Process assessment of renewable-based acrylic acid production from glycerol valorisation

The continuous growth of biodiesel production via transesterification is leading to an increase in the generation and availability of the by-product glycerol. In this study, a glycerol-based process for the production of acrylic acid has been designed and simulated. The valorisation of glycerol route includes a two-step conversion process where glycerol is first dehydrated to acrolein and acrolein is selectively oxidised to acrylic acid. This renewable-based process is then compared in terms of heat integration and techno-economic performance to the traditional petrochemical route from propylene from a techno-economic and environmental point of view. The study includes the detailed design of the separation train in which azeotropic distillation is also assessed along with the sensitivity analysis of the most relevant variables of the process. Using a production basis of approximately 10,250 kg h−1 of acrylic acid (purity>99.5 wt%), results show that the glycerol route generates 37.3% less CO2 emissions than the propylene-based. From the heat integration analysis, slightly lower heating (96.6%) but higher cooling (32.4%) energy savings can be attained in the glycerol route as opposed to heating (100%) and cooling (21.6%) energy savings available in the propylene-based route. In terms of economics, the glycerol-based route has a lower capital expenditure (£74.0 million) and operating expenditure (£171.4 million yr−1) compared to the propylene route (£91.3 million and £180.2 million yr−1, respectively). Nevertheless, considering the use of raw material and its cost, the glycerol route is more demanding (1.96 kg h−1 of pure glycerol per kg h−1 of acrylic acid amounting to £138.6 million yr−1) than the propylene route (0.92 kg h−1 of propylene per kg h−1 of acrylic acid at £117.2 million yr−1)

Water gas shift reaction in packed bed clc using ilmenite as oxygen carrier

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Integration of solid oxide fuel cell (SOFC) and chemical looping combustion (CLC) for ultra-high efficiency power generation and CO2 production

This work presents a thermodynamic analysis of the integration of solid oxide fuel cells (SOFCs) with chemical looping combustion (CLC) in natural gas power plants. The fundamental idea of the proposed process integration is to use a dual fluidized-bed CLC process to complete the oxidation of the H2-CO-rich anode exhausts from the SOFC in the CLC fuel reactor while preheating the air stream to the cathode inlet temperature in the CLC air reactor. Thus, fuel oxidation can be completed in N2-free environment without the high energy and economic costs associated to O2 production, avoiding at the same time the high temperature and high cost heat exchanger needed in conventional SOFC plants for air preheating. In the proposed configurations, the CLC plant is operated at mild conditions (atmospheric pressure and temperature in the range of 700–800 °C), already demonstrated in several pilot plants. Two different scenarios have been investigated: in the first one, the SOFC is designed for large-scale power generation (100 MWLHV of heat input), featuring a heat recovery steam cycle and CO2 capture for subsequent storage. In the second scenario, the system is designed for a small-scale plant, producing 145 kg/h of pure CO2 for industrial utilization, as a possible early market application. The main parameters affecting the plant performance, i.e. SOFC voltage (V) and S/C ratio at SOFC inlet, have been varied in a sensitivity analysis. Three different materials (Ni, Fe and Cu-based) are also compared as oxygen carriers (OCs) in the CLC unit. The integrated plant shows very high electric efficiency, exceeding 66%LHV at both small and large scale with a carbon capture ratio (CCR) of nearly 100%. It was found that, except for the cell voltage, the other operating parameters do not affect significantly the efficiency of the plant. Compared to the benchmark SOFC-based hybrid cycles using conventional CO2 capture technologies, the SOFC-CLC power plant showed an electric efficiency ∼2 percentage points higher, without requiring high temperature heat exchangers and with a simplified process configuration

Investigation of heat management for CLC of syngas in packed bed reactors

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Techno-economic assessment of different routes for olefins production through the oxidative coupling of methane (OCM): Advances in benchmark technologies

his paper addresses the techno-economic assessment of two technologies for olefins production from naphtha and natural gas. The first technology is based on conventional naphtha steam cracking for the production of ethylene, propylene and BTX at polymer grade. The unused products are recovered in a boiler to produce electricity for the plant. The plant has been designed to produce 1 MTPY of ethylene. In the second case, ethylene is produced from natural gas through the oxidative coupling of methane (OCM) in which natural gas is fed to the OCM reactor together with oxygen from a cryogenic air separation unit (ASU). The overall reactions are kinetically controlled and the system is designed to work at about 750–850 °C and close to 10 bar. Since the overall reaction system is exothermic, different layouts for the reactor temperature control are evaluated. For the naphtha steam cracking plant, the energy analysis shows an overall conversion efficiency of 67% (with a naphtha-to-olefins conversion of 65.7%) due to the production of different products (including electricity), with a carbon conversion rate of 70%. The main equipment costs associated with naphtha steam cracking are represented by the cracker (about 30%), but the cost of ethylene depends almost entirely on the cost associated with the fuel feedstock. In case of the OCM plant, the overall energy conversion efficiency drops to maximally 30%. In the studied plant design, CO2 capture from the syngas is also considered (downstream of the OCM reactor) and therefore the final carbon/capture efficiency is above 20%. The cost of ethylene from OCM is higher than with the naphtha steam cracking plant and the CAPEX affects the final cost of ethylene significantly, as well as the large amount of electricity required.The authors are grateful to the European Union’s HORIZON2020 Program (H2020/2014-2020) for the financial support through the H2020 MEMERE project under the grant agreement n° 679933

Challenges and opportunities of achieving European CO₂ transportation and storage specifications for carbon capture in the iron and steel industry

The application of CCS in the iron and steel industry faces particular challenges for achieving European CO2 transportation and storage in meeting CO₂ stream impurity limit specifications due to the unique and diverse composition of the steelworks off-gases targeted for CO₂ capture and the separation efficiency of proposed CO₂ capture solutions. This paper reviews the range and levels of compounds that could form potential CO₂ impurities in steelworks off-gases and provides estimates of the quality of CO₂ products obtained in primary CO₂ capture steps from Blast Furnace Gas (BFG) using different technologies of Pressure-Swing Adsorption (PSA) and amine scrubbing. Published CO₂ specifications from European transportation and storage operators are reviewed and compared. Additional suitable purification steps that are needed in order to reduce the levels of impurities from primary CO₂ product streams in order to achieve European CO₂ impurity limit specifications are identified, characterised and the associated cost implications discussed

Exploring the views on total quality human resources management between public and private educational units

The aim of the present study is to identify the attitudes of the directors of different types of educational units regarding the practices of Total Quality of Human Resources Management (TQHRM) in Greece. The specific objectives of the survey are the exploration and analysis of the following issues: a) The philosophy applied by each director on the unit they manage and the position of the HR in it; b) the directors’ opinion about the TQHRM Practices; and c) the difference in the approach of these practices between the public and private educational unit directors.The data is collected using a questionnaire that was sent electronically to Greek schools of various levels in 2018 and the number of responses is 70, of which 53% are from the private and 47% from the public sector directors. To process responses and draw conclusions, both one-dimensional and multidimensional analysis were performed. The results of this survey show that the HRM practices followed by the directors do not have a clear orientation. This highlights the need for training those who run an educational institution on TQHRM and the understanding of the importance of Human Resources on achieving the goals of an organization

Direct route from ethanol to pure hydrogen through autothermal reforming in a membrane reactor: Experimental demonstration, reactor modelling and design

This work reports the integration of thin (∼3–4 μm thick) Pd-based membranes for H2 separation in a fluidized bed catalytic reactor for ethanol auto-thermal reforming. The performance of a fluidized bed membrane reactor has been investigated from an experimental and numerical point of view. The demonstration of the technology has been carried out over 50 h under reactive conditions using 5 thin Pd-based alumina-supported membranes and a 3 wt%Pt-10 wt%Ni catalyst deposited on a mixed CeO2/SiO2 support. The results have confirmed the feasibility of the concept, in particular the capacity to reach a hydrogen recovery factor up to 70%, while the operation at different fluidization regimes, oxygen-to-ethanol and steam-to-ethanol ratios, feed pressures and reactor temperatures have been studied. The most critical part of the system is the sealing of the membranes, where most of the gas leakage was detected. A fluidized bed membrane reactor model for ethanol reforming has been developed and validated with the obtained experimental results. The model has been subsequently used to design a small reactor unit for domestic use, showing that 0.45 m2 membrane area is needed to produce the amount of H2 required for a 5 kWe PEM fuel-cell based micro-CHP system.The presented work is funded within the FluidCELL project as part of the European Union's Seventh Framework Programme (FP7/ 2007-2013) for the Fuel Cells and Hydrogen Joint Technology Initiative under grant agreement nº 621196