin

Liquefied synthetic natural gas from woody biomass. Investigation of cryogenic technique for gas upgrading

Biomass-based liquefied natural gas (bio-LNG) is very valuable renewable fuel as it has high energy density and transportability. Bio-LNG requires liquefaction of the synthetic natural gas (bio-SNG). Cryogenic technology is a promising option for integration of the gas upgrading and liquefaction streams with the main biomass gasification and methane synthesis plant. This thesis investigates the feasibility of this technology for future commercial bio-SNG production plants based on indirect gasification technology, similar to that adopted by Göteborg Energi for the GoBiGas project. Two process configurations for production of bio-LNG from woody biomass are investigated: (1) an integrated configuration which uses cryogenic technology for gas upgrading and liquefaction integrated with the gasification and SNG synthesis plant; (2) a base case which uses a traditional gas upgrading (chemical adsorption) and a stand-alone liquefaction unit located downstream of the main Bio-SNG plant. Both cases are simulated with Aspen Plus to obtain mass and energy balances. Pinch analysis is conducted for both cases to investigate utility demands as well as the potential to convert excess process heat to shaft work to improve the energy performance of the processes. The cryogenic unit investigated achieves the targeted product specifications and capacity, and the calculated performance is comparable to published data for commercial cryogenic units in terms of specific power demand and methane loss. The simulation results show that the integrated plant configuration with cryogenic technology has a higher power requirement than the base case. Shaft power outputs are estimated for both the integrated and base cases assuming a steam cycle combined heat and power unit which recovers process excess heat. The estimated work outputs are more than sufficient to cover the process power demands for both cases; thus the excess power can be exported to the grid. The base case achieves a slightly higher overall energy efficiency compared to the integrated case, whereas the cold gas efficiency is higher for the integrated case due to low methane loss. Cryogenic technology is still under development, therefore there is a high potential for performance improvement by application of energy efficiency measures. In addition, high purity liquid CO2 is produced at very low temperature as a by-product which could generate additional revenue.Outgoin