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Access to clean, affordable and sustainable energy is one of the greatest challenges people in Malawi are facing today. Ethanol briquettes are a viable source of energy for cooking instead of charcoal. In this paper, combustion containers were designed, fabricated and retrofitted with Chitetezo Mbaula and Kenya Ceramic Jiko stoves. Results of ethanol briquettes calorimetry showed 37.4 MJ/kg and 36.1 MJ/kg for high and low heating values respectively. Boiling 1 L of distilled water was faster in Chitetezo Mbaula because ethanol briquettes contributed to high stove firepower. Controlled cooking tests showed no significant differences in the time taken to cook a meal in all the stoves and fuel combinations. However, the specific fuel consumptions and the rate of emissions were significant at a 95% confidence level. Finally, the release of carbon monoxide and particulate matter from ethanol briquettes were below the World Health Organization benchmarks of 0.07 g/min and 0.15 mg/min, respectively. • Performance assessment of ethanol briquettes as fuel for cooking is evaluated in Malawi • Fuel performance is assessed when combustion containers are retrofitted in Kenya Ceramic Jiko and Chitetezo Mbaula stove • Maximum thermal efficiency of 96.31% is achieved with the Kenya Ceramic Jiko stove when a lid is used on a pot • Cooking with ethanol briquettes in Kenya Ceramic Jiko reduce particulate matter and CO2 emissions by 37.93% and 58.57%, respectively • The performance of ethanol briquettes achieved high user satisfaction than charcoal [ABSTRACT FROM AUTHOR]

• We present a novel integration for reducing CO 2 emissions in blast furnaces. • It combines top gas recycling, oxy-fuel regime, power to gas and biomass pyrolysis. • The integration was modelled using the extended operating line methodology. • The best performance was found for pyrolysis at 700 °C. • The CO 2 emissions were reduced by 58% (9.8 MJ/kg CO2 energy consumption) The paper introduces a novel approach for mitigating CO 2 emissions in blast furnaces by integrating top gas recycling, an oxy-fuel regime, power to gas, and biomass pyrolysis. Various case studies were conducted, involving the adjustment of pyrolysis temperatures (300 °C, 500 °C, 700 °C, and 900 °C) and varying the quantity of blast furnace gas directed to methanation for carbon recycling. Pinus radiata, abundant and cost-effective in Chile and Spain, was chosen as the biomass source. The integration was modeled using the extended operating line methodology and evaluated through 12 key performance indicators, such as flame temperature, coke consumption, CO 2 emissions, and specific primary energy consumption per unit of CO 2 avoided. Optimal performance was observed with pyrolysis at 700 °C and no blast furnace gas recycled through methanation. This configuration achieved a 58 % reduction in CO 2 emissions, with an energy consumption of 9.8 MJ/kg CO2 , and obviated the need for geological storage. Comparing this innovative proposal with other oxygen blast furnace approaches from the literature revealed a 13 percentage point improvement in CO 2 reduction over the second-best alternative. Additionally, the required electrolysis capacity, influencing capital expenditure, was 57 % lower, and energy consumption was reduced by 44 %. [ABSTRACT FROM AUTHOR]

Injecting new fuels like charcoal and semicoke into ironmaking blast furnaces (BF) helps reduce pulverized coal and coke consumption, leading to significant environmental and economic benefits. This paper comprehensively assesses the performance of blast furnace with the injection of charcoal, semicoke, or pulverized coal. For this purpose, a recently integrated BF model that simulates the whole BF below the burden surface in terms of the gas-solid-liquid-powder multiphase reacting flows is extended to simulate the application of charcoal and semicoke injection. The combustion characteristics of charcoal, semicoke, and pulverized coal in raceways are first revealed. Then, the effects of the combustion on the in-furnace states and overall BF performances are compared in detail. The results show that the overall BF performance in terms of gas flame temperature, coke rate, and hot metal temperature is susceptible to specific components in the injected fuels, including moisture content and fixed carbon ratio. A lower moisture and a higher fixed carbon ratio result in a higher gas flame temperature and fuel-coal replacement ratio and thus a lower coke rate. Overall, the charcoal and semicoke injection is feasible, however, subject to approximate pre-treatment. This integrated BF model can offer a cost-effective way to explore the injection of new fuels of various types to reduce carbon dioxide emissions. [Display omitted] • The complex gas-solid-liquid-power multiphase reacting flow in BF is simulated. • Particle combustion, gas-solid/liquid, and liquid-solid interactions are included. • The same modeling approach can be extended to other types of coal-like fuels. • Effects of coal-like fuel injection on BF inner thermochemical states are studied. • The specific requirements of the injectant's component are discussed. [ABSTRACT FROM AUTHOR]

• Measures for reducing the carbon intensity of blast furnace ironmaking were introduced. • Influences of low-carbon ironmaking processes on fuel requirements are reviewed. • The introduction of alternative reductants cannot eliminate the need for metallurgical coke. • Sustainability of blast furnace ironmaking depends on improving the H/C replacement ratio. • Introduction of hydrogen promotes the solution loss and structural degradation of coke. The blast furnace technology is still the main ironmaking route with a current global share of 70%. Reduction of fossil carbon consumption and CO 2 emissions in blast furnace operations are essential for the decarbonization of steelmaking. Potential solutions such as introducing renewable carbon-based materials (torrefied biomass, charcoal), using hydrogen-enriched reducing gases (i.e., hydrogen gas, coke oven gas, reformed coke oven gas, green methane), oxygen enrichment with top gas recycling, and carbon capture and storage/utilization have been considered to decrease emissions. The enhanced sustainability of blast furnace operations depends primarily on improving the hydrogen-to-carbon replacement ratio. Hydrogen is an effective reducing agent, producing steam during the reduction of ferrous burden. The replacement of coke and PCI with hydrogen leads to reduced fuel rates and CO 2 emissions. Although implementing the innovative ironmaking solutions reduces coke and coal consumption, coke cannot be replaced entirely as it plays an irreplaceable role as a mechanical support network and the permeable layer for gas movement in the blast furnace. The injection of alternative reducing agents into the blast furnace alters the reaction environment by changing gas composition and temperature. Therefore, understanding the impacts of new reaction conditions on coke rate and quality requirements is important to both coal producers and steel manufacturers. This paper reviews the current understanding of how the introduction of alternative reducing agents into the blast furnace influences the gasification behavior, degradation mechanism, and consumption rate of coke. The review also identifies the knowledge gaps and future research opportunities in the field. [ABSTRACT FROM AUTHOR]

• Explore markets effects of biomass competition between steel and forest industries. • Soft-linking technical energy system model and economic forest sector model. • Regional competition disrupts biomass prices and allocation, and supply costs. • Steel industry must consider market effects of new bio-production investment. • Beneficial to co-locate bio-production plants with iron and steel industries. Significant use of forest biomass in the iron and steel industry (ISI) to mitigate fossil CO 2 emissions will affect the biomass availability for other users of the same resource. This paper explores the market effects of increased forest biomass competition when promoting the use of forest-based bio-products in the ISI, as well as the interactions between the ISI and the forest industries. We employ a soft-linking approach that combines a geographically explicit techno-economic energy system model and an economic partial equilibrium model of the forest industries and forestry sectors. This allows for iterative endogenous modelling of new equilibrium price developments for different biomass assortments, determining locational choice of bio-products and assessing optimal bio-products technology choices. The results indicate an upward pressure on biomass prices when bio-products are introduced in the ISI (up to 62%), which affects both forest industries and the ISI itself. Prudence is thus warranted not to render bio-production investments uneconomical ex-post by neglecting to include potential price effects in investment decisions. The estimated price effects can be mitigated by increased domestic biomass supply, adjustments of international trade or by revising relevant policies. Even though the results suggest that the price effects will affect the geographical preferences for individual bio-production plants, proximity to the ISI production facility and integration benefits are more important than the proximity to cheaper biomass feedstocks. Product gas production integrated at ISI sites emerges as particularly attractive, while charcoal production exhibits sensitivity to fluctuating markets, both regarding resulting cost for the ISI, and preferred production locations. [ABSTRACT FROM AUTHOR]