| 1. |
- Ahlström, Johan, 1990, et al.
(författare)
-
Forest residues gasification integrated with electrolysis for production of SNG – modelling and assessment
- 2018
-
Ingår i: Computer Aided Chemical Engineering. - 1570-7946. ; , s. 109-114
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This study investigates opportunities for integrating an electrolysis unit with a biomass gasifier for production of synthetic natural gas (SNG). Gasification is a key technology for production of biofuels and chemicals from lignocellulosic biomass, for which an increased demand is expected in the future. H2produced through an electrolyser can be used to increase the output of a gasifier by reaction with CO2to form CH4. Four integrated flowsheet configurations are evaluated with respect to system energy efficiency and process operating revenue. The system energy efficiencies are in the range of 0.55 – 0.8, and the maximum value of operating revenues is 0.245 $/kWhdry biomass. The results show that feeding the Sabatier reactor with the full product gas flow coming from the methanation unit, and separating the unreacted CO2afterwards, is the most attractive configuration with respect to operating revenue.
|
|
| 2. |
- Ahlström, Johan, 1990, et al.
(författare)
-
The role of biomass gasification in the future flexible power system – BECCS or CCU?
- 2022
-
Ingår i: Renewable Energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 190, s. 596-605
-
Tidskriftsartikel (refereegranskat)abstract
- In this work we study if biomass gasification for production of advanced biofuels can also play a role in managing variability in the electricity system. The idea is a CCU/power-to-gas concept to enhance methane production from biomass gasification. The suggested process is flexible in that CO2 not used for methane production can be stored through a BECCS concept that implies negative GHG emissions. For this purpose, rigorous models of three different gasification process configurations were simplified through surrogate modeling and integrated into a dynamic optimization model of regional electricity systems. The results show the diverse advantages of flexible operation between CCU and BECCS and that it is economically beneficial for the system to invest in gasification at the investigated levels of CO2 charge. The gasification option also provides value for low-priced electricity and thus stimulate increased investments in renewable electricity generation, which indicates the importance of considering geographical diversities in the assessment and highlights the importance of studying this type of concept with a time-resolved model. It is clear that the BECCS option is the most used, however, the limited quantities of CO2 used for the CCU option has a large impact on the investments made in the electricity system.
|
|
| 3. |
- Badr, S., et al.
(författare)
-
A framework for the environmental, health and safety hazard assessment for amine-based post combustion CO2 capture
- 2017
-
Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 56, s. 202-220
-
Tidskriftsartikel (refereegranskat)abstract
- Given the environmental concerns driving process developments and considering the size and scale of potential application of post combustion capture (PCC), it is important to fully understand process hazards. In this work we present an environmental, health and safety (EHS) hazard assessment framework for screening and comparing amine based PCC options. A multi-criteria assessment compares the performance of 7 m Monoethanolamine (MEA), 4 m Diethanolamine (DEA), 10 m Diglycolamine (DGA), 8 m Piperazine (PZ) and a blend of 7 m Methyldiethanolamine (MDEA) with 2 m PZ under a set of different process conditions. The EHS assessment takes into account varying circulating volumes, process conditions and potential for solvent degradation. The EHS assessment is also compared with operating costs and life cycle assessment (LCA) metrics. The EHS assessment is carried out on two levels. The first is less data intensive and provides a unified score that can be used to compare and screen process alternatives, while the second level studies the contribution of individual degradation products to different EHS hazard categories in detail. Results of the parametric study show that lean loading is an influential factor in determining first level EHS scores, process costs and environmental impacts and a trade-off is observed between EHS and LCA scores for some of the solvents. In the second level EHS assessment, the parent amine heavily influences most mass dependent hazard categories such as the fire/explosion, acute toxicity and air mediated effects category. Heat stable salts affect the solid waste category. Most degradation products are considered corrosive or irritant and therefore feature strongly in that category in addition to the parent amine. The second level EHS assessment is complemented with workplace exposure analysis to ensure the compliance with workplace threshold limits. Nitrosamines stand out for acute and chronic toxicity effects and are therefore used as an example to demonstrate the workplace exposure. Workplace amines and nitrosamine concentrations are estimated to assess long and potential short term worker exposure as a result of gas leakages and spills respectively. Indoor ventilation rates are inadequate to keep workplace amine and nitrosamine concentrations below the recommended guidelines. To reduce short term exposure effects, a steady state liquid nitrosamine concentration lower than 13.7 mM is required. The results of the parametric study show that changing process conditions can lower nitrosamine concentrations, but can also shift the contribution of the parent amine and degradation products of the other hazard categories and affect LCA metrics. The sensitivity of the EHS and LCA results to model assumptions and conditions are tested by varying inlet NOx, expected aerosols and solvent degradation levels. Low NOx levels in the flue gas are required for PZ and MDEA-PZ systems to meet the nitrosamine concentration thresholds for environmental and health concerns. This study also highlights the need to consider hazard effects during early process design phases, identifies degradation related data gaps and critical process parameters towards more environmentally benign PCC design.
|
|
| 4. |
- Badr, Sara, 1985, et al.
(författare)
-
Combined basic and fine chemical biorefinery concepts with integration of processes at different technology readiness levels
- 2018
-
Ingår i: Computer Aided Chemical Engineering. - 1570-7946. ; , s. 1577-1582
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Biorefineries offer promising alternatives to the use of fossil fuels to produce energy and chemicals. This work describes the development of a biorefinery concept to produce adipic acid from Swedish forest residues and lutein from micro-algae. A description is provided for each process line available, its technology readiness level (TRL) and the tools available to model it. Scenarios of the integrated concept are built with associated material flow analysis. Key results of the material inventory of the base case scenario are presented as well as insights into the development of further scenarios. Material flow inventories can then be further used for economic and environmental assessment. Major challenges of integration are discussed in terms of uncertainties and data gaps for processes with low TRL such as scaling up lab experiments, understanding the restrictions of material recycling and its impact on process performance. The feedback given through these scenarios can help guide further experimental efforts.
|
|
| 5. |
|
|
| 6. |
- Baxevanidis, Pantelis, et al.
(författare)
-
Group contribution-based LCA models to enable screening for environmentally benign novel chemicals in CAMD applications
- 2022
-
Ingår i: AICHE Journal. - : Wiley. - 1547-5905 .- 0001-1541. ; 68:3
-
Tidskriftsartikel (refereegranskat)abstract
- This study considers the development of suitable models for the estimation of life cycle assessment (LCA) indices of organic chemicals. Unlike state-of-the-art models, the tools developed here correlate LCA indices with the molecular composition according to the well-established group contribution (GC) approach. The LCA indices considered here are global warming potential, cumulative energy demand, and Eco-Indicator 99. The model development uses data from existing LCA databases, where each material is associated with its cradle-to-gate LCA metrics. A variety of regression and nonregression methodologies are recruited to achieve the optimum correlation. GC models can be used to screen for molecules with optimal and/or desirable properties, using appropriate molecular design synthesis algorithms. In this framework, the models developed here are linked to the design algorithm to enable the consideration of LCA features together with other properties, for the design of environmentally benign liquid–liquid extraction solvents.
|
|
| 7. |
- Calvo-Serrano, Raul, et al.
(författare)
-
Cradle-to-gate environmental impact prediction from chemical attributes using mixed-integer programming
- 2017
-
Ingår i: Computer Aided Chemical Engineering. - 1570-7946. ; , s. 1999-2004
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Life Cycle Assessment (LCA) has recently gained widespread acceptance in green chemistry as an effective tool for quantifying the environmental impact of chemicals along their life cycle. Unfortunately, LCA studies require large amounts of data that are hard to gather in practice, a limitation that is particularly critical when assessing the complex processes and value chains present in the chemical industry. With the aim at simplifying these calculations and promoting the wider adoption of environmental principles, in this work we develop an approach that predicts the cradle-to-gate life cycle production impact of organic chemicals from attributes based on their molecular structure and thermodynamic properties. The approach presented relies on a mixed-integer programming (MIP) optimisation framework that streamlines the LCA calculations by systematically constructing multi-linear short-cut predictive models of cradle-to-gate life cycle impact. These models contain key molecular and thermodynamic attributes that are identified using binary variables. On applying our method to an LCA data set containing 83 chemicals, 17 molecular descriptors and 15 thermodynamic properties, we produced estimates for widely used metrics such as cumulative energy demand (CED), global warming potential (GWP) and Eco-indicator 99 (EI99) with relative errors within acceptable ranges considering the nature of any LCA study. Our optimisation-based streamlined LCA framework ultimately leads to simple linear models that are amenable for implementation in computer aided molecular design software, thereby opening new avenues for the inclusion of sustainability principles in the early stages of the development of new chemicals.
|
|
| 8. |
- Calvo-Serrano, R., et al.
(författare)
-
Predicting the cradle-to-gate environmental impact of chemicals from molecular descriptors and thermodynamic properties via mixed-integer programming
- 2018
-
Ingår i: Computers and Chemical Engineering. - : Elsevier BV. - 0098-1354. ; 108, s. 179-193
-
Tidskriftsartikel (refereegranskat)abstract
- Life Cycle Assessment (LCA) has recently gained wide acceptance in the environmental impact evaluation of chemicals. Unfortunately, LCA studies require large amounts of data that are hard to gather in practice, a critical limitation when assessing the processes and value chains present in the chemical industry. We here develop an approach that predicts the cradle-to-gate life cycle production impact of organic chemicals from attributes related to their molecular structure and thermodynamic properties. This method is based on a mixed-integer programming (MIP) optimisation framework that systematically constructs short-cut predictive models of life cycle impact. On applying our approach to a data set containing 88 chemicals, 17 molecular descriptors and 15 thermodynamic properties, we estimate with enough accuracy (for the purposes of a standard LCA) several impact categories widely applied in LCA studies, including the cumulative energy demand, global warming potential and Eco-indicator 99. Our framework ultimately leads to linear models that can be easily integrated into existing modelling and optimisation software, thereby facilitating the design of more sustainable processes.
|
|
| 9. |
- D'Angelo, Sebastiano C., et al.
(författare)
-
Techno-Economic Analysis of a Glycerol Biorefinery
- 2018
-
Ingår i: ACS Sustainable Chemistry & Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 6:12, s. 16563-16572
-
Tidskriftsartikel (refereegranskat)abstract
- Biodiesel is an environmentally friendly alternative to fossil fuels, which is experiencing a steep growth in market size. Because the most common biodiesel production technology is based on the transesterification of triglycerides, a burgeoning amount of glycerol byproduct is obtained. In order to address this economic and ecologic drawback, several chemocatalytic technologies have been developed to exploit this compound to feed the market with added-value products. Lactic acid, acrylic acid, allyl alcohol, propanediols, and glycerol carbonate have emerged as the most relevant candidates for this purpose. In previous studies, an environmental and economic assessment of a glycerol biorefinery built on these valorization pathways has been performed, taking into account only the operating costs in relation to the economic aspects. This study evaluates for the first time the investment required by these glycerol valorization processes, based on the Guthrie, Taylor, and Aspen capital cost estimation methods, and then assesses the potential of a heat-integrated glycerol biorefinery. Glycerol carbonate stands out as the dominant product to maximize the profitability with respect to the glycerol utilized, while 1,2-propanediol and allyl alcohol are determined as target compounds to be included in the glycerol biorefinery product mix if further reductions of the environmental impact are sought after. This early stage techno-economic analysis provides a sounder basis toward the practical realization of an integrated facility sustainably upgrading waste streams from the processing of renewables into commodities, thus promoting the concept of circular economy.
|
|
| 10. |
- Eberle, L., et al.
(författare)
-
Data-driven tiered procedure for enhancing yield in drug product manufacturing
- 2016
-
Ingår i: Computers and Chemical Engineering. - : Elsevier BV. - 0098-1354. ; 87, s. 82-94
-
Tidskriftsartikel (refereegranskat)abstract
- Enhancing efficiency of pharmaceutical batch production processes is an important challenge in times of increasing public pressure on healthcare costs and decreasing research productivity. This study presents a data-based procedure for systematic yield enhancements in drug product manufacturing, based on four steps. On the first step, production is reviewed to select relevant loss causes, which are assessed on the second step deductively with the goal of assigning measurable parameters. Descriptive Statistical Modelling of loss causes is then performed on the third step, enabling model-based enhancements of processes on the fourth step or, if necessary, a loop-back review of a given loss cause. An industrial case study was performed on production data of 88 batches and demonstrated the applicability of the procedure by prioritizing relevant loss causes, reducing required sample quantities by up to 8% and a cosmetic defect by about 70% by a process change.
|
|
