Full oxygen blast furnace steelmaking: From direct hydrogen injection to methanized BFG injection

This paper presents a novel concept of Power to Gas in an oxygen blast furnace, through blast furnace gas methanation and direct H2 injection. The PEM electrolyser produces H2, which reacts with the CO and CO2 from the blast furnace gas forming synthetic natural gas. The latter gas is injected into the blast furnace, closing a carbon loop and avoiding CO2 emissions. A parametric analysis is performed to vary the H2:CO2 ratio in the methanation reaction. Different ratios are simulated and compared, among of which the most representative are: (i) 2.5, where unreacted CO2 is directly recycled with the synthetic natural gas; (ii) 4, where stoichiometric conditions are found and the synthetic gas is composed mostly by CH4; and (iii) 8, where an excess of H2 is found in the synthetic gas; and (iv) an infinite ratio, where only H2 is injected in the blast furnace. In the latter, the methanation plant is not required, and no synthetic natural gas is produced. The results show that low H2:CO2 ratios perform poorly, involving high PEM sizes and high costs but only a 5% of CO2 avoidance (compared to conventional blast furnaces). A H2:CO2 ratio of 4 and full H2 injection results in higher reduction of CO2 emissions (33.8 % and 28.6%) with carbon abatement costs of 260 and 245 €/tCO2, respectively

The influence of the Ratio Bias phenomenon on the elicitation of Standard Gamble utilities

This paper tests whether logically equivalent risk formats can lead to different health state utilities elicited by means of the standard gamble (SG) method. We compare SG utilities elicited when probabilities are framed in terms of frequencies with respect to 100 people in the population (i.e., X out of 100) with SG utilities elicited for frequencies with respect to 1,000 people in the population (i.e., Y out of 1,000). We found that utilities were significant higher when success and failure probabilities were framed as frequencies type “Y out of 1,000” rather than as frequencies type “X out of 100”. This framing effect, known as Ratio Bias, may have important consequences in resource allocation decisions.Framing effect, risk format, standard gamble, health state, dual-process theories.

El Valor Monetario de la Vida Estadística en España a través de las Preferencias Declaradas

En este trabajo estimamos el Valor Monetario de una Vida Estadística en España a partir de preferencias declaradas por la población general. El contexto de valoración elegido es el de los accidentes de tráfico. La metodología empleada es la Valoración Contingente. En la encuesta realizada se intentaron comunicar correctamente los riesgos mediante el recurso a ayudas visuales. Los valores obtenidos (no inferiores a 2,7 millones de euros) son similares a otras estimaciones efectuadas en Europa, si bien un aspecto de la consistencia de estos resultados (cuasi-proporcionalidad) sólo se verifica parcialmente. Investigaciones futuras deberán emplear estrategias alternativas a la aquí utilizada con la finalidad de intentar incrementar la consistencia de los valores obtenidos. El procedimiento “encadenado” ideado por Carthy et al. (1999) puede ser un instrumento adecuado para ese objetivo.Valor de la vida, preferencias declaradas, accidentes de tráfico, valoración contingente, comunicación de riesgos.

Debiasing EQ-5D Tariffs. New estimations of the spanish EQ-5D value set under nonexpected utility

Este proyecto tiene como objetivo estimar las utilidades asociadas a los estados de salud definidos mediante el sistema EuroQol-5D a partir de la medición directa de las preferencias de una muestra de la población andaluza. Los valores obtenidos serán susceptibles de ser utilizados en el marco de estudios de evaluación económica de políticas sanitarias (análisis coste-utilidad) realizados en la comunidad andaluza y en el conjunto del estado. Para la valoración directa de un subconjunto de estados de salud se realizará una encuesta personal asistida por ordenador a una muestra representativa por sexo y cuotas de edad de la población española, extraída de la población residente en Andalucía. Los métodos que se aplicarán para obtener las preferencias y calcular las utilidades tratarán de corregir algunos de los sesgos que pueden afectar a las estimaciones existentes. Así, se adoptarán enfoques teóricos alternativos a los habitualmente empleados que permitirán relajar algunos de los supuestos que han sido puestos en cuestión a la luz de la evidencia empírica, como es el caso de la linealidad de la función de utilidad del tiempo de vida, la validez descriptiva de la teoría de la utilidad esperada o la separabilidad multiplicativa de las preferencias por cantidad y calidad de vida.EQ-5D, social tariff, utility curvature, probability weighting, rank-dependent utility, time trade-off, value lottery equivalence, certainlty equivalence

Improving scope sensitivity in contingent valuation: joint and separate evaluation of health states

We present data of a contingent valuation survey, testing the effect of evaluation mode on the monetary valuation of preventing road accidents. Half of the interviewees was asked to state their willingness to pay (WTP) to reduce the risk of having only 1 type of injury (separate evaluation, SE), and the other half of the sample was asked to state their WTP for 4 types of injuries evaluated simultaneously (joint evaluation, JE). In the SE group, we observed lack of sensitivity to scope while in the JE group WTP increased with the severity of the injury prevented. However, WTP values in this group were subject to context effects. Our results suggest that the traditional explanation of the disparity between SE and JE, namely, the so-called “evaluability,” does not apply here. The paper presents new explanations based on the role of preference imprecision

CO2 recycling in the iron and steel industry via power-to-gas and oxy-fuel combustion

The iron and steel industry is the largest energy-consuming sector in the world. It is responsible for emitting 4-5% of the total anthropogenic CO2. As an energy-intensive industry, it is essential that the iron and steel sector accomplishes important carbon emission reduction. Carbon capture is one of the most promising alternatives to achieve this aim. Moreover, if carbon utilization via power-to-gas is integrated with carbon capture, there could be a significant increase in the interest of this alternative in the iron and steel sector. This paper presents several simulations to integrate oxy-fuel processes and power-to-gas in a steel plant, and compares gas productions (coke oven gas, blast furnace gas, and blast oxygen furnace gas), energy requirements, and carbon reduction with a base case in order to obtain the technical feasibility of the proposals. Two different power-to-gas technology implementations were selected, together with the oxy blast furnace and the top gas recycling technologies. These integrations are based on three strategies: (i) converting the blast furnace (BF) process into an oxy-fuel process, (ii) recirculating blast furnace gas (BFG) back to the BF itself, and (iii) using a methanation process to generate CH4 and also introduce it to the BF. Applying these improvements to the steel industry, we achieved reductions in CO2 emissions of up to 8%, and reductions in coal fuel consumption of 12.8%. On the basis of the results, we are able to conclude that the energy required to achieve the above emission savings could be as low as 4.9 MJ/kg CO2 for the second implementation. These values highlight the importance of carrying out future research in the implementation of carbon capture and power-to-gas in the industrial sector. © 2021 by the authors

High oxygen and SNG injection in blast furnace ironmaking with Power to Gas integration and CO2 recycling

In the last years, reduction of CO2 emissions from the steel industry has been of great importance. Carbon capture, oxygen blast furnaces and top gas recycling technologies, among others, have been deeply studied as low carbon solutions. In this paper, a novel integration of carbon capture and power to gas technologies in the steelmaking industry is presented. Green hydrogen via proton exchange membrane (PEM) electrolysis and CO2 via methyldiethanolamine (MDEA) scrubbing from the blast furnace gas (BFG) are used to produce synthetic natural gas in an isothermal fixed bed methanation plant. The latter gas is injected into the blast furnace, closing a carbon loop and reducing coal consumption. The oxygen by-produced in the electrolyser covers the entire oxygen demand of the steelmaking plant and avoids the need for an air separation unit (ASU). The novelty of this work relies on the variation of the oxygen enrichment and its temperature in the hot blast, and how it influences the power to gas integration concept. This power to gas integration is compared with a conventional BF-BOF plant from a technical, economic, energy and environmental point of view. Both plant process configurations were implemented in Aspen Plus simulations, assessing the fossil fuel demand, energy penalty, cost and CO2 emissions. Emission reduction up to 34% can be achieved with power to gas integration, with an energy penalty of 17 MJ/tHM and a cost of 352 €/tCO2

Technical and economic assessment of iron and steelmaking decarbonization via power to gas and amine scrubbing

The iron and steel industry is one of the most energy-intensive industries, emitting 5% of the total anthropogenic carbon dioxide (CO2). The control of CO2 emissions has become increasingly stringent in the European Union (EU), resulting in EU allowance above 90 €/tCO2. Carbon capture will be required to achieve CO2 emissions control, and carbon utilization via power-to-gas could significantly increase interest in carbon capture in the iron and steel sector. This paper presents a new concept that combines amine scrubbing with power-to-gas to reduce emissions in blast furnace-basic oxygen furnace steelmaking plants. Synthetic natural gas (SNG) is produced using green hydrogen from water electrolysis and CO2 from steelmaking. The synthetic natural gas is later used as a reducing agent in the blast furnace, constantly recycling carbon in a closed loop and avoiding geological storage. The oxygen by-produced via electrolysis eliminates the necessity of an air separation unit. By applying these innovations to steelmaking, a reduction in CO2 emissions of 9.4% is obtained with an energy penalty of 16.2 MJ/kgCO2, and economic costs of 52 €/tHM or 283 €/tCO2. A sensitivity analysis with respect to electricity and the CO2 allowances prices is also performed

El Valor Monetario de la Vida Estadística en España a través de las Preferencias Declaradas

En este trabajo estimamos el Valor Monetario de una Vida Estadística en España a partir de preferencias declaradas por la población general. El contexto de valoración elegido es el de los accidentes de tráfico. La metodología empleada es la Valoración Contingente. En la encuesta realizada se intentaron comunicar correctamente los riesgos mediante el recurso a ayudas visuales. Los valores obtenidos (no inferiores a 2,7 millones de euros) son similares a otras estimaciones efectuadas en Europa, si bien un aspecto de la consistencia de estos resultados (cuasi-proporcionalidad) sólo se verifica parcialmente. Investigaciones futuras deberán emplear estrategias alternativas a la aquí utilizada con la finalidad de intentar incrementar la consistencia de los valores obtenidos. El procedimiento “encadenado” ideado por Carthy et al. (1999) puede ser un instrumento adecuado para ese objetivo.Valor de la vida, preferencias declaradas, accidentes de tráfico, valoración contingente, comunicación de riesgos

La valoración monetaria de los costes humanos de la siniestralidad vial en España

ResumenLos análisis coste-beneficio en el ámbito de la seguridad vial han de computar la totalidad de los costes, y dentro de ellos ocupan un lugar clave los costes humanos. En esta nota se da cuenta de dos estudios promovidos por la Dirección General de Tráfico orientados a la obtención de valores oficiales para España de los costes asociados a las víctimas mortales y no mortales de los accidentes de tráfico. Mediante la combinación del enfoque de la valoración contingente con la técnica de la lotería estándar (modificada), y con muestras amplias (n1=2020, n2=2000) representativas de la población española, se estimó en 1,4 millones de euros el valor monetario de prevenir un fallecido por accidente de tráfico. Para las lesiones graves y leves, los valores estimados fueron de 219.000 y 6100 euros, respectivamente. Las cifras obtenidas tienen un orden de magnitud similar al de los países de nuestro entorno.AbstractCost-benefit analyses in the field of road safety compute human costs as a key component of total costs. The present article presents two studies promoted by the Directorate-General for Traffic aimed at obtaining official values for the costs associated with fatal and non-fatal traffic injuries in Spain. We combined the contingent valuation approach and the (modified) standard gamble technique in two surveys administered to large representative samples (n1=2,020, n2=2,000) of the Spanish population. The monetary value of preventing a fatality was estimated to be 1.4 million euros. Values of 219,000 and 6,100 euros were obtained for minor and severe non-fatal injuries, respectively. These figures are comparable to those observed in neighboring countries