Economic assessment of CO2-based methane, methanol and polyoxymethylene production

The potential and capability of the methylotrophic yeast Ogataea methanolica in a "methanol bioeconomy"

Efficient bioconversion of methanol, which can be generated from greenhouse gases, into valuable resources contributes to achieving climate goals and developing a sustainable economy. The methylotrophic yeast Ogataea methanolica is considered to be a suitable host for efficient methanol bioconversion because it has outstanding characteristics for the better adaptive potential to a high methanol environment (i.e., greater than 5%). This capacity represents a huge potential to construct an innovative carbon-neutral production system that converts methanol into value-added chemicals under the control of strong methanol-induced promoters. In this review, we discuss what is known about the regulation of methanol metabolism and adaptation mechanisms for 5% methanol conditions in O. methanolica in detail. We also discuss about the potential to breed "super methylotrophic yeast," which has potent growth characteristics under high methanol conditions.

Environmental and Economic Performance of CO2-Based Methanol Production Using Long-Distance Transport for H2 in Combination with CO2 Point Sources: A Case Study for Germany

The use of CO2-based hydrocarbons plays a crucial role in reducing the climate footprint for several industry sectors, such as the chemical industry. Recent studies showed that regions which are favorable for the production of CO2-based hydrocarbons from an energy perspective often do not provide concentrated point sources for CO2, which leads to an increased environmental impact due to the higher energy demand of direct air capture processes. Thus, producing H2 in regions with high renewable power potential and transporting it to industrialized regions with concentrated CO2 point sources could provide favorable options for the whole process chain. The aim of this study is to analyze and compare pathways to produce CO2-based methanol in Germany using a local CO2 point source in combination with the import of H2 per pipeline or per ship as well as H2 produced in Germany. The environmental and economic performance of the pathways are assessed using life cycle assessment and cost analysis. As environmental indicators, the climate, material, water, and land footprints were calculated. The pathway that uses H2 produced with electricity from offshore wind parks in Germany shows the least environmental impacts, whereas the import via pipeline shows the best results among the importing pathways. The production costs are the lowest for import via pipeline now and in the near future. Import via ship is only cost-efficient in the status quo if waste heat sources are available, but it could be more competitive in the future if more energy and cost-efficient options for regional H2 distribution are available. It is shown that the climate mitigation effect is more cost-effective if the H2 is produced domestically or imported via pipeline. Compared to the import of CO2-based methanol, the analyzed H2 import pathways show a comparable (pipeline) or worse environmental and economic performance (ship).

Environmental management of industrial decarbonization with focus on chemical sectors: A review

A considerable portion of fossil CO₂ emissions comes from the energy sector for production of heat and electricity. The industrial sector has the second order in emission in which the main parts are released from energy-intensive industries, namely metallurgy, building materials, chemicals, and manufacturing. The decarbonization of industrial wastes contemplates the classic decarbonization through optimization of conventional processes as well as utilization of renewable energy and resources. The upgrading of existing processes and integration of the methodologies with a focus on efficiency improvement and reduction of energy consumption and the environment is the main focus of this review. The implementation of renewable energy and feedstocks, green electrification, energy conversion methodologies, carbon capture, and utilization, and storage are also covered. The main objectives of this review are towards chemical industries by introducing the potential technology enhancement at different subsectors. For this purpose, state-of-the-art roadmaps and pathways from the literature findings are presented. Both common and innovative renewable attempts are needed to reach out both short- and long-term deep decarbonization targets. Even though all of the innovative solutions are not economically viable at the industrial scale, they play a crucial role during and after the energy transition interval.

Critical Analysis and Evaluation of the Technology Pathways for Carbon Capture and Utilization

Carbon capture and utilization (CCU) is the process of capturing unwanted carbon dioxide (CO2) and utilizing for further use. CCU offers significant potential as part of a sustainable circular economy solution to help mitigate the impact of climate change resulting from the burning of hydrocarbons and alongside adoption of other renewable energy technologies. However, implementation of CCU technologies faces a number of challenges, including identifying optimal pathways, technology maturity, economic viability, environmental considerations as well as regulatory and public perception issues. Consequently, this research study provides a critical analysis and evaluation of the technology pathways for CCU in order to explore the potential from a circular economy perspective of this emerging area of clean technology. This includes a bibliographic study on CCU, evaluation of carbon utilization processes, trend estimation of CO2 usage as well as evaluation of methane and methanol production. A value chain analysis is provided to support the development of CCU technologies. The research study aims to inform policy-makers engaged in developing strategies to mitigate climate change through reduced carbon dioxide emission levels and improve our understanding of the circular economy considerations of CCU in regard to production of alternative products. The study will also be of use to researchers concerned with pursuing empirical investigations of this important area of sustainability.

Use of carbon dioxide as raw material to close the carbon cycle for the German chemical and polymer industries

This article explores how far the use of CO₂ as raw material could enable the German chemical and polymer industries to contribute to a circular economy. Material Flow Analysis was conducted for all carbon flows for material use in Germany, comprising chemical production, polymer production, domestic use and waste management. For scenario modelling, Carbon Capture and Utilization technologies were included, and key parameters determining carbon flows were altered to show potential corridors for the future development. The results show that current carbon flows are dominated by fossil sources and are highly linear, with a secondary input rate of only 6%. Additionally, 12% (2 Mt/a) of the primary carbon input is lost due to dissipation. Currently available Carbon Capture and Utilization technologies would allow reaching a secondary input rate of 65% for the chemical industry. However, to achieve this rate between 80% (processes of direct synthesis) and 103% (methanol-based processes) of the total net supply for renewable electricity in Germany would be required in 2030 and between 41% and 50% in 2050. In contrast, the unavoidable substance related CO₂-point sources in Germany could probably fulfill the carbon requirement for material use of the chemical industry in 2050. The authors conclude that the utilization of CO₂ as a carbon source is necessary to close the carbon cycle where material or chemical recycling is technically not feasible or reasonable. The very high demand for renewable electricity indicates that the required production facilities for CO₂-based chemicals will probably not be completely based in Germany.

Scale-up and Sustainability Evaluation of Biopolymer Production from Citrus Waste Offering Carbon Capture and Utilisation Pathway

Poly(limonene carbonate) (PLC) has been highlighted as an attractive substitute to petroleum derived plastics, due to its utilisation of CO2 and bio-based limonene as feedstocks, offering an effective carbon capture and utilisation pathway. Our study investigates the techno-economic viability and environmental sustainability of a novel process to produce PLC from citrus waste derived limonene, coupled with an anaerobic digestion process to enable energy cogeneration and waste recovery maximisation. Computational process design was integrated with a life cycle assessment to identify the sustainability improvement opportunities. PLC production was found to be economically viable, assuming sufficient citrus waste is supplied to the process, and environmentally preferable to polystyrene (PS) in various impact categories including climate change. However, it exhibited greater environmental burdens than PS across other impact categories, although the environmental performance could be improved with a waste recovery system, at the cost of a process design shift towards energy generation. Finally, our study quantified the potential contribution of PLC to mitigating the escape of atmospheric CO2 concentration from the planetary boundary. We emphasise the importance of a holistic approach to process design and highlight the potential impacts of biopolymers, which is instrumental in solving environmental problems facing the plastic industry and building a sustainable circular economy.

The Future Agricultural Biogas Plant in Germany: A Vision

After nearly two decades of subsidized and energy crop-oriented development, agricultural biogas production in Germany is standing at a crossroads. Fundamental challenges need to be met. In this article we sketch a vision of a future agricultural biogas plant that is an integral part of the circular bioeconomy and works mainly on the base of residues. It is flexible with regard to feedstocks, digester operation, microbial communities and biogas output. It is modular in design and its operation is knowledge-based, information-driven and largely automated. It will be competitive with fossil energies and other renewable energies, profitable for farmers and plant operators and favorable for the national economy. In this paper we discuss the required contribution of research to achieve these aims.