Hydrogen production from natural gas and biomethane with carbon capture and storage - A techno-environmental analysis

This study presents an integrated techno-environmental assessment of hydrogen production from natural gas and biomethane, combined with CO2 capture and storage (CCS). We have included steam methane reforming (SMR) and autothermal reforming (ATR) for syngas production. CO2 is captured from the syngas with a novel vacuum pressure swing adsorption (VPSA) process, that combines hydrogen purification and CO2 separation in one cycle. As comparison, we have included cases with conventional amine-based technology. We have extended standard attributional Life Cycle Assessment (LCA) following ISO standards with a detailed carbon balance of the biogas production process (via digestion) and its by-products. The results show that the life-cycle greenhouse gas (GHG) performance of the VPSA and amine-based CO2 capture technologies is very similar as a result of comparable energy consumption. The configuration with the highest plant-wide CO2 capture rate (almost 100% of produced CO2 captured) is autothermal reforming with a two-stage water-gas shift and VPSA CO2 capture – because the latter has an inherently high CO2 capture rate of 98% or more for the investigated syngas. Depending on the configuration, the addition of CCS to natural gas reforming-based hydrogen production reduces its life-cycle Global Warming Potential by 45–85 percent, while the other environmental life-cycle impacts slightly increase. This brings natural gas-based hydrogen on par with renewable electricity-based hydrogen regarding impacts on climate change. When biomethane is used instead of natural gas, our study shows potential for net negative greenhouse gas emissions, i.e. the net removal of CO2 over the life cycle of biowaste-based hydrogen production. In the special case where the biogas digestate is used as agricultural fertiliser, and where a substantial amount of the carbon in the digestate remains in the soil, the biowaste-based hydrogen reaches net-negative life cycle greenhouse gas emissions even without the application of CCS. Addition of CCS to biomethane-based hydrogen production leads to net-negative emissions in all investigated cases.ISSN:2398-490

On the climate impacts of blue hydrogen production

Natural gas based hydrogen production with carbon capture and storage is referred to as blue hydrogen. If substantial amounts of CO2 from natural gas reforming are captured and permanently stored, such hydrogen could be a low-carbon energy carrier. However, recent research raises questions about the effective climate impacts of blue hydrogen from a life cycle perspective. Our analysis sheds light on the relevant issues and provides a balanced perspective on the impacts on climate change associated with blue hydrogen. We show that such impacts may indeed vary over large ranges and depend on only a few key parameters: the methane emission rate of the natural gas supply chain, the CO2 removal rate at the hydrogen production plant, and the global warming metric applied. State-of-the-art reforming with high CO2 capture rates combined with natural gas supply featuring low methane emissions does indeed allow for substantial reduction of greenhouse gas emissions compared to both conventional natural gas reforming and direct combustion of natural gas. Under such conditions, blue hydrogen is compatible with low-carbon economies and exhibits climate change impacts at the upper end of the range of those caused by hydrogen production from renewable-based electricity. However, neither current blue nor green hydrogen production pathways render fully “net-zero” hydrogen without additional CO2 removal

Life Cycle Assessment of Direct Air Carbon Capture and Storage with Low-Carbon Energy Sources

Prospective energy scenarios usually rely on carbon dioxide removal (CDR) technologies to achieve the climate goals of the Paris Agreement. CDR technologies aim at removing CO2 from the atmosphere in a permanent way. However, the implementation of CDR technologies typically comes along with unintended environmental side-effects such as land transformation or water consumption. These need to be quantified before large-scale implementation of any CDR option by means of life cycle assessment (LCA). Direct air carbon capture and storage (DACCS) is considered to be among the CDR technologies closest to large-scale implementation, since first pilot and demonstration units have been installed and interactions with the environment are less complex than for biomass related CDR options. However, only very few LCA studies - with limited scope - have been conducted so far to determine the overall life-cycle environmental performance of DACCS. We provide a comprehensive LCA of different low temperature DACCS configurations - pertaining to solid sorbent-based technology - including a global and prospective analysis

Life Cycle Assessment of Direct Air Carbon Capture and Storage with Low-Carbon Energy Sources

Direct air carbon capture and storage (DACCS) is an emerging carbon dioxide removal technology, which has the potential to remove large amounts of CO2 from the atmosphere. We present a comprehensive life cycle assessment of different DACCS systems with low-carbon electricity and heat sources required for the CO2 capture process, both stand-alone and grid-connected system configurations. The results demonstrate negative greenhouse gas (GHG) emissions for all eight selected locations and five system layouts, with the highest GHG removal potential in countries with low-carbon electricity supply and waste heat usage (up to 97%). Autonomous system layouts prove to be a promising alternative, with a GHG removal efficiency of 79-91%, at locations with high solar irradiation to avoid the consumption of fossil fuel-based grid electricity and heat. The analysis of environmental burdens other than GHG emissions shows some trade-offs associated with CO2 removal, especially land transformation for system layouts with photovoltaics (PV) electricity supply. The sensitivity analysis reveals the importance of selecting appropriate locations for grid-coupled system layouts since the deployment of DACCS at geographic locations with CO2-intensive grid electricity mixes leads to net GHG emissions instead of GHG removal today.ISSN:0013-936XISSN:1520-585

Hydrogen from Wood Gasification with CCS - a Technoenvironmental Analysis of Production and Use as Transport Fuel

In the presented work, we performed an integrated techno-environmental assessment of hydrogen production from woody biomass gasification, combined with CO2 capture and storage (CCS). We have included three different types of gasification technologies for syngas production. CO2 is captured from the syngas with conventional amine-based technology. Based on our integrated approach linking detailed process simulation with Life Cycle Assessment, we are able to quantify benefits and potential trade-offs of a wide range of process configurations from both technical and environmental perspectives in a consistent way. We have also performed a comparative evaluation of hydrogen use in fuel cell electric vehicles (passenger cars and freight trucks), to investigate the role of hydrogen in decarbonizing the transport sector.</p

Hydrogen from wood gasification with CCS-a techno-environmental analysis of production and use as transport fuel

The use of biomass as a resource for hydrogen production can contribute to the transition towards carbon neutral or carbon negative energy systems. This paper offers a comprehensive investigation of the technical performance and life cycle environmental footprint of three gasification technologies for H2 production, using dry biomass (wood) as input. These are compared with H2 production from reforming of natural gas or biomethane and electrolysis as presented in our previous work. This is followed by an evaluation of the use of H2 as fuel for passenger cars and trucks. The quantity of biomass required for the production of 1 MW H2 is calculated with an integrated process simulation approach on the basis of Aspen Plus simulations and real-plant literature data. We observe that all the technologies analysed provide negative CO2 emissions when coupled with CCS. However, the sorption enhanced reforming and the entrained flow gasifiers are more suited to this scope than the heat pipe reformer, because higher overall CO2 capture rates can be achieved. As CO2 is from biogenic sources, the life cycle carbon footprint of the produced H2 is only slightly positive (without CCS) or negative (with CCS). This negative carbon footprint is not obtained at the cost of important trade-offs with regards to ecosystem quality, human health or resource depletion, with the exception of high forest land use. Fuel cell electric vehicles using hydrogen from biomass (both wood and biomethane) with CCS as fuel turn out to be the most climate friendly among all options, with even possible negative total greenhouse gas emissions. However, limited biomass resources and potential alternative uses need to be considered. This journal isISSN:2398-490

Correction: Hydrogen production from natural gas and biomethane with carbon capture and storage – A techno-environmental analysis: vol 4, pg 2967, 2020

ISSN:2398-490

Life cycle inventory of power producing technologies and power grids at regional grid level in India

PurposeIndian electricity production mix, technology level, and local production conditions vary across the states and union territories. This variability is obscured in existing national-level life cycle inventories of Indian power producing technologies and power systems, which potentially leads to inaccurate results from LCA studies that include Indian activities. This study aims to create a consistent regionalized inventory model of Indian power system parameters and to evaluate how that influences life cycle impact assessment (LCIA) calculations.MethodsData collection covers state-specific key parameters of domestic power production and distribution, and inter-exchanges among the regional grids and with other countries in 2012–2013. However, such regionalization work faces some data availability challenges. Power plant parameter data (e.g., efficiency, fuel quality, exact technology used) are mostly unavailable on plant level for India; if at all, relevant data are available on a state level. Moreover, local emission data are also mostly unavailable except emissions of CO2. Quantities of other important emissions (NOx, SOx, CH4, CO, PM) are, therefore, calculated based on emission factors from literature.Results and discussionVariation in electricity production volumes among the states and regional grids are found notably high. Six states contribute 55% of the national power supply, whereas ten states contribute only 2.1% to the total. Moreover, the five regional electricity grids—Eastern, Western, Southern, Northern, and North-eastern grids—show high variation in production mixes. These differences have a considerable impact on LCIA results. For instance, the contribution to the global warming potential per 1\ua0kWh of electricity supplied to the grid is nearly twice as high in the Eastern grid as in the North-eastern grid. Furthermore, transformation and transmission losses are found to be high in the Indian electricity grids with an average of 17% technical losses along the transmission chain from high voltage to the low voltage.ConclusionsHence, we conclude that the inventory data produced in this study on Indian electricity production and distribution at grid level, taking local variations in technology mix and key parameters into account, enables higher accuracy in life cycle assessment studies compared to using average national-level data.Full access link: https://rdcu.be/9lP

Sources of Primary Electricity Supply

This synthesis report provides an overview of primary electricity supply sources, including power generation potentials and costs as well as the as- sociated environmental burdens of electricity pro- duction in Switzerland. It gives a synthesis of the main findings and selected deep-dives into key tech- nologies supporting the transition of the Swiss en- ergy system, namely solar photovoltaics (PV), hy- dropower, biomass and deep geothermal energy generation.CRYO