Novel process design and techno-economic simulation of methanol synthesis from blast furnace gas in an integrated steelworks CCUS system

A novel process design and techno-economic performance assessment for methanol synthesis from Blast Furnace Gas (BFG) is presented. Methanol synthesis using BFG as a feedstock, based on direct CO2 hydrogenation at commercial scale was simulated using Aspen Plus software to evaluate its technical performance and economic viability. The applied process steps involve first conditioning BFG using adsorption based desulfurisation, water-gas shift, dehydration, then separation of components into N2, CO2 and H2 rich streams using pressure swing adsorption. The H2 stream and a fraction of the CO2 stream are fed to a methanol synthesis system, while the remaining CO2 may be considered for geological storage in a Carbon Capture, Utilization and Storage (CCUS) case, or not in a Carbon Capture Utilization (CCU) case. Techno-economic analysis confirms methanol production from BFG is economically attractive under certain conditions, with Levelized Cost of Methanol production (LCOMeOH) calculated to be 344.61 £/tonne-methanol, and costs of CO2 avoided of - 20.08 £/tonne-CO2 for the CCU process and 9.01 £/tonne-CO2 for the CCUS process when using a set of baseline engineering assumptions. Sensitivity analysis of the process simulation explores opportunities for optimising the methanol synthesis system in terms of the impact of reactor size and/or recycle ratio on LCOMeOH. Economic viability of the CCU(S) processes is also found to be highly dependent on the cost of the feedstock BFG. Future cost savings as compared to business-as-usual steel production by 2030 in consideration of expected increases in the carbon price are estimated to be 10.59 £/tonne-steel for CCU and 24.61 £/tonne-steel for CCUS

An Aspen Plus Kinetic Model for the Gasification of Biomass in a Downdraft Gasifier

Gasification is a useful technology to recover energy from renewable biomass by producing a versatile syngas which can be converted into useful chemicals or fuels, or used directly for energy generation. The quality and composition of the syngas is highly dependent on the biomass feedstock, design parameters and process conditions, such as temperature, gasifying agent and Equivalence Ratio (ER). Downdraft gasifiers are considered to be a good option for low tar syngas production. In this work, a kinetic model for a downdraft gasifier is assembled and incorporated into a flowsheet using Aspen Plus with the aim of performing detailed process analysis. The model is organised according to the assumption that in a downdraft gasifier pyrolysis, oxidation and reduction occur almost as separate consecutive processes, with the pyrolysis considered as an instantaneously occurring process while oxidation and reduction are governed by chemical kinetics. The model has been validated against experimental data for different conditions of ER ranging from 0.2 to 0.35. The results show an overall agreement of the main species, with slight discrepancies in the prediction of CH4, which is over-predicted at lower ERs and under predicted at ER 0.345. This has an effect on the calculated Lower Heating Value (LHV) of the syngas which is generally higher than the experimental value. A set of sensitivity analyses were performed to investigate the impact of the value of the Char Reactivity Factor (CRF) on the composition of the producer gas and the kinetic parameters used in the model on the production of CH4. Sensitivity analyses show that a CRF of 14 gives the best prediction of the syngas composition and that the kinetics of the reactions in the reduction zone do not have a large impact on the final levels of methane in the syngas. More important is the sensitivity to variation of the kinetic parameters in the oxidation stage. By doubling the rate of oxidation of CH4 in the oxidation zone, the final levels of CH4 in the syngas are reduced by almost 20%

Biomass gasification in a downdraft gasifier with in-situ CO2 capture: A pyrolysis, oxidation and reduction staged model

Biomass gasification with in-situ CO2 capture, using calcium oxide as sorbent, has attracted increasing interest as a renewable source of high value products through the production of H2 rich syngas, while simultaneously presenting considerable potential for mitigating global warming by reducing CO2 emissions. Many factors influence the final composition of the syngas, such as type and amount of gasifying agent and residence time. Kinetic models play an important role in identifying the specific conditions for controlling the yield and composition of the product gas. When in-situ CO2 capture is used, accurate characterisation of the adsorption reactions in the kinetic scheme is essential for accurate prediction of the H2 rich syngas composition and the overall assessment of the technology. In this work, a kinetic model for biomass gasification with in-situ CO2 capture in a downdraft gasifier is developed. The model is divided into thermochemical stages of pyrolysis, oxidation and reduction in which gasification in a downdraft gasifier occurs, characterised by different compositions and temperature gradients. The model extends the kinetics to the oxidation zone and includes a mechanism for tar oxidation. Given downdraft gasifier designs, a simplification is made where the kinetic behaviour in each of the different stages is modelled separately and in series by a unique set of reactions. The model is validated against two sets of experimental data and different scenarios of equivalence ratio, steam-to-biomass ratio and sorbent-to-biomass ratio are analysed. Sensitivity analysis show that, employing carbon capture, H2 yields can increase of up to 50% under selected conditions. The study aims to provide a better understanding of biomass gasification kinetics and to aid the design and operation of downdraft gasifiers

Techno-economic assessment of CO2 quality effect on its storage and transport: CO2QUEST: An overview of aims, objectives and main findings

This paper provides an overview of the aims, objectives and the main findings of the CO2QUEST FP7 collaborative project, funded by the European Commission and designed to address the fundamentally important and urgent issues regarding the impact of the typical impurities in CO2 streams captured from fossil fuel power plants and other CO2 intensive industries on their safe and economic pipeline transportation and storage. The main features and results recorded from some of the unique test facilities constructed as part of the project are presented. These include an extensively instrumented realistic-scale test pipeline for conducting pipeline rupture and dispersion tests in China, an injection test facility in France to study the mobility of trace metallic elements contained in a CO2 stream following injection near a shallow-water qualifier and fluid/rock interactions and well integrity experiments conducted using a fully instrumented deep-well CO2/impurities injection test facility in Israel. The above, along with the various unique mathematical models developed, provide the fundamentally important tools needed to define impurity tolerance levels, mixing protocols and control measures for pipeline networks and storage infrastructure, thus contributing to the development of relevant standards for the safe design and economic operation of CCS

Carbon capture: Whole system experimental and theoretical modeling investigation of the optimal CO<inf>2</inf> stream composition in the carbon capture and sequestration chain

Rapid increase in emissions of greenhouse gases (GHGs) has become a major concern to the global community. This is associated with the rapid growth in population and corresponding increase in energy demand. Combustion of fossil fuels accounts for the majority of CO2 emissions. Coal is used mostly for electricity generation, for instance, about 85.5% of coal (produced and imported) in the United 459Kingdom was used for electricity generation in 2011 [1]. Coal-fired power plants are therefore the largest stationary source of CO2

Particle identification in ALICE : a Bayesian approach

Peer reviewe

清涼飮料税論

The production of J/\).psi\) and $\psi(2S)$ was measured with the ALICE detector in Pb-Pb collisions at the LHC. The measurement was performed at forward rapidity 2.5 < y < 4 \() down to zero transverse momentum \(p_{\rm T} in the dimuon decay channel. Inclusive J/\).psi\) yields were extracted in different centrality classes and the centrality dependence of the average $p_{\rm T}$ is presented. The J/\).psi\) suppression, quantified with the nuclear modification factor $R_{\rm AA}$ , was studied as a function of centrality, transverse momentum and rapidity. Comparisons with similar measurements at lower collision energy and theoretical models indicate that the J/\).psi\) production is the result of an interplay between color screening and recombination mechanisms in a deconfined partonic medium, or at its hadronization. Results on the $\psi(2S)$ suppression are provided via the ratio of $\psi(2S)$ over J/\).psi\) measured in pp and Pb-Pb collisions

Exclusive J/psi Photoproduction off Protons in Ultraperipheral p-Pb Collisions at root s(NN)=5.02 TeV

We present the first measurement at the LHC of exclusive J/psi photoproduction off protons, in ultraperipheral proton-lead collisions at root s(NN) = 5.02 TeV. Events are selected with a dimuon pair produced either in the rapidity interval, in the laboratory frame, 2.5 J/psi + p) are 33.2 +/- 2.2(stat) +/- 3.2(syst) +/- 0.7(theor) nb in p-Pb and 284 +/- 36(stat)(-32)(+27)(syst) +/- 26(theor) nb in Pb-p collisions. We measure this process up to about 700 GeV in the gamma p center of mass, which is a factor of two larger than the highest energy studied at HERA. The data are consistent with a power law dependence of the J/psi photoproduction cross section in gamma p energies from about 20 to 700 GeV, or equivalently, from Bjorken x scaling variable between similar to 2 x 10(-2) and similar to 2 x 10(-5), thus indicating no significant change in the gluon density behavior of the proton between HERA and LHC energies

Measurement of charged jet suppression in Pb-Pb collisions at sNN\sqrt{s_{NN}}=2.76TeV

A measurement of the transverse momentum spectra of jets in Pb-Pb collisions at $\sqrt{s_{NN}}$=2.76TeV is reported. Jets are reconstructed from charged particles using the anti-$k_T$ jet algorithm with jet resolution parameters R of 0.2 and 0.3 in pseudo-rapidity |$\eta$|<0.5. The transverse momentum p_T of charged particles is measured down to 0.15 GeV/c which gives access to the low p_T fragments of the jet. Jets found in heavy-ion collisions are corrected event-by-event for average background density and on an inclusive basis (via unfolding) for residual background fluctuations and detector effects. A strong suppression of jet production in central events with respect to peripheral events is observed. The suppression is found to be similar to the suppression of charged hadrons, which suggests that substantial energy is radiated at angles larger than the jet resolution parameter R=0.3 considered in the analysis. The fragmentation bias introduced by selecting jets with a high p_T leading particle, which rejects jets with a soft fragmentation pattern, has a similar effect on the jet yield for central and peripheral events. The ratio of jet spectra with R=0.2 and R=0.3 is found to be similar in Pb-Pb and simulated PYTHIA pp events, indicating no strong broadening of the radial jet structure in the reconstructed jets with R<0.3.A measurement of the transverse momentum spectra of jets in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV is reported. Jets are reconstructed from charged particles using the anti-$k_{\rm T}$ jet algorithm with jet resolution parameters $R$ of $0.2$ and $0.3$ in pseudo-rapidity $|\eta|<0.5$. The transverse momentum $p_{\rm T}$ of charged particles is measured down to $0.15$ GeV/$c$ which gives access to the low $p_{\rm T}$ fragments of the jet. Jets found in heavy-ion collisions are corrected event-by-event for average background density and on an inclusive basis (via unfolding) for residual background fluctuations and detector effects. A strong suppression of jet production in central events with respect to peripheral events is observed. The suppression is found to be similar to the suppression of charged hadrons, which suggests that substantial energy is radiated at angles larger than the jet resolution parameter $R=0.3$ considered in the analysis. The fragmentation bias introduced by selecting jets with a high $p_{\rm T}$ leading particle, which rejects jets with a soft fragmentation pattern, has a similar effect on the jet yield for central and peripheral events. The ratio of jet spectra with $R=0.2$ and $R=0.3$ is found to be similar in Pb-Pb and simulated PYTHIA pp events, indicating no strong broadening of the radial jet structure in the reconstructed jets with $R<0.3$