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1.
Heliyon ; 10(10): e30768, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38774313

RESUMO

Malaysia is the second largest producer and exporter of palm oil. Though several works have explored achieving emissions reduction in the palm oil sector, there existing gaps in analysing pathways for achieving net-zero emissions. Moreover, there are limited studies that evaluate the potential of palm oil biomass utilisation pathways based on emissions reduction capabilities, the cost of emissions reduction, and the technology readiness for implementation. Therefore, this study analysed decarbonisation pathways for the upstream and midstream segments of the palm oil sector in Malaysia, encompassing oil palm plantations and palm oil mills. Various sources of greenhouse gas emissions in oil palm plantations and palm oil mills were identified and estimates of emissions were determined as theoretical emissions. The current emissions were established based on the current best practice in the plantation and mill. Several biomass conversion technologies for the recovery of palm-based by-products and conversion into value-added products to decarbonise the palm oil sector and evaluated strategies to attain net-zero status are considered. In this work, the analysis considered both the existing technologies that are adopted by plantations and mills as well as the emerging technologies that have scope for implementation. With the proposed approach, the current emissions level for crude palm oil (CPO) production in Malaysia is estimated as 1121.49 kg CO2-eq/t CPO. In current industry practice, empty fruit bunch (EFB) is underutilised as mills are typically located at rural areas with lack of suitable transportation. Besides, the lack of accessibility to the grid also limits the potential of converting EFB into electricity as supply for national grid. This work examined various pathways for EFB utilisation under different scenarios evaluating their contribution potential towards net-zero target in an energy self-sustained CPO production. As shown in the results, converting EFB to briquettes and pellets are able to achieve the net-zero objective. Furthermore, EFB-biochar and EFB-syngas pathways also exhibit the potential to accomplish the net-zero target. Note that this work also assessed the technologies' readiness levels, identified challenges in implementation, and proposed several recommendations.

2.
Regul Toxicol Pharmacol ; 116: 104753, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32745583

RESUMO

Consumers are commonly exposed to numerous chemical ingredients found in various formulated products especially household and personal care products. Therefore, identification of hazardous ingredients contained in those products should be performed at the early stages of product design to reduce the high cost of redesigning the products at the final stage. Thus, a systematic safety and health risk assessment methodology is required for the product formulation design. In this work, a two-step index-based methodology is presented to estimate the severity of the hazards and the magnitude of risks. In Tier 1 assessment, potential hazards of the ingredients were identified by following the Product Ingredient Safety Index (PISI). The basic toxicology information of ingredients was required for this assessment. In Tier 2 assessment, the extent of risks of the ingredients via dermal and inhalation exposure routes were evaluated. At this stage, the concentration of ingredients and the amount of exposure were considered. The value of Margin of Exposure (MOE) was used as an indicator in the development of Product Ingredient Exposure Index (PIEI). To demonstrate the proposed methodology, a case study on the evaluation of potential hazards and the risks from ingredients used in personal care product formulations were performed.


Assuntos
Cosméticos/toxicidade , Exposição por Inalação/efeitos adversos , Medição de Risco/métodos , Pele/efeitos dos fármacos , Animais , Qualidade de Produtos para o Consumidor , Humanos
3.
Heliyon ; 5(10): e02594, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31720447

RESUMO

Designers of energy systems often face challenges in balancing the trade-off between cost and reliability. In literature, several papers have presented mathematical models for optimizing the reliability and cost of energy systems. However, the previous models only addressed reliability implicitly, i.e., based on availability and maintenance planning. Others focused on allocation of reliability based on individual equipment requirements via non-linear models that require high computational effort. This work proposes a novel mixed-integer linear programming (MILP) model that combines the use of both input-output (I-O) modelling and linearized parallel system reliability expressions. The proposed MILP model can optimize the design and reliability of energy systems based on equipment function and operating capacity. The model allocates equipment with sufficient reliability to meet system functional requirements and determines the required capacity. A simple pedagogical example is presented in this work to illustrate the features of proposed MILP model. The MILP model is then applied to a polygeneration case study consisting of two scenarios. In the first scenario, the polygeneration system was optimized based on specified reliability requirements. The technologies chosen for Scenario 1 were the CHP module, reverse osmosis unit and vapour compression chiller. The total annualized cost (TAC) for Scenario 1 was 53.3 US$ million/year. In the second scenario, the minimum reliability level for heat production was increased. The corresponding results indicated that an additional auxiliary boiler must be operated to meet the new requirements. The resulting TAC for the Scenario 2 was 5.3% higher than in the first scenario.

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