Techno-economic assessment of an integrated algae-based biorefinery with palm oil mill

Palm oil production has become a major contributor to the economy of several tropical countries where palm oil trees can be grown commercially, particularly due to its high productivity and capability to yield more oil from less land area. Palm oil milling activities generate wastewater that is highly polluted and requires to be treated before it can be discharged into the environment. The wastewater generated from the milling activities is defined as palm oil mill effluent (POME). Studies have shown that algae can be grown using wastewater. The utilisation of algae for POME treatment coupled with biogas facilities in the palm oil mill can simultaneously remediate the wastewater and reduce the cost for nutrient and freshwater supplies required for algae growth. This paper investigates the techno-economic potentials of an integrated algae-based biorefinery with palm oil mill. The proposed superstructure for the integrated bio-refinery includes carbon sequestration, algae growth with wastewater integration from biogas effluent, algae harvesting and dewatering, algal oil extraction, algal oil upgrading, and residual algae processing. Based on the techno-economic analysis conducted, the results show that the processing pathway which consists of open pond, flocculation with alum and centrifugation, drying, solvent extraction with hexane/isopropanol, base catalysed transesterification of algal oil, and combustion of residual algae produces the highest profit of 7.73 x 105 USD/y

Production decision support system for multi-product with multiple different size processors

Aggregate planning is an operational activity with the objective of providing upfront information on quantity of material to be procured and resources to be secured. At a point of time, it might also influence both demand and supply. This is where the sales division will work closely with operation on aggregate planning to deliver maximum profit. Aggregate planning does not only serve as a master plan for the production planner, it is also closely linked to organisational decision-making. Realising its importance, researchers have worked on this subject consistently since 1950s but due to complexity and practicality issue, industry did not manage somehow to adopt the research work. In 2016, the concept of Production Decision Support System (PDSS) was introduced following the Pinch Analysis extended into supply chain area. In this work, the PDSS is applied to a batch industry case which involve multi-products with multiple different size processors. From the assessment, the PDSS has not only demonstrated its practicality but also helped the plant to realise their potential capacity. This has assisted the plant management to realign the strategy and avoided the original intention of expensive expansion

Process assessment, integration and optimisation: The path towards cleaner production

This contribution starts from the broad perspective of the global material cycles, analysing the main resource and pollution issues world-wide from the viewpoint of the disturbances to these cycles caused by human activities. The issues are analysed in the light of the currently developing COVID-19 pandemic with the resulting behavioural and business pattern changes. It has been revealed in the analysis of previous reviews that there is a need for a more comprehensive analysis of the resource and environmental impact contributions by industrial and urban processes, as well as product supply chains. The review discusses the recent key developments in the areas of Process Integration and Optimisation, the assessment and reduction of process environmental impacts, waste management and integration, green technologies. That is accompanied by a review of the papers in the current Virtual Special Issue of the Journal of Cleaner Production which is dedicated to the extended articles developed on the basis of the papers presented at the 22nd Conference on Process Integration for Energy Saving and Pollution Reduction. The follow-up analysis reveals significant advances in the efficiency and emission cleaning effects of key processes, as well as water/wastewater management and energy storage. The further analysis of the developments identifies several key areas for further research and development – including increases of the safety and robustness of supply networks for products and services, increase of the resources use efficiency of core production and resource conversion processes, as well as the emphasis on improved product and process design for minimising product wastage

Ultimate and proximate analysis of Malaysia pineapple biomass from MD2 cultivar for biofuel application

MD2 pineapple is a highly demanded hybrid pineapple other than Josephine and Sarawak. The decomposition process of the pineapple biomass by burning may contribute towards carbon emission and increase the greenhouse effect. To address these negative impact, this biomass can be used as a raw material for the alternative solid biofuel to coal and substitute coal for the application in heavy industry or domestic use. The aim of this study is to investigate the characteristic of the MD2 pineapple biomass for their use as a feedstock for biofuel and energy production. The ultimate analysis was carried out by using CHNS Elemental Analyser, where the proximate analysis was identified by the thermo-gravimetric (TGA) analysis under dynamic condition. The results of the conducted study were compared with other biomass reported in the past literature. The ultimate analysis of the MD2 pineapple (i.e. 43.43 wt% C, 6.69 wt% H for leaf and 41.09 wt% C, 6.705 wt% H for stem) appears to correlate with the ultimate analysis range of the other biomass which is used as a raw material of the solid biofuel. The thermo-gravimetric analysis showed that each single part of the MD2 pineapple had pyrolysis and combustion characteristic based on its own main pseudo-components (hemicellulose, cellulose and lignin). The characteristics of the MD2 pineapple had ensured the potential of biomass as raw materials for alternative solid biofuel

Organic rankine cycle and steam turbine for intermediate temperature waste heat recovery in total site integration

The utilization of waste heat for heat recovery technologies in process sites has been widely known in improving the site energy saving and energy efficiency. The Total Site Heat Integration (TSHI) methodologies have been established over time to assist the integration of heat recovery technologies in process sites with a centralized utility system, which is also known as Total Site (TS). One of the earliest application of TSHI concept in waste heat recovery was through steam turbine using the popular Willan’s line approximation. The TSHI methodologies later were extended to integrate with wide range of heat recovery technologies in many literatures, whereby Organic Rankine Cycle (ORC) has been reported to be the one of the beneficial options for heat recovery. In general, the medium to high temperature waste heat is recovered via condensing/backpressure steam turbine, whereas ORC is targeted for recovering the low temperature waste heat. However, it is known that condensing turbine is also abled to generate power by condensing low grade steam to sub-ambient pressure, which is comparable with ORC integration. In this work, the integration of ORC and condensing turbine was considered for a multiple-process system to recover intermediate temperature waste heat through utility system. This study presented a numerical methodology to investigate the performance analysis of integration of ORC and condensing turbine in process sites for recovering waste heat from a centralized utility system. A modified retrofit case study was used to demonstrate the effectiveness application of the proposed methodology. The performances of ORC and condensing steam turbine were evaluated with the plant total utility costing as the objective function. The turbine integration was found to be more beneficial in the modified case study with lower utility cost involved. However, the capital cost has not been considered in the analysis

Energy efficiency award system in Malaysia for energy sustainability

Many countries have organised energyawards as an instrument to promote energy efficiency (EE), to contribute towards energy sustainability and to provide a mechanism for organisations to continuously search, benchmark and acknowledge initiatives and best practices in EE. To be effective, an award system must be tailored towards the needs, the level of readiness and the acceptance of a nation. This paper presents a framework for implementation of a national EE award in the context of Malaysia. The current energy scenario and energy issues relevant to Malaysia are first highlighted to establish the premise for organising a national energy award. Models and success stories of EE awards in other countries are discussed as possible benchmarks for implementation. The results of a survey conducted on various energy stakeholders in Malaysia confirmed the needs, readiness and acceptance for a national EE award. A framework for the implementation of a Malaysian EE award is proposed based on the survey conducted, and on various models of energy award implementation worldwide

Eco village concept for green economic development: Iskandar Malaysia as a case study

Renewable Energy (RE) based on town concept in Iskandar Malaysia (IM) that can serve as a global model for a smart eco - village in tropical countries is proposed. In this research, renewable energy (RE) based distributed energy generation (DEG) system for Kulai eco-village (KEV) driven by integrating of biomass, biogas and solar energy. Thus, this paper discusses RE supply and demand side estimation ahead of implementation of RE DEG. The preliminary study has shown that energy supply from local RE included from oil palm biomass, landfill and solar was greater than energy demand for basic amenities at KEV such as lights, air-conditioner, and water heater by 221 times. The results of this study support the idea that it is possible to utilize local renewable energy as green energy resource and will become a first green eco town (GET) showcase from design, construction and operations

Efficiency of Microalgae Chlamydomonas on the Removal of Pollutants from Palm Oil Mill Effluent (POME)

AbstractMalaysia is considered as a major palm oil producer in the world. Therefore, it is vital to utilize an environmentally friendly and inexpensive method to treat palm oil mill effluent (POME) in Malaysia. Nowadays, the use of microalgae to remove pollutants from POME has gained a lot of attention. The main objective of this research was to investigate the effect of POME as a nutrient on the microalgae growth and analyze the removal rate of pollution. In this study, a pure culture Chlamydomonas incerta was aseptically transferred to an Erlenmeyer flask containing POME. The effect of POME as a high nutritional substrate, different cultivation scales, carbon total nitrogen (C:TN) ratio, and the lipid productivity of microalgae C. incerta were assessed. C. incerta was grown at room temperature under continuous illumination with the intensity of ± 15 (μmol/m2/s) for 28 days, followed by the measurement of chemical oxygen demand (COD) reduction at different substrate concentrations. The results of this study demonstrated that organic carbon was removed by C. incerta for the ratio of 100:7, 100:13, and 100:31 respectively within the second day of cultivation. Fast growth of microalgae was observed in organic and inorganic substrates for adoption within the second day of experiment. The optimum achievement rate of nutrient removal with C. incerta was about 67.35% of COD for 250mg/L of POME concentrations in 28 days. The significance of this study is regarding the introduction of a new microalgae strain with a high ability to remove nutrients from POME, which can contribute to the effort in finding an efficient and economic technology for improving our environment

Water-Energy Nexus Cascade Analysis (WENCA) for simultaneous water-energy system optimisation

This paper presents a new numerical method called the Water-Energy Nexus Cascade Analysis (WENCA), developed based on the principal of Pinch Analysis. Water and energy are both valuable resources that are majorly used in industrial processes. Both water and energy are interdependent where increasing water demand will increase the energy demand and vice versa. In this paper, WENCA is introduced to simultaneously optimise both water and energy system that is interdependent. The methodology applies Cascade Analysis to individually optimise both system. As both systems are interdependent, altering one of the system will result in a change to the other system. An iterative method is then introduced to converge the analysis to obtain the optimal result for both systems. A case study comprising of both electricity and water demand of 6,875 kWh and 3,000 m3 from a residential area with 1,000 unit of houses is applied in this work. The electricity demand is met using fuel cell where hydrogen is produced through coal gasification (which utilised water as it raw material), a water treatment plant (WTP) is also introduced for water treatment to fulfil the water demands. The optimal result reveals that the WTP capacity is 3,200.73 m3, its corresponding water storage tank capacity is 175 m3, hydrogen power plant is 9 MW and its corresponding energy storage capacity is 4.13 MW

Optimization approach for greenhouse gas to green energy for a low carbon region of Iskandar Malaysia

Landfill gas (LFG) like any other greenhouse gases (GHG) is a threat to the environment; hence its mitigation through effective utilization is necessary. The objective of this study is to estimate the amount of LFG captured using IPCC methodology and then develop optimization model for the LFG utilization for green energy production for Iskandar Malaysia. Of the three MSW Scenarios considered, the most appropriate was Scenario MIX, giving projection of MSW to landfill ranging from 600,000 tons in 2010 to 711,000 tons in 2035 for Iskandar Malaysia. From this, a mean annual LFG capture of 21,672 tons was estimated. The Mixed Integer Programing model considered Scenario ST as the more appropriate of the two LFG Scenarios, favoring combined heat and power generation with steam turbines over other options. The optimal result yielded a mean annual electricity and steam generation of 20,588 MWh (2.3 MW) and 150 million MJ respectively. The mean electricity generation represents 0.16% and 0.02% of the maximum electricity demand for Iskandar Malaysia and Peninsular Malaysia respectively. Additionally, GHG emission reduction of 12,000 tons CO2 equivalent was achieved. The findings revealed the potentials in LFG capture from the case study in terms of green energy and GHG emission reduction for sustainable development