Pengaruh Temperatur Pada Microwave Pirolisis Cangkang Kelapa Sawit dan Low Density Polyethylene Dengan Katalis Zeolite/Kalsium Oksida

In general, the use of oil palm parts can be utilized by industry, but it is different from oil palm shells which become waste. The high use of plastic is proportional to the waste generated. So far, both types of waste are problems that have not been resolved. The utilization of waste shell waste and low-density polyethylene using the pyrolysis method. Microwave technology has been widely used as a heat source in the pyrolysis process. The advantages of using microwaves in pyrolysis are fast and selective heating, efficient energy use, and control of pyrolysis products. This study aimed to determine the characteristics of Pyrolytic-oil from the pyrolysis of waste oil palm shells and Low-density polyethylene. The research was conducted using a microwave with temperature variations of 400oC, 450oC, 500oC, 550oC and 600oC. The composition of the main ingredients consisted of 75 grams of palm shells, 75 grams of low-density polyethylene plastic, 56.25 grams of a zeolite catalyst, 56.25 grams of calcium oxide and 131.25 grams of charcoal carbon absorber. The results showed the effect of temperature on pyrolytic-oil productivity; as the temperature increases, the product gas increases. The lowest density value at a temperature of 400oC is 966.8 Kg/m. The lowest viscosity at a temperature variation of 500oC is 2.1 Mpa.s. The highest acidity value is at a temperature of 550oC.

Life cycle assessment of aquaculture bivalve shellfish production — a critical review of methodological trends

Purpose The increase of shellfish production has raised environmental concerns, i.e., enrichment and redistribution of nutrients and energy consumption. Efforts assessing the environmental burdens arising from the expansion of shellfish production have been made using the life cycle assessment (LCA) methodology. Although LCA has been extensively applied and reviewed in aquaculture systems, shellfish production remains scarcely studied. The objective of this review is to identify methodological trends, highlight gaps and limitations, and provide guidelines for future studies. Methods A systematic literature review was applied to scientific studies published up to 2021. A total of 13 documents were shorted by abstract and full text-screening. Literature meeting the inclusion criteria were further analyzed in six different aspects of a LCA (functional unit, system boundaries, data and data quality, allocation, impact assessment methods, interpretation methods). Discussion and guidelines are provided for each reviewed aspect. Results and discussions Shellfish LCAs differ considerably from other aquaculture studies mainly because shellfish avoids the allocation of impacts derived from the production of fishmeal. Co-products are present when the shellfish is processed, e.g., in canned products. Furthermore, shellfish studies do not take into account the positive credits from the removal of nutrients from the ecosystems and from the valorization of the shellfish waste (shell and organic remains). Limited information was found for countries outside Europe and species different from mussels. Despite the variability on goals and scopes of the studies, methodological trends were found. The local impacts of the shellfish with the farming area and the impacts on biodiversity have not been included into the studies. Conclusions and recommendations Effort should be made in providing the data associated with the fore-background system within the studies in order to improve transparency and to allow the reproduction of the results. Information regarding the natural condition of the cultivation area should be provided as the shellfish production depends mainly on non-anthropogenic conditions. Application of biodiversity assessment methodologies should be encouraged, despite their limitations.

Progress on Modified Calcium Oxide Derived Waste-Shell Catalysts for Biodiesel Production

The dwindling of global petroleum deposits and worsening environmental issues have triggered researchers to find an alternative energy such as biodiesel. Biodiesel can be produced via transesterification of vegetable oil or animal fat with alcohol in the presence of a catalyst. A heterogeneous catalyst at an economical price has been studied widely for biodiesel production. It was noted that various types of natural waste shell are a potential calcium resource for generation of bio-based CaO, with comparable chemical characteristics, that greatly enhance the transesterification activity. However, CaO catalyzed transesterification is limited in its stability and studies have shown deterioration of catalytic reactivity when the catalyst is reused for several cycles. For this reason, different approaches are reviewed in the present study, which focuses on modification of waste-shell derived CaO based catalyst with the aim of better transesterification reactivity and high reusability of the catalyst for biodiesel production. The catalyst stability and leaching profile of the modified waste shell derived CaO is discussed. In addition, a critical discussion of the structure, composition of the waste shell, mechanism of CaO catalyzed reaction, recent progress in biodiesel reactor systems and challenges in the industrial sector are also included in this review.

PENENTUAN KONDISI OPTIMUM HIDROLISIS PATI OLEH ASPERGILLUS NIGER DALAM LIMBAH KULIT KENTANG

Determination of optimum condition for starch hydrolysis Aspergillus niger in shell potato waste. Shell Potato waste can be used as a raw material for making bioethanol because it contains carbohydrate ingredients, starch. The process of making bioethanol from starchy materials can be done through the hydrolysis process, then proceed with the fermentation process. The hydrolysis process is carried out to hydrolyze starch into glucose with the help of amylase enzyme produced from the Aspergillus nigerbacterium. This research was carried out at the Chemistry Laboratory of FMIPA Malang State University. The purpose of this study was to determine the optimum conditions for hydrolysis of starch from potato skin which includes temperature, pH, time and amount of Aspergillus niger used. The glucose level produced from the hydrolysis process is determined using the Somogy-Nelson method. The results showed that the optimum conditions for starch hydrolysis to produce optimum glucose levels were using 1.25 grams of Aspergillus niger (equivalent to 50 mL of culture), at pH 5 and temperature of 300C within 2 hours, with glucose produced as much as 0.0167 g of 100 g of shell potato waste flour.

Abu Cangkang Kerang Anadara granosa, Linnaeus 1758 (Bivalvia: Arcidae) sebagai Adsorben Logam Berat dalam Air Laut

Kerang Darah merupakan komoditi ekonomis yang tersebar di seluruh wilayah perairan Indonesia, salah satunya adalah Perairan Demak. Adanya permintaan yang tinggi pada daerah demak dari hasil survey DKP Kabupaten Demak pada tahun 2018 dapat menimbulkan terjadinya limbah cangkang yang cukup banyak. Melalui pendekatan teknologi yang tepat, limbah cangkang kerang tersebut dapat diolah menjadi abu cangkang. Berdasarkan komposisi senyawa kimia abu cangkang mengandung CaO cukup tinggi sehingga abu cangkang berpotensi untuk menjerap logam berat. Materi yang digunakan dalam penelitian adalah abu cangkang hasil olahan dari limbah cangkang sisa produksi kerang darah. Metode eksperimental laboratoris dilakukandalam penelitian yaitu dengan mengontakkan secara langsung logam dan abu cangkang kerang dara (Anadara granosa) dengan pengaruh variasi jenis logam berat dengan analisis spektroskopi serapan atom (SSA). Penyerapan yang optimal terjadi pada logam berat Mangan (Mn) konsentrasi awal 0,103 mg/L menjadi <0,001 dan kontak waktu 24 jam daya serap sebesar 100%. Dapat disimpulkan bahwa pada abu cangkang cukup baik dalam penyerapan logam berat Besi (Fe), Mangan (Mn), Seng (Zn) di air laut perairan Morosari Demak karena dalam proses menghilangkan logam berat dengan struktur CaO disebut pertukaran ion dipengaruhi oleh beberapa faktor jenis adsorben yang digunakan, luas permukaan adsorben, dan konsentrasi zat yang di penjerapan. Blood cockle are economic commodities that are spread throughout the territorial waters of Indonesia, one of which is the Demak waters. The high demand in the Demak area from the results of DKP survey in 2018 can causing a lot of cockle shell waste. Through the right technological approach, the waste is processed into blood cockle shell ash. Based on the chemical composition of shell ash containing CaO in the shell is high enough so the ash has potential to absorb heavy metals. The material used is the blood cockle shell ash that processed from waste shell from the production of blood cockle. The experimental laboratory method was carried out in this research, by directly contacting metal and blood cockle shell ash (Anadara granosa) with the influence of variations in heavy metal types by atomic absorption spectroscopy (AAS) analysis. Optimal absorption occurs in the heavy metal Manganese (Mn) initial concentration of 0.103 mg / L to <0.001 and 24-hour contact time absorption of 100%. It can be concluded that the shell of the product itself has not been efficient in carrying out all the absorption of heavy metals in the sea water samples of Morosari Demak waters because in the process of removing heavy metals with CaO structures is influenced by the type of adsorbent used, the surface area of the adsorbent, and the concentration of in absorption.

Fabrication of Ceramic Moulds Using Recycled Shell Powder and Sand with Geopolymer Technology in Investment Casting

Lost-wax casting, also called precision casting, is the process of casting a duplicate metal sculpture cast an original sculpture. The ceramic shell mould used in lost-wax casting usually consists of several layers formed with fine zircon and granular mullite particles using silica gel as a binder. However, it is a complicated and time-consuming process. Large amounts of waste moulds that need to be disposed and recycled become an environmental concern. In this study, waste shell sand from the recycled mould and calcium carbonate/metakaolin were used as raw materials to prepare geopolymer slurry and coating. The influence of mixing ratio and the SiO2/K2O modulus of the alkali solution on the setting time and green/fired strength were evaluated. Ceramic shells with one to four layers of geopolymer slurry and waste sand sprinkling were fabricated and tested for their permeability and green/fired strength. It was found that geopolymer shells had higher green/fired strength and better permeability than the original zircon/mullite shell. For foundry practice, metal casts were fabricated using recycled ceramic shell moulds with one to four layers of geopolymer coating. All cast results have their dimensions all within tolerance limitation and up to 13 h can be saved for the preparation of shell moulds.

Mini-review of waste shell-derived materials’ applications

This mini-review reports curbing waste shells (i.e. seashells, eggshells, snail shells, etc.), environmental health issues and liabilities by using them as material for heterogenous catalysts, blended cement manufacture, concrete aggregate, ceramics and plastics additives, biofilter medium and biomedical applications. The traditional materials used in the manufacture of these products could be relatively cheap; however, there are considerable environmental issues (i.e., ecological damage, disruption of eco-system and air contamination) as well as intense energy consumption associated with the exploitation of depleting natural resources. Waste shells are a renewable and cheap alternative, and will simultaneously decrease manufacturing cost while reducing their burden on the environment. This paper emphasizes environmental sustainability by summarizing articles published on various applications of waste shell-derived biomaterials. The properties of waste shell-derived biomaterials are presented and discussed. The materials’ properties suggest they are similar to limestone and their biological–natural origin and the high calcium carbonate content with a trace amount of other mineral elements makes them highly favorable for cement production, heterogenous catalysts and hydroxyapatite manufacture for biomedical and wastewater treatment applications. The purpose of this work is to offer new perspectives and direction for future research on waste shell-derived biomaterials while existing areas of applications demanding scale up are highlighted.

Preliminary Study on the Use of Biodiesel Obtained from Waste Vegetable Oils for Blending with Hydrotreated Kerosene Fossil Fuel Using Calcium Oxide (CaO) from Natural Waste Materials as Heterogeneous Catalyst

In this experimental work, calcium from natural seafood wastes was used as a heterogeneous catalyst separately or in a blend of “shell mix” for producing biodiesel. Several chemical reaction runs were conducted at varied reaction times ranging from 30 min to 8 h, at 60 °C, with a mass content of 5% (Wcat./Woil) and a methanol/oil molar ratio of 12. After the purification process, the biodiesel with fatty acid methyl ester (FAME) weight content measured was higher than 99%, which indicated that it was a pure biodiesel. This work also showed that the inorganic solid waste shell mixture used as the heterogeneous catalyst can be reused three times and the reused mixture still resulted in a FAME content higher than 99%. After 40 different transesterification reactions were performed using liquid (waste cooking oils) and solid (calcium seafood shells) wastes for producing biodiesel, under the specific conditions stated above, we found a successful, innovative, and promising way to produce biodiesel. In addition, blends prepared with jet fuel A1 and biodiesel were recorded with no invalid results after certain tests, at 25 °C. In this case, except for the 10% blend, the added biodiesel had no significant effect on the viscosity (fluidity) of the biojet fuel.

Sustainable Solutions for Oyster Shell Waste Recycling in Thailand and the Philippines

This paper studies the utilization and management of the waste mollusk shell. The two major export countries of mollusk shell are the Southeast Asia’s Thailand and the Philippines. First, the aquaculture of oysters and bivalve shells has been studied as background understanding. The effect of the global climate change on farming and the consequences of farming on the nearby environment and neighborhoods have also been discussed. The utilization technologies on the waste shell are available on a small scale and not industrialized. This study offers an enabling context under which a suitable method can take action to solve the overflow waste shell problem, and at the same time, provide sustainable management.