Municipal solid waste to liquid transportation fuels – Part II: Process synthesis and global optimization strategies

Production efficiency and safety assessment of the solid waste-derived liquid hydrocarbons

Global fossil resource utilisation remains a concern. Organic fuels and chemicals produced through catalytic synthesis out of biomass/waste feedstock can help reduce the share of fossil resource utilisation. In this study, a solid waste-derived producer gas from the cross/updraft sliding bed gasification process was applied in a fixed bed catalytic reactor with the goal of producing rich hydrocarbon chains. The specific producer gas with CO = 10%vol., H2 = 9%vol. and CH4 = 4%vol. was applied into the catalytic reactor along with catalysts Cat-Co or Cat-CoMnK at 15 bar pressure. Both catalysts were investigated in temperature regimes of 250, 280 and 310 °C, and the liquefaction number and hydrocarbon production were determined. The liquid products were qualitatively analysed afterwards, and the safety assessment, comprising the autoignition test, was performed. The obtained results defined an optimal operating temperature close to 280 °C a value for both catalysts. The individual hydrocarbon compounds were defined mostly by alkanes and alkenes of C10-C14 hydrocarbon groups in the case of both applied catalysts. The application of MnK-promoted catalyst resulted in the production of a significant amount of C6 hydrocarbon groups as well. The results point out a wide range of compounds utilisable in many different applications throughout the production sphere and suggest the possibility of autothermal air gasification of solid recovered fuel with the goal of producing gas for catalytic synthesis with reduced operation costs. From the safety point of view, the temperature of 227.7 °C was defined as the lowest value when autoignition occurs. This lowest temperature is relevant to the Cat-Co 280 °C synthesis scenario.

Energy System Modelling Challenges for Synthetic Fuels : Towards net zero systems with synthetic jet fuels

Long-distance air travel requires fuel with a high specific energy and a high energy density. There are no viable alternatives to carbon-based fuels. Synthetic jet fuel from the Fischer-Tropsch (FT) process, employing sustainable feedstocks, is a potential low-carbon alternative. A number of synthetic fuel production routes have been developed, using a range of feedstocks including biomass, waste, hydrogen and captured carbon dioxide. We review three energy system models and find that many of these production routes are not represented. We examine the market share of synthetic fuels in each model in a scenario in which the Paris Agreement target is achieved. In 2050, it is cheaper to use conventional jet fuel coupled with a negative emissions technology than to produce sustainable synthetic fuels in the TIAM-UCL and UK TIMES models. However, the JRC-EU-TIMES model, which represents the most production routes, finds a substantial role for synthetic jet fuels, partly because underground CO2 storage is assumed limited. These scenarios demonstrate a strong link between synthetic fuels, carbon capture and storage (CCS) and negative emissions. Future model improvements include better representing blending limits for synthetic jet fuels to meet international fuel standards, reducing the costs of synthetic fuels and ensuring production routes are sustainable.

A framework to predict the price of energy for the end-users with applications to monetary and energy policies

Energy affects every single individual and entity in the world. Therefore, it is crucial to precisely quantify the “price of energy” and study how it evolves through time, through major political and social events, and through changes in energy and monetary policies. Here, we develop a predictive framework, an index to calculate the average price of energy in the United States. The complex energy landscape is thoroughly analysed to accurately determine the two key factors of this framework: the total demand of the energy products directed to the end-use sectors, and the corresponding price of each product. A rolling horizon predictive methodology is introduced to estimate future energy demands, with excellent predictive capability, shown over a period of 174 months. The effectiveness of the framework is demonstrated by addressing two policy questions of significant public interest.

Global energy transformation requires quantifying the "price of energy" and studying its evolution. Here the authors present a predictive framework that calculates the average US price of energy, estimating future energy demands for up to four years with excellent accuracy, designing and optimizing energy and monetary policies.

An Investigation of the Feasibility of the Organic Municipal Solid Waste Processing by Coking

In the context of transition to a circular economy, one of the strategic priorities is the development of technological innovations aimed at waste processing. In this study, the foundations have been developed for a low-temperature, environmentally safe method for efficient processing of organic municipal solid waste, which may be further applied for processing both municipal and industrial waste organics in order to obtain liquid products. The maximum yield of liquid products is ensured when conducting the coking of a mixture of organic waste with long residuum in the temperature range of 400–420 °C, with a heating rate of 5–70 °C/min, and with an optimal heating time to the coking temperature of 80 min. Recommendations on the use of the waste recycling products are given. The proposed process is consistent with the principles of circular economy and does not require external energy costs because the energy needed for the process is generated by burning the gas produced during the waste coking. The process does not produce emissions into the environment and, in combination with standard refining processes, can be used to obtain commercial petroleum products.

Modeling and Simulation of Energy Systems: A Review

Energy is a key driver of the modern economy, therefore modeling and simulation of energy systems has received significant research attention. We review the major developments in this area and propose two ways to categorize the diverse contributions. The first categorization is according to the modeling approach, namely into computational, mathematical, and physical models. With this categorization, we highlight certain novel hybrid approaches that combine aspects of the different groups proposed. The second categorization is according to field namely Process Systems Engineering (PSE) and Energy Economics (EE). We use the following criteria to illustrate the differences: the nature of variables, theoretical underpinnings, level of technological aggregation, spatial and temporal scales, and model purposes. Traditionally, the Process Systems Engineering approach models the technological characteristics of the energy system endogenously. However, the energy system is situated in a broader economic context that includes several stakeholders both within the energy sector and in other economic sectors. Complex relationships and feedback effects exist between these stakeholders, which may have a significant impact on strategic, tactical, and operational decision-making. Leveraging the expertise built in the Energy Economics field on modeling these complexities may be valuable to process systems engineers. With this categorization, we present the interactions between the two fields, and make the case for combining the two approaches. We point out three application areas: (1) optimal design and operation of flexible processes using demand and price forecasts, (2) sustainability analysis and process design using hybrid methods, and (3) accounting for the feedback effects of breakthrough technologies. These three examples highlight the value of combining Process Systems Engineering and Energy Economics models to get a holistic picture of the energy system in a wider economic and policy context.

Life Cycle Greenhouse Gas Emissions and Costs of Production of Diesel and Jet Fuel from Municipal Solid Waste

This paper quantifies and compares the life cycle GHG emissions and costs of production of diesel and jet fuel derived from municipal solid waste (MSW) in the United States via three thermochemical conversion pathways: conventional gasification and Fischer-Tropsch (FT middle distillate, MD), plasma gasification and Fischer-Tropsch (Plasma FT MD), and conventional gasification, catalytic alcohol synthesis, and alcohol-to-jet upgrading (ATJ MD). We use expanded system boundaries to capture the change in existing MSW use and disposal, and account for parameter uncertainty with Monte Carlo simulations. We estimate median life cycle GHG emissions of 32.9, 62.3, and 52.7 gCO₂e/MJ for FT, Plasma FT and ATJ MD fuels, respectively, compared to a baseline of 90 gCO₂e/MJ for conventional MD fuels. Median minimum selling prices are estimated at 0.99, 1.78, and 1.20 $ per liter with the probability of achieving a positive net present value of fuel production at market prices of 14%, 0.1% and 7% for FT, Plasma FT and ATJ MD fuels, respectively. If the societal perspective rather than an investor's perspective is evaluated, then the probability of positive net present value of fuel production increases to 93%, 67%, and 92.5% for the FT, Plasma FT, and ATJ MD fuels, respectively.

Bioconversion of Municipal Solid Wastes for Bioethanol Production

ABSTRACT: The use of dilute acid (H2SO4, 3%) and alkali (NaOH, 3%) pretreatment methods has some potential how ever to date, these methods effectively increase ethanol production of municipal solid waste (MSW). Enzymatic hydrolysis was carried out with Aspergillus niger, Aspergillus fumigatus and Trichoderma reesei. Finally, the fermentation was done by sugar three ethanologenic yeasts, Saccharomyces cerevisiae, pichia stipitis, canida shehatae for bioethanol production.The highest ethanol yield (22.32%) v/v. was obtained with a pre-hydrolysis treatment consisting of NaOH at 3% concentration, followed by Pichia stipitis and enzymatic hydrolysis with Aspergillus niger. Pre-hydrolysis treatment consisted Enzymatic hydrolysis was carried out with Alkali pretreated wastes yield more sugar as compared to acid treatment using produced more ethanol than others at each time point. The experimental results observed that 80% of the cellulose converted to glucose from the waste which can be easily fermented to production. of ethanol. The ability focus on related environmental issues, such as sustainable waste management, climate change, land use and biodiversity, are discussed.