Gate Life Cycle Assessment Research Articles

Development of a green catalyst for production of synthetic banana flavoring based on low transition temperature mixture through numerical optimization, LCA assessment and sustainability metrics

The transition to cleaner production of chemicals to abate the prolonged environmental impairment has been an emerging concern worldwide, calling for alternative cost effective and greener process routes. The present study witnesses the ecofriendly preparation of synthetic banana flavoring or Isoamyl acetate (IAA) catalyzed by a low transition temperature mixture (LTTM) comprised of abundantly available natural resources. The chosen LTTM exhibited bifunctional properties of highly active acidic catalyst as well as an excellent solvent media which could phase out the product as an independent layer after the reaction assuring simpler downstream processing and direct recycle of the catalytic media for subsequent runs. Numerical optimization, executed to obtain the optimal process parameters using the Box-Behnken design yielded a maximum conversion of 99.81%. The LTTM catalyzed reaction kinetics is deciphered through the pseudo-homogeneous model inclusive of the system non-ideality estimated through the UNIFAC model and the thermodynamic functions of the reaction were also evaluated to aid the realistic process design. A comparison of the proposed route and that using sulfuric acid as catalyst has been performed through a cradle to gate life cycle assessment (LCA) using the Simapro 9.1 software for the laboratory production of 1 kg IAA which revealed that the adopted green approach decreased the damage to ecosystem and resource availability by 48.8% and 30.2% respectively. Furthermore, the environment profiling of the conventional and intensified reaction pathways using green metrics also indicated the LTTM mediated production of IAA to be extremely promising that paves the path for sustainable chemical industries.

Catalytic pyrolysis of linear low-density polyethylene using recycled coal ash: Kinetic study and environmental evaluation.

Catalytic pyrolysis offers a sustainable route to convert plastic wastes into fuel. We investigated the catalytic performance of coal ash (fly and bottom ash) at blending ratio of 5 wt%, and 15 wt% during pyrolysis of linear low-density polyethylene (LLDPE). The influence on activation energy and oil was characterized via thermogravimetric analyzer (TGA) and gas chromatography-mass spectrometry (GC-MS). Results have shown that 15 wt% bottom ash exhibited higher catalytic activity. The activation energy estimated by Coats-Redfern method decreased from 458.7 kJ·mol−1 to 437.8 kJ·mol−1, while the alicyclic hydrocarbon yield increased from 5.97% to 32.09%. This implies that CaO, which is abundant in bottom ash, could promote the conversion of LLDPE. Furthermore, a cradle-to-factory gate life cycle assessment was performed to investigate three scenarios (non-catalytic pyrolysis, 15 wt% fly ash, and 15 wt% bottom ash) of LLDPE conversion strategies via a normalization and weighting approach. It was found that LLDPE pyrolysis with 15 wt% bottom ash also showed the lowest normalized score of 2.83, implying the lowest environmental impact. This work has demonstrated that the recycling of coal ash, particularly bottom ash, as catalysts for LLDPE pyrolysis is effective.

Environmental assessment of United States dairy farms

Dairy farms in the United States are diverse and although regional dairy production and farm strategy has been evaluated for environmental impact, a comprehensive national assessment is important to define national priorities for sustainable intensification. We estimated important environmental footprints of dairy production using process-level simulation and cradle-to-farm gate life cycle assessment. Dairy farms representing the sizes and management practices found in six regions were simulated with the Integrated Farm System Model (IFSM). Regional and national environmental footprints were determined as an average of all simulated farms weighted by the portion of milk contributed by each to the total. Nationally, dairy farms were found to emit 99,000 ± 8480 Gg CO2e of greenhouse gas (GHG), equivalent to 1.5% of the estimated U.S. total GHG emission, with a commodity-based intensity of 1.01 ± 0.09 kg CO2e/kg of fat and protein corrected milk (FPCM) produced. Fossil energy use was 242,700 ± 38,400 TJ, 0.3% of the U.S. total, or 2.48 ± 0.39 MJ/kg FPCM. Blue (non-precipitation) water use was 11,600 ± 2480 Tg, roughly 3.0% of the estimated U.S. total freshwater withdraw, with an intensity of 119 ± 25 kg/kg FPCM. While these environmental footprints represent a small portion of the respective national inventories, the dairy industry's contribution to reactive nitrogen (N) losses appears to be considerably greater. Losses of reactive N were estimated at 970 ± 133 Gg, with an intensity of 9.92 ± 1.36 g/kg FPCM where 66% of the total was in the form of ammonia (NH3). Although there are no national estimates of total reactive N loss, dairy farms were found to contribute 19–24% of national inventories of NH3 emissions. While strategies are available to reduce NH3 emissions, finding economical and sustainable solutions that do not result in pollution swapping remains a challenge for the dairy industry.

Marginal Abatement Cost Curves for Latin American dairy production: A Costa Rica case study

This study utilises data collected from Costa Rican dairy farmers to conduct a cradle to farm gate Life Cycle Assessment and the first Marginal Abatement Cost Curve (MACC) for dairy production in Latin America. Ninety dairy farms across five farm typologies were assessed, reflecting Costa Rica's diverse agroclimatic zones and varying degrees of dairy/beef specialisation. The efficacy and cost-effectiveness of specific mitigation measures depend on farm typology, but several promising technologies are identified that increase efficiency whilst substantially reducing emissions across most farms – in particular, measures that improve animal health and increase pasture quality. Pasture measures are synergistic with silvopastoral practises and are highly effective at emission mitigation, although relatively expensive. The replacement of lower quality by-product feeds with high quality concentrate feed is a cost-effective mitigation measure at farm level, but emission reductions could be negated by indirect land use change outside the scope of the MACC analyses. Achieving carbon neutrality at farm level is not likely to be possible for most farms, with the exception of extensive farm typologies. Not all measures are suitable in every context, and additional policy support will be needed to offset financial and technical challenges related to adoption. Results of this first tropical dairy MACC study are constrained by lack of high-resolution data, but they highlight the need for farm-typology-specific mitigation recommendations. Overall, there is a high potential for pasture improvement and silvopastoral measures to mitigate the globally significant contribution of Latin American livestock production to climate change.

Life cycle analysis of fermentative production of succinic acid from bread waste

According to the US Department of Energy, succinic acid (SA) is a top platform chemical that can be produced from biomass. Bread waste, which has high starch content, is the second most wasted food in the UK and can serve as a potential low cost feedstock for the production of SA. This work evaluates the environmental performance of a proposed biorefinery concept for SA production by fermentation of waste bread using a cradle-to-factory gate life cycle assessment approach. The performance was assessed in terms of greenhouse gas (GHG) emissions and non-renewable energy use (NREU). Waste bread fermentation demonstrated a better environmental profile compared to the fossil-based system, however, GHG emissions were about 50% higher as compared to processes using other biomass feedstocks such as corn wet mill or sorghum grains. NREU for fermentative SA production using waste bread was significantly lower (~ 46%) than fossil-based system and about the same as that of established biomass-based processes, thus proving the great potential of waste bread as a valuable feedstock for bioproduction of useful chemicals. The results show that steam and heating oil used in the process were the biggest contributors to the NREU and GHG emissions. Sensitivity analyses highlighted the importance of the solid biomass waste generated in the process which can potentially be used as fish feed. The LCA analysis can be used for targeted optimization of SA production from bread waste, thereby enabling the utilization of an otherwise waste stream and leading to the establishment of a circular economy.

Environmental impacts of milk production and processing in the Eastern Alps: A “cradle-to-dairy gate” LCA approach

This study aimed to evaluate the environmental footprint and feed energy conversion ratio of Alpine dairy chains in the Eastern Alps, taking into account both the milk production and dairy processing phases, and to identify farm management features useful for targeting mitigation measures in the production phase. A cradle-to-farm gate Life Cycle Assessment model that included herd and manure management, on-farm feedstuff production and purchased feedstuffs and materials (dairy farm), and production inputs and dairy outputs (dairy processing) was applied to 75 farms (10 dairies). As functional units, we used 1 kg fat- and protein-corrected milk (FPCM) and 1 m2 of agricultural land, to account for production intensity and land managed by alpine farms, respectively. Impact categories (CML-IA and CED methods, background data from Ecoinvent database) assessed were global warming (GWP), GWP plus land-use change (GWP_LUC), acidification (AP) and eutrophication (EP) potentials, cumulative energy demand (CED) and land occupation (LO). Feed energy conversion ratio (whole diet - ECR; potentially human-edible portion of the diet - HeECR) was computed as the ratio between gross energy in feeds and that in milk. Mean ECR was 6.6 ± 0.5 MJ feed/MJ milk, of which only 8% derived from potentially human-edible feedstuffs. For 1 kg of FPCM at the dairy farm, GWP averaged 1.19 kg CO2-eq, GWP_LUC 1.31 kg CO2-eq, AP 17.3 g SO2-eq and EP 6.0 g PO4-eq (coefficients of variation, CV, ranged 17–21%), whereas mean CED was 2.7 MJ and LO 2.1 m2/y (CVs: 40–46%). When dairy processing was included, the impact values for 1 kg of dairy product were from 8 to 13 times greater than those obtained for 1 kg FPCM. Based on the outcomes of a principal component analysis, the farm management features most related to impacts and feed ratios were milk yield (MY, for the impacts per unit of milk and ECR), stocking rate (SR, for the impacts per unit of area), and percentages of concentrates (C, for GWP_LUC and HeECR). Step-wise analysis evidenced that strategies aiming to decrease the environmental footprint referred to milk and managed area at the same time and to improve the feed energy conversion ratios should include MY, SR and C jointly. These issues are particularly important for the sustainability of mountain farming systems, which need to create a virtuous link with local forage resources and the territory.

The simulated environmental impact of incorporating white clover into pasture-based dairy production systems

White clover (WC) offers an alternative source of nitrogen (N) for pasture-based systems. Substituting energy- and carbon-intensive synthetic N fertilizers with N derived from biological fixation by WC has been highlighted as a promising environmental mitigation strategy through the omission of emissions, pollutants, and energy usage during the production and application of synthetic fertilizer. Therefore, the objective was to investigate the effect of the inclusion of WC in perennial ryegrass (PRG) swards on the environmental impact of pasture-based dairy systems. Cradle-to-farm gate life cycle assessment of 3 pasture-based dairy systems were conducted: (1) a PRG-WC sward receiving 150 kg of N/ha per year (CL150), (2) a PRG-WC sward receiving 250 kg of N/ha per year (CL250), and (3) a PRG-only sward receiving 250 kg of N/ha per year (GR250). A dairy environmental model was updated with country-specific N excretion equations and recently developed N2O, NH3, and NO3- emission factors. The environmental impact categories assessed were global warming potential, nonrenewable energy, acidification potential, and eutrophication potential (marine and freshwater). Impact categories were expressed using 2 functional units: per hectare and per metric tonne of fat- and protein-corrected milk. The GR250 system had the lowest milk production and highest global warming potential, nonrenewable energy, and acidification potential per tonne of fat- and protein-corrected milk for all systems. The CL250 system produced the most milk and had the highest environmental impact across all categories when expressed on an area basis. It also had the highest marine eutrophication potential for both functional units. The impact category freshwater eutrophication potential did not differ across the 3 systems. The CL150 system had the lowest environmental impact across all categories and functional units. This life cycle assessment study demonstrates that the substitution of synthetic N fertilizer with atmospheric N fixed by WC has potential to reduce the environmental impact of intensive pasture-based dairy systems in temperate regions, not only through improvement in animal performance but also through the reduction in total emissions and pollutants contributing to the environmental indicators assessed.

Cradle to Gate Life Cycle Assessment of Palm Oil Industry

Crude palm oil production Indonesia especially in Aceh every year continues to increase because the consumption of its derivative products such as cosmetics, food and fuel increases. The increasing demand for CPO has caused palm oil companies expanding their plantations. Based on data from the Ministry of Agriculture in 2018, the total area of Indonesian palm oil reaches 14.3 million hectares. The focus of this paper aims to evaluate the cradle to gate impact produced at land preparation, the nursery stage and the process of producing palm oil. Life cycle assessment is used to evaluate the impact of product for its entire life cycle. This research was conducted with simulation using SimaPro 9.0 software and impact 2002+ method. The results of the data processing with the simulation showed that fertilization stage was the stage with the largest impact with persentage 83% of the category, namely human health, ecosystem quality, climate change and resources 0.0000567 DALY, 9.44 PDF.m2.year, 148 kg CO2 eq and 1650 main MJ, respectively. Meanwhile, the processing of palm oil into CPO the largest environmental impact was in the category of non-renewable energy and global warming of 90 MJ and 9.6 kg CO2 eq.

Cradle to Gate Life Cycle Assessment (LCA) of 3D Printing Houses

Cradle to Gate Life Cycle Assessment (LCA) of 3D Printing Houses

Evaluation of Sustainability Determinants of Small Farming Systems via Participatory Modeling and Fuzzy Multi-Criteria Processes: The Case Study of Heliciculture in Greece

Feasibility and sustainability of small-scale farming systems are the most critical factors that determine future investments of urban agro-farming while promoting eco-systematic livelihood development and biodiversity. The determination and the diversification of the ambivalent and heterogeneous factors that affect the investment decision making of small farming systems is studied in this work via the application of participatory modeling methodology of regional stakeholders. Defuzzification of the participants' categorical feedback is succeeded applying Fuzzy Analytical Hierarchy Process (F-AHP) to set the pairwise weight matrix of the determinants suggested by the stakeholders. At a second phase, an innovative Fuzzy Cognitive Map (FCM) model is utilized to determine the weighted inter-causalities between all agricultural, environmental, and socio-economic criteria from the F-AHP output. Apart from the concept circumscription, we use the FCM to provide an in-depth scenario analysis including steady state and dynamic evaluation of driver concepts to receiver concepts in the model. The methodology is applied for the case study of heliciculture farming systems in Greece. Results show that sustainability is affected primarily by agricultural and inventory factors and secondarily by social and environmental factors identifying such cradle-to-farm gate life cycle assessment to be of low carbon footprint.

Life cycle assessment of sugar and electricity production under different sugarcane cultivation and cogeneration scenarios in India

Sugarcane is a valuable raw material for bioenergy and bioproduct production. The environmental performance of sugarcane-derived bioenergy and bioproducts vary with sugarcane cultivation practices and energy conversion technologies. A farm to factory gate life cycle assessment (LCA) is conducted to assess the energy and environmental performance of sugar production and bagasse electricity cogeneration in Maharashtra, India under different scenarios. Altogether 20 scenarios were developed taking four sugarcane seasons (adsali, ratoon, preseasonal and suru) and four cogeneration boilers (low pressure, medium pressure, high pressure and very high pressure). The functional units are the production of 1 tonne of sugar and 1 MWh of surplus electricity. The ReCiPe 2016 midpoint (H) method is used for impact assessment. System expansion is applied to assess the alternative uses of sugarcane by-products (trash, press mud and bagasse ash). The global warming potential (GWP) of bagasse cogenerated electricity and sugar range from 90 to 142 kg CO2-eq MWh-1 and 324–834 kg CO2-eq t-1 among the scenarios. The water consumption potential (WCP) varies from 209 to 354 m3 MWh-1 for electricity and 768–2097 m3 t-1 for sugar. The Cumulative Energy Demand (CED) for electricity and sugar ranges from 0.8 to 1.2 MJ kWh-1 and 3–8 MJ kg-1. The Energy Return On Investment (EROI) differs from 2.7 to 4.5 for electricity and 2.1 to 5.3 for sugar. The alternative uses of sugarcane by-products contribute to negative emission and lower the overall GWP by 13–15%. Scenarios producing only sugar have a much higher environmental impact than scenarios producing both sugar and surplus electricity. The combination of adsali sugarcane and very high pressure cogeneration boiler provides the highest environmental benefits among all scenarios. The findings can help enhance cleaner production initiatives in the Indian sugarcane sector.

Carbon footprint, non-renewable energy and land use of dual-purpose cattle systems in Colombia using a life cycle assessment approach

Dual-purpose cattle systems (DPS) include more than 75% of all dairy cows in Latin America and produce 40% of total milk production. Colombia has the fourth largest cattle herd in Latin America, and DPS account for 39% of the cattle population, and 58% of national milk production. Therefore, focusing on reducing the carbon footprint (CF) of DPS can have a huge contribution on mitigating the environmental impacts of the cattle farming sector. The present study aimed to estimate, based on a farm gate life cycle assessment (LCA) approach, the environmental impact of 1313 dual-purpose farms in Colombia. The study also aimed at identifying the main hotspots of negative environmental impacts and proposing possible mitigation options and their cost-effectiveness. The impact categories such as CF, non-renewable energy use, and land use were estimated using the 2019 Refinement to 2006 IPCC, databases, and locally estimated emission factors. Three methods of allocating environmental burdens to meat and milk products were applied. A principal component multivariate analysis (PCA) and a Hierarchical Clustering on Principal Components (HCPC) were performed. The largest source of greenhouse gas (GHG) in dual-purpose cattle systems comes directly from enteric fermentation, and manure deposited on pasture. The proportion of environmental burdens allocated to meat differed, with the economic method assigning the greater burden (36%), followed by energy content (30%) and mass production (13%). Four farms clusters and two production strategies were identified, a more intensive strategy with high proportion of improved pastures and higher fertilizer application rates (Clusters 1 and 2), and a more extensive with low input of fertilizers and grazing on natural pastures (Clusters 3 and 4). The CF values ranged between 2.1 and 4.2 CO2-eq per kg fat and protein corrected milk (FPCM) and between 9.0 and 18.3 CO2-eq per kg meat among clusters. CF, land use, and non-renewable energy use were lowest for clusters 1 and 3. Concerning cost-effectiveness, the adoption of improved pastures is a negative-cost measure and a promising climate change mitigation option. Overall, the CF could be reduced by around 25 to 48% for milk and meat. Therefore, our results suggest that it is possible to reduce GHG emissions by adopting improved pastures, better agricultural management practices, efficient fertilizer usage, and using the optimal stocking rate. It is expected that these reductions can be achieved with at negative costs.

Life cycle assessment of wheat production and wheat-based crop rotations.

In the northern Great Plains (NGP), wheat is the primary grain commodity. There is a need for the NGP to have a detailed analysis of environmental impacts for wheat-based agricultural production systems to better understand regional agroecosystems. This article provides a cradle-to-field gate life cycle assessment (LCA) for NGP dryland wheat (Triticum aestivum L.) production. The environmental impacts for winter wheat production using crop rotation and agricultural intensification are quantified. Fourteen no-till crop rotations ranging in duration from 2 to 6 yr were evaluated and compared using data from a historical 13-yr replicated rotation study (>300 observations). Midpoint LCA categories chosen for this comparison are energy, agricultural land use, climate change potential, freshwater eutrophication, and freshwater ecotoxicity due to their direct links with agricultural management practices. The NGP farmers commonly use a fallow period every other year due to moisture limitations. This specific agricultural practice and allocations within rotations are critical considerations within agricultural LCAs. Two aspects of fallow considerations and a sensitivity analysis were also performed. The allocated midpoint impacts between crops in rotational studies averaged 0.31, 0.79, 0.62, and 0.63kg CO2 eq. per unit of winter wheat when energy, economic, mass, and cereal unit allocations were used, respectively. Economic analysis of the studied experimental crop was performed; results demonstrated that crop insurance policies improved diversification economics by 20%. Agricultural diversification benefits and burdens were better represented by endpoint damage assessments than by midpoint impact analysis.

Cost-effectiveness of environmental impact abatement measures in a European pig production system

Many emerging technologies and alternative farm management practices have the potential to improve the sustainability of pig production systems. The implementation of such practices is not always economically viable. The goal of this study was to assess the cost-effectiveness of such environmental mitigation strategies in pig systems, using an Environmental Abatement Cost analysis. We considered four pig housing (improved insulation, increased ventilation efficiency, frequent slurry removal, increased slurry dilution) and three manure management related abatement strategies (anaerobic digestion, slurry acidification, slurry separation), implemented as stand-alone and as a set of “pig housing–pig housing” and “pig housing–manure management” combinations. We calculated their annual equivalent value through a discounted cash flow analysis and then their annualised abatement potential through a cradle-to-farm gate life cycle assessment. The baseline system against which the analysis was conducted was a typical Danish pig production system, over a 25-year time horizon. The environmental impact categories considered were Non-Renewable Resource Use (NRRU), Non-Renewable Energy Use (NREU), Global Warming Potential (GWP), Acidification Potential (AP) and Eutrophication Potential (EP). Pig housing–anaerobic digestion combinations were the most cost-effective options for GWP, NRRU and NREU. Their abatement costs ranged from −€0.237 to €0.70 per tonne CO2 eq., −€0.146 to €0.36 per g Sb eq. and -€1.75−04 to €3.11−04 per GJ abated respectively. Anaerobic digestion was the most cost-effective stand-alone investment for GWP (−€0.206 per tonne CO2 eq.), NRRU (−€0.0493 per g Sb eq.) and NREU (−€1.00−04 per GJ), and slurry acidification for AP (€303 per tonne SO2− eq.) and EP (€1190 per tonne PO43− eq.) mitigation. Overall, measures for mitigation of GWP, NRRU and NREU required higher investments than for AP and EP, but also generated profit. The framework developed in this study can potentially aid decision making in the choice of environmentally and economically sustainable pig system modifications.

Environmental impact and efficiency of use of resources of different mountain dairy farming systems

In the European Alps traditional, low-input dairy farming systems still coexist with modern high-input intensive systems. This study aimed at evaluating the effect of different Alpine farming systems on the environmental footprint, production efficiency (gross energy conversion ratio, ECR) and competition between feed and food (potentially human-edible gross energy conversion ratio, HeECR). Data originated from 37 dairy farms located in the Trento province (eastern Italian Alps), from which four dairy systems were derived by performing non-hierarchical cluster analysis based on farm facilities and management features (traditional, either with tie or loose stalls, and intensive, either with or without use of silages, systems). Environmental footprint was computed using a cradle-to-farm gate Life Cycle Assessment model. One kg fat- and protein-corrected Milk (FPCM) and 1 m2 of agricultural land were used as functional units. Global warming (GWP), acidification (AP) and eutrophication (EP) potentials, cumulative energy demand (CED) and land occupation (LO) were included as impact categories. System boundaries included herd and manure management, on-farm feedstuffs production and purchased feedstuffs and materials. Mean impact values per 1 kg FPCM were 1.0 ± 0.3 kg CO2-eq (GWP), 21.1 ± 4.3 g SO2-eq. (AP), 6.3 ± 1.2 g PO4-eq. (EP), 5.0 ± 2.0 MJ (CED), 1.4 ± 0.5 m2/y (LO), whereas per 1 m2 were 0.8 ± 0.3 kg CO2-eq (GWP), 16.3 ± 4.2 g SO2-eq. (AP), 4.9 ± 1.3 g PO4-eq. (EP), 3.8 ± 1.8 MJ (CED). Mean ECR was 5.17 ± 0.89 MJ/MJ, with 88% of gross energy provided by non-human edible feedstuffs. A large variability was found both between and within dairy systems, in terms of environmental footprint and production efficiency. Impact values were slightly greater per unit of product and lower per unit of area in traditional than in intensive farms, although generally without significant differences. Production efficiency of traditional farms was 17% lower in terms of ECR but 59% greater in terms of HeECR, due to a lower proportion of purchased concentrates in animal rations, with a positive contribution to food balance and diet self-sufficiency. These results indicate that the transition from traditional towards intensive systems improved only slightly the environmental footprint of dairy farming, but increased markedly its dependence on external concentrate feeds and the feed-food competition. In perspective, different aspects of mountain dairy systems, such as the conversion into food of human non edible feeds, the low impacts at the local scale, the ability to conserve grasslands under a land-sharing perspective, and in general the associated ecosystem services, should be considered when aiming to improve their environmental sustainability.

Environmental and socio-economic assessment of wood pellet production from fast growing trees in Thailand

Sufficient quantity of raw materials is a critical factor for wood pellet production. The recommendations from past research on biomass have indicated that the cultivation of fast growing trees should be encouraged in wasteland. Leucaena and Acacia are the popular fast growing trees in Thailand because they are resistant to drought and can grow in low quality soil. Wood from them has a high heating value and entrepreneurs invite farmers to grow these varieties on contract farming for renewable energy. The purpose of this study is to assess the environmental and socio-economic of wood pellet production from Leucaena and Acacia. The environmental impacts were evaluated by cradle to gate life cycle assessment, covering fast growing tree cultivation (sprout preparation, plantation, cutting), transportation and wood pellet production. The ReCiPe2016 Midpoint method (version 1.02) was used to evaluate the environmental impacts of one tonne wood pellet production from Leucaena and Acacia. The indicators of socio-economic considered in this study were the profit from cultivation, economic assessment of wood pellet production (net present value, internal rate of return, payback period, discount payback period and benefit cost ratio) and opportunity of employment. The environmental results showed a better performance of wood pellets made from Leucaena are better than Acacia. The production capacity of 110 tonnes per day of wood pellet factory would return a profit when the price of raw material is less than 1,300 THB per tonne. Finally, Leucaena and Acacia cultivation increase the opportunity of employment at 0.16 and 0.10 person-year per ha, respectively. The wood pellet production increases the opportunity of employment at 0.0019 person-year per tonne. Considering the results of the environmental and socio-economic assessment, Leucaena is seen to be better than Acacia and should be supported as an alternative raw material for wood pellet production.

Environmental life cycle assessment of polypropylene made from used cooking oil

Used cooking oil (UCO) has received much attention as feedstock for the production of renewable fuels and bio-based materials. This study aims to assess the environmental impact of UCO-based polypropylene (PP) by a cradle-to-factory gate Life-Cycle Assessment (LCA). 16 impact categories were assessed. The results were interpreted with normalization and weighting steps. For several multi-output processes, different allocation procedures were scrutinized. On a normalized and weighted basis, the environmental impacts of UCO-based PP are dominated by climate change (28%), fossil resource use (23%) and water use (11%). The following environmental hotspots are identified: the polymerization process (38%), the production of hydrogen (21%), the production of LPG (18%) and the combustion of LPG (8%). Compared to petrochemical PP, cradle to factory gate impact reductions of 40–62% for climate change and 80–86% for fossil fuel resource use can be achieved by UCO-based PP, depending on the allocation approach chosen. For other impact categories, the environmental footprint of bio-based PP is strongly influenced by the choice of the allocation method.

Rotating algal biofilm versus planktonic cultivation: LCA perspective

Commercial microalgae production with conventional suspended cultures is still facing the challenge of high operational costs related to mixing and harvesting diluted biomass. Attached culture system is an emerging technology for replacing the suspended culture systems, were the biomass grows as a biofilm on a supporting belt that is continuously rotating between the liquid and gaseous phases. Immobilized culture systems have several advantages, when compared to suspended culture systems, such as higher biomass productivity and straightforward harvesting and concentration. Ready-to-use biomass with water content between 80 and 90% is harvested by simple scrapping, avoiding some dewatering steps. However, additional infrastructures are required increasing material and electricity demands. This study is a comparative pond to gate life cycle assessment of the environmental impacts, energetic and materials demands between the conventional Open Raceways Ponds (ORP) and Rotating Algal Biofilm (RAB), considering large-scale production of Tetraselmis suecica. Two products were analysed: microalgae biomass at 20%-DW and algae meal (protein concentrate powder). The results were also compared with the conventional protein sources, such as soymeal and fishmeal. Considering that both systems achieve the same productivity (20 g m−2·d−1), the environmental impacts, measured trough a single aggregated eco-point value, were 26% and 24% higher in attaching system than ORP, per kilogram of biomass at 20%-DW and protein powder (algae meal), respectively. Both solutions offer a significant environmental improvement when compared to soymeal and fishmeal. Productivities 40% higher in RAB are required to obtain lower environmental impacts than ORP system. Electrical demands reductions up to 83% and 62% per kilogram of biomass 20%-DW and kilogram of algae meal, respectively, were reached by RAB approach. If RAB can substantiate a 50% increase in productivity on the long run, then the eco-points gains will be 20%, with reductions higher than 55% in electricity requirements and around 30% in the water consumption. The efficient energy performance of RAB, and its considerable margin of improvement make it a promising alternative to conventional open raceway systems.

Regional environmental assessment of dairy farms

A comprehensive, yet in depth, assessment is needed of the environmental impacts of dairy farms at regional and national scales to better track improvements made by the industry. With Pennsylvania as an example, a method using process-level simulation and cradle-to-farm gate life cycle assessment was developed and used to assess important environmental footprints of dairy farms within a state. Representative dairy farms of various sizes and management practices throughout 7 regions of the state were simulated with the Integrated Farm System Model. Environmental footprints varied widely among farms, with this variation influenced primarily by soil characteristics and climate and secondarily by farm management. Therefore, prescriptive mitigation strategies for individual farms are more effective than uniform enforcement of specific strategies across the state. Footprints for the whole state were determined by totaling values among farms and regions based on the amounts of milk produced by each. Pennsylvania dairy farms were determined to emit 4,555 with an uncertainty of ±415 Gg of CO2 equivalent of greenhouse gas with an intensity of 0.99 ± 0.09 kg of CO2 equivalent/kg of fat- and protein-corrected milk (FPCM) produced. Fossil energy consumption was 12,324 ± 1,946 TJ or 2.69 ± 0.42 MJ/kg of FPCM. Blue (nonprecipitation) water consumption was 64.1 ± 13.5 Tg with an intensity of 14.0 ± 3.0 kg/kg of FPCM. A total of all forms of reactive N loss was 43.2 ± 5.0 Gg with an intensity of 9.4 ± 1.1 g/kg of FPCM. These metrics were equivalent to 1.6% of the greenhouse gas emissions, 0.4% of fossil energy use, and 0.8% of fresh water consumption reported for the state. Thus, greenhouse gas emissions, fossil energy use, and blue water use associated with dairy farm production are relatively small compared with total estimates for the state. Perhaps the greatest environmental concern is that of ammonia emission, where dairy farms accounted for about half the estimated emissions of the state. This method can be applied to assessments of the dairy industry at larger regional and national scales.

Life cycle assessment of natural and recycled gypsum production in the Spanish context

Spain occupies a very prominent position as a world producer of gypsum. Consequently, the industrial processes are more refined, as the production volumes of the factories are much higher than in other countries. Therefore, the environmental impacts of the production of one ton of gypsum are significantly lower. However, new cleaner alternatives must be studied to promote more sustainable construction. In that sense, this paper aims at studying the environmental assessment of the production of natural and recycled gypsum in the Spanish context. In order to conduct the environmental analysis, a from cradle to gate life cycle assessment (LCA) was carried out, using the Impact 2002 + methodology. All the input data was obtained from a medium-size gypsum manufacturer located in Jaen (Andalusia), one of the best regions in terms of gypsum purity. The results for all the scenarios under study were analyzed separately and compared with previous studies published by other investigators and manufacturers’ reports data. Contrary to most other previous researches, the LCA was performed on the basis of primary data given by the producer, and the regional factors were also taken into account.The results achieved in the LCA showed for the production of recycled gypsum (from plasterboard and powder waste) a significant improvement (more than 40%) in all the impact categories understudy, as compared to the natural gypsum production. Furthermore, the results obtained for the endpoint indicators showed an important reduction (56 and 58%) of the environmental impacts when recycled gypsum production was compared with the natural one. On the other hand, it was reaffirmed that the natural gypsum production process in Spain is less environmentally harmful than in other countries.