Advanced Process Integration Research Articles

Advanced process integration and machine learning-based optimization to enhance techno-economic-environmental performance of CO2 capture and conversion to methanol

Developing economically sustainable CO2 capture and conversion processes is essential to realize carbon neutrality. This study proposed an integrated process for CO2 capture and conversion-to-methanol (CCTM) and applied machine learning-based optimization to enhance techno-economic-environmental performance. After validating CO2 capture and CO2-to-methanol sections, an advanced CCTM design was developed and compared with conventional one regarding techno-economic-environmental performance across various operating scenarios. The advanced CCTM exhibited significant improvements in energy consumption (14.73–16.30%), production cost (0.81–1.28%), and net CO2 reduction (3.13–3.38%) owing to efficiently reusing waste heat, off-gas, and water resources. The one-at-a-time sensitivity analysis revealed roles of each variable and nonlinear variable-performance tendencies among operating variables in the advanced CCTM process. Subsequently, a well-developed deep neural network (DNN) model precisely formulated the relationship between key variables and performances. The DNN-based optimization provided optimum operating conditions within a minute, resulting in an 8.21 $/tMeOH (∼0.81%) reduction in production cost compared to base case of CCTM. Notably, the total CO2 capture rate of 92.53% at an optimal condition highlighted the significant contribution of advanced CCTM to carbon neutrality. The findings provide a viable reference for the effective and sustainable design and operation of an integrated CCTM process.

Automation of Modeling and Calibration of Integrated Preparative Protein Chromatography Systems

With the increasing global demand for precise and efficient pharmaceuticals and the biopharma industry moving towards Industry 4.0, the need for advanced process integration, automation, and modeling has increased as well. In this work, a method for automatic modeling and calibration of an integrated preparative chromatographic system for pharmaceutical development and production is presented. Based on a user-defined system description, a system model was automatically generated and then calibrated using a sequence of experiments. The system description and model was implemented in the Python-based preparative chromatography control software Orbit.

Cell culture\u2013based production of defective interfering influenza A virus particles in perfusion mode using an alternating tangential flow filtration system

Respiratory diseases including influenza A virus (IAV) infections represent a major threat to human health. While the development of a vaccine requires a lot of time, a fast countermeasure could be the use of defective interfering particles (DIPs) for antiviral therapy. IAV DIPs are usually characterized by a large internal deletion in one viral RNA segment. Consequentially, DIPs can only propagate in presence of infectious standard viruses (STVs), compensating the missing gene function. Here, they interfere with and suppress the STV replication and might act “universally” against many IAV subtypes. We recently reported a production system for purely clonal DIPs utilizing genetically modified cells. In the present study, we established an automated perfusion process for production of a DIP, called DI244, using an alternating tangential flow filtration (ATF) system for cell retention. Viable cell concentrations and DIP titers more than 10 times higher than for a previously reported batch cultivation were observed. Furthermore, we investigated a novel tubular cell retention device for its potential for continuous virus harvesting into the permeate. Very comparable performances to typically used hollow fiber membranes were found during the cell growth phase. During the virus replication phase, the tubular membrane, in contrast to the hollow fiber membrane, allowed 100% of the produced virus particles to pass through. To our knowledge, this is the first time a continuous virus harvest was shown for a membrane-based perfusion process. Overall, the process established offers interesting possibilities for advanced process integration strategies for next-generation virus particle and virus vector manufacturing.Key points• An automated perfusion process for production of IAV DIPs was established.• DIP titers of 7.40E + 9 plaque forming units per mL were reached.• A novel tubular cell retention device enabled continuous virus harvesting.

Advanced post combustion CO2 capture process – A systematic approach to minimize thermal energy requirement

The high thermal energy consumption required for solvent regeneration hinders the commercial-scale implementation of the solvent based carbon dioxide capture and storage process. Process modification is an effective method to reduce the energy requirement of the process. In this study we have developed a new systematic approach to modify and reduce the energy consumption of the process by splitting the regeneration energy into different parts to calculate the magnitude of avoidable components. The process is then modified, aiming to reduce the avoidable components of the regeneration energy. The process modification approach is used to design an advanced process with lower regeneration energy.Furthermore, a more realistic approach for retrofitting projects, off-design performance analysis, is used to study the integration of conventional and advanced processes with existing power plant. The power plant is modelled on Ebsilon Professional®, while the carbon dioxide capture process is modelled on Aspen Plus®. The advanced process reduces the reaction heat by 5%, sensible heat by 6.6%, and unproductive heat by 85.4%. The advanced process decreases the total thermal energy requirement by 25.5% compared to that of the conventional process. Off-design performance analysis reveals that integration of the advanced process improves the net power output by 17 MW and reduces the efficiency penalty from 9.2% to 8.1% as compared to conventional capture process. The advanced process reduces the cost of CO2 avoided by 2.8 USD/tonCO2 at the expense of a 0.45 USD/tonCO2 increase in capital cost.

Advanced process integration for supercritical production of biodiesel: Residual waste heat recovery via organic Rankine cycle (ORC)

Biodiesel production using supercritical methanolysis has received immense interest over the last few years. It has the ability to convert high acid value feedstock into biodiesel using a single-pot reaction. However, the energy intensive process is the main disadvantage of supercritical biodiesel process. Herein, a conceptual design for the integration of supercritical biodiesel process with organic Rankine cycle (ORC) is presented to recover residual hot streams and to generate electric power. This article provides energy and techno-economic comparative study for three developed scenarios as follows: original process with no energy integration (Scenario 1), energy integrated process (Scenario 2) and advanced energy integrated process with ORC (Scenario 3). The developed integrated biodiesel process with ORC resulted in electric power generation that has not only satisfied the process electric requirement but also provided excess power of 257 kW for 8,000 tonnes/annum biodiesel plant. The techno-economic comparative analysis resulted in favouring the third scenario with 36% increase in the process profitability than the second scenario. Sensitivity analysis has shown that biodiesel price variation has significant effect on the process profitability. In summary, integrating supercritical biodiesel production process with ORC appears to be a promising approach for enhancing the process techno-economic profitability and viability.

Emerging Tools for Energy System Design Increasing Economic and Environmental Sustainability

Energy is a fundamental element supporting societal development, particularly with the increasing dependency on the Internet of Things. It is also the main contributor to environmental impacts and subsequently, a potential sector for mitigation. Sustainable energy system design considers energy savings and energy efficiency, waste and consumption reduction, process efficiency enhancement, waste heat recovery, and integration of renewable energy. Emerging tools range from advanced Process Integration, modelling, simulation, and optimisation, to system analysis and assessment. This review covers selected emerging studies promoting sustainable system design, including the recent developments reported in the Special Issue (SI) of the 22nd Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (PRES’19). The primary emphasis was to enhance the economic and environmental performance. However, social factors were also highlighted as essential for future sustainable development. The discussion and analysis in this review focus on the most recent developments of (a) heat integration and heat transfer; (b) integrated and newly developed heat exchangers, (c) integration of renewables, and (d) roles in economic and environmental sustainability. The key results are highlighted, and future research ideas are suggested according to their links to a broader context.

Enhanced performance in graphene RF transistors via advanced process integration

The state-of-the-art performance of a graphene radio-frequency (RF) field-effect transistor (FET) made of chemical vapor deposition (CVD) graphene is presented. The record high cut-off frequency as high as 380 GHz using CVD graphene was attributed to the implementation of advanced process integration. On the one hand, interface engineering has become critical in two-dimensional (2D) electronics since the charge transport of a 2D electron system like graphene is highly affected by the interface. The interface engineering was made for both the top and bottom of the graphene surface by implementing a non-polar material (1, 3, 5-trimethyl-1, 3, 5-trivinyl cyclotrisiloxane). In contrast to conventional polar materials, such as SiO2, the non-polar materials significantly reduce the surface optical phonon scattering in the graphene channel, leading to the enhanced RF performance of graphene FET. On the other hand, micro-scaled holes over the multilayer graphene and self-aligned structure also become a critical factor in minimizing the parasitic resistance that is inversely proportional to RF performance. As the growth technique of CVD graphene greatly advances, the advanced process integration scheme could bring graphene electronics one step further towards practical application.

Integrating the processes of a Kraft pulp and paper mill and its supply chain

This paper investigates the possibility of combining different forest industries (a pulp and paper mill, its supply chain, and a wood-pellet plant) into an integrated industrial site in which they share a common heat and power utility. Advanced process integration and optimization techniques are used to study the site from both material and energy viewpoints. An existing pulp and paper mill is used as the site core plant and its pulp and paper production rates are kept fixed as they are in reality, while the other material flow links among the plants are based on the current industrial situation in Sweden. Different scenarios are evaluated in order to reflect the two main objectives that can be pursued (increased electricity production or biomass resource saving) and the two technologies that can be considered for the shared CHP system (boilers and product gas fired gas turbines). The corresponding non-integrated (standalone) configurations are compared to these scenarios to quantify the potential benefits of the integration. Investment opportunity is also calculated for the considered scenarios as an indicator of the economic convenience.

Recent Developments in Advanced Process Integration: Learning the Lessons from Industrial Implementations

Heat Integration (HI) has been developing in mutual cross-fertilisation with the industrial implementations over the last forty years. From the beginning, HI offered some guidance based on thermodynamic principles and their understanding. However, a number of aspects still need deeper consideration and solved problems have to be considered in more complexity to include the real-life issues. This presentation summarises the results of the three efficiently collaborating research groups: Centre for Process Integration and Intensification - CPI2 at University of Pannonia, Hungary, Faculty of Chemistry and Chemical Engineering, University of Maribor, Slovenia and Process Systems Engineering Centre (PROSPECT) at Universiti Teknologi Malaysia. This team exploits the experiences gathered from the industrial projects as well as from the most recent academic research. The aim of this presentation is to provide some tested and proven guidance for future industrial applications as well as a solid support for getting the results with acceptable and realistic payback periods.

Assessment of the Flue Gas Recycle Strategies on Oxy-Coal Power Plants using an Exergy-based Methodology

While oxy-combustion CO2 capture was foreseen to have higher improvement potential than post-combustion a decade ago, research has not been carried out at the same pace since then and today, the latter exhibits higher technological maturity along with low energy penalty thanks to advanced process integration and solvents formulation. Thus, significant efficiency improvement is needed for the oxy-combustion route to be competitive with post-combustion for carbon capture on coal-fired power plants. In order to achieve such improvements, process integration at system level is required to assess the true energy savings potential of oxy-combustion. In this study, an exergy-based methodology is performed to compare various flue gas recirculation strategies on a state-of-the-art 1100 MWe gross oxy-fired power plant. Exergy analysis at unit operation level allows the identification of the location and the magnitude of the thermodynamic irreversibilities occurring in the process, leading to an enhanced understanding of the studied system. In addition to the reference case in which the secondary recycle is fully depolluted and dehydrated; three alternative flue gas recirculation options have been investigated. Among the studied strategies, recirculation of the secondary flow prior the regenerative heat exchanger with a high temperature particle removal device leads to the highest net plant efficiency. This option not only allows the minimal exergy losses in the boiler but also minimizes the flowrate going through the downstream depollution devices. The net plant efficiency obtained for this architecture is 38.0%LHV, which represents a 3% increase compared to the reference oxy-combustion plant. Comparing this figure to an air-fired power plant modeled with the same set of hypotheses, the energy penalty is 8.1%-pts.

Implementation of lignin-based biorefinery into a Canadian softwood kraft pulp mill: Optimal resources integration and economic viability assessment

Implementation of a lignin-based biorefinery into one of the existing kraft pulp mills calls for increased consumption of resources such as steam (by up to 21.5%), water (by up to 3%), carbon dioxide (by up to 16.2%), and sulphuric acid (by up to 11.3%). To compensate for these extra demands on resources, an advanced process integration method was used to identify steam, water, and chemicals savings options and resource recovery opportunities within the kraft process. Given the importance of the lignin-based biorefinery, an economic viability assessment was carried out toward four scenarios, namely: a reference case relating to a stand-alone kraft pulp mill without a pulp production increase but with/without advanced process integration (scenarios #1 and #2) as well as to an integrated biorefinery with a pulp production increase by 5, 10 and 15% (scenarios #3 and #4).

Improving energy efficiency of sawmill industrial sites by integration with pellet and CHP plants

An essential strategy to lower energy and resources consumption is the development of highly integrated industrial sites including different kind of plants complementing one another. Sawmills are huge biomass suppliers to other industries, such as pulp and paper mills, pellet plants and CHP plants, and part of the biomass is also used for the internal heat requirement. In this paper the integration of a sawmill with a pellet plant and a CHP plant is investigated using advanced process integration techniques, so that the thermal energy and the electricity produced in the CHP plant by burning part of the sawmill biomass output are used for the heat and power requirements of the other two industries. The results show that up to 18% of the biomass by-products from the sawmill can be saved, but from the economic point of view the ratio between prices of the thermal energy sold for district heating and the low quality biomass has to be lower than the present one to make the integrated design solution more attractive than separate plant operation.

Sustaining high energy efficiency in existing processes with advanced process integration technology

To reduce emissions in the process industry, much emphasis has been put on making step changes in emission reduction, by developing new process technology and making renewable energy more affordable. However, the energy saving potential of existing systems cannot be simply ignored. In recent years, there have been significant advances in process integration technology with better modelling techniques and more advanced solution methods. These methods have been applied to the new design and retrofit studies in the process industry. Here attempts are made to apply these technologies to improve the environmental performance of existing facilities with operational changes. An industrial project was carried out to demonstrate the importance and effectiveness of exploiting the operational flexibility for energy conservation. By applying advanced optimisation technique to integrate the operation of distillation and heat recovery in a crude oil distillation unit, the energy consumption was reduced by 8% without capital expenditure. It shows that with correctly identified technology and the proper execution procedure, significant energy savings and emission reduction can be achieved very quickly without major capital expenditure. This allows the industry to improve its economic and environment performance at the same time.

Environmental performance assessment for reactive distillation processes

Direct or indirect CO 2 emission minimisation for energy intensive processes is a priority for reducing their environmental impact. For distillation this issue is observed redesigning the separation processes to improve the energy efficiency. Sustainability requests as well to enhance the usage of environmentally friendly products and to ensure good economic effectiveness. In this paper a new methodology is suggested for assessing environmental performance and economic viability of reactive distillation compared to classical schemes. Advanced process integration methodologies are used to save energy. Reactive distillation combines process integration and process intensification overcoming chemical equilibrium limitations, saving energy and ensuring economic effectiveness by reduced capital investment. Environmental performance is based on potential environmental impact (PEI), emissions, resource and energy conservation factors. PEI is obtained using waste reduction (WAR) algorithm as evaluation tool. Two examples illustrate the methodology comparing the performance of classical processes with reactive distillation synthesis processes (ethyl acetate - EtAc and t-amyl methyl ether - TAME) with the purpose to achieve a better sustainability. In both cases reactive distillation provides more sustainable schemes.

Scan Test Strategy for Asynchronous-Synchronous Interfaces

In the coming years, the well-known synchronous design style will not be able to keep pace with the increase speed and capabilities of integration of advanced processes. New design paradigms, like core reuse of the already designed synchronous modules and asynchronous designs, are considered in order to cope with the ever increasing complexity. The future SoCs will contain multiple synchronous and asynchronous cores. Asynchronous design will become more and more common among digital designers, while synchronous-asynchronous interactions will emerge as a key issue in the future SoC designs. This paper will present test strategies for 2-phase asynchronous-synchronous interfaces and vice versa. It will be shown how test vectors can be automatically generated using commercially available ATPG tools. The generated ATPG vectors will be able to test all stuck-at-faults within the asynchronous-synchronous interfaces.