Policy Analysis of CO2 Capture and Sequestration with Anaerobic Digestion for Transportation Fuel Production.

Low carbon fuel and waste management policies at the federal and state levels have catalyzed the construction of California's wet anaerobic digestion (AD) facilities. Wet ADs can digest food waste and dairy manure to produce compressed natural gas (CNG) for natural gas vehicles or electricity for electric vehicles (EVs). Carbon capture and sequestration (CCS) of CO2 generated from AD reduces the fuel carbon intensity by carbon removal in addition to avoided methane emissions. Using a combined lifecycle and techno-economic analysis, we determine the most cost-effective design under current and forthcoming federal and state low carbon fuel policies. Under many scenarios, designs that convert biogas to electricity for EVs (Biogas to EV) are favored; however, CCS is only cost-effective in these systems with policy incentives that exceed $200/tonne of CO2 captured. Adding CCS to CNG-producing systems (Biogas to CNG) only requires a single unit operation to prepare the CO2 for sequestration, with a sequestration cost of $34/tonne. When maximizing negative emissions is the goal, incentives are needed to either (1) fund CCS with Biogas to EV designs or (2) favor CNG over electricity production from wet AD facilities.

Cost and Life Cycle Emissions of Ethanol Produced with an Oxyfuel Boiler and Carbon Capture and Storage.

Decarbonization of transportation fuels represents one of the most vexing challenges for climate change mitigation. Biofuels derived from corn starch have offered modest life cycle greenhouse gas (GHG) emissions reductions over fossil fuels. Here we show that capture and storage of CO2 emissions from corn ethanol fermentation achieves ∼58% reduction in the GHG intensity (CI) of ethanol at a levelized cost of 52 $/tCO2e abated. The integration of an oxyfuel boiler enables further CO2 capture at modest cost. This system yields a 75% reduction in CI to 15 gCO2e/MJ at a minimum ethanol selling price (MESP) of $2.24/gallon ($0.59/L), a $0.31/gallon ($0.08/L) increase relative to the baseline no intervention case. The levelized cost of carbon abatement is 84 $/tCO2e. Sensitivity analysis reveals that carbon-neutral or even carbon-negative ethanol can be achieved when oxyfuel carbon capture is stacked with low-CI alternatives to grid power and fossil natural gas. Conservatively, fermentation and oxyfuel CCS can reduce the CI of conventional ethanol by a net 44-50 gCO2/MJ. Full implementation of interventions explored in the sensitivity analysis would reduce CI by net 79-85 gCO2/MJ. Integrated oxyfuel and fermentation CCS is shown to be cost-effective under existing U.S. policy, offering near-term abatement opportunities.

Do teachers believe that video games can improve learning?

Although video games are increasing their presence in teens/children's private entertainment and there is ample evidence to support their educational possibilities, they are seldom introduced in classrooms. One of the least studied factors relative to the insertion of video games in curricula is teachers' conceptions on their effectiveness to foster learning. In this study, we investigate how teachers conceive of the educational usage of video games, considering their reported value and which video game dimensions are reflected to be of importance, as well as personal traits linked to them (gender, educational level, area of knowledge, teaching experience, behavioral intention ...). We designed a Likert questionnaire with three main dimensions: pragmatic play, epistemic play, and learning outcomes (verbal information, skills, and attitudes). 595 Spanish teachers answered the questionnaire online. We applied ANOVA and multiple regression techniques, which revealed a broad acceptance of video games as educational media. The most relevant analyzed factors turned out to be the intention to use video games in classrooms, and the private use of video games. Teachers believe that video games promote more learning when played with an epistemic goal, mediated by scaffolding and especially under the teacher's guidance, compared to pragmatic play related to completion and success in the game. They also consider video games to mainly promote verbal information learning, procedural learning, and finally attitude learning, with the latter being less probable. We suggest the need to strengthen not only teacher training programs in the educational use of video games but also research on relationships between teachers' beliefs and practices in order to convert these favorable beliefs into actual real practices.

Innovative wood use can enable carbon-beneficial forest management in California.

Responsible stewardship of temperate forests can address key challenges posed by climate change through sequestering carbon, producing low-carbon products, and mitigating climate risks. Forest thinning and fuel reduction can mitigate climate-related risks like catastrophic wildfire. These treatments are often cost prohibitive, though, in part because of low demand for low-value wood "residues." Where treatment occurs, this low-value wood is often burned or left to decay, releasing carbon. In this study, we demonstrate that innovative use of low-value wood, with improved potential revenues and carbon benefits, can support economical, carbon-beneficial forest management outcomes in California. With increased demand for wood residues, forest health-oriented thinning could produce up to 7.3 million (M) oven-dry tonnes of forest residues per year, an eightfold increase over current levels. Increased management and wood use could yield net climate benefits between 6.4 and 16.9 million tonnes of carbon dioxide equivalent (M tCO2e) per year when considering impacts from management, wildfire, carbon storage in products, and displacement of fossil carbon-intensive alternatives over a 40-y period. We find that products with durable carbon storage confer the greatest benefits, as well as products that reduce emissions in hard-to-decarbonize sectors like industrial heat. Concurrently, treatment could reduce wildfire hazard on 4.9 M ha (12.1 M ac), a quarter of which could experience stand-replacing effects without treatment. Our results suggest that innovative wood use can support widespread fire hazard mitigation and reduce net CO2 emissions in California.

Teaching and Learning in Times of COVID-19: Uses of Digital Technologies During School Lockdowns.

The closure of schools as a result of COVID-19 has been a critical global incident from which to rethink how education works in all our countries. Among the many changes generated by this crisis, all teaching became mediated by digital technologies. This paper intends to analyze the activities carried out during this time through digital technologies and the conceptions of teaching and learning that they reflect. We designed a Likert-type online questionnaire to measure the frequency of teaching activities. It was answered by 1,403 teachers from Spain (734 primary and 669 secondary education teachers). The proposed activities varied depending on the learning promoted (reproductive or constructive), the learning outcomes (verbal, procedural, or attitudinal), the type of assessment to which the activities were directed, and the presence of cooperative activities. The major result of this study was that teachers used reproductive activities more frequently than constructive ones. We also found that most activities were those favoring verbal and attitudinal learning. The cooperative activities were the least frequent. Finally, through a cluster analysis, we identified four teaching profiles depending on the frequency and type of digital technologies use: Passive, Active, Reproductive, and Interpretative. The variable that produced the most consistent differences was previous digital technologies use These results show that Information and Communication Technologies (ICT) uses are reproductive rather than constructive, which impedes effective digital technologies integration into the curriculum so that students gain 21st-century competencies.

Decarbonizing agriculture through the conversion of animal manure to dietary protein and ammonia fertilizer.

The decarbonization of agriculture faces many challenges and has received a level of attention insufficient to abate the worst effects of climate change and ensure a sustainable bioeconomy. Agricultural emissions are caused both by fossil-intensive fertilizer use and land-use change, which in turn are driven in part by increasing demand for dietary protein. To address this challenge, we present a synergistic system in which organic waste-derived biogas (a mixture of methane and carbon dioxide) is converted to dietary protein and ammonia fertilizer. This system produces low-carbon fertilizer inputs alongside high-quality protein, addressing the primary drivers of agricultural emissions. If the proposed system were implemented across the United States utilizing readily available organic waste from municipal wastewater, landfills, animal manure, and commercial operations, we estimate 30% of dietary protein intake and 127% of ammonia usage could be displaced while reducing land use, water consumption, and greenhouse gas emissions.

Net-zero emissions energy systems.

Some energy services and industrial processes-such as long-distance freight transport, air travel, highly reliable electricity, and steel and cement manufacturing-are particularly difficult to provide without adding carbon dioxide (CO2) to the atmosphere. Rapidly growing demand for these services, combined with long lead times for technology development and long lifetimes of energy infrastructure, make decarbonization of these services both essential and urgent. We examine barriers and opportunities associated with these difficult-to-decarbonize services and processes, including possible technological solutions and research and development priorities. A range of existing technologies could meet future demands for these services and processes without net addition of CO2 to the atmosphere, but their use may depend on a combination of cost reductions via research and innovation, as well as coordinated deployment and integration of operations across currently discrete energy industries.

Near-term deployment of carbon capture and sequestration from biorefineries in the United States.

Capture and permanent geologic sequestration of biogenic CO2 emissions may provide critical flexibility in ambitious climate change mitigation. However, most bioenergy with carbon capture and sequestration (BECCS) technologies are technically immature or commercially unavailable. Here, we evaluate low-cost, commercially ready CO2 capture opportunities for existing ethanol biorefineries in the United States. The analysis combines process engineering, spatial optimization, and lifecycle assessment to consider the technical, economic, and institutional feasibility of near-term carbon capture and sequestration (CCS). Our modeling framework evaluates least cost source-sink relationships and aggregation opportunities for pipeline transport, which can cost-effectively transport small CO2 volumes to suitable sequestration sites; 216 existing US biorefineries emit 45 Mt CO2 annually from fermentation, of which 60% could be captured and compressed for pipeline transport for under $25/tCO2 A sequestration credit, analogous to existing CCS tax credits, of $60/tCO2 could incent 30 Mt of sequestration and 6,900 km of pipeline infrastructure across the United States. Similarly, a carbon abatement credit, analogous to existing tradeable CO2 credits, of $90/tCO2 can incent 38 Mt of abatement. Aggregation of CO2 sources enables cost-effective long-distance pipeline transport to distant sequestration sites. Financial incentives under the low-carbon fuel standard in California and recent revisions to existing federal tax credits suggest a substantial near-term opportunity to permanently sequester biogenic CO2 This financial opportunity could catalyze the growth of carbon capture, transport, and sequestration; improve the lifecycle impacts of conventional biofuels; support development of carbon-negative fuels; and help fulfill the mandates of low-carbon fuel policies across the United States.

Geospatial analysis of near-term potential for carbon-negative bioenergy in the United States.

Bioenergy with carbon capture and storage (BECCS) is a negative-emissions technology that may play a crucial role in climate change mitigation. BECCS relies on the capture and sequestration of carbon dioxide (CO2) following bioenergy production to remove and reliably sequester atmospheric CO2 Previous BECCS deployment assessments have largely overlooked the potential lack of spatial colocation of suitable storage basins and biomass availability, in the absence of long-distance biomass and CO2 transport. These conditions could constrain the near-term technical deployment potential of BECCS due to social and economic barriers that exist for biomass and CO2 transport. This study leverages biomass production data and site-specific injection and storage capacity estimates at high spatial resolution to assess the near-term deployment opportunities for BECCS in the United States. If the total biomass resource available in the United States was mobilized for BECCS, an estimated 370 Mt CO2⋅y-1 of negative emissions could be supplied in 2020. However, the absence of long-distance biomass and CO2 transport, as well as limitations imposed by unsuitable regional storage and injection capacities, collectively decrease the technical potential of negative emissions to 100 Mt CO2⋅y-1 Meeting this technical potential may require large-scale deployment of BECCS technology in more than 1,000 counties, as well as widespread deployment of dedicated energy crops. Specifically, the Illinois basin, Gulf region, and western North Dakota have the greatest potential for near-term BECCS deployment. High-resolution spatial assessment as conducted in this study can inform near-term opportunities that minimize social and economic barriers to BECCS deployment.